20201550 Ver 1_ER-EID_CS370431-07_20201007_20210210

FINAL SUBMITTAL
Town of Clayton Water Reclamation
Facility Capacity Expansion
CS370431-07
ENGINEERING REPORT AND
ENVIRONMENTAL IMPACT DOCUMENT
Prepared for ...
Town of Clayton CARo`�;`
Tr/ 033 710 II
j lli' 0
October 7, 2020 `' $... , , ::
Prepared by
cI1ZnL•
CH2M HILL North Carolina, Inc.
111 Corning Road
Cary,NC 27518
License No. F-1277

Contents
Section Page
Contents iii
Acronyms and Abbreviations ix
1 Executive Summary 1-1
1.1 Project Description 1-1
1.2 Reasons for the Project 1-1
1.2.1 Current Capacity Limitations 1-4
1.2.2 Regional Partnerships 1-4
1.3 Results of Alternatives Analysis 1-5
1.3.1 Preferred Alternative 1-5
1.3.2 Alternatives Discussion 1-6
1.4 Summary of Environmental Impacts and Mitigative Measures 1-8
1.5 Project Funding and User Fee Increases 1-10
2 Current Situation 2-1
2.1 Background 2-1
2.2 Overview of Current Situation 2-1
2.3 Collection System Condition 2-4
2.4 Water Reclamation Facility Condition 2-8
2.4.1 Condition of Water Reclamation Facility Equipment 2-9
2.4.2 Flood Information 2-15
2.4.3 Permit Information 2-16
2.4.4 Historical and Current Wastewater Flow 2-17
2.5 Current Treatment Capacity Limitations 2-18
2.5.1 Little Creek Water Reclamation Facility 2-18
2.5.2 Regional Partnerships 2-18
2.6 Current Population 2-19
3 Future Situation 3-1
3.1 Population Projections 3-1
3.2 Flow Projections 3-2
3.3 Speculative Limits for Capacity Expansion 3-4
4 Need and Purpose 4-1
5 Alternatives Analysis 5-1
5.1 Alternative Descriptions 5-2
5.1.1 Alternative 1: No Action 5-2
5.1.2 Alternative 2: Construction of a New Water Reclamation Facility, and
Continued Use of Surface Water Discharge 5-4
5.1.3 Alternative 3: Expansion of Little Creek Water Reclamation Facility, and
Continued Use of Surface Water Discharge 5-15
5.1.4 Alternative 4: Continued Use of Little Creek Water Reclamation Facility,
Maximizing Regional Connections to Existing Wastewater Treatment 5-22
5.1.5 Alternative 5: Construction of a New Water Reclamation Facility, and
Use of Land Application 5-24
iii

CONTENTS
5.1.6 Alternative 6: Construction of a New Water Reclamation Facility, and
Implementation of Larger-scale Wastewater Reuse 5-27
5.1.7 Alternative 7: Construction of New Water Reclamation Facility—
Alternative Secondary Treatment Process 5-29
5.1.8 Alternative 8: Construction of New Water Reclamation Facility—
Alternative Biosolids Treatment Strategy 5-31
5.1.9 Alternative 9: Combination of Alternatives 5-33
5.1.10 Alternative 10: Decentralized System 5-33
5.1.11 Alternative 11: Optimum Operation of Existing Facilities 5-33
5.1.12 Supporting Project Infrastructure 5-34
5.2 Present Worth Analysis 5-40
5.2.1 Methodology 5-40
5.2.2 Results 5-43
5.2.3 Total Present Worth Summary 5-53
6 Proposed Project Description 6-1
6.1 General 6-1
6.2 Proposed Project 6-1
6.2.1 Environmental Impacts 6-2
6.2.2 Project Costs 6-4
6.3 Proposed Project Details 6-5
6.3.1 Little Creek Pump Station 6-5
6.3.2 Influent Pumping 6-7
6.3.3 Flow Equalization 6-8
6.3.4 Septage Receiving 6-8
6.3.5 Headworks Facility 6-8
6.3.6 Secondary Treatment 6-10
6.3.7 Tertiary Treatment 6-13
6.3.8 Disinfection 6-13
6.3.9 Postaeration 6-14
6.3.10 Residuals Treatment 6-14
6.3.11 Chemical Feed System 6-16
6.3.12 Odor Control 6-17
6.3.13 Electrical 6-18
6.3.14 Administrative Facility 6-18
7 Environmental Impact Document 7-1
7.1 Existing Environmental Conditions 7-1
7.1.1 Topography and Floodplains 7-1
7.1.2 Water Resources 7-7
7.1.3 Soils 7-11
7.1.4 Wildlife Resources and Natural Vegetation 7-11
7.1.5 Aquatic Resources 7-14
7.1.6 Land Cover 7-19
7.1.7 Agricultural Land and Prime Farmland 7-21
7.1.8 Forested Resources 7-22
7.1.9 Public Lands and Scenic and Natural Areas 7-23
7.1.10 Archaeological and Historic Resources 7-24
7.1.11 Air Quality 7-24
7.1.12 Noise Levels 7-27
7.1.13 Toxic Substances and Hazardous Wastes 7-27
iv

CONTENTS
7.1.14 Environmental Justice 7-28
7.2 Environmental Effects and Mitigation 7-29
7.2.1 Direct Impacts 7-29
7.2.2 Secondary and Cumulative Impacts 7-48
7.2.3 Permitting and Other Regulatory Activities 7-60
7.3 Mitigative Measures 7-61
7.3.1 Summary of Federal and State Regulations and Programs 7-62
7.3.2 Summary of Local Programs 7-66
8 Financial Analysis 8-1
8.1 Determination of Rates to Median Household Income Percentage 8-1
8.2 Determination of Funding Sources 8-1
8.3 Determination of Loan Repayment Output 8-2
8.4 Determination of User Fee Increase and Impact to User Rates 8-3
8.5 Determination of Impacts to Utility Bill per Median Household Income 8-4
9 Public Participation 9-1
10 References 10-1
Appendixes
A Asset and Inventory Assessment Grant Report
B National Pollutant Discharge Elimination System Permitting
C Little Creek Water Reclamation Facility Information
D Capacity Agreements
E Historical Wastewater Flows
F Flow Projections Supporting Documents
G Present Worth Analysis
H Environmental Justice Analysis
I Preferred Alternative Information
Solids Disposal Agreement Letter
K Agency Involvement
L Site Environmental Reports
M Sediment and Erosion Control Measures
N State and Local Ordinances
0 Rate Study
Tables
2-1. Town of Clayton Permitted Wastewater Treatment Capacity and Current Usage 2-4
2-2. Existing Wastewater Pump Stations 2-5
2-3. Collection System Age 2-7
2-4. Collection System Size 2-7
2-5. Reported Sanitary Sewer Overflows 2-8
2-6. Preliminary Treatment Equipment 2-10
2-7. Biological Nutrient Removal Activated Sludge Equipment 2-11
2-8. Secondary Clarifier Equipment 2-11
2-9. Tertiary Filter Equipment 2-12
2-10. Disinfection Equipment 2-12
2-11. Effluent Pump Station Equipment 2-13
2-12. Reclaimed Water Equipment 2-13
V

CONTENTS
2-13. Sludge Thickening Equipment 2-14
2-14. Aerated Holding and Digestion Equipment 2-14
2-15. Sludge Disposal Equipment 2-15
2-16. Power Generation Equipment 2-15
2-17. National Pollutant Discharge Elimination System Permit Effluent Limits 2-16
2-18. Little Creek Water Reclamation Facility National Pollutant Discharge Elimination System Permit
Total Nitrogen Allocations 2-17
2-19. Historical Wastewater Flow Data 2-17
2-20. Current Population Analysis 2-19
3-1. Projected Annual Town of Clayton and Extra-Territorial Jurisdiction Population Totals 3-1
3-2. Housing Unit Growth in the Town of Clayton 3-2
3-3. Projected Wastewater Maximum Month Flow Forecast 3-4
3-4. Speculative National Pollutant Discharge Elimination System Permit Effluent Limits 3-5
5-1. Design Flows 5-5
5-2. Town Waste Stream Characteristics (Maximum Month Concentrations) 5-7
5-3. Design Loads and Effluent Limits 5-7
5-4. General Liquids Treatment System Design Criteria 5-8
5-5. Solids Treatment System Design Criteria 5-10
5-6. Little Creek Water Reclamation Facility Expansion Design Criteria 5-18
5-7. Little Creek Water Reclamation Facility Expansion Solids Treatment System Design Criteria 5-20
5-8. Denitrification Filtration System Design Criteria 5-23
5-9. Land Application System Design Criteria 5-25
5-10. Water Conservation Programs of East Clayton Industrial Area Facilities 5-28
5-11. Secondary Treatment System Design Criteria 5-29
5-12. Alternative Solids Treatment System Design Criteria 5-32
5-13. Supporting Project Infrastructure 5-34
5-14. Potential Environmental Impacts 5-35
5-15. Construction Cost Markups 5-42
5-16. Annual Operations and Maintenance Costs 5-43
5-17. Estimated Construction Cost- New Water Reclamation Facility at the Neuse 2 Pump Station Site
5-43
5-18. Present Worth Cost Summary-New Water Reclamation Facility at the Neuse 2 Pump Station
Site 5-45
5-19. Estimated Construction Cost- New Water Reclamation Facility at the East Clayton Industrial
Area Site 5-45
5-20. Present Worth Cost Summary-New Water Reclamation Facility at the East Clayton Industrial
Area Site 5-46
5-21. Estimated Construction Cost-Expand Little Creek Water Reclamation Facility to 6 MGD 5-47
5-22. Present Worth Cost Summary-Expand Little Creek Water Reclamation Facility to 6 MGD 5-48
5-23. Estimated Construction Cost-Land Application 5-48
5-24. Present Worth Cost Summary-Land Application 5-50
5-25. Estimated Construction Cost-Alternative Secondary Treatment 5-50
5-26. Present Worth Cost Summary-Alternative Secondary Treatment 5-51
5-27. Estimated Construction Cost-Alternative Biosolids Strategy 5-52
5-28. Present Worth Cost Summary-Alternative Biosolids Strategy 5-53
5-29. Total Present Worth for Feasible Alternatives 5-54
6-1. Total Present Worth-New Water Reclamation Facility at the Neuse 2 Pump Station Site 6-4
6-2. Little Creek Pump Station and Force Main Design Criteria 6-6
6-3. Influent Pumping and Force Mains Design Criteria 6-7
6-4. Flow Equalization Design Criteria 6-8
vi

CONTENTS
6-5. Influent Screening Design Criteria 6-9
6-6. Grit Removal Design Criteria 6-9
6-7. Bioreactor Design Criteria 6-11
6-8. Secondary Clarifier Design Criteria 6-12
6-9. Aeration Blower Design Criteria 6-13
6-10. Tertiary Treatment Design Criteria 6-13
6-11. Ultraviolet Disinfection Design Criteria 6-14
6-12. Postaeration Design Criteria 6-14
6-13. Thickening Design Criteria 6-14
6-14. Aerated Sludge Holding Design Criteria 6-15
6-15. Dewatering Design Criteria 6-16
6-16. Metal Salt Feed Design Criteria 6-17
6-17. Carbon Feed Design Criteria 6-17
6-18. Odor Control Design Criteria 6-18
7-1. Federally Listed Terrestrial Wildlife and Plant Species Potentially Occurring Within the Study
Area 7-13
7-2. Habitat for Federally Listed Terrestrial Wildlife and Plant Species in the Project Area 7-14
7-3. NHEOs documented within the Proposed WRF site 7-14
7-4. Federally Listed Aquatic Species Potentially Occurring Within the Study area 7-15
7-5. Habitat for Federally Listed Aquatic Wildlife and Plant Species in the Project Area 7-15
7-6. Survey Results for the Neuse River near the Little Creek Water Reclamation Facility Outfall 7-16
7-7. Land Cover Classifications by Area and Percentage of the Study Area 7-19
7-8. Forest Types within the Study Area 7-22
7-9. National Register Historic Places in the Study Area 7-24
7-10. Number of Dwelling Units within a 0.5-Mile Buffer of Site Boundaries 7-28
7-11. Summary of Proposed Project Potential Direct and Indirect Impacts 7-30
7-12. Little Creek Transmission Main Stream and Wetland Crossings 7-36
7-13. Proposed Water Reclamation Facility USFWS Biological Opinion for Federally Listed Terrestrial
Wildlife and Plant Species for Johnston County, North Carolina 7-40
7-14. Potential Access Road USFWS Biological Opinion for Federally Listed Terrestrial Wildlife and
Plant Species for Johnston County, North Carolina 7-41
7-15. Little Creek Transmission Main USFWS Biological Opinion for Federally Listed Terrestrial Wildlife
and Plant Species for Johnston County, North Carolina 7-41
7-16. Proposed Water Reclamation Facility USFWS Biological Opinion for Federally Listed Aquatic
Wildlife and Plant Species for Johnston County, North Carolina 7-44
7-17. Little Creek Transmission Main Alignment USFWS Biological Opinion for Federally Listed Aquatic
Wildlife and Plant Species for Johnston County, North Carolina 7-45
7-18. Summary of Existing State and Federal Programs and Regulations and the Environmental
Resources they Protect 7-63
8-1. Applicant Local Government Unit Financial Condition 8-1
8-2. Utility System Capital Improvement Plan and Capital Improvement Plan Financing a 8-2
8-3a. Current Funding Distribution 8-2
8-3b. Potential Future Funding Distribution 8-3
8-4a. Year 1 Interest and Repayment on Current Funding Distribution 8-3
8-4b. Year 1 Interest and Repayment on Potential Future Funding Distribution 8-3
8-5. Fiscal Year 2025 Impact to Bills 8-4
vii

CONTENTS
Figures
1-1 Project Vicinity Map 1-2
1-2 Project Location Map 1-3
2-1 Town of Clayton Wastewater Treatment Capacity Planning Timeline Since 2001 2-2
2-2 Existing Wastewater System and Regional Partnerships 2-3
2-3 Wastewater Treatment and Collection System 2-6
3-1 Town of Clayton Wastewater Maximum Month Flow Forecast 3-3
5-1 Proposed WRF at Neuse 2 Site 5-6
5-2 Proposed WRF at ECIA Site 5-13
5-3 Proposed WRF at LCWRF Site 5-17
5-4 Potential Access Alignments Overall Project Aerial Exhibit (2017) 5-36
5-5 Little Creek Transmission Main Aerial with Topo (2017) 5-38
5-6 Linear Project Infrastructure 5-41
6-1 New Water Reclamation Facility Site Layout 6-3
6-2 New Water Reclamation Facility Proposed Processes 6-5
6-3 Secondary Treatment Process 6-10
7-1 Study Area 7-2
7-2 Water Supply Watershed Overlay 7-4
7-3 Access Road and Transmission Main with FEMA 7-5
7-4 Wetland/Buffer Delineation Exhibit 7-9
7-5 Soils 7-12
7-6 Aquatic Species Habitat 7-17
7-7 Proposed WRF Site 7-20
7-8 Natural and Historic Features 7-25
7-9 Stream and Wetland Exhibit 7-37
7-10 Expanded Outfall Construction Area 7-43
7-11 Future Comprehensive Land Use Plan Map 7-53
7-12 Downtown Future Land Map 7-55
7-13 Parks and Recreation Map 7-57
7-14 Transportation Priority Projects 7-71
viii

Acronyms and Abbreviations
µg/L microgram(s) per liter
7Q10 7-day, 10-year low-flow
AACE AACE International
ACS American Community Survey
ADA Americans with Disabilities Act
ADF average daily flow
AIA Asset and Inventory Assessment
amp ampere(s)
amsl above mean sea level
AQI Air Quality Index
ARS at-risk species
BGPA Bald and Golden Eagle Protection Act
bgs below ground surface
Black &Veatch Black&Veatch Management Consulting LLC
BMP best management practice
BNR biological nutrient removal
BOD biochemical oxygen demand
BOD5 5-day biochemical oxygen demand
CAA Clean Air Act
CAMPO NC Capitol Area Metropolitan Planning Organization
CCTV closed-circuit television
Census U.S. Census Bureau
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
CFR Code of Federal Regulations
cfs cubic foot (feet) per second
CH2M CH2M HILL North Carolina, Inc.
CIP Capital Improvement Plan
City City of Raleigh
CMMS Computerized Maintenance Management System
COD chemical oxygen demand
County Johnston County
CPES Conceptual and Parametric Engineering System
CWA Clean Water Act
ix

ACRONYMS AND ABBREVIATIONS
CWSRF Clean Water State Revolving Fund
DAPI Diabetes Active Pharmaceutical Ingredients
DI ductile iron
DO dissolved oxygen
DR dimension ratio
DWI Division of Water Infrastructure
DWR Division of Water Resources
E endangered
E. coil Escherichia coli
ECIA East Clayton Industrial Area
EDA Economic Development Administration
EDR Environmental Data Resources
EID Environmental Information Document
EPA U.S. Environmental Protection Agency
ER Engineering Report
ESA Endangered Species Act
ESC erosion and sediment control
ETJ extra-territorial jurisdiction
FEMA Federal Emergency Management Agency
FIRM Flood Insurance Rate Map
FONSI Finding of No Significant Impact
Froehling & Robertson Froehling & Robertson, Inc.
FRP fiber-reinforced plastic
ft2 square foot(feet)
FY fiscal year
GIS geographic information system
gpd gallon(s) per day
gpd/ft2 gallon(s) per day per square foot
gph gallon(s) per hour
gpm gallon(s) per minute
gpm/ft2 gallon(s) per minute per square foot
Grifols Grifols Therapeutics
H2S hydrogen sulfide
HP horsepower
HST high-speed turbo
X

ACRONYMS AND ABBREVIATIONS
HVAC heating, ventilation, and air conditioning
IPS influent pump station
Jacobs Jacobs Engineering Group Inc.
JCRWWTP Johnston County Regional Wastewater Treatment Plant
kV kilovolt(s)
kVA kilovolt(s)-ampere
kW kilowatt(s)
Ib/ac/y pound(s) per acre per year
Ib/d pound(s) per day
lb/ft2/d pound(s) per square foot per day
lb/y pound(s) per year
IbTSS/d/ft2 pound(s) of total suspended solids per day per square foot
IbTSS/h pound(s) of total suspended solids per hour
LC Little Creek
LCWRF Little Creek Water Reclamation Facility
LF linear foot(feet)
LGC Local Government Commission
LGU local government unit
LOIF Letter of Intent to Fund
LPHO low-pressure, high-output
LS lump sum
MAREA Managed Area
McGill McGill Environmental Systems
MG million gallons
mg/L milligram(s) per liter
MGD million gallons per day
mg02/L milligram(s) per oxygen per liter
mgTSS/L milligram(s)total suspended solids per liter
MHI median household income
mil square mile(s)
mL milliliter(s)
mL/g milliliter(s) per gram
MLSS mixed liquor suspended solids
mm millimeter(s)
MM maximum month
xi

ACRONYMS AND ABBREVIATIONS
MPN most probable number
NC 42 NC Highway 42
NCAC North Carolina Administrative Code
NCDAQ North Carolina Division of Air Quality
NCDEQ North Carolina Department of Environmental Quality
NCDOT North Carolina Department of Transportation
NCDWR North Carolina Division of Water Resources
NCGAP North Carolina Gap Analysis Program
NCNHP North Carolina Natural Heritage Program
NCWRC North Carolina Wildlife Resources Commission
Neuse 2 Pump Neuse 2 and Clayton to Raleigh Pump Stations
Station site
NFIP National Flood Insurance Program
NHEO Natural Heritage Element Occurrence
NHNA Natural Heritage Natural Area
NLCD National Land Cover Database
NMFS National Marine Fisheries Service
No. number
NPDES National Pollutant Discharge Elimination System
NRCS Natural Resources Conservation Service
NRHP National Register of Historic Places
NRWWTP Neuse River Wastewater Treatment Plant
NSW Nutrient Sensitive Water
NWI National Wetlands Inventory
NWP Nationwide Permit
O&M operations and maintenance
PE proposed endangered
PFD process flow diagram
PHF peak hour flow
PRCA Primary Resource Conservation Area
PT proposed threatened
PVC polyvinyl chloride
R&R renewal and replacement
RAS return activated sludge
RCRA Resource Conservation and Recovery Act
xii

ACRONYMS AND ABBREVIATIONS
RDII rainfall-derived inflow and infiltration
RDT rotary drum thickener
RO reverse osmosis
ROW right-of-way
RTZ Research Training Zone
scfm standard cubic foot (feet) per minute
SCI secondary and cumulative impact
SEPA State Environmental Policy Act
SHFA Special Hazard Flood Area
SHPO State Historic Preservation Office
SNHA Significant Natural Heritage Area
SR State Road
SRCA Secondary Resource Conservation Area
SSO sanitary sewer overflow
SWIA State Water Infrastructure Authority
T threatened
TDH total dynamic head
TDS total dissolved solids
TMDL total maximum daily load
TN total nitrogen
Town Town of Clayton, North Carolina
TP total phosphorus
TRC total residual chlorine
TSS total suspended solids
U.S. 70 Business U.S. Highway 70 Business
U.S. 70 U.S. Highway 70
U.S. United States
U.S.C. United States Code
UDC Unified Development Code
UPS uninterruptible power supply
USACE U.S. Army Corps of Engineers
USDA U.S. Department of Agriculture
USFWS U.S. Fish and Wildlife Service
USGS U.S. Geological Survey
UV ultraviolet
xiii

ACRONYMS AND ABBREVIATIONS
V volt(s)
VFD variable frequency drive
WAS waste activated sludge
WRF water reclamation facility
WSBTE Report Wetland, Stream & Riparian Buffer and Threatened & Endangered Species
Assessment Report
WWTP wastewater treatment plant
yd3 cubic yard(s)
xiv

SECTION 1
Executive Summary
1. 1 Project Description
Clayton is located in Johnston County, North Carolina. The Town of Clayton (Town) has initiated the
process to expand the Town's wastewater treatment capacity, which is currently 4.9 million gallons per
day(MGD)via its Little Creek Water Reclamation Facility(LCWRF) and wholesale contracts with
Johnston County(County) (for 1.4 MGD with the Johnston County Regional Wastewater Treatment Plant
[JCRWWTP]) (County and Town, 2005, 2006) and the City of Raleigh (City) (for 1.0 MGD with the Neuse
River Wastewater Treatment Plant [NRWWTP]) (City and Town, 2007).
The Town is planning a phased approach to meet current and projected demands, beginning with
construction of a new 6-MGD treatment facility.
The proposed project includes the following major components:
• New 6-MGD water reclamation facility(WRF) constructed on a Town-owned site adjacent to the
Neuse River and including the Town's existing outfall as a first phase, with anticipated incremental
expansion to 10 MGD to meet future needs
• Abandonment of the Town's existing LCWRF
• Construction of a pump station at the LCWRF site and associated Little Creek (LC)Transmission Main
infrastructure to convey flow to the new WRF (WithersRavenel, 2020a)
A Project Vicinity Map is included as Figure 1-1, and a Project Location Map is included as Figure 1-2.
These maps also show a separate project also being planned by the Town, expansion of the Town's
existing East Clayton Industrial Area (ECIA) pump station and construction of the ECIA Transmission
Main to convey flow to the new WRF (Town, 2020f). This separate project is separately funded and
permitted as part of the Town's overall master planning to meet future needs.
1.2 Reasons for the Project
The Town is seeking to replace existing capacity and prepare for known increasing near-term demands
with construction of a 6-MGD WRF. This plan is needed because of the LCWRF's aging infrastructure,
expiration of its contract with the County, and known near-term demands. The Town is also planning to
meet future rising demands through 2040. A recent capacity study indicated that the Town will require
approximately 10 MGD in total wastewater treatment capacity over the next 20 years to meet future
needs, including major increases in industrial flow from industrial and commercial customers (Wooten,
2018).The Town is planning a phased approach to meet this expected demand, with an initial step to
reach 6 MGD.
1-1

1 89 i I' --- \J".'`l _\ ., ti ,�_ _ ,t
jpy� A -,, \
wager .6„, i •
f:. ,L, 1L.. ., is, ) ,_,-_, ( ...
..L\`� 8r ;' j. / )+ Raleigh11114.11;r—
County
NV �/' / • �� .2 �v. ; ,• n g ,<
1111
111 Johnston
kr".1
. 'Aiikki
ti L. \ County
" ��� ,' _iAtli
Clayton
i s ,A0
\ \z ,ll ' / ilillibMii �40 el
`� Neuse 2 _., •
A _- . J PS Site ��0, Little Creek P'r o . V /�
lit v� vR ? �J / `� WRF Outfall -' '_.9s '`, -
. ^ f ..J`\y?: over`l _ � \ jit ` :.'✓, ,'
f v
lam; -
g 1'IDI� r \ \A, e; .
ip b
`, `� Clayton i ,
I Little Creek 's �1 `� ~ y -
/ WRF �'Rawly ' �c p
�'Se• age, i 5� , \�
lied V_ lei J
.41/1 �, Legend
�, ,n ,-? Interstate
free_ Pond �-� Highway h
.off;°' ao`o "�e — Major Road
;,'� _� e, — Major Hydrology /
.` U f Town Limits f
. ae �,' _ 1 i East Clayton �/ I ETJ
` _ J Industrial Area ,
County Border ,3
,_ 1r_ ti �' •'�� \Copyright:® 013 N4\nal e`o•raphic Sa�e)ty c�&d.
0 1 2 N Figure 1-1
eh • I I I A Project Vicinity Map
Miles Water Reclamation Facility Expansion
2/11111111,
Town of Clayton, NC

e It ____
__,
/
_ "—
Proposed Water
_____
_I
Reclamation ! ' ;,i
a
‘,7Facility '
ti
, ) .
xX ":wi
Proposed Influent Pump Station
a x `'' I
_ c U
X
` NeuseARiver '� ' /
♦ r't
•
/) '•sal
Proposed Little Creek Pump Station j - R�
y/� 11 \\J —_`\ / ,; ��'A`' d .v-1 fi, M•
J (l\`I— \ , � n k £ 1` ADS ° ev.! I .3,
(' _ s�. 7 ♦ F''t, 4 ,(Lsy Wn1�' '"rn'3a t"N °" '� '@�4
42 �� J EC1A/
Tr "� P � �4 40.
LL�',� ss. ,,,„'*. }rah' i ^. a a,
_ So- •
4
R. Steven Biggs Regional
i Pretreatment Facility E� Legend
"� �- � Plant Footprint
Current Little Creek
Proposed Force Main
Water Reclamation ) )
a
Proposed Gravity Main '.;
Facility Parcel Limits
�} �s� �,� Pavement '
r Expanded ECIA Pump Station ' ��` -StreamorRiver
Town Limits
7� ` ETJ
CD
nI ,,. � _
corn �� �..
0 3,900 7,800 Figure 1-2
. I I I N Project Location Map
5M Feet Water Reclamation Facility Expansion
Town of Clayton, NC

SECTION 1-EXECUTIVE SUMMARY
1.2.1 Current Capacity Limitations
While well maintained, the LCWRF includes aging infrastructure,which contains equipment both
approaching and beyond its expected useful life. A recent criticality analysis conducted as part of a
state-funded Asset Inventory and Assessment Grant indicated the facility will require a capital
investment of more than $4 million within the next 5 years for renewal and replacement (R&R) of aging
systems and equipment, and will require additional significant capital investments over the next
20 years as the facility continues to age and degrade (CH2M, 2019a). Additionally, analysis indicated
capital investments would be needed for the treatment process to continue to meet nutrient discharge
limits as a discharger to the Neuse River basin and to protect infrastructure from potential flooding
(Wooten, 2018, 2019).
The LCWRF is prone to flooding, being partially located within the 100-year flood extent of Little Creek
(North Carolina Floodplain Mapping Program, 2020).Another Town goal is to increase the reliability of
the Town's treatment capacity and improve provisions for continuity of service during storm events.
Building a new WRF outside the floodplain and decommissioning the LCWRF removes this risk.
The Town's wastewater flows from both residential and industrial and commercial customers have been
growing along with the strong economy in the greater Raleigh area. Housing units are being built to
support the growing population in the service area, adding to the Town's customer base. Additionally,
facilities in the ECIA are making significant investment in expansions, increasing the industrial and
commercial contribution of wastewater flows and providing job growth.The ECIA is part of a state-
created Research and Training Zone (RTZ)where these biopharma facilities partner with the Johnston
County Workforce Center to provide biotechnology education opportunities.These projected flow
increases, supported by historically increasing population and wastewater flows, contribute to the
Town's need for an expansion of wastewater treatment capacity.
By constructing a new 6-MGD WRF, the Town would improve the reliability of service to its customers,
including industries, with treatment capacity and improved nutrient removal capabilities. Nutrient
management goals and potential changes in future waste streams, with additional higher-strength
waste from the ECIA and residential flows that are more concentrated from water conservation, have
also led the Town to plan for the reliability provided by a new WRF. Operation of a new WRF coupled
with maintenance of interconnections for emergency needs provides the Town and its customers with
resiliency moving forward.
1.2.2 Regional Partnerships
The Town currently relies on regional partnerships for 2.4 MGD of capacity.The Town has historically
leveraged these partnerships as a cost-effective means of delaying major capital investments related to
the expansion of Town-owned and -operated wastewater treatment capabilities. Under the 1.4-MGD
County contract, the Town conveys 900,000 gallons per day (gpd) pretreated industrial wastewater from
the ECIA to the JCRWWTP for final treatment.
The pretreated industrial wastewater conveyed to the County includes total dissolved solids (TDS)
exceeding domestic-strength limits; therefore, this wastewater is considered high-strength for
treatment (and billing) purposes.The County decided to treat effluent at their new WRF to high-grade
reuse standards to minimize the need for nitrogen credits for a surface discharge.This is reflected in
their new National Pollutant Discharge Elimination System (NPDES) permit.As a result, the County has
made the decision to not accept any wastewater with characteristics exceeding domestic-strength limits
beginning beyond the expiration of the current agreement after July 1, 2022.This eliminates the future
use of the County contract as an option for increasing flows from the R. Steven Biggs Regional
Pretreatment Facility in the ECIA.The Town does not have the infrastructure in place to transport
domestic-strength wastewater to the County from other parts of its service area.
1-4

SECTION 1-EXECUTIVE SUMMARY
Under the City contract,the Town conveys domestic-strength wastewater from the northeastern side of
Clayton using the Clayton to Raleigh Pump Station to the City's NRWWTP.The City has indicated the
current contract for 1.0 MGD maximum month (MM) capacity could be extended from 2027 to 2032,
and an additional 0.25 MGD of treatment capacity is available to the Town for purchase. The City is also
experiencing growth. With growing capacity demand from its customers,the City has indicated it is not
interested in supporting economic development beyond its retail rate base in eastern Wake County by
expanding the current agreement with the Town after 2032.
The County and the City have communicated their intent to increase the fees associated with conveying
and treating the Town's wastewater. The County intends to increase its fees by 20 percent in 2020, and
the Town anticipates the fees will continue to increase by at least 5 percent annually;they will also
discontinue acceptance of flows exceeding domestic-strength waste in 2022.
The City intends to increase the fees associated with the current contract capacity by as high as
40 percent in 2020 and has proposed new fees and charges for any additional capacity beyond the
currently contracted 1.0 MGD. In short, these regional partnership contract opportunities are limited
and do not meet all future expected needs, and the Town must build its own treatment capacity.
The purposes of the proposed project,to meet current and future capacity demands while replacing
aging treatment infrastructure and prohibitive new wholesale contract provisions from a new NPDES
permit, are described in Section 4. The LCWRF is aging, and the facility is not well-suited for expansion to
meet long-term capacity needs and more stringent nutrient treatment requirements.The purpose of the
project is to provide the Town's customers with reliable, increasing treatment capacity through a
combination of Town investment in a new WRF for treatment reliability and continuation of current
contracts with regional partners for resiliency.
1.3 Results of Alternatives Analysis
1.3.1 Preferred Alternative
The Preferred Alternative consists of construction of a new WRF to be built on Town property currently
housing the Neuse 2 and Clayton to Raleigh Pump Stations (referred to herein as the Neuse 2 Pump
Station site) and LCWRF discharge to the Neuse River. Initial treatment capacity of 6 MGD will replace
the aging LCWRF and support wastewater flows from both residential and industrial and commercial
customers that have been growing along with the strong economy.
To best position the Town to meet 2040 projected needs, including nutrient removal, the Town's
approach involves the construction of the initial 6-MGD plant with the capability of expanding
incrementally to 10 MGD to meet future demands if needed, while for resiliency, maintaining limited
additional capacity through regional contracts with the City and County. Investing in treatment capacity
via a new WRF will support the Town in meeting its future capacity needs and keep pace with regulatory
requirements.
The Preferred Alternative includes construction of a pump station at the LCWRF and the associated
LC Transmission Main to convey flows to the new WRF. An existing pump station in the ECIA will be
expanded and the ECIA Transmission Main constructed to convey flows from east Clayton to the new
WRF. Grifols Therapeutics (Grifols) is currently investing in an expanded pretreatment facility, and the
effluent from that facility would be conveyed to the new WRF via the expanded ECIA Pump Station and
new ECIA Transmission Main. This pump station and transmission main are being permitted and funded
as a separate project. These and other flows from industrial expansions currently being constructed in
the ECIA are accounted for in the demands forecast.
Under this alternative, the contract with Pine Hollow Golf Course for reuse water will be terminated
after the construction of the new WRF due to the distance between the golf course and the new WRF.
1-5

SECTION 1-EXECUTIVE SUMMARY
The Preferred Alternative balances cost, environmental considerations, and the ability to meet 2040
treatment capacity needs.
1.3.2 Alternatives Discussion
A range of alternatives to meet the Town's needs were considered.These were:
• No Action
• Construction of a new WRF, and continued use of surface water discharge at the following locations:
— Neuse 2 Pump Station site
— ECIA Pretreatment Facility site
• Expansion of LCWRF, and continued use of a surface water discharge
• Continued use of LCWRF, maximizing regional connections to existing wastewater treatment facilities
• Construction of a new WRF, and use of land application
• Construction of a new WRF, and implementation of larger-scale wastewater reuse
• Construction of new WRF—Alternative secondary treatment process
• Construction of new WRF—Alternative biosolids treatment strategy
• Combination of alternatives
• Decentralized system
• Optimum operation of existing facilities
The No Action alternative included no significant improvement or increase in the Town's available
treatment capacity. In fact, under the No Action alternative, overall capacity will reduce with the
imposition of prohibitive new wholesale contract provisions from a new NPDES permit.This alternative
relies on existing infrastructure and regional interconnections with the County and the City.
This alternative was rejected, as is does not meet the purpose and need:to reliably meet the Town's
projected increase in customer demand for wastewater capacity.The alternative is considered
infeasible.
Construction of a new WRF, and continued use of a surface water discharge at the Neuse 2 Pump
Station site, as described, is the Preferred Alternative.
Construction of a new WRF, and continued use of a surface water discharge at the R. Steven Biggs
Regional Pretreatment Facility in the ECIA.This site is located near the Town's industrial customers;
however, it is not in an area expected to experience significant residential growth.This alternative
would include a similar 6-MGD facility as the Preferred Alternative,with an effluent pump station to
convey flow to the existing LCWRF discharge location at the Neuse 2 Pump Station site. As with the
preferred site, a new pump station would be constructed at LCWRF to convey flow to the new WRF.
Under this alternative,the contract with Pine Hollow Golf Course for reuse water will be terminated
after the construction of the new WRF due to the distance between the golf course and the new WRF.
This alternative was rejected, as it has a higher capital and operational cost than the Preferred
Alternative, and had higher environmental impacts associated with wetlands at the site if they could not
be avoided. Additionally,the current Town-owned land is limited in size, and is also the intended site of
future expansion of the R. Steven Biggs Regional Pretreatment Facility. Additional land in the area is
limited and constrained by existing features and development. As such, the opportunity to expand
incrementally to a 10-MGD facility is limited on this site.
The expansion of LCWRF, and continued use of a surface water discharge alternative includes
rehabilitation and expansion of the existing LCWRF. In addition, the discharge pump station and force
main, and gravity line to the discharge location would be expanded.The Neuse 2 Pump Station would be
expanded to convey future flows to the LCWRF, and the ECIA Pump Station would be expanded and a
new force main constructed to direct flow to the LCWRF.
1-6

SECTION 1-EXECUTIVE SUMMARY
This alternative is feasible; however, it is not recommended because it involves potential impacts to the
Little Creek floodplain and involves investment in both rehabilitation of infrastructure and new
construction, and the added complexity of expanding and upgrading an active plant when compared to
the Preferred Alternative. In addition, this alternative exposes the Town to costs to rehabilitate
structures outside of the planning window as compared to the Preferred Alternative. This potential site
is also affected by Environment Justice considerations.
Under the continued use of LCWRF, maximizing regional connections to existing wastewater
treatment facilities alternative,the Town would reach agreement with the County and City to expand
contracts for the existing infrastructure connections while maintaining operation of the LCWRF to meet
future projected demands. Additional conveyance infrastructure would be required, with the details
depending on which regional contract would be increased. Under this alternative, regional contracts for
treatment capacity in the amount of approximately 4 MGD would be necessary to meet the initial
capacity expansion of 6 MGD. Both the County and City are raising rates and are expected to implement
water quality parameters (lowered TDS)that must be met in the waste stream. This alternative would
also require significant renegotiation or expansion of agreements with the County and the City.
This alternative is not considered feasible because, to date, the Town has been unable to reach
long-term agreements with these utilities. The Town also does not currently have the infrastructure in
place to transport domestic-strength wastewater to the County. Future incremental expansion through
regional contracts to a capacity of 10 MGD would be more difficult, so this is not considered to be a
viable alternative.
Under the construction of a new WRF at the Neuse 2 Pump Station site, and use of land application
alternative, the Town would build a new 6-MGD WRF, with plans for future incremental expansion to
10 MGD. The effluent discharge would be abandoned, and the treated effluent would be diverted to
suitable locations for spray irrigation. Approximately 1,300 acres would be required for spray irrigation,
and based on a preliminary review of available land, it is assumed that multiple sites would be required
and would be within 10 miles of the WRF.
While the cost of treatment reduces relative to a surface water discharge, and the alternative eliminates
the need to expand the outfall into the Neuse River, the costs associated with conveyance of the
effluent, the land application site, and operation and maintenance (O&M) significantly increase the
overall cost of the project compared to other alternatives.This alternative also likely has less feasibility
to meet the Town's long-term needs of 10 MGD of treatment capacity. Given the costs of land
application and the limited availability of land, this alternative was rejected.
Under the construction of a new WRF at the Neuse 2 Pump Station site, and implementation of larger-
scale wastewater reuse alternative, the Town would build a customer base to support wastewater
reuse of effluent. The Town has a limited reuse program and currently provides a small amount of reuse
water to a single golf course; however, demand is seasonal. For large-scale reuse to be feasible and
practical to the Town, available land for irrigation (such as golf courses) or large industrial users would
need to be available within a reasonable distance of the WRF and have year-round demands.
A review of potential reuse customers reveled very limited potential for a large-scale reuse program.
Golf courses have low requirements, relative to the proposed flow; and large industrial users have
environmental sustainability programs in place to conserve water and energy. Under these programs,
each facility's water cycle conserves and reuses water where possible. As a result, the amount of water
purchased is minimized and leaves little opportunity for additional outside purchase of reuse water.
Given the limited nature of potential industrial and golf course irrigation demand, development of a
reuse system that could eliminate or greatly reduce the need for a treated surface water discharge from
the WRF is not feasible. Large-scale wastewater reuse is, therefore, not a feasible alternative to
expanding wastewater capacity.
1-7

SECTION 1-EXECUTIVE SUMMARY
The Preferred Alternative includes a five-stage Bardenpho process for biological nutrient removal (BNR),
with a chemical feed system for phosphorous trimming. As an alternate, construction of new WRF—
alternative secondary treatment process, a four-stage biological process for BNR, coupled with
chemical phosphorous removal was assessed. While this saves some capital cost relative to a five-stage
Bardenpho process,the anticipated lifecycle cost would be similar between the two options.
Additionally, the cost of chemicals is subject to fluctuation, leading to more uncertainty in operations
costs for chemical phosphorous removal. This alternative is feasible, but not preferred for these reasons.
The Preferred Alternative included a solids treatment process of thickening, aerobic holding, and
dewatering prior to disposal to either contract composting or landfill. Construction of new WRF—
alternative biosolids treatment strategy considered a chemical-physical thermal hydrolysis process
(Lystek THP®)to produce Class A biosolids in accordance with the 40 Code of Federal Regulations (CFR)
Part 503 requirements (EPA, 2018). This alternative is a feasible option; however, it is not preferred over
the Preferred Alternative, as it as a higher initial capital cost than the Preferred Alternative, and
marginally higher lifecycle cost.
A combination of alternatives was assessed. One alternative was to continue operation of LCWRF at its
current capacity and construct a smaller(4-MGD) plant at a new site. While this would have a lower
capital cost for the WRF than the 6-MGD Preferred Alternative, rehabilitation of aging equipment at the
LCWRF would still require investment to maintain operational functionality of 2 MGD. Operational cost
efficiencies would also be lost if two facilities remained in operation. This combination does not yield
significant cost-savings for the Town and was not considered further.
A further combination of alternatives could be to land apply effluent during the dry periods and revert
to NPDES discharge during the wet periods. A large area would be required for land application, and the
cost of that land and the associated infrastructure is very high. In addition, because the WRF would be
required to treat to a high enough level for a surface water discharge, there would be no cost-savings
related to the reduced effluent quality associated with land application. As such,this combination of
alternatives provides no benefit over the other options and was not considered further.
Similarly, a combination of land application and large-scale reuse would be no more feasible than the
two options independently.
A decentralized system was considered infeasible, as the Town's wastewater treatment strategy is to
collect wastewater at centralized points and transmit it to LCWRF and regional partners for treatment.
Expansion of capacity by transitioning to a decentralized approach would not be efficient or effective.
Optimum operation of existing facilities was a reviewed alternative. The current LCWRF is already
treatment capacity limited to less than its permitted 2.5 MGD, as is cannot reduce total nitrogen (TN) to
a low enough level to meet the existing NPDES permit limit at the permitted capacity. Optimization
beyond the current capacity limit would require system upgrades beyond the intended scope of this
alternative. A total capacity of 6 MGD could not be achieved through optimization. This alternative was
considered infeasible.
In conclusion, the Preferred Alternative is construction of a new WRF, and continued use of a surface
water discharge at the Neuse 2 Pump Station site.
1.4 Summary of Environmental Impacts and Mitigative
Measures
Construction and operation of the proposed WRF, its access road, and the LC Transmission Main
infrastructure are not expected to significantly impact the environment.The proposed WRF site layout
was planned to avoid streams, wetlands, and buffers on the parcel and keep new site infrastructure out
1-8

SECTION 1-EXECUTIVE SUMMARY
of the floodplain.The developed area on the site would remain under the maximum allowable
developed area under Water Supply Watershed Rules(15A North Carolina Administrative Code [NCAC]
02B.0621). Other project infrastructure was also planned to avoid and minimize impacts.The current
LCWRF discharge into the Neuse River would be expanded to make use of existing infrastructure and
easement.The transmission main from the LCWRF would be routed to maximize use of the existing,
maintained easement to the extent practicable.
The following list summarizes the potential for impacts to the environment:
• Approximately 24 acres of forest lands would be cleared for construction of the WRF; approximately
70 percent of forested area on the site would remain, including stream buffers. Along the
LC Transmission Main route, forest impacts and Zone 1 stream buffers are minimized through use of
the existing LCWRF discharge line easement where possible.
• The biological phosphorous removal process reduces environmental impacts associated with
chemical use, namely the chemicals themselves and chemical delivery vehicles, when compared to a
chemical phosphorous removal process.
• Temporary impacts associated with construction will be minimized through use of erosion and
sediment control measures as approved through a Major Land Disturbance permit acquired from
the Town and erosion and sediment control (ESC) permits administrated by the County.
• Most stream and wetland impacts associated with the LC Transmission Main will be temporary.
Impacts would be minimized through use of the existing easement for the LCWRF discharge line to
the outfall into the Neuse River; five stream crossings would be required. Approximately 0.024 acre
of wetlands at a total of three locations along the route would be temporarily impacted. Potential
impacts would be minimized by following general and regional conditions included in Clean Water
Act (CWA) Sections 401 and 404 Nationwide Permits (NWPs). Specifically, NWP 7 is applicable for
the outfall structure upgrade into the Neuse River, and NWP 12 is applicable for linear
infrastructure.
• Temporary impacts to the Neuse River from turbidity would occur during construction of the outfall
expansion but would be minimized through use of a cofferdam system.The streambank would also
be stabilized after construction,with no permanent floodplain impacts. Increased discharge into the
Neuse River is not expected to impact the environment. Water quality will be protected through
compliance with the facility's NPDES permit.The additional flow volume is minimal compared to the
flows in the Neuse River.
• The Sam's Branch and Neuse Riverwalk greenways would be temporarily closed during construction
of linear infrastructure and the outfall expansion.They would be restored to existing conditions
after construction is completed and reopened. A native seed mix will be used to reestablish
vegetation within the LC Transmission Main alignment adjacent to Sam's Branch at the WRF site.
This will provide habitat for pollinator species and provide an educational opportunity for greenway
users.
• The Neuse River waterdog and Carolina madtom are proposed for federal protections. Habitat for
the Neuse River waterdog is likely present in the lower reaches of Sam's Branch and the Neuse River
near the outfall.To limit potential impacts to these species and other aquatic species, ESC measures
beyond those typically required will be used to minimize sediment loading into waterways. Impacts
to these species are not expected.
• Habitat for the federally protected Michaux's sumac was also identified along maintained utility and
power easements associated with the project. A growing season survey was conducted, and the
species was not located (WithersRavenel, 2020a, 2020b, 2020c).Therefore, the project is unlikely to
affect protected species.
1-9

SECTION 1-EXECUTIVE SUMMARY
1.5 Project Funding and User Fee Increases
Funding for the project will be from the Clean Water State Revolving Fund (CWSRF) low-interest loans
and revenue bond issue.The Town is eligible for up to $90 million of CWSRF funding based on current
status with North Carolina Department of Environmental Quality(NCDEQ) Department of Water
Infrastructure (DWI) and the State Water Infrastructure Authority(SWIA).The Town has engaged
Davenport &Co. to support them with bond issuances.
The Local Government Commission (LGC) has approved $15 million, which includes money for nitrogen
credit purchases. Letters of intent have been signed for the nitrogen credits, and purchases are being
executed.
To date, one round of CWSRF funding has been approved for$30 million, at an interest rate of
1.38 percent over a 20-year period and with an administrative fee of 1.5 percent.The Year 1 principal
and interest on this loan is$1,914,000.
The Town conducted an analysis in 2019 to assess the impact of the proposed project on rates and fees.
Program costs for a new WRF and associated transmission infrastructure is currently estimated at
$153 million, based on a construction cost of$121 million and project administration costs of
$31 million, and rate increases for the first 5 years on the order of 10 percent per year have been
identified.This rate increase is public information and is published on the Town's website
(Town, 2O2Og).The Town's consultant, Black &Veatch Management Consulting LLC (Black &Veatch),
has completed several versions of the rate model over the past 2 years, and Council has already
proactively raised rates in each of past 2 years in anticipation of the project.
Town Council continues to support the rate increases associated with full program delivery. CWSRF and
bond capacity are available. Regardless of available funds, the LGC must approve all debt issuance.The
Town continues to work with LGC to officially approve the issuance of debt.
The Town adopted Fiscal Year(FY) 2021 rates as recommended in the rate study finalized in 2020 (Black
&Veatch, 2020), which incorporates the Town's Capital Improvement Plan, including increases in
wastewater treatment capacity.
1-10

SECTION 2
Current Situation
2. 1 Background
The Town has initiated the process to expand their wastewater treatment capacity. The Town currently
has an effective wastewater treatment capacity of 4.9 MGD via its LCWRF and wholesale contracts with
the JCRWWTP and NRWWTP. The plan to replace and expand capacity is required due to the LCWRF's
aging infrastructure, expected growth, and the upcoming imposition of prohibitive new wholesale
contract provisions form a new NPDES permit associated with one of these contracts. A recent capacity
study indicated that the Town will require approximately 10 MGD in total wastewater treatment
capacity over the next 20 years to meet future needs, including major increases in industrial flow from
industrial and commercial customers (Wooten, 2018). The Town is planning a phased approach to meet
this expected demand, with an initial step to reach 6 MGD.
The Town has undertaken multiple actions to address treatment capacity needs and plan for the future,
including the items outlined on Figure 2-1.The next milestone is to increase the Town's current treatment
capacity from 4.9 to 6 MGD.This expansion is necessary to meet the projected needs from residential growth
and increasing industrial and commercial customer demands, and to maintain status as a cost-effective
provider of wastewater treatment.As flows increase in the future,the Town will plan to incrementally increase
capacity beyond 6 MGD to meet future wastewater treatment capacity needs through 2040.
Another Town goal is to increase the resilience of the Town's treatment capacity; the LCWRF is aging,
and parts are susceptible to floods; also, contracted capacity agreements will expire during the planning
period. The Town seeks to continue reliably providing its customers, including industries, with treatment
capacity and quality performance by increasing the wastewater treatment capacity provided by the
Town. Nutrient management goals and potential changes in future waste streams, with additional
higher-strength waste from the ECIA and residential flows that are more concentrated from water
conservation, have also led the Town to plan for the reliability provided by a new WRF.
2.2 Overview of Current Situation
The Town provides wastewater conveyance and treatment services to a population of over
22,800 within the Town limits, a population of over 10,000 in its extra-territorial jurisdiction (ETJ), and
several industrial and commercial customers (Census, 2019). The Town currently owns and operates the
2.5-MGD capacity LCWRF (Permit NC0025453), which discharges to the Neuse River.
LCWRF was originally constructed in the 1950s as a trickling filter plant but has undergone major
upgrades and modifications, including:
• In 1990 (Ragsdale, 1990), when conversion of the plant to an oxidation ditch facility was completed
• In the mid-1990s (McKim & Creed, 1996), when a second oxidation ditch was added
• In the mid-2000s (Wooten, 2003), when anaerobic and anoxic zones were added for BNR
The current biological treatment process consists of two oxidation ditches with additional anaerobic and
anoxic zones for BNR (CH2M, 2019a; Wooten, 2007).
Additionally, the Town has purchased treatment capacity via regional contracts from neighboring
utilities. The Town owns 1.4 MGD in capacity at the JCRWWTP and has contracted 1.0 MGD in capacity
through 2027 from the City's NRWWTP. This brings the Town's current total permitted wastewater
treatment capacity to 4.9 MGD (Figure 2-2). In 2019,the Town's MM average daily flow (ADF) was
3.2 MGD (Table 2-1) (Town, 2020a).
2-1

SECTION 2—CURRENT SITUATION
Town of Clayton
Comprehensive
Plan 2040
Clayton Southeast
Basin Master Plan
Sam's Branch Basin
Pump Station Water and Wastewater Asset
Decommissioning Inventory and Assessment
Feasibility Evaluation
Risk/Criticality Analysis and
Renewal&Replacement
Town of Clayton Model Results Summary
Wastewater Town of Clayton
Conveyance Study Wastewater Flow
Town of Projection Update
`Clayton Nitrogen /
Town of Clayton Removal Study
Wastewater Treatment Town of Clayton Town of Clayton
Capacity Study Strategic Growth Plan Grifols Pre-treatment Utility Rate Study
Evaluation
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2046 2017 2018 2019 2020
/ N.
Phase 1- `
Town purchases Neuse 2 Pump Station Sam's Branch Grifols Pump Town purchases N
Town purchases
capacity at the and Force Main Interceptor Station Upgrades additional capacity
additional capacity Construction
Johnston in service in service Completed / at the Johnston
County WWTP at the Johnston County WWTP of the ECIA
Town purchases County WWTP Novo Nordisk Pump Station
announces
Town purchases capacity at the capacityfacility
additional City of Raleigh,
at theJohnston Neuse River WWTP /
Town takes
County WWTP / \ Cl ownership of
ayton-Raleigh (Steve Biggs)
Novo Nordisk Regional
Johnston County Town purchases breaks ground on Pump Station WWPTF
transfers ownership And Force Main
additional capacity facility expansion
of capacity at the in service
at the Johnston / \
Neuse River WWTP to CountyWWTP Central Pump
the Town Station
Rollingwood 1 and 2 Novo Nordisk breaks decommissioned
Pump Stations ground on(Steve Biggs)
decommissioned Regional WWPTF
Figure 2-1.Town of Clayton Wastewater Treatment Capacity Planning Timeline Since 2001
2-2

.
'II Try"., .f't ':M ,
To Raleigh Clayton to Raleigh ! r t
, 4
: \ \%r "}' Neuse WWTP y . 9 ,'! dift �; t "`r
,,.
i4
,� �r r±�r .t! for Treatement: �« ,+ ` ..r\4\
' ' 1 y * , 1.0 MGD ,:,° :.n
..., _ ,
...„,,,,,,:„... .,., ,.
4%,,.... .....,,,, ,..„ lik ..
C '�l l .. = ��- • - )- 4V
is tii
,*_li for.„'4-\.,4
/ ' �, ` M� Jim. 4 �' 1 4 • • 1 ,4-..t.,.N4,)
,„O:. ,
i c . er, `f Alt` •f.Jg •` y(• •1
•
°. tip4" ( i'i ', 3
•
s,
* Little .I. ., n - ar ; r�► , ,
Creek RF >; ,.. : r! t, ,i. ,• �. ,,+,-1 t ;. , \` . i�� ,
,,,, S '
„� z ° gy ,f} j '
k,,,,ii.,,,, , ligil i 3rir,‘ ..T.:,, 1,, 10! .._,.. , .. 1 ,,,,i44, 1% :” . ‘. \, 4 - r•—.7=7x. 1-0,:,-;.7-' •-41t.k , Allr-o• '(-t." \ o' '
'..ks ' Permitted �. `s AF' •1 �` . - ., 1
* , Capacity: 2.5 r , 'f '' � �, - ,4,,# f'
• MGD _ i �'`•- o4 r '
•
, 1RR r may. n. ' I. J.•',.. ,.Il,,,li4. ",.,
t .'" K, z. , , Novo Nordisk t ,Ill
A.v , `, , • ' Grifols ' `' �~ if
,,,4, i
- ..itki
' - To Johnston Co. .— : . } -
,;�;� s '0 WWTP for '. `r"
` L.. , ' . �`" /!�� Treatment: ; 4f r
�` �{ 1.4 MGD Q� Biggs ;
'' _ RegionalPretreatment Facility
i: v '). `�" 1. iy ."Cam, o o'r�-IGI o bet, @To,E3 C ni - e�pGliiz,ONC4iL-AJi}ui DO,UODA,I33�3g3,1Vairoc37I],1
Ilgtit "
Figure 2-2
0 0.5 1 N Existing Wastewater System and Regional Partnerships
Ch2AM111,1) I I I A Water Reclamation Facility Expansion
Miles Town of Clayton, NC

SECTION 2—CURRENT SITUATION
Table 2-1.Town of Clayton Permitted Wastewater Treatment Capacity and Current Usage
Treatment MM Capacity 2019 MM ADF
Location (MGD) (MGD) Status
LCWRF 2.5 2.2 Permitted capacity of 2.5 MGD.
JCRWWTP 1.4 0.8 a New discharge limits in 2022 relative to industrial characteristics.
NRWWTP 1.0 0.2 b Contract expires in 2027.
Total 4.9 3.2
a Industrial flow from ECIA
b Residential flow
Flow is conveyed to the JCRWWTP from a pump station in the ECIA.The ECIA includes two major
industrial facilities (Grifols Therapeutics and Novo Nordisk Diabetes Active Pharmaceutical Ingredients
[DAPI]), along with a number of other residential, commercial, and industrial customers. Most of the
flow from the ECIA, including from the two major industries, is currently sent to JCRWWTP for
treatment.The remainder of the ECIA flow is conveyed to LCWRF for treatment.
The Town also has the flexibility to send a portion it its residential flow to the NRWWTP via a pump
station located on the Neuse 2 Pump Station site.
When a facility's MM ADFs near 80 percent of permitted flows, 15A NCAC 02T.0118 requires that a
utility begin planning for future treatment and disposal needs.The Town met with the NCDEQ in 2016
and presented plans for increased contracts with the County and City,which are now in place.These
plans demonstrate the Town's efforts, including those outlined on Figure 1-1,to meet near-term needs;
and NCDEQ responded with permission to continue issuing sewer permits and allocating flow, including
for industrial increases associated with facility expansions.
While many of the processes at LCWRF are in good condition, much of the mechanical and electrical
equipment is approaching, or already beyond, the expected useful life. In addition, the plant is
treatment limited to approximately 2 MGD but continues to meet permit limits at current flows, and
previous evaluations have proposed improvements to TN removal, such as denitrifying filters (CH2M,
2013; Hazen, 2013; Wooten, 2018, 2019).
Clayton is a growing area, and both residential and industrial flows have been increasing and are
projected to continue to increase. LCWRF is relieved from the pressure of some of this growth through
the Town's use of interlocal agreements to convey a portion of the wastewater flow to the County's or
the City's wastewater treatment facilities.
2.3 Collection System Condition
The LCWRF treats wastewater collected from Clayton in a wastewater collection system consisting of
close to 160 miles of gravity sewer lines and force mains. Figure 2-3 shows the extents of the collection
system,which includes 28 pump stations with capacities ranging from 40-2,100 gallons per minute
(gpm).Table 2-2 provides information on the existing pump stations in the Town's collection system.
2-4

SECTION 2—CURRENT SITUATION
Table 2-2. Existing Wastewater Pump Stations
Name of Pump Firm Pump Name of Pump Firm Pump Name of Pump Firm Pump
Station Capacity(gpm) Station Capacity(gpm) Station Capacity(gpm)
Brittany Woods 40 Olde Towne 100 Arbors 400
Fire Station 2 40 Powhatan 100 Glen Laurel 2 480
Animal Hospital 54 Walmart 118 Summerlyn 590
Colonial Carton 80 Peele 150 Glen Laurel 1 600
Liberty Lane 80 JHM 180 Neuse River 1 750
Starmount 80 Glen Laurel 3 200 Neuse River 2 750
West Main 80 Wynston 200 Clayton to Raleigh 1,740
City Road 100 Cobblestone 220 ECIA 2,100
Flamingo 100 South Tech Park 220 - -
Hardee Lane 100 Walnut Creek 315 - -
Source:CH2M,2019a
In 2019,the Town completed an evaluation under an Asset and Inventory Assessment (AIA) grant to
examine the condition of the Town's pump station inventory(CH2M, 2019a) (Appendix A).The pump
station assets were rated according to condition on a 1-5 scale, with 1 indicating very good condition,
and 5 indicating very poor condition. For an inventory of 488 individual pump station assets,the
condition assessment results are summarized as follows:
• 12 percent of the assets were found to be in Condition 1 (Very Good Condition).
• 55 percent of the assets were found to be in Condition 2 (Good Condition).
• 24 percent of the assets were found to be in Condition 3 (Moderate Condition).
• 7 percent of the assets were found to be in Condition 4 (Poor Condition).
• 2 percent of the assets were found to be in Condition 5 (Very Poor Condition).
The Town has also assessed which pump stations in the Sam's Branch basin to the northeast of Clayton
could be taken offline by connection to the gravity system as that system grows (CH2M, 2015). In recent
years,the Town has noted that a number of pump stations have been decommissioned in this
northeastern part of Clayton that naturally drains away from the LCWRF and toward the Neuse River.
2-5

�';I...,..ti#.r.4'a,z,,#.
1 iAt 7 ck'iir,.‘ci-
J
...
,, ,,,-,-,,,.-
4
1aI1F0g-o_„A...iik,i,
,7...., s 4//'4 0,Ali i,t
.. . , , :
.1.
ii. .
.1),I.0 ir--62
it ' , v
♦ . O d
.. coer
2 Neu v
v ki
0.
.� el'‘set 1 0 ,..,--
i
C ' :7 Ap, --.4..
1
• 1 *
\� mirr
'• • Q r lei '
Ailt ri.
ilk
a • IV
-6
' II
�� -/ Pam,`t PS-. 'i '' 4 , f • �
A ., i. Ps
4,4i -
., ,./... ..., .,,,,,,, , •• p 0 „Lot,' e It V#4,
• 4
, In
Ai ,I....,,, p g il I 111 41 I lil i,, 0. 4 ir
*11,
0 iG 4, PS lee, TV*:� A. /A '';‘,44Sts';'A•,::..- -' s
� r psi , , PS 7, — s��` �� A��'�m� �' �Ps 1-. of Ps ) II • Legend
( �„ * .PS PS 1/ PS V v PS A Little Creek WRF
r �•�7G � ` � PS f �
�a,,, ` � i` . _ Proposed WRF
a Yiry f�pc la)v' ----PS 'et 1�'(/�1 PS _ 4 ��t1111007
� / v
i� ( 4 PS k r, 11 5 Q l/ A �..�Count Line
N. ;� PS Pump Stations
_1 �� O - J1iAvPs ' y
41 AA• PS • .■■. Existing Force Main
�� 'f � Force Main to ' v 1 Town Limits
a t 1 ii), O �� �v'� `� —Stream or River
�,��Om'
. �� o _ Johnston County
1TaUJuu1
PS' o '+? o Ps Regional WWTP
— Major Roads
-
•
Pr En sli,
o s.
o . I ` Other Roads /
4 / ¢ ‘11:-
illp . �— + Raiload
4'
. ,
- ,.. ., 1
0 8,000 16,000 N Figure 2-3
241411
I I I Wastewater Treatment and Collection System
Feet A Water Reclamation Facility Expansion
Town of Clayton, NC
The treatment systems depicted on this conceptual layout represent conservative footprints,and may be revised as the design develops.

SECTION 2—CURRENT SITUATION
Except for the pump stations, the collection system condition was not directly assessed as part of the
AIA project, but collection system criticality was assessed to prioritize ongoing efforts to investigate and
evaluate conditions and to refine ongoing system improvements. One important element of the project
included filling asset data gaps with information such as age, size, and material.Table 2-3 summarizes
the approximate age of the collection system.
Table 2-3.Collection System Age
Age Range Gravity Sewer Force Main
(years) (%) (%)
0-10 20 19
10-20 31 43
20-30 26 31
30-50 11 7
50+ 12 0
Source:CH2M,2019a
Notes:
=percent
The Town's gravity sewer system is generally older than the force mains, which is indicative of growth
away from the area close to LCWRF and the older part of Clayton into areas (primarily to the north and
east)that require pumping to convey flow back to LCWRF.
Table 2-4 summarizes the lengths of gravity sewer and force main and pipe diameter in the Town's
wastewater collection system.
Table 2-4.Collection System Size
Gravity Sewer Force Main
Pipeline Diameter
(inches) Length(LF) Inch-miles Length(LF) Inch-miles
2 - - 2,490 0.9
4 1,040 0.8 30,680 23.2
6 10,490 11.9 31,200 35.4
8 539,520 817.5 51,340 77.8
10 26,900 51.0 13,770 26.1
12 33,740 76.7 26,400 60.0
15 980 2.8 - -
16 8,800 26.6 35,370 107.2
18 13,350 45.5 - -
20 5,800 22.0 - -
24 10,940 49.7 - -
Source:CH2M,2019a
Notes:
-=not applicable
LF=linear foot(feet)
2-7

SECTION 2—CURRENT SITUATION
To help support asset management practices,the Town has been using an Azteca Cityworks®
Computerized Maintenance Management System (CMMS) since 2016 to record both preventive and
corrective maintenance.The Town uses work orders to track activities against assets. For the collection
system, these activities include:
• Investigation of issues
• Line cleaning
• Closed-circuit television (CCTV) inspection
• Manhole rehabilitation
• Easement maintenance
One finding of the AIA grant project was an understanding that the vitrified clay gravity sewer pipes
within the collection system are in poor condition, and the Town is actively working to replace those
pipe sections as funding allows.
A history of overflows from the Town's collection system from June 2014 to July 2019 was reviewed.
Over this period, a total of 15 reportable sanitary sewer overflows (SSOs) occurred.The largest of these
occurred at LCWRF in 2016-2017 and was associated with severe weather, including Hurricane Matthew.
Most of the other SSOs were a result of collection system damage.Table 2-5 provides a summary of the
reported SSOs.
Table 2-5. Reported Sanitary Sewer Overflows
No.of Spills Caused By:
Year No.of Debris and Structural Damage and
(June-July) Spills Gallons Spilled Roots Equipment Failure Grease Heavy Rain
2014-2015 4 13,000 1 2 - 1
2015-2016 1 600 - 1 - -
2016-2017 6 385,410 - 1 - 5
2017-2018 1 2,250 - 1 - -
2018-2019 3 31,358 1 2 - -
Source:Town,2015,2016,2017,2018a,2019a
Notes:
No.=number
2.4 Water Reclamation Facility Condition
Current LCWRF liquid treatment facilities include (CH2M, 2019a; Wooten, 2007):
• Automated screening and grit removal
• Influent pumping
• Dual oxidation ditches with BNR
• Secondary clarifiers
• Tertiary filters
• Ultraviolet(UV) disinfection
• Standby chlorination and dechlorination
• Pumped discharge through an outfall to the Neuse River
2-8

SECTION 2-CURRENT SITUATION
Solids are processed through thickening and aerated sludge storage,with ultimate disposal typically
through land application. On occasion,temporary dewatering equipment is used, and the dewatered
cake is transported to composting or landfill.The permitted capacity of the WRF is 2.5 MGD, and
Appendix B provides a copy of the existing NPDES permit. Figure 5-1 shows the main treatment features.
The WRF has had one Notice of Violation and one Notice of Deficiency over the last 5 years. A Notice of
Violation was issued in June 2017 (NCDEQ, 2017a), as the reported weekly and monthly biochemical
oxygen demand (BOD) concentrations exceeded the permit limit.These exceedances were attributed to
high flows during a storm event. A Notice of Deficiency was issues in August 2017 (NCDEQ, 2017b), as
there were 3 days in May 2017 when the reported dissolved oxygen (DO) concentration was less than
the daily minimum permit value.These low numbers were attributed to electrical issues with the plant's
aerators.The WRF is not under a Special Order of Consent and is not currently negotiating one with the
Division of Water Resources (DWR).
Under the AIA grant-funded project, the condition of the existing LCWRF was assessed in 2019
(Appendix A).The condition assessment included two phases. Initially, a desktop approach was used to
review maintenance records and discuss asset history with LCWRF O&M staff. Staff from CH2M HILL
North Carolina Inc. (CH2M), now a Jacobs Engineering Group Inc. (Jacobs) Company, then performed a
plant walkthrough to determine condition scores based on a visual assessment.The project summary
noted that a more detailed, formal condition assessment may reveal that assets are in worse condition
than could be readily assessed from a visual inspection.This assessment considered only mechanical and
electrical equipment, not the condition of structures. For the 212 individual mechanical and electrical
assets assessed, conditions are summarized as follows:
• 18 percent of the assets were found to be in Condition 1 (Very Good Condition).
• 70 percent of the assets were found to be in Condition 2 (Good Condition).
• 10 percent of the assets were found to be in Condition 3 (Moderate Condition).
• 2 percent of the assets were found to be in Condition 4 (Poor Condition).
• 0 percent of the assets were found to be in Condition 5 (Very Poor Condition).
While most assets were in good or very good condition, many are approaching, or past, the end of their
expected useful life. Based on the data collected, 60 percent of mechanical and electrical assets were
found to be beyond their expected useful life, and 50 percent were found to be more than 20 years old.
The assessed condition of assets was factored into the R&R model,with replacement timing delayed
beyond the expected useful life based on the condition; however, this delay is not indefinite, and even
good condition assets will require replacement. For the WRF to continue to function and effectively
treat wastewater, many of the mechanical and electrical assets will require replacement within the next
5-10 years.
Using a R&R forecast to estimate future R&R funding needs, the AIA grant project projected that a total
of$5.95 million would have to be spent on R&R of existing assets within the next 10 years,with over
$4 million of that being within the next 5 years if the plant were to remain in operation in the long term
(CH2M, 2019a; Appendix A).This expenditure would not increase treatment capacity.
2.4.1 Condition of Water Reclamation Facility Equipment
As described in Section 2.3, condition scores were assigned to each plant asset as part of the AIA grant
project in 2019 (Appendix A).Those scores were on a 5-point scale but, for this Engineering Report (ER)
and Environmental Information Document (EID),the condition scores in the following subsections are
reported on a 3-point scale of Good, Fair, or Poor consistent with NCDEQ guidance (NCDEQ, 2015).
Appendix C provides photographs of LCWRF equipment.
2-9

SECTION 2—CURRENT SITUATION
2.4.1.1 Preliminary Treatment
Raw influent enters the facility through at 24-inch-diameter gravity sewer.The influent structure
consists of a 6.25-MGD capacity mechanical screen, vortex grit removal, and a 9-inch throat-width
Parshall flume for influent flow measurement. A grit pump conveys grit to a classifier prior to disposal.
After flow measurement,wastewater enters the influent pump station (IPS).The IPS contains four
dry-pit submersible pumps that operate on variable frequency drives (VFDs) and convey flow to
secondary treatment(CH2M, 2019a).Table 2-6 provides an overview of the preliminary treatment
equipment.
The R&R forecast projected that the listed headworks equipment was recommended for replacement in
the first 5 years of the forecast (2019—2023).
Table 2-6. Preliminary Treatment Equipment
Equipment Condition Age(years) Size
Mechanical Screen Fair 20a 6.25 MGD;3-HP motor
Vortex Grit Removal Poor 29 8-foot diameter and 4 MGD
Grit Pump Fair 29 5 HP;200 gpm
Grit Classifier Fair 29 200 gpm
Parshall Flume Fair 29 9-inch-wide throat
3 at 2,170 gpm
Influent Pumps Good 19
1 at 1,200 gpm
Source:CH2M,2019a;Wooten,2007
a Screen rehabilitated in 2018.
Notes:
HP=horsepower
2.4.1.2 Secondary Treatment
The BNR system consists of the following major equipment(CH2M, 2019a):
• Anaerobic tanks
• Anoxic tanks
• Oxidation ditches
• Secondary clarifiers
• Sludge recirculation and waste pump station
• Chemical feed systems for pH and alkalinity control, and polishing phosphorus removal
Excess sludge produced in the system is pumped to a rotary drum thickener (RDT) and aerobic sludge
stabilization facilities for further processing.
Return activated sludge (RAS) and influent wastewater are pumped to the anaerobic selector tank to
facilitate phosphorus removal.The mixed liquor from the anaerobic basin flows to a splitter box, and
from there, it is proportionally distributed the pre-anoxic zones for each ditch. In the pre-anoxic zones,
the nitrified nitrogen is denitrified by maintaining the desired internal mixed liquor recycle flow to the
oxidation ditches and the respective pre-anoxic zones (Wooten, 2007).
Biological Nutrient Removal Activated Sludge
The system includes one three-pass anaerobic tank,which receives all flow from the IPS. Each pass
contains a single mixer. From there, flow passes to anoxic zones.There are two anoxic zones associated
2-10

SECTION 2—CURRENT SITUATION
with each of the two oxidation ditches. Each anoxic zone has one mixer,for a total of four mixers
(CH2M, 2019a).
LCWRF has two oxidation ditches.The larger one, which is also newer, has a volume of 1.15 million
gallons (MG); and the smaller, older ditch has a volume of 0.75 MG. Each ditch has two surface aerators
(Wooten, 2007).
Table 2-7 provides an overview of the BNR activated sludge equipment.
The R&R forecast projected that the listed BNR equipment was recommended for replacement in the
first 5 years of the forecast(2019—2023).
Table 2-7. Biological NUtrient RemoVal ActiVated Sludge Equipment
Equipment Condition Age(years) Size(HP)
Anaerobic tank mixers(3) Good 12 3.8
Anoxic tank mixers(4) Good 12 3.8
Oxidation Ditch 1 aerators(2) Fair 28 50
Oxidation Ditch 1 aerator VFDs(2) Fair 28 50
Oxidation Ditch 2 aerators(2) Fair 23 75
Oxidation Ditch 2 aerator VFDs(2) Fair 23 75
Source:CH2M,2019a;Wooten,2007
Secondary Clarifiers
LCWRF includes three circular secondary clarifiers: two 65-foot diameter and one 55-foot diameter.The
larger clarifiers have a sidewater depth of 14 feet, and the smaller one has a sidewater depth of 12 feet.
The existing clarifiers provide a solids loading rate, including 100 percent sludge recycle flow, of
18.52 pounds per square foot per day (Ib/ft2/d) and a surface overflow rate of 277 gallons per day per
square foot (gpd/ft2) at design ADF.The clarifiers have rake arm mechanisms (Wooten, 2007).
Sludge is conveyed to a sludge recirculation pump station. RAS is pumped to the anaerobic zone ahead of
the oxidation ditches. Waste activated sludge (WAS) is pumped to an RDT for further processing (Wooten,
2007).
Table 2-8 provides an overview of the secondary clarifier equipment.
Table 2-8.Secondary Clarifier Equipment
Equipment Condition Age(years) Size
Clarifier 1 mechanism Good 5 1-HP drive motor
Clarifier 2 mechanism Good 23 1-HP drive motor
Clarifier 3 mechanism Good 17 1-HP drive motor
RAS pump 1 Fair 28 800 gpm;20 HP
RAS pump 2 Good 28 1,100 gpm; 15 HP
RAS pump 3 Good 4 1,700 gpm; 10 HP
WAS pump Poor 12 250 gpm;5 HP
WAS pump VFD Fair 12 5 HP
Source:CH2M,2019a;Wooten,2007
2-11

SECTION 2—CURRENT SITUATION
The R&R forecast projected that the older clarifier mechanisms, RAS pumps 1 and 2, and the WAS pump
and VFD were recommended for replacement in the first 5 years of the forecast (2019—2023).
2.4.1.3 Tertiary Filters
LCWRF has two traveling bridge-type shallow bed filters, each 48 feet 8 inches long by 12 feet 6 inches
wide, which provide a filtration rate of 1.42 gallons per minute per square foot(gpm/ft2) at ADF, and
3.31 gpm/ft2 at peak flow (Wooten, 2007).The filter media is made up of layers of coarse sand, silica
sand, and anthracite, with a total depth of 20 inches.The filter system includes the following major
components (CH2M, 2019a):
• Filter backwash pumps
• Traveling bridge
• Controls
• Hood backwash pumps
Table 2-9 provides an overview of the tertiary filter equipment.
Table 2-9.Tertiary Filter Equipment
Equipment Condition Age(years) Size
Filter media (2) Good 6 -
Traveling bridge mechanism(2) Good 21 0.25-HP motor
Backwash pumps(2) Good 21 5-HP motor
Hood backwash pumps(2) Good 21 5-HP motor
Source:CH2M,2O19a;Wooten,2007
The R&R forecast projected that the filter media, traveling bridge, and associated pumps were
recommended for replacement in the first 5 years of the forecast (2019—2023).
2.4.1.4 Disinfection
UV light is used for disinfection.The system has 2 banks, each with 9 modules and 8 lamps per module,
for a total of 144 lamps.The current system was installed in 2017. LCWRF also has a chlorination and
dichlorination system to provide a backup to the UV disinfection system (CH2M, 2019a).
Table 2-10 provides an overview of the disinfection equipment.
Table 2-10. Disinfection Equipment
Equipment Condition Age(years) Size
UV System Good 3 6.25 MGD
UV System Transformer Good 3 3 kVA
Source:CH2M,2O19a;Wooten,2007
Notes:
kVA=kilovolt(s)-ampere
The UV system is only 3 years old and was not recommended for replacement in the R&R forecast until
after 2035.
2-12

SECTION 2—CURRENT SITUATION
2.4.1.5 Effluent Pump Station
Treated effluent from LCWRF is conveyed to the Neuse River discharge location by an effluent pump
station.The pump station includes three vertical turbine pumps with a capacity of 1,650 gpm each, and
they operate on VFDs (Wooten, 2007).
Table 2-11 provides an overview of the effluent pump station equipment.
Table 2-11. Effluent Pump Station Equipment
Equipment Condition Age(years)a Size
Effluent pump 1 Good 12 1,650 gpm; 100 HP
Effluent pump 2 Good 8 1,650 gpm; 100 HP
Effluent pump 3 Good 3 1,650 gpm; 100 HP
Effluent pump VFD(3) Good 6 100 HP
Source:CH2M,2019a;Wooten,2007
a Since most recent rehabilitation.
The Town has programmatically rehabilitated the effluent pump motors on a 4-to 5-year cycle. On this
basis, only one pump is scheduled for rehabilitation in first 5 years of the forecast.The pumps
themselves are older (installed in 1996) and are recommended to be replaced within the first 5 years of
the forecast (2019—2023).
2.4.1.6 Reclaimed Water
LCWRF provides reclaimed water to the Pine Hollow Golf Club.The reclaimed system comprises two
vertical turbine pumps equipped with 100-HP motors (CH2M, 2019a).
Table 2-12 provides an overview of the reclaimed water equipment.
Table 2-12. Reclaimed Water Equipment
Equipment Condition Age(years) Size
Reclaimed Water Pump 1 Fair 15 300 gpm; 100-HP motor
Reclaimed Water Pump 2 Fair 15 300 gpm; 100-HP motor
Source:CH2M,2019a;Wooten,2007
The R&R forecast projected replacement of the reclaimed water pumps within the first 5 years of the
forecast (2019—2023).
2.4.1.7 Solids Thickening
WAS thickening of the solids consists of the following components (CH2M, 2019a):
• Polymer feed system
• Flocculation tanks
• RDT
• Thickened sludge pumping
WAS is pumped into the flocculation tank, where it is conditioned by adding polymer.The conditioned
sludge flows into the RDT. Filtrate from the thickener is pumped back to the treatment process, while
the thickened sludge collects in a hopper at the discharge of the thickener prior to being pumped to
2-13

SECTION 2—CURRENT SITUATION
aerobic sludge holding. Although described locally as sludge holding, these facilities stabilize sludge to
Class B standards in accordance with the 503 regulations (EPA, 2018).
Table 2-13 provides an overview of the major sludge thickening equipment.
Table 2-13.Sludge Thickening Equipment
Equipment Condition Age(years) Size
Polymer feed system Good 12 25 gph(polymer feed capacity)
RDT Good 12 300 gpm;2-HP motor
Thickened sludge pump Good 12 300 gpm;10 HP
Source:CH2M,2O19a
Notes:
gph=gallon(s)per hour
The R&R forecast projected replacement of the thickener, polymer feed system, and thickened sludge
pump within the first 5 years of the forecast(2019—2023).
2.4.1.8 Aerated Holding and Digestion
Thickened sludge is held in two 360,000-gallon aerobic sludge holding tanks with a 12-foot sidewater
depth,which provide 60-day storage for Class B pathogen reduction in accordance with the
503 regulations (EPA, 2018). Each tank uses centrifugal blowers to deliver air through a diffuser grid.
Each tank also includes mixers.
The LCWRF also has a 90,000-gallon aerobic sludge digester with a 12-foot sidewater depth (Wooten,
2007).
Table 2-14 provides an overview of the major aerated holding and digestion equipment.
Table 2-14.Aerated Holding and Digestion EgUipment
Equipment Condition Age(years) Size
Aerated Holding Tank 1 blower(1) Fair 28 1,100 scfm;60-HP motor
Aerated Holding Tank 2 blowers(2) Good 12,3 1,100 scfm;60-HP motor
Aerated Holding Tank 1 diffusers Fair 28 -
Aerated Holding Tank 2 diffusers Good 12 -
Aerated Holding Tank 2 mixers(2) Good 12 10 HP
Aerobic digester blower Fair 28 200 scfm;15 HP
Aerobic digester mixer Fair 28 10 HP
Source:CH2M,2O19a;Wooten,2007
Notes:
scfm=standard cubic foot(feet)per minute
The R&R forecast projected replacement of the listed equipment, with the exception of the newest
blower,within the first 5 years of the forecast (2019—2023).
2-14

SECTION 2—CURRENT SITUATION
2.4.1.9 Solids Disposal
Sludge is disposed of via land application, and the solids treatment process includes a truck loading
station, consisting of a flow meter,truck loading pump, and sludge loading recirculation pump. At times
when land application is not possible, a temporary belt press is brought in to dewater solids for disposal
at either a composting facility or landfill (CH2M, 2O19a).
Table 2-15 provides an overview of the major sludge disposal equipment.
Table 2-15.Sludge Disposal Equipment
Equipment Condition Age(years) Size
Sludge loading flow meter Good 28 -
Sludge loading recirculation and truck loading pump Good 28 10 HP
Source:CH2M,2O19a
The R&R forecast projected replacement of the listed equipment within the first 5 years of the forecast
(2019—2023).
2.4.1.10 Backup Power
LCWRF has two diesel-powered generators to provide backup power to the plant in the event of loss of
utility power(CH2M, 2O19a).
Table 2-16 provides an overview of the power generation equipment.
Table 2-16. Power Generation Equipment
Equipment Condition Age(years) Size
Generator 1 Good 22 1,000 kW
Generator 1 automatic transfer switch Good 22 1,000 amp
Generator 2 Good 8 500 kW
Generator 3 automatic transfer switch Good 17 1,600 amp
Source:CH2M,2O19a
Notes:
amp=ampere(s)
kW=kilowatt(s)
The R&R forecast projected replacement of the listed equipment within the first 5 years of the forecast
(2019—2023).
2.4.2 Flood Information
The Flood Insurance Rate Map for the LCWRF site is dated June 20, 2018, and the 100-year flood
elevation at the LCWRF ranges from approximately 237-234 feet above mean sea level (amsl) (North
Carolina Floodplain Mapping Program, 2020).The current plant does not include flood protection and is
partially at risk from inundation. In particular, the headworks, the IPS, and solids handling are located, at
least partially,within the 100-year flood plain, as shown on Figure 5-1. If the WRF were expanded, then
flood protection would be required.
2-15

SECTION 2—CURRENT SITUATION
2.4.3 Permit Information
LCWRF operates under NPDES Permit NC0025453,which is valid through March 31, 2024.The current
NPDES permit sets effluent limits for the existing capacity of 2.5 MGD, as shown in Table 2-17 and
summarized as follows:
• The monthly average summer and winter 5-day biochemical oxygen demand (BOD5) effluent limits
are 5 and 10 milligrams per liter(mg/L), respectively.
• The average summer and winter ammonia-nitrogen effluent limits are 1 and 2 mg/L, respectively.
• The annual TN loading must be less than or equal to 22,832 pounds per year (Ib/y), or a target
concentration of 3 mg/L at a flow of 2.5 MGD.
• The quarterly average total phosphorus (TP) limit is 2 mg/L.
• The total suspended solids (TSS) limit is 30 mg/L based on a monthly average.
Appendix B provides a copy of the existing is NPDES permit.
Table 2-17. National Pollutant Discharge Elimination System Permit Effluent Limits
Parameter Monthly Average Weekly Average
Flow,MGD 2.5
BOD5(summer),mg/L 5 7.5
BOD5(winter),mg/L 10 15
TSS,mg/L 30 45
Ammonia-nitrogen(summer),mg/L 1 3
Ammonia-nitrogen(winter),mg/L 2 6
DO,mg/La 6
TN Monitor and report
TN,Ib/y b 22,832
TP,mg/L C 2
Fecal coliform,MPN/100 mL 200 400
Quarterly chronic Toxicityd -
Source:NCDEQ,2020a
a The daily average DO effluent concentration will not be less than 6.0 mg/L.
b TN load limits are annual limits and are applied for the calendar year.
Effluent limit is for the quarterly average.Limit of 2 mg/L assumes continued membership in the Lower Neuse Basin
Association.Otherwise,TP limit would be 1 mg/L.
d Inhibition of reproduction or significant mortality of Ceriodaphnia dubia must not be observed at an effluent concentration
of 2%.
Notes:
mL=milliliter(s)
MPN=most probable number
With the discharge into the Neuse River, the Town's nutrient limits are subject to the Neuse&
Tar-Pamlico Rivers Nutrient Monitoring Strategy set forth in 15A NCAC 02B.0713, and the facility is
assigned a transport factor of 50 percent, which means that the base loading allocated to the facility
was 21,400 lb/y(Table 2-18).
2-16

SECTION 2-CURRENT SITUATION
To achieve the TN load limits with its current 2.5-MGD permit, the Town held 32,206 Ib/y or the equivalent
of 3.5 MGD of nitrogen credits to offset nitrogen loading into the watershed based on its original allocation
in the rules and purchases of nitrogen credits (Table 2-18) (NCDEQ, 2020a). Credit purchases were necessary
because the LCWRF is not capable of treating to a target of 3 mg/L TN (Hazen, 2013).To accommodate
future credit needs, the Town purchased 31,816 lb/y of credits from Restoration Systems in 2020.The
NPDES permit was updated to reflect these reserve credits (Appendix B) (NCDEQ, 2020a).The Town
anticipates the purchase of additional credits to meet its long-term needs.
Table 2-18. Little Creek Water Reclamation Facility National Pollutant Discharge Elimination Systehi Permit Total
Nitrogeh Allocations
Allocation Amount at Discharge
Allocation or Credit Type (Ib/y) Current Status
Base allocation assigned by 15A NCAC 02B.0234 21,400 Active
Supplemental purchases 10,626 Active and Reserve
Offset Credits 31,816 Reserve
Total available 63,842 Mixed
Currently used with 2.5-MGD permit 22,832 Active
Available for future capacity expansion 41,010 Reserve
Source: NCDEQ,2020a
As described in Section 2.1,the Town has agreements for treatment capacity in the JCRWWTP and the
NRWWTP. Combined with the permitted capacity of LCWRF, this brings the Town's current total
permitted wastewater treatment capacity to 4.9 MGD. In 2019, the Town's ADF was 3.2 MGD (Table 2-1).
2.4.4 Historical and Current Wastewater Flow
Table 2-19 presents the most recent 4 years of flow data as provided by the Town. Under agreements
with the County for treatment capacity, a portion of the flow in the Clayton service area is directed to
the JCRWWTP. In the most recent 2 years, a portion of the flow has also been directed to the NRWWTP.
The balance of flow is treated at LCWRF.The flow transferred to JCRWWTP includes the industrial
effluent from Grifols, which is located in the ECIA. Flow diverted to NRWWTP is typically residential from
the northeastern part of the service area. Appendix E provides additional details about historical
wastewater flow data.
Table 2-19. Historical Wastewater Flow Data
Minimum Components of Total ADF
Annual Monthly
ADF(MGD) MM Average Average Flow Transfer to Transfer to Annual ADF
-Total Flow(MGD)- (MGD)-Total County Annual City Annual to LCWRF
Year System Total System System ADF(MGD) ADF(MGD) (MGD)
2016 1.98 2.44 1.76 0.50 - 1.48
2017 2.36 2.52 2.06 0.69 - 1.67
2018 2.60 3.05 2.32 0.71 0.20 1.69
2019 2.71 3.19 2.31 0.73 0.26 1.72
4-year average,four 2.41 2.80 2.11 0.66 0.23 1.64
quarters per year
Source:Annual flow data provided by the Town.
2-17

SECTION 2-CURRENT SITUATION
Over the past 4 years, flows have increased, both in what has been transferred and what has been
treated at LCWRF.This reflects a growth in both residential and industrial and commercial flow.The
flows treated at LCWRF are predominately residential and have increased by approximately 16 percent
in the period from 2016—2019. Over the same period,flows transferred to the County have increased
by approximately 46 percent, which is a result of an increasing industrial flow. Systemwide peaking
factors have remained relatively stable at around 1.2 for the ratio of MM average to annual average
flow.
Some of the older areas of the collection system are thought by the Town to have rainfall-derived inflow
and infiltration (RDII) issues. Most of the system is relatively new and does not have an infiltration issue
but still may have inflow problems.The Town is planning a study to investigate RDII by using pump
station runtime data to identify basins with high wet weather peaking factors to focus their reduction
efforts.
2.5 Current Treatment Capacity Limitations
Current capacity limitations will be addressed in a phased approach, beginning with an initial increase in
capacity to 6 MGD. During planning, the Town has assessed the capacity and condition of its LCWRF, and
the potential to increase regional partnerships and build new treatment capacity. Details of those
options are discussed in Section 5.
2.5.1 Little Creek Water Reclamation Facility
As mentioned, the facility is process capacity limited, as it cannot reduce TN to a low enough level to
meet the existing NPDES permitted capacity.The actual treatment capacity is reported to be
approximately 2 MGD from the permitted capacity of 2.5 MGD, and previous evaluations have proposed
improvements to TN removal (Wooten, 2018, 2019; Hazen, 2013).To achieve the TN load limits with its
current 2.5-MGD permit, the Town held 32,206 lb/y, or the equivalent of 3.5 MGD of nitrogen credits,to
offset nitrogen loading into the watershed based on its original allocation in the rules and purchases of
nitrogen credits(Table 2-18) (NCDEQ, 2020a). Credit purchases were necessary because the LCWRF is
not capable of treating to a target of 3 mg/L TN, and facility evaluations show the LCWRF cannot
improve TN reduction cost-effectively(Wooten, 2018, 2019).
Much of the plant's mechanical equipment is also approaching the end of its anticipated useful life. A
portion of the facility is prone to flooding.A recent criticality analysis indicated the facility will require
capital investment of over$4 million within the next 5 years for R&R of aging systems and equipment,
and will require additional significant capital investments over the next 20 years as the facility continues
to age and degrade. Additionally,this analysis indicated capital investments would be needed so that
the treatment process will continue to meet stringent nutrient limits required of discharges to the
Neuse River basin and to protect infrastructure from potential flooding (Wooten, 2018, 2019).
2.5.2 Regional Partnerships
The Town has historically leveraged its regional partnerships as a cost-effective means of delaying major
capital investments related to the expansion of Town-owned and -operated wastewater treatment
facilities (Figure 2-2). The contracts with these regional partners are included in Appendix D.
Under the 1.4-MGD County contract,the Town owns capacity at the JCRWWTP and conveys pretreated
industrial wastewater from the ECIA to the JCRWWTP for final treatment.The pretreated industrial
wastewater conveyed to the County includes TDS exceeding domestic-strength limits; therefore,this
wastewater is considered high strength for treatment(and billing) purposes.The County treats effluent
at their new WRF to high-grade reuse standards to minimize the need for nitrogen credits for a surface
discharge.This is reflected in their new NPDES permit. As a result, the County has made the decision to
not accept any wastewater with characteristics exceeding domestic-strength limits beginning in 2022.
2-18

SECTION 2—CURRENT SITUATION
This eliminates the future use of the County contract as an option for increasing flows from the ECIA.
The Town does not have the infrastructure in place to transport domestic-strength wastewater to the
County from other parts of its service area.
Under the City contract,the Town conveys domestic-strength wastewater from the northeastern side of
Clayton using the Clayton to Raleigh Pump Station to the City's NRWWTP (Appendix B).The City has
indicated the current contract for 1.0-MGD capacity could be extended from 2027 to 2032, and an
additional 0.25-MGD treatment capacity is available to the Town for purchase.The City is also
experiencing growth. With growing capacity demand from its customers,the City has indicated it is not
interested in supporting economic development beyond its retail rate base in eastern Wake County by
expanding the current agreement with the Town after 2032.
The County and the City have communicated their intent to increase the fees associated with conveying
and treating the Town's wastewater.The County increased its fees over 20 percent this year (Johnston
County, 2020d), and the Town anticipates the fees will continue to increase by at least 5 percent
annually; they will also discontinue acceptance of flows exceeding domestic-strength waste in 2022.
The City has also increased the fees associated with the current contract capacity by 40 percent this year
and has proposed new fees and charges for any additional capacity beyond the currently contracted
1.0 MGD.
2.6 Current Population
Wastewater flows within the Town's service area are made up of flows within the Town's local
government unit (LGU) and within the Town's ETJ.The 2018 Clayton LGU population was
22,850(Census, 2019), with a population density, based on 2010 U.S. Census Bureau (Census) data, of
1,192.8 persons per square mile (mi2), and an area of 13.51 mi2 (Census, 2019).The total ETJ area is
approximately 46 mi2 but is less densely populated than the LGU, so applying the same density would
overestimate the total population.To determine the total service area population, projections for the
ETJ and Clayton were taken from the 2040 Comprehensive Plan (LandDesign, 2015).This established the
relative proportion of population in Clayton and within the ETJ.Table 2-20 shows populations for 2018
and 2019 and estimates for 2020.
Table 2-20.Current Population Analysis
Year Clayton Population ETJ Population a Total Residential Population
2018 22,850 b 14,170 37,020
2019 24,887 b 15,180 40,067
2020 25,360 c 15,580 41,120
a Estimated using relationship between Clayton and Planning Area populations(LandDesign,2015);Town annexations have
expanded Clayton limits into the ETJ over time.
b Clayton population(Census,2019).
c Escalated from 2019 Census data using an estimated annual growth rate of 3%.
2-19

SECTION 3
Future Situation
The Town's MM ADF is approaching 80 percent of its available total permitted capacity. With residential
growth occurring and industries notifying the Town of upcoming expansions, the Town is planning to
implement next steps to increase treatment capacity, as described in this section.
3. 1 Population Projections
Expected population growth in the Town's service area (the project study area) is typical of the growth
being experienced in the greater Raleigh metropolitan area.The Census released a population estimate
of 22,850 for Clayton in 2018 and 24,887 in 2019 (Census, 2019).The estimated 2040 Clayton service
area population is 70,870(Table 3-1).These service area population numbers are higher than the
current population served, as not all residents have public water and wastewater services.The Town is
expanding its service into the ETJ as development occurs.
Table 3-1. Projected Annual Town of Clayton and Extra-Territorial Jurisdiction Population Totals
Year Town Population a ETJ Population b Total Residential Population
2010 16,116 c 10,930 27,046
2018 22,850 c 14,170 37,020
2019 24,887 c 15,180 40,067
2020 25,630 15,580 41,210
2021 26,400 15,960 42,360
2022 27,190 16,350 43,540
2023 28,010 16,760 44,770
2024 28,850 17,170 46,020
2025 29,710 17,590 47,300
2026 30,600 18,020 48,620
2027 31,520 18,470 49,990
2028 32,470 18,920 51,390
2029 33,440 19,390 52,830
2030 34,440 19,870 54,310
2031 35,480 20,300 55,780
2032 36,540 20,740 57,280
2033 37,640 21,190 58,830
2034 38,770 21,650 60,420
2035 39,930 22,120 62,050
2036 41,130 22,640 63,770
2037 42,360 23,170 65,530
2038 43,630 23,720 67,350
3-1

SECTION 3—FUTURE SITUATION
Table 3-1. Projected Annual Town of Clayton and Extra-Territorial Jurisdiction Population Totals
Year Town Population a ETJ Population b Total Residential Population
2039 44,940 24,280 69,220
2040 46,290 24,580 70,870
a Escalated from 2019 Census data using an estimated annual growth rate of 3%.
b Estimated using relationship between Clayton and Planning Area population(LandDesign,2015);Town
annexations have expanded Clayton limits into the ETJ over time.
c Clayton population(Census,2019)
This population growth is evident in the Town Planning Department's requests for approvals for
additional housing units. In recent years,the Town has approved approximately 40-50 units per month,
or just under 500 units per year.Table 3-2 shows the housing units approved by the Town but not yet
built.These units are expected to be occupied by 2025 (Town, 2020c).
Table 3-2. Housing Unit Growth in the Town of Clayton
Units Total
Housing Units Built from 2015—2020 a 4,499
Housing Units Entitled from 2015—2020 9,406
Housing Units Entitled but Not Yet Built and Expected to be Served by 2025 4,907
Source:Town,2O2Oc
a Data through April 2020
3.2 Flow Projections
While it is typical to base flow projections on population growth,there are unique aspects of the Town's
customer base that led to an alternative flow projection approach being employed. In the standard
approach presented in the ER and EID guidance and workbook(NCDEQ, 2015), industrial flow is
estimated at 10 percent of the combined residential and commercial flow. For Clayton, industrial
development,which is concentrated in the ECIA, is significantly more that 10 percent of the total, and
major industries have shared their future flow expectations. Use of the ER and EID flow projection
method would result in underestimating current and future industrial treatment demands within the
Town's system; therefore, a different approach to developing a flow projection was required.
The current flow projection approach was originally developed as part of a conveyance optimization
project (CH2M, 2013) by first dividing the Town's service area into different zones, and then assessing the
current and projected flows for each zone.This allowed for higher growth projections for faster growing
zones where new development predominated, and slower growth in more established areas where infill
development was more likely. Pump station capacities and runtimes were analyzed to develop initial flows
for each zone, and the individual zone growth rates were then applied. When specific industrial flow
expectations were known, they were included directly in the flow estimate.This was applied in the ECIA,
where specific Grifols and Novo Nordisk flow projections were included (CH2M, 2020).
The flow projections included a probabilistic aspect,whereby several inputs were allowed to vary to
create an envelope of potential future flows,to allow the Town deeper insight into the important
factors behind future growth. For the residential component of flows, the Town understands the near-
term potential for growth because of housing units approved but not yet built. Uncertainty around the
potential growth increases into the future was incorporated into the forecast.The probabilistic model
provides flow projection for the 5th-95th percentile estimate, representing the range from low to high
3-2

SECTION 3—FUTURE SITUATION
growth scenarios. Details of this approach are presented in the conveyance optimization project
summary report,which is included as Appendix F.
The current flow projection reflects known and anticipated changes to existing flows and future
industrial demands, and incorporates uncertainty associated with growth forecasts in the ETJ and the
Town's Municipal Service Boundary, including potential for wholesale customers. Uncertainty in
industrial growth is also captured in the projection. Industrial and commercial flows were projected with
input from the Town's long-term industrial customers and expected growth in the commercial sector
that typically follows residential growth patterns.These facilities continue to invest and expand their
production capabilities, increasing industrial demands.
Figure 3-1 depicts the projected residential, industrial, and commercial wastewater forecast through
2040 against the available capacity.Table 3-3 summarizes the projected flows. Permitted capacity of the
Town's existing LCWRF is 2.5 MGD and is presented in light green.The Town's total treatment capacity,
including regional contracts, is depicted with a 1.0-MGD drop in the Town's total capacity in 2027 due to
the expected expiration of the agreement with the City.The Town recognizes that expected total
wastewater flows will exceed the Town's capacity before 2025.
The Town's residential growth is steadily increasing. In addition, industrial facilities in the ECIA are
investing in expansions.These facilities are in close coordination with the Town regarding those
expansions. An increase in flow from approved ECIA facility expansions is expected in 2023, pushing the
Town's wastewater treatment demands close to the currently available treatment capacity of 4.9 MGD
before 2025. So, while the Town is not yet at 80 percent of its current capacity, the need to increase
treatment capacity requires the Town to plan its next steps now.
10.0
9.0
8.0
7.0
6.0
C7
5.0 /
3
0
11 4.0
3.0
2.0
1.0
2015 2020 2025 2030 2035 2040
Year
---Total Histor€cal Demand(2015-2019) —Total Forecast Demand
Clayton Total Capacity LC WRF Permitted Ca peaty
Figure 3-1.Town of Clayton Wastewater Maximum Month Flow Forecast
3-3

SECTION 3-FUTURE SITUATION
Table 3-3. Projected Wastewater Maximum Month Flow Forecast
Residential and Commercial Flow Industrial Flow Total Flow
Year (MGD) (MGD) (MGD)
2020 2.49 1.27 3.76
2021 2.50 1.27 3.77
2022 2.51 1.27 3.79
2023 2.72 1.84 4.56
2024 2.76 1.94 4.70
2025 2.80 2.94 5.74
2026 2.84 2.94 5.78
2027 2.88 2.94 5.82
2028 2.93 3.30 6.22
2029 2.97 3.30 6.27
2030 3.16 3.80 6.96
2031 3.23 4.05 7.27
2032 3.30 4.05 7.35
2033 3.37 4.05 7.42
2034 3.70 4.51 8.21
2035 4.15 4.76 8.91
2036 4.31 4.76 9.07
2037 4.36 4.76 9.12
2038 4.42 4.76 9.18
2039 4.49 4.76 9.25
2040 4.56 4.76 9.32
Source:CH2M,2020
3.3 Speculative Limits for Capacity Expansion
A request for speculative limits was submitted to the NCDEQ NPDES Unit for expanded discharges of
6 MGD and 10 MGD, with 6 MGD being the initial capacity expansion (Appendix B) (Town, 2020d).
NCDEQ's determination of speculative limits is summarized in Table 3-4 and included in Appendix B
(NCDEQ, 2020b).
3-4

SECTION 3—FUTURE SITUATION
Table 3-4.Speculative National Pollutant Discharge Elimination System Permit Effluent Limits
Parameter Monthly Average Weekly Average
Flow,MGD 6 -
BOD5,mg/L 5 7.5
TSS,mg/L 30 45
Ammonia-nitrogen,mg/L 1 3
DO,mg/La 6
TRC(if used for disinfection),µg/L 28(daily maximum)
TN 63,842 lb/y
TP,mg/L V 2.0
Fecal coliform,No./100 mL 200 400
Chronic toxicity,pass or fail,quarterly test 4.8%
Source: NCDEQ,2020b
a The daily average DO effluent concentration will be greater than or equal to 6.0 mg/L
b Equivalent to a concentration of 3.5 mg/L at 6 MGD and 2.1 mg/L at 10 MGD.
Effluent limit is for the quarterly average.
Notes:
µg/L=microgram(s)per liter
TRC=total residual chlorine
The speculative limit for TN is equivalent to a 3.5-mg/L TN concentration at the permitted capacity of
6 MGD and 2.1-mg/L TN at 10 MGD.The Town will achieve the TN limit through a combination of readily
available treatment technologies and nitrogen credit purchases. Other limits are carried forward from
the existing permit, also included in Appendix B. Expansion of the existing LCWRF would require process
improvements, as well as additional capacity to meet the speculative limits.
3-5

SECTION 4
Need and Purpose
The Town has invested in planning, evaluating, and managing system improvements over the last
decade, as shown on Figure 2-1,to increase treatment capacity and minimize large capital investments.
With the Town's allocated capacity nearing 80 percent of its available capacity and capacity needed by
2025,the Town is planning to implement additional steps to meet wastewater treatment needs.A
recent capacity study indicated that the Town will require approximately 10 MGD in total wastewater
treatment capacity over the next 20 years to meet future needs, including major increases in industrial
flow from industrial and commercial customers (Wooten, 2018).The Town is planning a phased
approach to meet this expected demand, with the initial step to reach 6 MGD.
The Town's wastewater flows from both residential and industrial and commercial customers have been
growing. Housing units are being built to support the growing population in the service area, adding to
the Town's customer base. Additionally, facilities in the ECIA are making significant investment in
expansions, contributing to the industrial and commercial wastewater flows and providing job growth.
The ECIA is part of a state-created RTZ where these biopharma facilities partner with the Johnston
County Workforce Center to provide biotechnology education opportunities.These projected flow
increases, supported by historically increasing population and wastewater flows, contribute to the
Town's need for an expansion of wastewater treatment capacity.
The facilities in ECIA are in close coordination with the Town regarding their expansions. An increase in
flow from approved ECIA facility expansions is expected in 2023, pushing the Town's wastewater
treatment demands close to the currently available treatment capacity of 4.9 MGD before 2025.
This initial step will replace existing capacity and prepare for known increasing near-term demands with
construction of a 6-MGD WRF.This plan is needed due to the LCWRF's aging infrastructure, expiration of
its contract with the County, and known near-term residential, industrial, and commercial demands.
With replacement of the LCWRF, the Town plans to improve the reliability of service to its customers
through replacement of its current treatment capacity(both contracted and owned) and improvement
of nutrient removal capabilities.The Town has also assessed the capital investments that would be
needed for the treatment process to continue to meet nutrient discharge limits as a discharger to the
Neuse River basin and to protect infrastructure from potential flooding. Nutrient management goals and
potential changes in future waste streams, with additional higher-strength waste from the ECIA and
more concentrated residential flows from water conservation, support the Town's plan for the reliability
provided by a new WRF.
The Town has concluded that LCWRF is not well-suited for expansion to meet long-term capacity needs
and more stringent treatment requirements. Operation of a new WRF, coupled with maintenance of
interconnections for emergency needs, provides the Town and its customers with resiliency moving
forward.
With expiration of its contract with County, the Town will see reduction in the 2.4 MGD of capacity
currently available through regional partnerships and rises in these costs.The Town has historically
leveraged these regional partnerships as a cost-effective means of delaying major capital investments
related to the expansion of Town-owned and -operated wastewater treatment capabilities.The County
and the City have communicated their intent to increase the fees associated with conveying and treating
the Town's wastewater, and the County has made the decision to not accept any wastewater with
characteristics exceeding domestic-strength limits beyond 2023.The Town does not have the
infrastructure to transport domestic-strength wastewater to the County. In short, these regional
4-1

SECTION 4-NEED AND PURPOSE
partnership contract opportunities are limited and do not meet all future expected needs, and the Town
must build its own treatment capacity.
To meet this purpose and need, the Town is planning for the construction of new treatment capacity in
a phased approach after considering the following:
• Operational needs and costs to rehabilitate the LCWRF
• Available capacity from regional partners
• Wholesale costs to send future flows to regional partners
• The timing of flow increases from residential and industrial and commercial customers
Investing in additional treatment capacity via a new WRF will support the Town in meeting its capacity
needs in a cost-effective and environmentally sensitive manner. Section 5 describes the details
supporting this decision.
4-2

SECTION 5
Alternatives Analysis
This section presents the evaluation of alternatives, including the No Action alternative, an alternative to
maximize regional connections to the existing wastewater treatment system, and site selection
alternatives for additional treatment capacity.This section also evaluates new WRF treatment
technology and treated effluent disposal alternatives.
The Town began this alternatives evaluation with objectives of:
• Minimizing environmental impacts
• Minimizing impacts to rate payers
• Meeting projected wastewater treatment flows and loads through 2040
• Improving nutrient removal capabilities to meet upcoming nutrient discharge requirements
• Providing certainty to rate payers
All proposed alternatives incorporate the Town's resilience goals by, at a minimum, maintaining the
existing connections with the Town's regional partners, the County and the City.All proposed
alternatives, except No Action, include improving nutrient removal capabilities to meet the Town's
environmental goals; and some include a combination of treatment technology and purchase of
nitrogen credits to meet Neuse River nutrient loading limits.
Alternatives described in this section were evaluated using the following criteria:
• Ability to reliably meet 2040 treatment capacity needs—Alternatives that do not feasibly meet
these treatment capacity needs or lack the potential to meet these needs through additional
expansion were eliminated from further consideration, as they do not meet the project purpose and
need.The first step in this timeline of incremental capacity improvements is to expand to 6 MGD.
• Environmental considerations—Alternatives that were likely to have a significant impact on
environmental resources in comparison with other alternatives were eliminated from further
consideration.
• Cost considerations— In this case,the No Action alternative is not a no cost alternative because
investment in the LCWRF is necessary for continued operation and for the facility to be able to
reliably meet its permitted capacity of 2.5 MGD. Other alternatives are compared to this expected
investment cost and include operations considerations.The Town developed and performed
business case evaluations, evaluating costs for the proposed alternatives presented in this section,
and are further discussed here (CH2M, 2019b, 2019c).
Based on these criteria, each alternative was either retained for additional evaluation in the ER or
dismissed as not being feasible or adequately able to meet the purpose and need.
The following 11 potential alternatives are discussed in the following sections:
• Alternative 1: No Action
• Alternative 2: Construction of a new WRF, and continued use of a surface water discharge at the
following locations
— 2a: Neuse 2 Pump Station site
— 2b: ECIA Pretreatment Facility site
• Alternative 3: Expansion of LCWRF, and continued use of surface water discharge
• Alternative 4: Continued use of LCWRF, maximizing regional connections to existing wastewater treatment
• Alternative 5: Construction of a new WRF, and use of land application
• Alternative 6: Construction of a new WRF, and implementation of larger-scale wastewater reuse
5-1

SECTION 5-ALTERNATIVES ANALYSIS
• Alternative 7: Construction of new WRF—Alternative secondary treatment process
• Alternative 8: Construction of new WRF—Alternative biosolids treatment strategy
• Alternative 9: Combination of alternatives
• Alternative 10: Decentralized system
• Alternative 11: Optimum operation of existing facilities
Cost estimates were developed for alternatives that were determined feasible. Section 5.1 presents
capital and present worth costs for each feasible alternative. A detailed description of the method used
for cost estimate development is provided in Section 5.2.
In addition to the present worth cost analysis,the nonfinancial benefits of the feasible alternatives were
considered in the evaluation process. Nonfinancial evaluation criteria were developed to qualitatively
rank the benefits of each feasible alternative.The following nonfinancial benefits were used in this
analysis,which broadly fall under the general categories of:
• Natural Resource Protection
• Responsible Growth
• Proven, Practical Treatment Technologies
• Maintenance of Regional Partnership
These broad categories align to the goals outlined in the Town's Comprehensive Plan 2040 (LandDesign,
2015), including:
• Decrease environmental impacts
• Improve aesthetics(visual, odor, noise, traffic)
• Improve land use and compatibility
• Support the maximum use of existing assets
• Provide resiliency from climate impacts
• Provide the potential to facilitate economic growth to serve new industrial, commercial, and
domestic customers
• Increase the Town's control over the cost of treatment
• Provide the potential for resource recovery or beneficial reuse of residuals
• Include adaptability and phasing
First, nonfinancial criteria were weighted using a 1-10 scale to reflect importance and compatibility with
the project purpose and need.Then, every feasible alternative was scored for each of the non-financial
criteria using a 1-5 scale, based on the perceived level of benefit provided.The cumulative weighted
score for all nonfinancial criteria were then used to compare the total benefit of each feasible
alternative. Results of the nonfinancial evaluation are presented for feasible alternatives in Section 5.1.
Appendix G contains a summary of the nonfinancial alternative criteria weights and scoring for each of
the feasible alternatives.
5. 1 Alternative Descriptions
5.1.1 Alternative 1: No Action
The No Action alternative includes no significant improvement or increase in capacity and maintains the
status quo.This alternative relies on existing treatment systems, infrastructure, and regional
interconnections, as the Town would continue to use LCWRF and maintain its existing regional contracts
with the County and the City.
This alternative is included to provide a basis of comparison for other alternatives.This alternative does
not support the Town's ability to meet projected demands and requires significant investment to
replace or rehabilitate major equipment, such as screens, pumps, and blowers, of the existing treatment
5-2

SECTION 5-ALTERNATIVES ANALYSIS
systems at LCWRF to continue providing reliable treatment. Capacity would remain at the current
operational limit of 2 MGD, which is less than its permitted amount of 2.5 MGD. Investment would be
necessary to continue meeting current discharge limits (Hazen, 2013; Wooten, 2018, 2019).
To continue using the connection with the County, new infrastructure would be needed to send
domestic-strength waste only. And the City contract expires in 2027 (Appendix B). So, by 2027, the
Town's total permitted capacity would drop to less than its current customer base. It is expected that
the connection with the City will remain active as a backup option, providing some resiliency but not
providing the necessary additional treatment capacity to the Town.
Components of the No Action alternative include:
• Continued use of the LCWRF and investment in aging treatment systems to maintain system
reliability using the existing treatment system structures (for example, oxidation ditch and clarifiers)
• Continuation of the contract with the County
• Extension of the contract with the City after expiration in 2027 to maintain 1.0 MGD of the Town's
total capacity
• Continued availability of approximately 4.4 MGD in total treatment capacity,with the use of
regional contracts, given the limitations of the LCWRF
5.1.1.1 Environmental Considerations
The LCWRF's resiliency from flood impacts and reliability with aging infrastructure is a risk for the Town.
This alternative also creates environmental and permit compliance risk because it would not increase
treatment capacity sufficiently to meet capacity assurance commitments to the existing customer base.
Appendix B provides the NCDEQ approval letter for the most recent industrial capacity commitments.
Environmental impacts of the No Action alternative are less than the Preferred Alternative, as the
Preferred Alternative results in environmental impacts related to construction of conveyance
infrastructure.
5.1.1.2 Cost Estimate
As this alternative is not considered to be feasible,the estimated capital cost and total present worth of
this option have not been calculated.
5.1.1.3 Acceptance or Rejection
With the projected expiration of the City agreement in 2027 and the expected change in the County
agreement, the Town is facing a reduction in treatment capacity from its current capacity of 4.9 MGD.
With 2019 MM flows of 3.4 MGD and other customer commitments not yet online, the Town would be
facing a capacity shortfall. Beginning in 2022, the County's contract will be limited to domestic-strength
wastewater only, and the City's rate increases will increase the overall cost of wastewater treatment.
Additionally, regional partnerships are changing. Beginning in 2022,the County contract will be limited
to domestic-strength wastewater only, and the impact of the City's rate increases will increase the
overall cost of wastewater treatment for the Town, making the No Action alternative less favorable for
the Town's customers. It is expected that the connection with the City will remain active as a backup
option, providing some resiliency but not providing the necessary additional treatment capacity to the
Town.
Additionally, investments would be necessary at the LCWRF to improve nutrient removal and mitigate
for flood risks.These investments would add to making the No Action alternative less favorable for the
Town's customers.
5-3

SECTION 5-ALTERNATIVES ANALYSIS
The No Action alternative does not meet the purpose and need of the project:to reliably and
cost-effectively meet the Town's current and projected increases in customer demand for wastewater
capacity.This alternative is considered infeasible and eliminated from the evaluation. Present worth
cost for the No Action alternative was not calculated.
5.1.2 Alternative 2: Construction of a New Water Reclamation Facility, and
Continued Use of Surface Water Discharge
Under this alternative, the Town would build a new 6-MGD WRF with potential for future incremental
expansion to 10 MGD.Two sites have been considered under this alternative: the Neuse 2 Pump Station
site (Alternative 2a) and the site of the ECIA Pretreatment Facility(Alternative 2b).
The following project components are common among the two sites considered:
• Continued use of the LCWRF, understanding limited treatment capacity of 2 MGD until the new
facility is online
• Decommissioning of LCWRF and conversion of the site use to a new pump station to convey 3-MGD
ADF
• Continued reliance on regional contracts with the City and County through 2023
• Retention of regional contracts as backup after 2023; minimization flow to the City and County
• Expansion of the LCWRF surface water discharge to the Neuse River at the Neuse 2 Pump Station
site
• Planning for future incremental expansion of the facility to 10 MGD as flows increase
Under this alternative, the contract with Pine Hollow Golf Course for reuse water will be terminated
after the construction of the new WRF due to the distance between the golf course and the new WRF.
5.1.2.1 Alternative 2a: Construction of a New Water Reclamation Facility at the Neuse 2 Pump
Station Site
Under this alternative, the Town would build a new 6-MGD WRF at the Neuse 2 Pump Station site,with
potential for future incremental expansion to 10 MGD.The Town-owned parcel with the Neuse 2 and
Clayton to Raleigh Pump Station and LCWRF Neuse River discharge into the Neuse River is of sufficient
size for the construction of a new 6-MGD WRF and could maintain stream and property buffers and
avoid the floodplain along the Neuse River. Public greenway infrastructure along Sam's Branch and the
Neuse River could remain available to the community. Connecting infrastructure would be necessary,
including conversion of the LCWRF to a pump station.
This site is more centrally located to the Town's operation and to most expected development within
the Town's ETJ. Other site improvements necessary for the WRF include a construction access road and
water service line. Easements through adjacent properties may be necessary for this infrastructure.
Construction of a new WRF would include the following elements:
• IPS
• Odor control
• Headworks (screening and grit removal)
• Flow equalization,which will reduce peak hour to peak day flow for follow-on treatment systems
• Five-stage biological treatment for nitrogen and phosphorus removal
• Supplemental carbon for enhanced nitrogen removal
• Supplemental metal salts for backup and polishing of phosphorous removal
• Cloth media (disc)tertiary filtration
5-4

SECTION 5—ALTERNATIVES ANALYSIS
• UV disinfection
• Cascade re-aeration
• Solids treatment, including:
— Thickening with RDTs
— 30-day aerated sludge holding
— Dewatering with screw press
• Effluent outfall to Neuse River
Figure 5-1 shows the proposed new WRF layout at the Neuse 2 Pump Station site.
Design Criteria
This section describes the WRF unit process design criteria.
The new 6-MGD WRF is expected to serve the Town's initial wastewater treatment capacity needs from
both residential, industrial, and commercial customers and allow the Town to expand incrementally to
10 MGD to meet future demands as needed.The new WRF will be designed to an MM flow of 6 MGD;
Table 5-1 lists the design flows.
Table 5-1. Design Flows
Combined Plant Influent
Metric (MGD)
ADF 5.25
MM ADF 6.0
Peak Day 9.7
PHF 11.2 a.
a Flow equalization will reduce the incoming PHF(11.2MGD)to peak day(9.7 MGD)for the secondary and
tertiary treatment systems.
Notes:
PHF=peak hour flow
Peaking factors used to develop the flows presented in Table 5-1 were determined individually for the
residential and commercial flows and the major industrial flows from the ECIA.The industrial flows are
subject to much less variability than residential and commercial flows, and that difference in variability is
reflected in the flows presented.
5-5

a likt"
-) 4se
20 d co
�'�
'14. 1111k__1114110111". AI' ,./ 1,.
\1 7 28 O 25
27 8i.
�6 O O 'Qii
t . - _ Og ®�4 3022,21 13 28
Fig.No. Name ; 411'
17 /-�/��� ®1 Administration/Maintenance Building - 29' 30 42 Electrical and Backup Power S4 Influent Pump Station 22 10 1> r Legend
4 Headworks �/
5 EQ Tanks Water Line to be Installed
6 Secondary Pump Station
l BNRs A- �0 ' —Proposed Gravity Main t
8 Blowers • -
9 Secondary Clarifiers •- - --• Proposed Force Main
10 Chemical Feed&Storage , - --• Existing Force Main
11111 11 Filters
12 UV Disinfection
F �G • Existing Gravity Main
13 Post-Aeration Ia ,.
14 RAS)WAS Pump Station •g� �r I—I 6 MGD Proposed WRF
15 Thickening Building ` aS k,L /
16 Dewatering Building S ` 10 MGD Future WRF
17 Aerated Sludge Holding Tanks
10
18 Influent Junction Box
N4111
19 Odor Control Facility CI Expansion
20 Septage Receiving } Pavement
21 Plant Water Pump Station • Proposed Manhole
22 Drain Pump Station
23 Effluent splinerBox =Parcel Boundary
24 Expanded Outfall
25 Future EQ Tanks - �� Hydrology
26 Future Primary Clarifiers Split/Junction Box f.,,,"• -
27 Future Primary Clarifier ," . ' +s ,�=$ 111 l ';,, 50-Foot Buffer
28 Future BNRs •
` Wetlands
29 Future Aerated Sludge Holding Tanks -
30 Future Secondary Clarifiers
31 Future Odor Contra!Facility a -ilk;
+'t Q 100-Year Floodplain
Figure 5-1
0 500 1,000 N Proposed WRF at Neuse 2 Site
ch 1� I I IA Water Reclamation Facility Expansion
sM• Feet Town of Clayton, NC
The treatment systems depicted on this conceptual layout represent conservative footprints,and may be revised as the design develops.

SECTION 5—ALTERNATIVES ANALYSIS
Influent loading conditions for the new WRF were developed based on the wastewater characteristics of
the Town's three major waste streams: LCWRF influent, Grifols pretreated effluent, and Novo Nordisk—
DAPI pretreated effluent.The Grifols and Novo Nordisk waste streams represent the Town's major
industrial customers; all other commercial and minor industrial customer waste streams currently
discharge to the LCWRF and are included in the domestic source characteristics presented in Table 5-2,
which summarizes wastewater characteristics for the Town's major waste streams.
Table 5-2.Town Waste Stream Characteristics(Maximum Month Concentrations)
Source Domestic and Commerciala Grifols Novo Nordisk—DAPIb
Flow(MM ADF,MGD) 3.2 c 2.0 0.8
BOD(mg/L) 308 409 250
TSS(mg/L) 347 725 250
TN(mg/L) 66 73 20
TP(mg/L) 9 9 8
COD:BOD ratio 2.0 2.9 2.0
a Based on current LCWRF influent characteristics.
b Based on existing Town industrial pretreatment permit limits.
Includes 0.5 MGD future nonresidential flow,assumed to be domestic-strength wastewater.
Notes:
COD=chemical oxygen demand
The new 6-MGD WRF will provide for BNR to comply with NPDES discharge limits for the Neuse River.
The new WRF will treat the existing permit limits of the LCWRF.Table 5-3 summarizes the WRF's
aggregate design loading.
Table 5-3. Design Loads and Effluent Limits
Influent Loading Effluent Limit
Source (MM ADF,lb/d) (Monthly Average,mg/L)
BOD 16,450 10.0
COD 39,730 -
TSS 22,370 30.0
TN 3,100 a 3.0
TP 450 2.0
a Assumes recalcitrant nitrogen from industries in influent is at typical domestic strength.
Notes:
Ib/d=pound(s) per day
Table 5-4 summarizes the design criteria for each treatment system in the primary liquids process.
5-7

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-4.General Liquids Treatment System Design Criteria
Component Value
Influent Pumping
Pumps
Type Submersible
No.Pumps 4
Design Point 4.4 MGD at 105 ft TDH
Minimum Required Firm Capacity(2.5 x MMF) 15 MGD
Installed Firm Capacity 17.6 MGD
Standby Pumps
Type Dri-Prime
No.Pumps 2
Design Point 6.6 MGD at 105 ft TDH
Influent Flow Meter
Type Magnetic flow meter
Flow Range(MGD) 5.25-17.6
Influent Force Main
No.of Force Mains 2
Diameter,inches 24
Influent Screening
Type Inclined cylindrical with integral washer and compactors
No.of Screens(duty and standby) 1 and 1
Screen Opening 6-mm perforated plate
Design PHF per Screen,MGD 15
Grit Removal
Type Stacked tray(HeadCell)
No.of Units 2
Capacity per Unit,MGD 7.5
Flow Equalization
Total Volume,MG 1.60
No.of Tanks 2
No.of Equalization Pumps(duty and standby) 2 and 1
Bioreactors
Process Five-stage Bardenpho
No.of Basins 3
Basin Volume,MG(each) 2.45
Diffuser Type Membrane discs
Nitrified Recycle Pumps
Type Propeller pumps with VFD
5-8

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-4.General Liquids Treatment System Design Criteria
Component Value
No.of Pumps(duty and standby) 3 and 1
Surface Wasting Pumps(biofoam removal pumps)
Type Horizontal centrifugal nonclog with VFD
No.of Pumps(duty and standby) 3 and 1
Secondary Clarification(Final Clarifiers)
No.of Clarifiers 3
Geometry Circular
Diameter,ft(each) 75
Sidewater Depth,ft 18
RAS
Type Horizontal centrifugal nonclog with VFD
No.of Pumps(duty and standby) 3 and 1
WAS
Type Horizontal centrifugal nonclog with VFD
No.of Pumps(duty and standby) 3 and 1
Aeration Blowers
Type High-speed turbo
No.of Blowers(duty and standby) 2 and 1
Average Air Total Flow,scfm 4,500
Tertiary Treatment
Type Cloth(disc)filtration
No.of Units(duty and standby) 2 and 1
Capacity, MGD(each) 2.7(average)and 4.9(peak)
Disinfection
Type Open channel LPHO UV
No.of Units 2
Capacity, MGD(each) 5
Postaeration
Type Cascade aeration
Minimum DO,mgO2/L 6.0
Effluent Flow Meter
Type Magnetic flow meter
Flow range(MGD) 5.25-10
Notes:
ft=foot(feet)
LPHO=low-pressure,high-output
mgO2/L=milligram(s)per oxygen per liter
5-9

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-4.General Liquids Treatment System Design Criteria
Component Value
mm=millimeter(s)
TDH=total dynamic head
The solids treatment process will produce unclassified solids per the 503 Regulations (EPA, 2018)to be
composted or disposed of at a landfill.Table 5-5 provides the design criteria for each treatment system
in the solids process.
Table 5-5.Solids Treatment System Design Criteria
Component Value
Thickening
Type Rotary drum
No.of Units(duty and standby) 1 and 1
Target Thickened Solids Concentration,%TSS 5
Aerated Sludge Holding
Average Retention Time,days 30
No.of Tanks 1
Volume,gallons 670,000
Mixing and Aeration Method Coarse bubble diffuser
Dewatering
Type Screw press
No.of Units(duty and standby) 1 and 1
Target dewatered cake concentration,%TSS 18
Water and Energy Conservation
VFDs will be provided for pumps and blowers, which results in more efficient operation and reduced
energy consumption.Treated effluent will be used for process washdown water, reducing consumption
of potable water at the plant.
Environmental Considerations
The proposed parcel is large enough that the facility plan can avoid impacts to floodplains, wetlands,
streams, and stream buffers (WithersRavenel, 2020a). Parcel development will also comply with water
supply watershed development rules. Other than temporary closure for construction of linear infrastructure,
greenways would not be impacted. Odor control technologies would be used to offset potential odor
impacts. Potential impacts to the Neuse River from increased discharge will be offset by purchase of
additional nitrogen credits and to comply with the facility's NPDES permit. Other, mostly temporary impacts
would occur with construction of linear infrastructure, an access road, and the expanded outfall.
5-10

SECTION 5-ALTERNATIVES ANALYSIS
Cost Estimate
The estimated total capital cost of Alternative 2a is$120,198,000.This cost includes 10 percent
contingency applied to the construction costs and all estimated administrative costs for the project.The
following project components are included in this estimate:
• Conversion of LCWRF to a pump station
• New transmission pipes and upgrades to existing transmission pipes to convey flow to the Neuse 2
Pump Station site
• Nitrogen credit purchase
The estimated total present worth of the new 6-MGD WRF at the Neuse 2 Pump Station site is$154,487,401.
Acceptance or Rejection
Alternative 2a received a score of 4.14, the highest nonfinancial score of the six feasible alternatives,
with higher scores being better aligned to the goals. Of these six alternatives,three compared different
potential sites for a 6-MGD facility,while the other three compared treatment options. When compared
to the other potential sites (ECIA and existing LCWRF),Alternative 2a had the highest weighted score.
This alternative received high scores under the following nonfinancial criteria:
• Resiliency from climate impacts
• Increase the Town's control over the cost of treatment
• Adaptability and phasing
Alternative 2a, construction of a new 6-MGD WRF at the Neuse 2 Pump Station site, provides significant
long-term benefits to the Town that align with the project purpose and need.
This alternative incorporates moderate water and energy conservation measures by using treated
effluent for process washdown water and employing VFDs.
This alternative is feasible, and the investment would provide long-term resiliency to the Town and its
customers.The construction of a new WRF at the Neuse 2 Pump Station site and continued use of a
surface water discharge is considered the Preferred Alternative.
5.1.2.2 Alternative 2b: Construction of a New Water Reclamation Facility at the East Clayton
Industrial Area Pretreatment Facility
Under this alternative, the Town would construct a new WRF adjacent to the R. Steven Biggs Regional
Pretreatment Facility.This site is located near the Town's primary industrial and commercial customers;
however, it is not in an area expected to undergo significant residential growth or development.This
land is currently intended for pretreatment facility expansions that would allow the Town to serve more
industrial customers in the future.
To expand the footprint of the pretreatment facility to accommodate a 6-MGD WRF, the Town would
use the current athletic field area adjacent to the pretreatment facility.Additional land acquisition may
be necessary.This athletic field area is bounded by:
• Railroad to the east
• Powhatan Road to the south
• Wetlands to the north
• Grifols property to the west
It is unlikely this site is large enough to accommodate future facility expansions. Additionally, wetland
areas border the ECIA site, and construction of the new WRF may result in environmental impacts.
5-11

SECTION 5-ALTERNATIVES ANALYSIS
This alternative includes conveyance system work to connect existing pump stations and sewer
infrastructure to the new WRF, including conversion of the LCWRF to a pump station and upgrades to
the Neuse 2 Pump Station.
The treatment facility would include similar treatment infrastructure as discussed under the Neuse 2
Pump Station site alternative,with the following variations:
• Re-aeration would be diffused aeration rather than cascade aeration due to limited elevation
changes on the site.
• Transmission of the treated effluent would require pumping to the existing Neuse River outfall.
Figure 5-2 shows the preliminary new WRF layout at the ECIA Pretreatment Facility site.
5-12

\- °' 7 ----"--..*- )‘ '
(:::) 1.
(ji--• S--..:**/:: 13."--2. 1\%4. . kcz:3. 0. .c).
. 0 ,_ ,
., c____,):, %f
, i ) .4 -44, •71(< - ,• .,
ir Wit/
•.
0 . . , • •
1,%% -,, k.T /41111116. 0
)1 1 ,I( 0 %t / )
)....)
. I
%t%%••.."/ 0 0 0 a •
( 'A % % $
•`,` -' ''Y/I /\ ,
17 :41
6
�V T, 8lik.
...
Fig.No. Name f, ,1 O
1 Administration Building
2 Main Switch Building&Backup Generators/ 10 Ca3 l/�
3 Influent Pump Station ��
4 Headworks&Odor Control ,1 11 , 7 Legend
�, 5 Influent Equalization 12 R.Steven Biggs
6 Influent Equalization Pump Station 1 3 - Regional Pretreatment
7 BNRs 1 Facility Footprint
8 Blowers&Electrical 14 (.1/ O Proposed WRF
9 Secondary Clarifiers Footprint
10 Chemical Feed&Storage 9L..._. i Existing Gravity Mains
11 Filters •••I Existing Force Mains
12 Disinfection
Pavement
13 Post-Aeration&Plant Water Pump Station
14 RAS/WAS V. ,,,' 411111004' Q Parcel Limits
15 Gravity Belt Thickener Building&Electrical .:®Wetlands
16 Centrifuge Buildingsil./;...............yN''' Contours
•17 Aerobic Digesters , \
I I
F. ) \ ��- Source4NC Orpolmagery Program (2017)
Figure 5-2
ellk2 � 0 350 0 700 N Proposed WRF at ECIA Site
5M Feet A Water Reclamation Facility Expansion
Town of Clayton, NC
IThe treatment systems depicted on this conceptual layout represent conservative footprints,and may be revised as the design develops.

SECTION 5-ALTERNATIVES ANALYSIS
Design Criteria
The new WRF under this alternative is subject to the same flow and load characteristics detailed in
Section 5.1.2.1.Treatment system design criteria detailed in Tables 5-1 and 5-3 remain unchanged in
this alternative, with the exception of the postaeration system. Due to site limitations, a diffused system
would be better suited than a cascade aeration system.
Environmental Considerations
The footprint of this facility would be on a recreational area currently owned by the Town and managed
by the County YMCA, reducing current public land recreational use. Additional land purchase may be
needed under this alternative to expand beyond 6 MGD. Wetland impacts are also likely. Potential
impacts to the Neuse River from increased discharge will be offset by purchase of additional nitrogen
credits and compliance with the facility's NPDES permit. Other, mostly temporary impacts would occur
with construction of linear infrastructure and the expanded outfall.There are more environmental
impacts under this alternative than for the Preferred Alternative, given the likely impacts to wetlands.
Cost Estimate
The estimated total capital cost of Alternative 2b is$33,089,000.This cost includes 10 percent
contingency applied to the construction costs and all estimated administrative costs for the project.This
cost includes 6-MGD treatment capacity, as described in Section 5.1.2.1. Conveyance infrastructure to
transmit treated effluent to the Neuse River outfall was added to this the cost estimate.
The estimated total present worth cost of the new WRF at the ECIA site is$173,317,373.
Acceptance or Rejection
Alternative 2b received a score of 3.79,the median nonfinancial score of the six feasible alternatives,
and the central score for the three potential site alternatives. Refer to Appendix G for details on the
scoring of each alternative in the nonfinancial evaluation.This alternative received high scores under the
Resiliency from climate impacts and Increase the Town's control over the cost of treatment categories
but scored lower than the Preferred Alternative in all other categories. Alternative 2b scored the lowest
in the Maximum use of existing assets category because this alternative requires construction of more
conveyance infrastructure than the other feasible alternatives.
This alternative will also incorporate moderate water and energy conservation measures by using
treated effluent for process washdown water and VFDs. However, because this alternative relies on
effluent pumping to convey treated effluent to the outfall, energy and water conservation are less than
the Preferred Alternative.
This alternative is feasible, and the investment would provide increased resiliency to the Town and its
customers. However, construction of the new 6-MGD WRF adjacent to the R. Steven Biggs Pretreatment
Facility will limit the Town's ability to expand capacity at the pretreatment facility to meet future
industrial customer demands. Investment would be higher than the Neuse 2 Pump Station site due to
the purchase of land and potential environmental mitigation if wetland impacts were unavoidable.
Operations costs are higher, as treated effluent would be pumped a longer distance to the Neuse River
outfall.There would also be impacts to the recreational area.The cost and environmental impacts of
this alternative are greater than the Preferred Alternative.
5-14

SECTION 5-ALTERNATIVES ANALYSIS
5.1.2.3 Conclusion
The construction of a new WRF at the Neuse 2 Pump Station site and continued use of a surface water
discharge is considered the Preferred Alternative.This alternative was selected as the best fit to meet
the Town's purpose and need for additional wastewater capacity for the following reasons:
• New facility construction best supports the Town's long-term goals for treatment and capacity
needs up to 10 MGD.
• New facility construction provides the Town with resilience while retiring existing LCWRF
infrastructure that is at or near the end of its useful life.
• Site location maximizes the use of Town-owned land with existing infrastructure, including the
Neuse 2 Pump Station and Neuse River outfall.
• Site location is next to the Neuse River outfall, limiting conveyance of treated effluent to maximize
effluent DO into the Neuse River.
• Facility cost-effectively treats effluent to the NPDES permit requirements.
• Facility footprint at the Neuse 2 Pump Station site avoids impacts to environmental resources on the
property, including Neuse River floodplain, wetlands, streams, and stream buffers.
Other factors that influenced selection of this site include the Town's elimination of environmental
liability associated with the previous law enforcement firing range and an analysis of environmental
justice considerations included in Appendix H.This site did not raise any environmental justice concerns.
5.1.3 Alternative 3: Expansion of Little Creek Water Reclamation Facility, and
Continued Use of Surface Water Discharge
Under this alternative, the Town would rehabilitate the existing LCWRF and expand its capacity to
6 MGD by 2023 from its current permitted capacity of 2.5 MGD. In addition, the following infrastructure
would require upgrades:
• Discharge force main
• Pump station
• Gravity line to the discharge location
• Neuse River discharge
Much of the projected development within the Clayton ETJ is occurring nearer to the Neuse River side of
the watershed, rather than the Little Creek side. Flow into the Neuse River basin is conveyed to LCWRF
from the Neuse River 2 Pump Station. Given the projected development, this pump station will need to
be expanded to convey flow to LCWRF,from a current firm capacity of 1.1 MGD to approximately
1.6 MGD for the initial expansion, and approximately 3.2 MGD to meet the future expected flows;these
future expansions would need to be considered in the initial expansion.
In addition to investing in the rehabilitation of aging LCWRF treatment system components, the
following treatment systems would be added to increase capacity and add resiliency to the facility:
• Expanded headworks to add screen and grit removal capacity
• Expanded IPS to accommodate peak flow
• New flow equalization basin to reduce PHF to peak day for downstream treatment processes and
minimize TDS variability
• New flow equalization pump station to convey equalized flow from the basin to follow-on treatment
processes
5-15

SECTION 5-ALTERNATIVES ANALYSIS
• Addition of postanoxic and postaerobic zones to the existing oxidation ditches to support
reconfiguration of biological process to enhance nitrogen removal
• Additional five-stage BNR basins for expanded treatment capacity
• Additional final clarifiers for expanded treatment capacity
• Tertiary filter replacement with cloth disc filters
• Expanded UV disinfection system
• New re-aeration facility to maximize DO in effluent
• Upgraded effluent pump station,with associated transmission line to outfall location, to convey
peak flow associated with 6-MGD permitted capacity
• Supplemental carbon for enhanced nitrogen removal
• Supplemental metal salts for backup and polishing of phosphorous removal
• Expanded Neuse 2 Pump Station to a firm capacity of approximately 1.6 MGD and associated force
main to convey an annual ADF of 0.6 MGD to LCWRF
• Addition of flood mitigation infrastructure to protect low-lying areas of the site
• Interprocess piping for new facilities
• Upgraded electrical system, including new duct banks
• Replacement of standby generator capacity(or more capacity added)
• Replacement of aging equipment in existing facilities
The existing treatment system structures (that is,the oxidation ditch and clarifiers) are approximately
30 years into their expected minimum 50-year useful life; therefore, it has been assumed that upgrades
to and rehabilitation of existing LCWRF treatment systems would be accomplished using the existing
structures.
The proposed facility would continue to be on a steeply graded parcel with limited readily available
space for expansion without significant site work.The site is also partially located in the floodplain of
Little Creek and is not well-suited for treatment infrastructure. The currently unused portions of the site
are steeply graded and include streams, and floodplains in the lower areas of the site that would reduce
the readily available land that could be used for expansion. A preliminary layout indicates that stream
and buffer impacts would occur and would have to be mitigated. A flood wall would be required to
protect infrastructure in the lower-lying parts of the site. Permitting of additional flood protection
measures is typically a 6-to 9-month process and poses an added schedule risk to the project when
compared to the Preferred Alternative. In addition, this alternative requires investment to replace or
rehabilitate major components of existing treatment systems at LCWRF, as well as construction of the
expansion.The complexity of operating the existing plant while constructing an expansion would need
to be managed during construction. It may be necessary to temporarily increase flow to the County and
City during facility rehabilitation and construction.
To discharge 6 MGD into the Neuse River, additional capacity is needed at the outfall structure.
Consistent with the existing outfall,which will remain, the proposed adjacent parallel outfall will mirror
the existing end-of-pipe outfall.
Figure 5-3 shows the proposed expanded WRF layout at the LCWRF site.
5-16

v _.......„
I N \.._,,, ,\ MAPLEWOOD
CEMETERY
) ,, ---------„(
j
r � ----------- - ,,,,,,.,._., '-.- '-:"---\'''.----- -"•-•--1
) Z (e
1
� 4 ----------\_____________ .......:1 -----\
i N 2l 3 / 4 I \1(112
i cc 0 5 7 1'\4'
14 6
/ / V
g (113)
Fig.No. NameAt ( \ /
1 U-- 11. \`: DURHAM ST
/i
1 Headworks Expansion
2 Influent Pump Station 13
3 Flow Equalization Pump Station Q 12
4 Flow Equalization
5 Flow Splitter Structure
()-
6 Bioreactor Basins <,
7 Blowers&Electrical f'oc ILegend
8 SecnodaryClarifiers oo�� X.-7-
Hydrology
9 RAS/WAS q \ Plant Footprint
10 Post-Anoxic and Reaeration for Existing Bioreactors \ ----__IN /I 1 Pavement
11 Chemical Feed&Storage ` __________,- ---7 / Qparcel Limits
,.____
12 Filters O \1 \` -- ,100 Year Floodplain
13 UVDe / � -------_ 2 foot Contour
14 Dewatering Building \
//l(((/l
��� !\- \' Source:NO Orthoimagery Program(2017)
Figure 5-3
all 0 390 780 N Proposed WRF at LCWRF Site
2,ii4M A Water Reclamation Facility Expansion
Feet
Town of Clayton, NC
The treatment systems depicted on this conceptual layout represent conservative footprints,and may be revised as the design develops.Hydrology representations may be off from actual locations.

SECTION 5—ALTERNATIVES ANALYSIS
5.1.3.1 Design Criteria
The new WRF under this alternative is subject to the same flow and load characteristics detailed in
Section 5.1.2.1.
The upgraded LCWRF will provide for BNR to comply with NPDES discharge limits to the Neuse River.
Table 5-6 presents the design criteria for each treatment system in the primary liquids process.The data
presented represent the additional equipment to be added to upgrade LCWRF.
Table 5-6. Little Creek Water Reclamation Facility Expansion Design Criteria
Component Value
Influent Pumping
Pumps
Type Dry-pit submersible
No.Pumps(duty) 2
Influent Flow Meter
Type Magnetic flow meter
Flow Range(MGD) 5.25-17.6
Influent Screening
Type Inclined cylindrical with integral washer and compactors
No.of Screens(duty and standby) 1 and 1
Screen Opening 6-mm perforated plate
Design PHF per Screen,MGD 7.5
Grit Removal
Type Vortex
No.of Units 1
Capacity per Unit,MGD 7.5
Flow Equalization
Total Volume,MG 1.60
No.of Tanks 2
No.of Equalization Pumps(duty and standby) 4 and 1
Bioreactors
Process Five-stage Bardenpho
No.of Basins 3
Basin Volume,MG(each) 1.8
Diffuser Type Membrane discs
Nitrified Recycle Pumps
Type Propeller pumps with VFD
No.of Pumps(duty and standby) 3 and 1
Surface Wasting Pumps(biofoam removal
pumps)
5-18

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-6. Little Creek Water Reclamation Facility Expansion Design Criteria
Component Value
Type Horizontal centrifugal nonclog with VFD
No.of Pumps(duty and standby) 3 and 1
Secondary Clarification(Final Clarifiers)
No.of Clarifiers 2
Geometry Circular
RAS
Type Horizontal centrifugal nonclog with VFD
No.of Pumps(duty and standby) 2 and 1
WAS
Type Horizontal centrifugal nonclog with VFD
No.of Pumps(duty and standby) 1 and 1
Aeration Blowers
Type Multistage centrifugal
No.of Blowers(duty and standby) 3 and 1
Tertiary Treatment
Type Cloth(disc)filtration
No.of Units(duty and standby) 2 and 1
Capacity, MGD(each) 2.7(average)and 4.9(peak)
Disinfection
Type Open channel LPHO UV
No.of Units 1
Capacity, MGD(each) 6.25
Postaeration
Type Diffused aeration
Minimum DO,mg02/L 6.0
Effluent Pumping
Pumps
Type Dry-pit submersible
No.Pumps(duty) 4
Effluent Flow Meter
Type Magnetic flow meter
Flow range(MGD) 5.25-10
5-19

SECTION 5—ALTERNATIVES ANALYSIS
The LCWRF solids treatment process will be expanded to produce unclassified solids per the
503 regulations (EPA, 2018)to be composted or disposed of at a landfill.Table 5-7 provides the design
criteria for the upgraded treatment system components in the solids process.
Table 5-7. Little Creek Water Reclamation Facility Expansion Solids Treatment System Design Criteria
Component Value
Thickening
Type Rotary drum
No.of Units(duty and standby) 1 and 1
Target Thickened Solids Concentration,%TSS 5
Aerated Sludge Holding
Average Retention Time,days 30
No.of Tanks 2
Volume,gallons 282,000
Mixing and Aeration Method Coarse bubble diffuser
Dewatering
Type Screw press
No.of Units(duty and standby) 1 and 1
Target dewatered cake concentration,%TSS 18
5.1.3.2 Water and Energy Conservation
This alternative will also incorporate moderate water and energy conservation measures by using
treated effluent for process washdown water and rotating equipment that will operate on VFDs.
5.1.3.3 Environmental Considerations
To mitigate risk to LCWRF infrastructure,flood protection, such as a flood wall, is included in this
alternative. As a result of the expansion and flood wall construction,floodplain impacts may occur with
this alternative. Site constraints may also limit the ability to provide cost-effective TN removal when
future expansion to 10 MGD is necessary, although process alternatives may be available to limit the
footprint. Expansion at the LCWRF site would likely have stream and buffer impacts,which would have
to be mitigated. Potential impacts to the Neuse River from increased discharge will be offset by
purchase of additional nitrogen credits and compliance with the facility's NPDES permit. Other, mostly
temporary impacts would occur with construction of linear infrastructure and the expanded outfall.
The Town currently limits noise and public lands impacts by directing truck traffic along a residential
road, Durham Street, to the LCWRF but maintains access through Maplewood Cemetery. If the facility
were to expand, additional traffic impacts would occur, and odor control would be necessary to limit
impacts to adjacent residences associated with additional treatment capacity to the LCWRF.
Environmental impacts under this alternative are the same as the Preferred Alternative.
From an environmental justice evaluation of the three sites (Appendix H), LCWRF has a higher
percentage of minority, lower income, and special populations than the other two sites.This is a
function of this site being located adjacent to the original Clayton downtown area.
5-20

SECTION 5-ALTERNATIVES ANALYSIS
5.1.3.4 Cost Estimate
The estimated total capital cost of Alterative 3 is$96,493,000.This cost includes 10 percent contingency
applied to the construction costs and all estimated administrative costs for the project.This estimate
assumes existing LCWRF treatment system structures will be used in the upgraded and expanded
process.This assumption about reuse of existing structure accounts for the capital cost differential
between this and the Preferred Alternative. While this option makes use of existing structures, which
are not expected to need replacement within the 20-year planning period, they would reach the end of
their expected useful life sooner after the planning period than the Preferred Alternative structures
would.This reflects a future cost liability for the Town that is not captured in the 20-year cost estimate.
The initial construction cost also includes major existing equipment that would need to be replaced
within the next 5 years or so, as identified in the AIA grant project, and which is expected to cost
$4.2 million.Those costs are included in the present worth calculation.
The estimated total present worth of the expansion of LCWRF to 6 MGD is$134,079,516.
5.1.3.5 Acceptance or Rejection
Alternative 3 received a score of 3.67, the median nonfinancial score of the six feasible alternatives.This
score was the lowest of the three potential sites,with Alternative 2a scoring 4.14, and Alternative 2b
scoring a slightly higher 3.79. Refer to Appendix G for details on the scoring of each alternative in the
nonfinancial evaluation.
This alternative received the highest score of all alternatives in the Maximum use of existing assets
category and a high score under the Increase the Town's control over the cost of treatment category.
This alternative received the lowest scores in the following criteria:
• Aesthetics
• Resiliency from climate impacts
• Potential to facilitate economic growth to serve new residential, commercial, and industrial customers
• Adaptability and phasing
The nonfinancial analysis indicates Alternative 3, expansion of the LCWRF to 6 MGD, provides the least
long-term benefit to the Town.
The Town currently limits public lands impacts by directing truck traffic along a residential road, Durham
Street,to LCWRF but maintains access through Maplewood Cemetery. If the facility were to expand,
additional traffic impacts would occur, and odor control would be necessary to limit impacts associated
with additional treatment capacity to adjacent residences.
Environmental justice considerations indicate that other sites would be preferable.
Unlike the Preferred Alternative, LCWRF is located away from the center of anticipated future
development.
This alternative will also incorporate moderate water and energy conservation measures by using
treated effluent for process washdown water and VFDs. However, because this alternative relies on
effluent pumping to convey treated effluent to the outfall, energy and water conservation are less than
the Preferred Alternative.
While reuse of existing structures keeps the initial capital cost down relative to the Preferred
Alternative, there is significant cost expected to be associated with structure rehabilitation and
replacement sooner under this option than with the Preferred Alternative.The operational challenges
presented by the need to maintain treatment at LCWRF during construction and the potential need to
temporarily increase flow to the County and City during facility rehabilitation and construction are also
potential costs that are not captured in the cost estimate.
5-21

SECTION 5-ALTERNATIVES ANALYSIS
The limited readily available space on the parcel also limits potential cost-effective nutrient treatment
options if the facility is expanded to 10 MGD.
This alternative is feasible; however, it is not recommended because it involves potential impacts to the
Little Creek floodplain, streams, and stream buffers, and involves investment in both rehabilitation of
infrastructure and new construction. In addition,there is added complexity of expanding and upgrading
an active plant when compared to the Preferred Alternative.This alternative also exposes the Town to
cost to rehabilitate or replace structures outside of the planning window much sooner than would occur
with the Preferred Alternative. Permitting of additional flood protection measures is typically a 6-to
9-month process, which, while manageable, adds a schedule risk to the project.
5.1.4 Alternative 4: Continued Use of Little Creek Water Reclamation Facility,
Maximizing Regional Connections to Existing Wastewater Treatment
Under this alternative,the Town would reach agreement with the County and the City to expand
contracts for the existing infrastructure connections while maintaining operation of the LCWRF to meet
future projected demands.These utilities are currently unwilling to reach these types of long-term
agreements with terms that are cost-effective for the Town.This alternative was included because it
could be technically feasible if cost-effective agreements were reached.
Additional conveyance capacity is likely necessary; details would be determined depending on which
regional contract would be increased. An expansion of the existing outfall into the Neuse River would
not be necessary.
Components of this alternative include:
• Maximized expansion of regional contracts and existing conveyance capacity with the City and
County to 4 MGD total
• Continued use of the LCWRF and investment in aging treatment system components
• Addition of denitrifiying filters to LCWRF to improve the level of TN removal and increase
operational capacity to the permitted 2.5 MGD
• Continued use of the LCWRF discharge into the Neuse River
Other components include permitting and building conveyance infrastructure from ECIA to the
JCRWWTP, permitting and building additional conveyance infrastructure to the NRWWTP, or some
combination of these.
Under this alternative, increased regional contracts for treatment capacity in the amount of
approximately 4 MGD would be necessary. Both the County and City are raising rates, and both are
experiencing their own increasing demands.The County has stated that it will only accept domestic-
strength waste (lower TDS) beginning in 2022.
This alternative is not considered feasible because, to date, the Town has been unable to reach
cost-effective agreements with these utilities. It is also highly unlikely that this alternative would be able
to meet the Town's long-term planning for 10 MGD of treatment capacity.
5.1.4.1 Design Criteria
This alternative includes limited improvements to the LCWRF to increase the facility treatment capacity
to 2.5 MGD (current permitted capacity). Process improvements include rehabilitation of existing
treatment systems and the construction of denitrification filters to comply with NPDES discharge limits
to the Neuse River.
5-22

SECTION 5—ALTERNATIVES ANALYSIS
The existing treatment system structures (that is, the oxidation ditch and clarifiers) are approximately
30 years into their expected minimum 50-year useful life and in good condition; therefore, near-term
rehabilitation of existing LCWRF treatment system components include the following systems and
processes:
• Grit removal
• Influent pumping
• Oxidation ditch aerators and VFDs
• RAS and WAS pumping
• Effluent pumping
• Reclaimed water pumping
• Plant water pumping
• Sludge thickener and associated pumping
• Sludge holding blowers
• Electrical system, including generators and transformers
Table 5-8 provides the design criteria for the denitrification filtration system.
Table 5-8. Denitrification Filtration System Design Criteria
Component Value
Type Deep bed granular media filter
No.of Units(duty and standby) 5 and 1
Depth,ft 6
Capacity, MGD(each) 0.54(average)and 1.5(peak)
Average Hydraulic Loading Rate,gpm/ft2 1.5
Peak Hydraulic Loading Rate,gpm/ft2 3.0
Carbon Feed System
Carbon Feed Dose Rate,mg/L 18
No.of Tanks 1
No.of Pumps 2
5.1.4.2 Environmental Considerations
Temporary and some permanent impacts would occur with construction of linear infrastructure.The
LCWRF resiliency from flood impacts and reliability with aging infrastructure is a risk for the Town that
would need to be remedied. Environmental impacts under this alternative are greater than the
Preferred Alternative, given the impacts of the additional infrastructure that would be required to
convey flow to either JCRWWTP or NRWWTP.
5.1.4.3 Cost Estimate
As this alternative is not considered to be feasible, the estimated capital cost and total present worth of
this option have not been calculated.
5-23

SECTION 5-ALTERNATIVES ANALYSIS
5.1.4.4 Acceptance or Rejection
The County and the City are the only neighboring utilities that would be options for contracting capacity.
This alternative is not considered feasible because, to date, the Town has been unable to reach
long-term agreements with these utilities.
The County has made the decision to not accept any wastewater with characteristics exceeding
domestic-strength limits.This eliminates the use of the County contract for increasing flows from the
ECIA Pretreatment Facility.The City intends to increase the fees associated with the current contract
capacity as high as 40 percent in 2020 and has proposed new fees and charges for any additional
capacity beyond the currently contracted 1.0 MGD. It is also highly unlikely that this alternative would
be able to cost-effectively meet the Town's long-term planning for 10 MGD of treatment capacity.This
alternative was eliminated from the evaluation. Present worth cost for Alternative 4 was not calculated.
5.1.5 Alternative 5: Construction of a New Water Reclamation Facility, and Use
of Land Application
Under this alternative, the Town would build a new 6-MGD WRF,with plans for future incremental
expansion to 10 MGD, as described in Section 5.1.2.1.The effluent discharge location at the Neuse River
would be abandoned, and the WRF treated effluent disposal would be diverted to suitable locations for
spray irrigation. Land application nutrient removal requirements are less stringent than for surface
water discharge, and the purchase of nitrogen credits in the Neuse River basin would be reduced or not
necessary.The Town currently provides a small amount of reuse water to the Pine Hollow Golf Course;
however, demand is seasonal, and other land application sites would be necessary. For this evaluation,
the Neuse 2 Pump Station site was used as the new WRF site.The amount of land necessary for land
application was estimated using area soil conditions.
Once a new WRF is online,the land application of effluent would include the construction of
transmission infrastructure, storage ponds, and land application facilities at the dedicated land
application site. Other components of this discharge alternative would include:
• Identification of other land application sites for additional effluent disposed using spray irrigation
• Retention of regional contracts as capacity backup after 2023, but minimization of flow to the City
and the County
• Plan for future expansion of the facility to 10 MGD as flows increase
Due to the less-stringent effluent treatment requirements associated with land application (NCAC 15A
NCAC 02T.0505), certain elements of the WRF as described in Section 5.1.2.1 can be eliminated from the
design, including tertiary treatment (effluent filtration) and supplemental carbon feed.
Preliminary estimates for the application rate, application area, and onsite storage capacity were
calculated.The preliminary loading rate for soils in the area is 1.5 inch per week per acre. Based on the
potential for extended wet periods in the spring and summer months in the county, 30 days of storage
was assumed.The total acreage required to land apply 6 MGD has been calculated as 1,300 acres.
Based on a preliminary review of open land near the Town, finding a suitable land application site with
adequate capacity for the total plant flow of 6 MGD within a reasonable distance of the new WRF will
prove difficult. For the basis of cost estimating and assessment of potential impacts, it has been assumed
that multiple (three) land application sites would be required and would be within 10 miles of the WRF site.
Considerations for this alternative include:
• Available land with suitable soils
• Pump stations at the WRF to send flows to the land application sites
5-24

SECTION 5—ALTERNATIVES ANALYSIS
• Conveyance from the pump station to the land application sites
• Lined storage point and irrigation pump at each site
• Solid-set sprinkler application system
• Site development costs, including:
— Clearing
— Crop establishment
— Access roads
— Fencing
— Monitoring wells
• Land purchase costs
5.1.5.1 Design Criteria
The new WRF under this alternative is subject to the same influent flow and load conditions detailed in
Section 5.1.2.1. Due to the less-stringent effluent treatment requirements associated with land
application, the following elements of the WRF as described in Section 5.1.2.1 can be eliminated from
the design:
• Tertiary treatment(effluent filtration)
• Supplemental metal salt feed
• Supplemental carbon feed
• Reduction in bioreactor volume
This design induces the flowing components for land application of the new WRF effluent:
• Reclaimed water storage reservoir
• Reclaimed water transfer pump station and transmission pipe
• Land application site distribution pump stations
• Irrigation piping and sprinkler application system
Table 5-9 provides the design criteria for the land application discharge system.
Table 5-9. Land Application System Design Criteria
Component Value
Reclaimed Water Storage and Transfer System
Reservoir
Type Earthen, lined
Volume,MG 20
Pump Station
Type Centrifugal
No.of Pumps(duty and standby) 2 and 1
Transmission Pipe
No.of Pipes 1
Diameter,inches 24
Length, LF 132,000
Material Concrete-lined DI pipe
5-25

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-9. Land Application System Design Criteria
Component Value
Land Application Sites
No.of Sites 3
Storage Reservoir
Type Earthen, lined
No.of Reservoirs 3
Volume,MG(each) 68.3
Irrigation Distribution Pump Stations
No.of Pump Stations 3
Type Vertical turbine
No.of Pumps(each station,duty and standby) 2 and 1
Irrigation Mains
Diameter,inches 16
Length, LF(total) 15,000
Material DR 18 PVC
Notes:
DI=ductile iron
DR=dimension ratio
PVC=polyvinyl chloride
5.1.5.2 Water and Energy Conservation
This alternative will incorporate moderate water and energy conservation measures by using treated
effluent for process washdown water and VFDs for rotating equipment. Given the long distance that
effluent would be conveyed the overall energy consumption of this alternative would be much higher
than the Preferred Alternative.
5.1.5.3 Environmental Considerations
Temporary and some permanent impacts would occur with construction of linear infrastructure,
including lines to convey effluent to the land application sites. Operations would be carefully monitored
to avoid impacts to soils and land uses, such as accumulation of salts in the soils over time. Operations
would also monitor runoff rates so that adjacent surface waters are not impacted by nutrient loading.
Environmental impacts under this alternative are less than the Preferred Alternative, as this alternative
would eliminate a surface water discharge.
5.1.5.4 Cost Estimate
The estimated total capital cost of Alterative 5 is$186,800,000.This cost includes 10 percent
contingency applied to the construction costs and all estimated administrative costs for the project.This
cost includes 6-MGD treatment capacity, as described in Section 5.1.2.1.The cost was estimated by
eliminating the cost of the tertiary treatment system,the supplemental carbon system, and outfall
upgrades from the cost presented in Section 5.1.2.1.
5-26

SECTION 5-ALTERNATIVES ANALYSIS
The estimated total present worth cost of the new WRF with the land application is$225,201,816.
5.1.5.5 Acceptance or Rejection
Alternative 5 received a score of 3.28, the lowest nonfinancial score of the six feasible alternatives. Refer
to Appendix G for details on the scoring of each alternative in the nonfinancial evaluation.This
alternative received a high score under the Increase the Town's control over the cost of treatment and
Resiliency from climate impacts nonfinancial criteria but received the low scores in the following criteria:
• Environmental impacts
• Land use compatibility or improvement
• Maximum use of existing assets
• Adaptability and phasing
Alternative 5, construction of a new 6-MGD WRF with land application provides the least long-term
benefit to the Town.
This alternative will also incorporate moderate water and energy conservation measures by using
treated effluent for process washdown water and VFDs for rotating equipment. However, this
alternative requires significantly more pumping to convey treated effluent to the land application sites;
therefore, energy and water conservation are less than the Preferred Alternative.
While there are sites with suitable soils available to the Town for this alternative to be feasible, costs
were estimated using the required acreage and an estimated conveyance distance of 10 miles. Although
the cost of treatment under this alternative reduces the cost of a new WRF and eliminates the need to
expand the outfall into the Neuse River,the costs associated with conveyance of the effluent, the land
application site, and O&M significantly increase the overall cost of the project compared to other
alternatives.This alternative also likely has less feasibility to meet the Town's long-term needs of
10 MGD of treatment capacity when compared to the Preferred Alternative. Given the costs of land
application and the limited availability of land, this alternative was dismissed from further consideration.
5.1.6 Alternative 6: Construction of a New Water Reclamation Facility, and
Implementation of Larger-scale Wastewater Reuse
Under this alternative, the Town would build a new 6-MGD WRF,with the potential to incrementally
expand to 10 MGD, as described in Section 5.1.2.1.Additionally, the Town would build a customer base
to support wastewater reuse of effluent.The Town has a limited reuse program and currently provides a
small amount of reuse water to a single golf course; however, demand is seasonal. Based on analysis of
LCWRF flow records, the average flow provided to the golf course over the period 2015—2018 was
11.4 MG per year, spread over a 7-or 8-month period each year.This is a functional equivalent of
0.05 MGD while operating.To evaluate this alternative, the Neuse 2 WRF site alternative was used
because the Town owns the land.
For large-scale reuse to be feasible and practical to the Town, available land for irrigation (such as golf
courses) or large industrial users would need to be available within a reasonable distance of the WRF
and have year-round demands. Based on an initial review of potential effluent reuse sites, two
additional golf courses were identified within a reasonable distance from the WRF. Using the
assumption that those golf courses would require a similar amount of irrigation water as the existing
reuse customer, the total expected to be used for irrigation would be 0.15 MGD of seasonal demand.
The largest industrial users in Clayton's ETJ are in the ECIA.The Town reached out to the two largest
pharmaceutical manufacturers to assess their potential as reuse customers. Each facility has
environmental sustainability programs in place to conserve water and energy, as listed in Table 5-10.
Under these programs, each facility's water cycle conserves and reuses water where possible. As a
5-27

SECTION 5—ALTERNATIVES ANALYSIS
result, the amount of water purchased is minimized and leaves little opportunity for additional outside
purchase of reuse water.
Table 5-10.Water Conservation Programs of East Clayton Industrial Area Facilities
Novo Nordisk Practicesa• Grifols Practicesb
Capture of RO reject water and HVAC condensate for reuse Replacement of RO units with units that generate much less
in cooling towers reject
Installation of efficient fixtures,including ultra-low-flow Capture of RO reject water,blowdown water,final rinse
toilets(1.0 gallon per flush)and waterless urinals water from clean-in-place systems,and air conditioning
condensate for reuse in cooling towers
Use of closed-loop cooling systems to reduce water Upgrade of a vacuum pump with reservoir vessel to eliminate
demands continuous run,saving"1.6 MGD per year
Use of steam systems with 100%condensate on dirty Use of water meters and inspections to detect leaks or
stream return malfunctions and repair quickly
Use of heat exchangers on high-temperature processes to Increase of time between water use for injection system
limit cooling demands and reduce evaporate losses sanitization cycles,and decrease of cycle time to save water
Use of water meters and inspections to detect leaks or Use of native vegetation to reduce irrigation demands
malfunctions and repair quickly
Use of native vegetation to reduce irrigation demands -
a Kuntz,pers.comm.,2020
b Grifols,pers.comm.,2020
Notes:
=approximately
HVAC=heating,ventilation,and air conditioning
RO=reverse osmosis
5.1.6.1 Design Criteria
The new WRF under this alternative is subject to the same flow and load characteristics detailed in
Section 5.1.2.1.Treatment system design criteria detailed in Tables 5-3 and 5-4 remain unchanged in
this alternative.
5.1.6.2 Environmental Considerations
An increase in discharge to the Neuse River would be avoided. Other, mostly temporary impacts would
occur with construction of linear infrastructure, including to the reuse locations.This alternative, if
feasible, could also lower potable water demand or groundwater usage by the reuse customers, and this
would be beneficial to the environment. Environmental impacts of this alternative are less than the
Preferred Alternative, as this alternative would eliminate a surface water discharge.
5.1.6.3 Cost Estimate
As this alternative is not considered to be feasible,the estimated capital cost and total present worth of
this option have not been calculated.
5.1.6.4 Acceptance or Rejection
With the sustainability programs already in place, limited potential exists for the large-scale reuse of
wastewater by industrial users in the ECIA. Other irrigation customers only generate seasonal demands
and likely total approximately 0.15 MGD. Given the limited nature of potential industrial and golf course
5-28

SECTION 5—ALTERNATIVES ANALYSIS
irrigation demand, development of a reuse system that could eliminate the need for a treated surface
water discharge from the WRF is not feasible. Large-scale wastewater reuse is, therefore, not a viable
alternative to expanding wastewater capacity.This alternative was dismissed from further
consideration.
5.1.7 Alternative 7: Construction of New Water Reclamation Facility—
Alternative Secondary Treatment Process
This alternative evaluates replacing the biological phosphorus removal process for the new 6-MGD WRF
with a four-stage BNR process with metal salt addition for phosphorus removal.The remainder of the
treatment processes are unchanged from those described in Section 5.1.2.1.This alternative includes
conveyance system work to connect existing pump stations and sewer infrastructure to the new WRF,
including conversion of the LCWRF to a pump station, as described in Section 5.1.2.1.
5.1.7.1 Design Criteria
The new WRF under this alternative is subject to the same flow and load characteristics detailed in
Section 5.1.2.1. Under this alternative, chemical phosphorus removal using a four-stage BNR was
selected as the basis for secondary treatment. Under this alternative, the treatment process could rely
heavily on metal salts to precipitate phosphorus to facilitate removal during secondary treatment.The
remaining treatment system design criteria detailed in Tables 5-3 and 5-4 remain unchanged.Table 5-11
provides the design criteria for the secondary treatment system.
Table 5-11.Secondary Treatment System Design Criteria
Component Value
Bioreactors
Process Four-stage Bardenpho
No.of Basins 3
Basin Volume,MG(each) 1.95
No.of Zones 5
Anoxic Zone Volume,MG 0.19
Swing Zone Volume,MG 0.08
Aerobic Zone Volume, MG 1.40
Postanoxic Zone Volume,MG 0.19
Postaerobic Zone Volume,MG 0.09
No.of Diffuser Grids 5
Average Day MLSS(all units),mgTSS/L 2,000
MM MLSS(all units),mgTSS/L 3,500
Diffuser Type Membrane discs
Nitrified Recycle Pumps
Type Propeller pumps with VFD
No.of Pumps(duty and standby) 3 and 1
Surface Wasting Pumps(biofoam removal pumps)
5-29

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-11.Secondary Treatment System Design Criteria
Component Value
Type Horizontal centrifugal non-nonclog with VFD
No.of Pumps(duty and standby) 3 and 1
Metal Salt Feed and Storage
Type Ferric chloride
Solution Strength 38%
Type of Feed Pumps Peristaltic
No.of Feed Pumps(duty and standby) 3 and 1
No.of Storage Tanks 1
Storage Tank Material FRP
Storage Days(Average Flow) 36
Minimum Storage Tank Volume,gallons 5,600
5.1.7.2 Water and Energy Conservation
This alternative will also incorporate moderate water and energy conservation measures by using
treated effluent for process washdown water and VFDs for rotating equipment, with these conversation
measures being similar to the Preferred Alternative.
5.1.7.3 Environmental Considerations
Environmental impacts of this alternative are expected to be similar as those described for the Preferred
Alternative, Section 5.1.2.1., although there is an increased impact from the additional hauling and
applying chemicals for phosphorous reduction under this option.
5.1.7.4 Cost Estimate
The estimated total capital cost of Alterative 7 is$116,538,000 This cost includes 10 percent contingency
applied to the construction costs and all estimated administrative costs for the project.The following
project components are included in this estimate:
• Conversion of LCWRF to a pump station
• New and upgrades to transmission mains to convey flow to the Neuse 2 Pump Station site
• Nitrogen credit purchase
• The estimated total present worth cost of the new WRF with a four-stage BNR and chemical
phosphorus removal is$152,238,474.
5.1.7.5 Acceptance or Rejection
Alternative 7 received a score of 4.04, the third highest nonfinancial score of the six feasible
alternatives.This alternative assumed construction of a new WRF at the Neuse 2 Pump Station site,
which is the preferred site alternative.This alternative differs from the Preferred Alternative by
replacing biological phosphorous removal with metal salt addition for chemical phosphorus removal.
The score of 4.0 is slightly lower than the Preferred Alternative's score of 4.14. Refer to Appendix G for
details on the scoring of each alternative in the nonfinancial evaluation.
5-30

SECTION 5-ALTERNATIVES ANALYSIS
This alternative received a high score under the following categories:
• Resiliency from climate impacts
• Increase the Town's control over the cost of treatment
• Adaptability and phasing
Alternative 7, construction of a new 6-MGD WRF using four-stage BNR with chemical phosphorus
removal, provides similar long-term benefit to the Town as the Preferred Alternative.
This alternative will also incorporate moderate water and energy conservation measures by using
treated effluent for process washdown water and VFDs for rotating equipment.This alternative results
in similar energy and water conservation as the Preferred Alternative.
This alternative is feasible and would produce the same quality of effluent as the Preferred Alternative.
However, it is not recommended, as chemicals used for phosphorus removal have the potential to vary
in price, leading to uncertainty of operational cost.The slightly higher capital cost of biological
phosphorous removal is offset by these considerations.
In addition, there is an environmental benefit to biological phosphorous removal when compared to
chemical phosphorous removal,given the increased chemical use and delivery truck traffic associated
with chemical phosphorous removal.
5.1.8 Alternative 8: Construction of New Water Reclamation Facility—
Alternative Biosolids Treatment Strategy
This alternative evaluates use of a physical-chemical thermal hydrolysis process (Lystek THP®)to
produce Class A biosolids liquid per the 503 regulations (EPA, 2018) at 16.5 percent solids content.
Under this alternative, the Town would contract Lystek for management and disposal of biosolids at the
new WRF.This solids treatment process employs the same thickening and dewatering equipment as the
Preferred Alternative (Alternative 2a) and adds Lystek THP reactors to produce Class A biosolids capable
of being sold as biosolids fertilizer.The primary benefit of this alternative is the contracted management
of biosolids with Lystek, and the potential for significantly reduced disposal costs (approximately
20 percent of composting costs) believed possible with this approach.This process produces a more
concentrated product; therefore, the 30-day solids storage and aeration equipment are reduced in size
relative to the Preferred Alternative.The remainder of the treatment processes are unchanged from
those described in Section 5.1.2.1.
This alternative includes conveyance system work to connect existing pump stations and sewer
infrastructure to the new WRF, including conversion of the LCWRF to a pump station, as described in
Section 5.1.2.1.
5.1.8.1 Design Criteria
The new WRF under this alternative is subject to the same flow and load characteristics detailed in
Section 5.1.2.1. Under this alternative,the 30-day solids storage and aeration equipment are reduced in
size, and Lystek THP reactors are added.The aerated sludge holding tanks would be used to store the
dewatered sludge after it is processed by the Lystek THP.The remaining treatment system design
criteria detailed in Tables 5-3 and 5-4 remain unchanged.Table 5-12 provides the design criteria for each
treatment system in the solids process.
5-31

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-12.Alternative Solids Treatment System Design Criteria
Component Value
Aerated Sludge Holding
Average Retention Time,days 30
No.of Tanks 2
Volume,gallons 200,000
Mixing and Aeration Method Coarse bubble diffuser
Average Air Demand,scfm 700
Lystek THP Reactors
No.of Units(duty and standby) 1 and 0
Target Thickened Solids Concentration,%TSS 13-16%
Processing Rate(Total),dry tons per hour 1
5.1.8.2 Water and Energy Conservation
This alternative will also incorporate moderate water and energy conservation measures by using
treated effluent for process washdown water and VFDs for rotating equipment,with these conversation
measures being similar to the Preferred Alternative.
5.1.8.3 Environmental Considerations
Environmental impacts of this alternative are expected to be the same as those described in the
Preferred Alternative.
5.1.8.4 Cost Estimate
The estimated total capital cost of Alterative 8 is$123,400,000.This cost includes 10 percent
contingency applied to the construction costs and all estimated administrative costs for the project.This
cost includes 6-MGD treatment capacity, as described in Section 5.1.2.1.The cost was estimated by
replacing the cost for aerated holding from the cost presented in Section 5.1.2.1 and incorporating the
cost for the Lystek THP.
The estimated total present worth cost of the new WRF with a Class A biosolids treatment is
$155,869,749.
5.1.8.5 Acceptance or Rejection
Alternative 8 received a score of 4.19, the highest nonfinancial score of the six feasible alternatives.This
alternative assumed construction of a new WRF at the Neuse 2 Pump Station site,which is the preferred
site alternative.This alternative differs from the Preferred Alternative by adding a physical-chemical
thermal hydrolysis process to the residuals management approach to produce Class A biosolids.The
score of 4.2 is slightly higher than the Preferred Alternative's score of 4.1. Refer to Appendix G for
details on the scoring of each alternative in the nonfinancial evaluation.
This alternative received a high score under the following categories:
• Resiliency from climate impacts
• Increase the Town's control over the cost of treatment
• Adaptability and phasing
5-32

SECTION 5-ALTERNATIVES ANALYSIS
Alternative 8, construction of a new 6-MGD WRF with Class A biosolids, provides similar long-term
benefit to the Town as the Preferred Alternative.
This alternative will also incorporate moderate water and energy conservation measures by using
treated effluent for process washdown water and VFDs for rotating equipment.This alternative results
in similar energy and water conservation as the Preferred Alternative.
This alternative is a feasible option; however, it is not preferred over the Preferred Alternative, primarily
because it has a slightly higher initial cost, as an additional unit process is added.The residuals
management approach of the Preferred Alternative would allow addition of this type of Class A biosolids
process to be added in the future if desired by the Town.
5.1.9 Alternative 9: Combination of Alternatives
Combinations of alternatives to meet the timing of wastewater capacity needs while also meeting the
project purpose have also been considered. One such alternative is to continue operation of the LCWRF
at its current capacity and construct a smaller plant at a new site.This alternative would require the
construction of a 4-MGD WRF at a second site. While this would have a lower capital cost than a new
6-MGD facility, rehabilitation of aging equipment at the LCWRF would still require investment to
maintain operational functionality of 2 MGD. Operational cost efficiencies would also be lost if two
facilities remained in operation.This combination does not yield significant cost-savings for the Town
and was not considered further.
A further combination of alternatives could be to land apply effluent during the dry season and revert to
NPDES discharge via the LCWRF outfall during the wet season. As noted in Section 5.1.5, a large area
would be required for land application, and the cost of that land and the associated infrastructure is
very high. In addition, because the WRF would be required to treat to a high enough level for a surface
water discharge,there would be no cost-savings related to the reduced effluent quality associated with
land application. As such,this combination of alternatives provides no benefit over the other options
and was not considered further.
Similarly, a combination of land application and large-scale reuse would be no more feasible than the
two options independently.These combinations of alternatives were eliminated.
5.1.10 Alternative 10: Decentralized System
The Town's wastewater treatment strategy is to collect wastewater at centralized points and transmit it
to LCWRF and regional partners for treatment. Given the Town's approach for centralized collection and
treatment, it would not be efficient or effective to transition to a decentralized approach. Based on
these factors, development of a decentralized system is not considered a viable or feasible alternative
for the Town's WRF expansion project. Construction of a new 6-MGD WRF at the Neuse 2 Pump Station
site is required to meet the purpose and need of the project:to reliably meet the Town's projected
increases in customer demand for wastewater capacity.
The decentralized system alternative was removed from the evaluation, and present worth was not
considered.
5.1.11 Alternative 11: Optimum Operation of Existing Facilities
This evaluation also considered whether optimizing existing facility operation would be a viable
approach for meeting the Town's growing demand and more stringent Neuse River discharge limits.
While optimization of operations is an important consideration, optimizing operation of the existing
LCWRF will not meet the Town's growth needs or comply with the more stringent Neuse River discharge
limits.The LCWRF permitted treatment capacity is 2.5 MGD; however, the actual treatment capacity is
approximately 2 MGD. Optimization beyond the current capacity limits would require system upgrades
5-33

SECTION 5—ALTERNATIVES ANALYSIS
beyond the intended scope of this alternative. In addition, normal maintenance at this facility is
becoming costly, and this alternative requires investment to replace or rehabilitate existing
infrastructure at the LCWRF.
Based on these factors, optimum operation of existing facilities is not considered a viable or feasible
alternative for the Town's WRF expansion project. Construction of a new 6-MGD WRF at the Neuse 2
Pump Station site is required to meet the purpose and need of the project: to reliably meet the Town's
projected increases in customer demand for wastewater capacity.
The optimum operation of the existing facility was removed from the evaluation, and present worth was
not considered.
5.1.12 Supporting Project Infrastructure
Selection of the Neuse 2 Pump Station site for a new 6-MGD WRF led to consideration of additional project
infrastructure, including site access, an upgrade to the current LCWRF outfall structure, and transmission
mains to convey flow to the new WRF.Table 5-13 includes an overview of the supporting project
infrastructure.This section is included to present a comprehensive discussion of the need to meet the Town's
wastewater capacity needs.These project components are also included in the environmental discussion,
Section 7.
Table 5-13.Supporting Project InfrastrUcture
Infrastructure Function Features
Provide construction-related access to the
Access Road Neuse 2 Pump Station site. Construction-grade gravel road of—4,000 LF
Support an increase of permitted discharge Splitter box
Outfall Structure into the Neuse River.Environmental impacts
minimized by installing a parallel outfall Parallel outfall pipe and structure at the
structure at the current LCWRF outfall location. existing LCWRF outfall
Convey flows currently going to the LCWRF by —16,500 LF; majority of alignment along
installation of a pump station at the LCWRF current LCWRF outfall pipe easement
LC Pump Station and p p
LC Transmission Main and a new LC Transmission Main. 24-inch-diameter force main with odor control
Environmental impacts minimized by use of
LCWRF outfall pipe easement where feasible. 36-inch to 48-inch-diameter gravity line
Notes:
ROW=right-of-way
5.1.12.1 Site Access
An alternatives evaluation was performed to determine the most suitable access to the selected
Neuse 2 Pump Station site. Four access road alternatives were considered to assess environmental and
cost considerations.
Descriptions
Current access to the Neuse 2 Pump Station site is from Atwood Drive in the Ashcroft subdivision.This
access and three other options were considered, as shown on Figure 5-4 (WithersRavenel, 2020b):
1. Atwood Drive Access:The current gravel access road from Atwood Drive, a neighborhood street
without driveways, to the Neuse 2 Pump Station site would be improved to allow for construction
equipment and truck traffic.
2. Pond Road Access: Construction access of almost 3,400 LF would be constructed parallel to an
existing aerial powerline easement from North O'Neil Street to the existing access road to the
Neuse 2 Pump Station site.
5-34

SECTION 5—ALTERNATIVES ANALYSIS
3. Transmission Easement Access: Construction access would be built from North O'Neil Street to the
existing access road parallel to the existing aerial high-voltage transmission easement for a distance
of approximately 4,000 LF.
4. Northern Connector—North Access: Construction access would be built from North O'Neil Street to
the existing access road for a distance of approximately 4,000 LF and would follow the alignment of
the planned Northern Connector.
5. Northern Connector—South Access: Construction access would be built from NC Highway 42
(NC 42)to the existing access road, crossing Sam's Branch. Of the approximately 8,800 LF of access,
approximately 1,900 LF consists of the existing Glen Laurel Road ROW, which provides access to the
Caterpillar facility.
Environmental and Cost Considerations
Construction access was evaluated based on environmental and cost considerations.Table 5-14
summarizes potential environmental impacts, with a focus on aquatic impacts identified using field and
desktop surveys(WithersRavenel, 2020b). Potential perennial stream and stream buffer impacts and
associated aquatic habitat impacts eliminated the two Northern Connector alignments from
consideration.These two options would also be the costliest. From O'Neil Street,the Northern
Connector alignment crosses the junction of two perennial streams. From NC 42,the Northern
Connector alignment crosses Sam's Branch. Due to the steep grade in the area, a bridge could be
necessary to limit stream impacts.
Table 5-14. Potential Environmental Impacts
Access Alignment Forests Wetlands Stream Crossings Riparian Buffers a
Atwood Drive No 0 0 0
Pond Road No 2 2 1
Transmission Easement No 0 0 0
Northern Connector-North Yes 2 3 2
Northern Connector-South Yes 1 3 3
a Final riparian buffer determinations have not been made.
Conclusions
The selected alternative for the access road is the transmission easement.This route has the lowest
potential for environmental impacts and limits noise and construction traffic impacts to the Ashcroft
neighborhood along Atwood Drive, the current Neuse 2 Pump Station site access route.
5-35

lr" f
•r '. fios•^. . ! �v —�' ..,... - GRAPHIC SCALE
. F: '+' . ?—� 0 600 1200
�O y
�.._ . OPT - 1 inch = 1200 ft.
i it
V *4 . .,... ,. 1 ...„0.,. ..1... . 41:::. '...P, -3.-, ..p_ 7
4 i - . \
•i .
- Y x.
.y.,g - -' ' .
Ir
s'- PROPOSED CLAYTON
yr 4 , �:� ` :uFty r:it;-.: WRF SITE /
'rat = '' ;�9�L /
voiy.
•P;My .i , . ' C:..r. , ...;'S.- 0,% ai tirlt
w.r� 1 & }' S
•*G' •3 Fri^* m. Fw .,. =i.. y `,' ••72N
ice
0
I, J
t W
F
c,
t'
$ LEGEND:
3 ATWOOD DRIVE ACCESS ALIGNMENT
e r'•
g POND ROAD ACCESS ALIGNMENT
N
TRANSMISSION EASEMENT ACCESS ALIGNMENT
i NORTHERN CONNECTOR-NORTH ACCESS ALIGNMENT
2 PA
NORTHERN CONNECTOR-SOUTH ACCESS ALIGNMENT NcNWy az
CLAYTON WRF FIGURE 5-4 Ai WithersRavenel
POTENTIAL ACCESS ALIGNMENTS
x OVERALL PROJECT AERIAL EXHIBIT (2017) A.
Eng;neers l Planners l Surveyors
CLAYTON JOHNSTON COUNTY NORTH CAROLINA

SECTION 5-ALTERNATIVES ANALYSIS
5.1.12.2 Discharge Outfall
To discharge 6 MGD into the Neuse River, additional capacity is needed at the outfall structure.
Descriptions
Two options are feasible: (1) Replacement of the current pipe and structure with larger capacity, and
(2) installation of a similar parallel outfall pipe and structure. Operationally, it is easier to construct a
parallel discharge while the current one is in operation, so this approach was selected.
The proposed adjacent parallel outfall will mirror the existing end-of-pipe outfall for operational efficiency,
and a splitter box will be used to evenly split flows from the WRF.The final segment of the outfall will be
epoxy-coated welded steel and will project into the river as far as the existing pipe (approximately 10 feet).
Environmental Considerations
Construction of the outfall will be performed using cofferdams to create a dry area for access from the
riverbank. Construction is estimated to take approximately 3 weeks, depending on weather conditions,
and will be limited to the extent feasible. Cofferdams will limit turbidity during construction, although
turbidity will be temporarily elevated during cofferdam installation and removal. Riprap will be installed
on the disturbed riverbank for protection after construction is complete.
Conclusions
Expansion of the LCWRF outfall using a parallel second structure better supports operations during
construction. Methods to limit environmental impacts during construction will be used. Using the
current outfall construction requires modification of the LCWRF's current NPDES permit.
5.1.12.3 Little Creek Pump Station and Transmission Main
Description
A new 3-MGD (average day) pump station will be built at the LCWRF to send flows to the proposed WRF.
This pump station with odor control would be located next to the existing LCWRF IPS. Headworks
screening and grit removal will be part of the pump station. Initially, pumps with 3 MGD of total capacity
(average day)will be installed to align with demand projections for the planned 6-MGD WRF.The pump
station is planned for a peak flow of 7.5 MGD and a firm capacity of 8.6 MGD and will include backup
pumping and emergency power generation (WithersRavenel, 2020c). As demands grow in the future,
the pump station will be expanded, including the addition of pumps to the wet well.
LC Transmission Main options to cross U.S. Highway 70 Business (U.S. 70 Business)were considered by
WithersRavenel, and the selected option is shown on Figure 5-5.This route maximizes use of
Town-owned easement by routing down Durham Street; crossing under U.S. 70 Business, East Main
Street, and a rail line; and then follows the existing utility easement for the current LCWRF outfall line to
the discharge at the Neuse River(WithersRavenel, 2020c).
Environmental Considerations
This approximately 16,500-LF alignment avoids the Downtown Historic District and Maplewood
Cemetery and maximizes use of approximately 14,000 LF of Town-owned easements along Sam's
Branch. Use of these easements also minimizes environmental impacts because the easements have
been previously disturbed and are currently maintained. Multiple perennial and intermittent streams
and five wetlands would be crossed.
Conclusions
The pump station and new transmission main are needed because the current transmission main is a 16-inch-
to 24-inch-diameter line that is not sized to carry flows associated with expanded treatment capacity.The new
transmission main would be sized to handle future flows and would include a 24-inch-diameter force main
with odor control and 36-inch-to 48-inch-diameter gravity line (WithersRavenel, 2020c).
5-37

Q N/ ' __, GRAPHIC SCALE
W izta
( D 0 600 1200
N \ PROPOSED CLAYTON
g WRF SITE 4, ih\
ro CI 1 inch = 1200 ft.
\ _
cH 0.
D i . Nil
-Ni v. f A.
( L c-)7(
‘ \,.k\t, 47-Pfrooc,04,
O . 0 e 10 ) (ili �FG
LITTLE CREEK TRANSMISSION O � � 0�9�!%n
1 :-?,x44, O MAIN REVIEW AREA ` r J
1
P.
Aig, 6
CD O O
? Le..„_,. °
o Q
, ,,,if:r 1
/---\-1 Z
00011
0 t
KANppLPH f
cc
i Iw
V.
iv ¢
_1?7—)
% \ z r----f
rti,„
g I Q
O I
i 2 g 7.t
l'—' o , i igIi
( 0"113,
— ' ' ca...-°
s c LITTLE CREEK TRANSMISSION ma O
MAIN REVIEW AREA J \Y _-) ---‘' .' -k'hIlii.am '
-. ..li C::›
C-1) agy---isA
8 ` Yr
FIL-WV1 a�
k 1 q 4---
1 ).___..------- ------i- Q. 1. ST�9oy, /
3 s< kw
.: C:l .6,
CD
g 1 0 C�—
s EXISTING LCWRF , URyAMst
t. , FACILITIES 9FFT
4"-N 0
--A
8 //-7?)-
( l n /, 1. AD
P51gnef sae �� WithersRavenel
ss CLAYTON WRF - LITTLE CREEK TRANSMISSION MAIN FIGURE 5-5 - AERIAL WITH TOPO (2017) 1 No
o�w�By oar
.R ouwnmo
Checked By lob No. Engineers I Planners I Surveyors
i MO 02190247.00 CLAYTON JOHNSTON COUNTY NORTH CAROLINA

SECTION 5-ALTERNATIVES ANALYSIS
5.1.12.4 East Clayton Industrial Area Pump Station Improvements and Transmission Main
Description
This element of the Town's overall program is part of a separate funding and permitting process through
the federal Economic Development Administration (EDA). A description of this transmission main is
included because it is part of the Town's master plan for serving its customers with additional
wastewater treatment capacity. A pump station capacity increase would be necessary to accommodate
projected flow increases to the Neuse 2 Pump Station site and the County.The alignment shown on
Figure 5-6 provides a route for flows to the proposed WRF while keeping options to send flow to either
the County or the City, although it is anticipated that the County will stop accepting this higher-strength
wastewater in 2022.
5.2 Present Worth Analysis
5.2.1 Methodology
5.2.1.1 Opinion of Capital Cost
The CH2M Conceptual and Parametric Engineering System (CPES) cost estimating tool, supplemented
with vendor quotes where appropriate, was used to develop capital cost opinions for the alternatives.
Opinions of probable cost generated from CPES are considered to be consistent with Class 5 estimates
as defined by ACCE International (AACE). As detailed engineering design has not been done, the final
opinion of probable cost for any project will depend on the following factors:
• Market conditions
• Site conditions
• Final project scope
• Schedule
• Other variable factors
As a result, final project costs will vary from the estimates presented here.
Capital costs for project components related to conveyance system and pump station modification and
expansion were developed from the Little Creek Pump Station and Discharge Technical Memorandum
(WithersRavenel, 2020d) and the East Clayton Industrial Area Transmission Improvements Preliminary
Engineering Report(Town, 2020f).
The Town does not intend to demolish unused structures at the LCWRF site within this scope of work;
therefore, costs associated with demolishing and regrading are not included in this estimate.
Construction-related markups were applied to the capital cost estimates and reflect typical contractor
overhead, profit, and mobilization costs.Table 5-15 presents construction-related markups applied to
the opinion of capital costs.
Administrative costs are the nonconstruction costs associated with a project and were estimated as a
percent of the construction costs. Markups for administrative costs, such as engineering, permitting,
services during construction, and startup, are presented in Table 5-15.The cost of purchasing additional
nitrogen credits in the Neuse River basin is included in the administrative costs for each project.The
Town currently owns the equivalent of 3.5 MGD in nitrogen credits and would purchase additional
credits to bring the Town's treatment capacity to 6 MGD.The current cost of nitrogen in the Neuse River
basin is $363.42 per pound of nitrogen, which is equivalent to $3,429,617 per MGD.
5-40

..- N- ajy,
t,... n.' r ,h jry = «� b ,.. 'yam „,ax s''✓ 1.1 ° a** c 'hr�
.1- �' '. -:,r� r `'' t . d' �+-Y ` f '� ,o - iy• 4 - s �1 / t
" a . ;.
-4 ,,.0 ( ''.
'
. .,„_ , __., 4.Z r d� .§/firA �4 r^ -_ 4
Propmaosed WFceirity `
rtat4
,,
..
' r z . ,. Re c latio,tern a "R"✓%n,,
' e`.at ve° .t Ca :� N ° F w� ry r d tdi x' ,, { •
p f "-'s`* � ','We'- 4+�`Tt` J ' ,:.,,, •5 as• ,. .eC�� .♦.
•
s! a; Greek ♦i ,. r l r
. a ':'; � 1 fl`} ; "�, r,',�' ,'` ♦ _ s 'k�." fig;_
g >
•
P �.
o
xy!� • m��,rar drw
tip
• O
a • _ � :.44:p -. .?" -.. -'44:::.'..-- '''.,k,• •,;:'.' '.'.1',-; ,
ytjv yg�t. t _
C_-':c. 3: '..-. + - :?i .�', ., ,_• ^ t�\ ' � n I d4
42 "
42 Current Little,CreekiZ` �
Reclamation n�
.;. . -FCIPAransmission iM , c- r :•,
/o>
♦
•
i
•
Legend
•
O-N -Plant Footprint
- .' •■■■Proposed Force Main
♦ of its ■ 1,9
Proposed Gravity Main
♦♦ Access Road
r66,' Parcel Limits
R. Steven.Biggs Regional -Stream or River
Pretreatment Facility
m�
0 3,900 7,800 N Source:NC Orthoimagery ProgramFigure 5-J67)
C112/1111,* I I I Linear Project Infrastructure
5M Feet Water Reclamation Facility Expansion
Town of Clayton, NC
The treatment systems depicted on this conceptual layout represent conservative footprints,and may be revised as the design develops.

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-15.Construction Cost Markups
Value
Component (%)
Construction-related Markups a
Contractor Markups b
Overhead 12
Profit 10
Mobilization,Bonds,and Insurance 3
Contingency 10
Administrative Costs d
Engineering 8
Services During Construction 8
Commissioning and Startup 2
Permitting 2
a Applied to estimated construction cost.
bApplied to construction cost,including construction-related markups.
Applied to total construction estimate,including markups.
dApplied to total construction,including markups and contingency.
5.2.1.2 Opinion of Lifecycle Costs
Opinions of lifecycle costs were developed following State guidelines (NCDEQ, 2015). Process modeling
results were incorporated into the CPES tool to develop annual operating costs associated with the
following items:
• Chemicals
• Energy
• Annual O&M
• Solids disposal
LCWRF rehabilitation costs developed during the AIA grant project were incorporated in the O&M costs
for the LCWRF expansion alternative (CH2M, 2019a). Labor costs were estimated assuming the
expanded and new treatment facilities would require 10 full-time operators, at an annual salary of
$66,500(including benefits).Table 5-16 summarizes the components of the annual O&M cost.
Intermittent maintenance costs were developed for major system components, such as pumps and
blowers, that would undergo refurbishment during the planning period. A 5-year refurbishment interval
was used for pumps larger than 10 HP at a cost equal to 25 percent of the capital cost for a new pump.
For pumps smaller than 10 HP, no refurbishment interval was used; instead, it was assumed small
pumps would be replaced every 5 years. A 10-year refurbishment interval was used for blowers at a cost
equal to 1 percent of the capital cost for a new blower.
Replacement costs are based on the capital cost of major equipment components of each treatment
system rather than the total capital cost for a treatment system. Costs were incorporated for equipment
that would require replacement within the planning period.
5-42

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-16.Annual Operations and Maintenance Costs
Component Value
Labor Costs
Labor Cost(including benefits),$/yr 655,600
Chemical and Energy Costs
Energy,$/kWh 0.06
40%ferric chloride,$/dry ton 1,067
External carbon costs,$/dry ton 488
Dry polymer,$/lb 1.50
Solids
Landfill,$/wet ton 55
Composting costs,$/wet ton 50
a Assumes 10 employees at an average annual rate of$65,560 for salary and
benefits.
Notes:
$/y=dollar(s)per year
$/kWh=dollar(s)per kilowatt-hour
5.2.2 Results
5.2.2.1 Alternative 2a: Construction of a New Water Reclamation Facility at the Neuse 2 Pump
Station Site
The estimated total present worth of the new 6-MGD WRF is$154,487,401.The following project
components are included in this estimate:
• Conversion of LCWRF to a pump station
• New and upgraded transmission mains to convey flow to the Neuse 2 Pump Station site
• Nitrogen credit purchase
Table 5-17 is a summary of the construction costs for this alternative. Costs are expressed in 2020
dollars. A 10 percent factor is applied to estimated construction costs for contingencies.
Table 5-17. Estimated Construction Cost—New Water Reclamation Facility at the Neuse 2 Pump Station Site
Unit Cost Total Costa
Component ($) Unit Quantity ($)
IPS 2,361,000 LS 1 2,361,000
Headworks(Screening and Grit Removal) 5,753,000 LS 1 5,753,000
Flow Equalization(Tank and Pump Station) 4,268,000 LS 1 4,268,000
Five-Stage BNR 12,768,000 LS 1 12,768,000
Secondary Clarifiers 3,744,000 LS 1 3,744,000
RAS and WAS Pump Station 3,165,000 LS 1 3,165,000
5-43

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-17. Estimated Construction Cost—New Water Reclamation Facility at the Neuse 2 Pump Station Site
Unit Cost Total Costa
Component ($) Unit Quantity ($)
Blowers 4,589,000 LS 1 4,589,000
Cloth Filters 3,974,000 LS 1 3,974,000
Disinfection(UV) 3,170,000 LS 1 3,170,000
Solids Treatment(RDT,Aerated Holding Tank,Screw
Press) 8,370,000 LS 1 8,370,000
Chemical Feed and Storage Facilities 588,000 LS 1 588,000
Cascade Re-aeration 367,000 LS 1 367,000
Site Work 12,451,000 LS 1 12,451,000
Electrical 5,109,000 LS 1 5,109,000
Access Road 370 LF 3,950 1,462,000
LC Pump Station 4,338,000 LS 1 4,338,000
LC Force Main to Neuse 2 Pump Station Site
(24-inch-diameter PVC) 238 LF 4,310 1,026,000
LC Gravity Main to Neuse 2 Pump Station Site
(36-inch-diameter DI pipe) 443 LF 4,420 1,959,000
LC Gravity Main to Neuse 2 Pump Station Site
(42-inch-diameter DI pipe) 433 LF 5,030 2,179,000
LC Gravity Main to Neuse 2 Pump Station Site
(48-inch-diameter DI pipe) 513 LF 2,380 1,221,000
Administrative and Maintenance Facility 2,373,000 LS 1 2,373,000
Total Construction Cost: 85,235,000
Construction Contingency Cost: 8,524,000
Project Administration Cost b,c: 26,439,000
Total Capital Cost: 120,198,000
a 15%markup is applied to component cost to address cost estimate uncertainty at Conceptual Design Phase.This markup is
in addition to the construction cost markups.
b Project administration includes permitting,engineering,services during construction,commissioning,and startup.
c Includes$8,938,678 for nitrogen credit purchase.
Notes:
LS=lump sum
Table 5-18 provides a summary of the total present worth cost.
5-44

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-18. Present Worth Cost Summary—New Water Reclamation Facility at the Neuse 2 Pump Station Site
Cost Item Total Cost($)
Capital Costs 120,198,000
Replacement Cost Present Worth a-b 7,524,499
O&M Costs Present Worth—Annual c 25,538,423
O&M Costs Present Worth—Intermittent d 1,226,479
O&M Costs Present Worth—Total 26,764,902
Total Present Worth 154,487,401
a Replacement costs are based on the capital cost of major equipment components for each treatment system presented in
Table 5-17 rather than the total capital cost for a treatment system.
b First year of operation of new plant is 2023.
c Annual O&M cost is over a 17-year period from 2023—2040.
d Intermittent O&M cost is over a 17-year period from 2023—2040.
5.2.2.2 Alternative 2b: Construction of a New Water Reclamation Facility at the East Clayton
Industrial Area Site
The estimated total present worth cost of the new WRF at the ECIA site is$173,317,373.
Table 5-19 is a summary of the construction costs for this alternative. Costs are expressed in
2020 dollars. A 10 percent factor is applied to estimated construction costs for contingencies.This cost
includes 6-MGD treatment capacity as described for Alternative 2a.The cost was estimated by adding
conveyance infrastructure to transmit treated effluent to the Neuse River outfall to the cost estimate.
Table 5-19. Estimated Construction Cost—New Water Reclamation Facility at the East Clayton IndUstrial Area Site
Component Unit Cost($) Unit Quantity Total Cost($)a
IPS 2,361,000 LS 1 2,361,000
Headworks(Screening and Grit Removal) 5,753,000 LS 1 5,753,000
Flow Equalization(Tank and Pump Station) 4,268,000 LS 1 4,268,000
Five-stage BNR 12,768,000 LS 1 12,768,000
Secondary Clarifiers 3,744,000 LS 1 3,744,000
RAS and WAS Pump Station 3,165,000 LS 1 3,165,000
Blowers 4,589,000 LS 1 4,589,000
Cloth Filters 3,974,000 LS 1 3,974,000
Disinfection(UV) 3,170,000 LS 1 3,170,000
Solids Treatment(RDT,Aerated Holding Tank,Screw Press) 8,370,000 LS 1 8,370,000
Chemical Feed and Storage Facilities 588,000 LS 1 588,000
Cascade Re-aeration 367,000 LS 1 367,000
Site Work 13,645,000 LS 1 13,645,000
Electrical 5,109,000 LS 1 5,109,000
5-45

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-19. Estimated Construction Cost—New Water Reclamation Facility at the East Clayton Industrial Area Site
Component Unit Cost($) Unit Quantity Total Cost($)a
LC Pump Station 4,338,000 LS 1 4,338,000
LC Force Main to ECIA Site(24-inch-diameter DI pipe) 311 LF 550 172,000
LC Force Main to ECIA Site(24-inch-diameter PVC) 201 LF 16,350 3,291,000
Neuse 2 Pump Station Upgrade 770,000 LS 1 770,000
Neuse 2 Force Main to ECIA Site(16-inch-diameter PVC) 245 LF 9,915 2,426,000
Neuse 2 Force Main to ECIA Site(16-inch-diameter DI pipe) 271 LF 735 199,000
Neuse 2 Gravity Main to ECIA Site(24-inch-diameter DI pipe) 355 LF 3,725 1,321,000
Outfall Pump Station 2,610,000 LS 1 2,610,000
Outfall Force Main to Neuse River(24-inch-diameter PVC) 233 LF 24,050 5,603,000
Outfall Force Main to Neuse River(24-inch-diameter DI pipe) 343 LF 790 271,000
Administrative and Maintenance Facility 2,373,000 LS 1 2,373,000
Total Construction Cost: 95,245,000
Construction Contingency Cost: 9,525,000
Project Administration Cost b'c: 28,319,000
Total Capital Cost: 133,089,000
a 15%markup applied to component cost to address cost estimate uncertainty at Conceptual Design Phase.This markup is in
addition to the construction cost markups.
b Project administration includes permitting,engineering,services during construction,commissioning,and startup.
c Includes$8,938,678 for nitrogen credit purchase.
Table 5-20 provides a summary of the total present worth cost.
Table 5-20. Present Worth Cost Summary—New Water Reclamation Facility at the East Clayton Industrial Area
Site
Cost Item Total Cost($)
Capital Costs 133,089,000
Replacement Cost Present Worth a-b 8,757,577
O&M Costs Present Worth—Annual c 30,244,316
O&M Costs Present Worth—Intermittent d 1,226,479
O&M Costs Present Worth—Total 31,470,795
Total Present Worth 173,317,373
a Replacement costs are based on the capital cost of major equipment components for each treatment system presented in
Table 5-19 rather than the total capital cost for a treatment system.
b First year of operation of new plant is 2023.
c Annual O&M cost is over a 17-year period from 2023—2040.
d Intermittent O&M cost is over a 17-year period from 2023—2040.
5-46

SECTION 5—ALTERNATIVES ANALYSIS
5.2.2.3 Alternative 3: Expansion of Little CreekWater Reclamation Facility, and Continued Use
of Surface Water Discharge
The estimated total present worth of the expanding the LCWRF to 6 MGD is $134,079,561.Table 5-21
provides a summary of the construction costs for this alternative.This estimate assumes existing LCWRF
treatment system structures will be used in the upgraded and expanded process. Costs are expressed in
2020 dollars. A 10 percent factor is applied to estimated construction costs for contingencies.
Table 5-21. Estimated Construction Cost—Expand Little Creek Water Reclamation Facility to 6 MGD
Component Unit Cost($) Unit Quantity Total Cost($)a
IPS 1,341,000 LS 1 1,341,000
Headworks(Screening and Grit Removal) 1,812,000 LS 1 1,812,000
Flow Equalization(Tank and Pump Station) 4,268,000 LS 1 4,268,000
Five-stage BNR 9,818,000 LS 1 9,818,000
BNR Upgrades 2,076,000 LS 1 2,076,000
Secondary Clarifiers 2,660,000 LS 1 2,660,000
RAS and WAS Pump Station 1,888,000 LS 1 1,888,000
Blowers 2,702,000 LS 1 2,702,000
Cloth Filters 3,974,000 LS 1 3,974,000
Disinfection(UV) 1,912,000 LS 1 1,912,000
Solids Treatment(Centrifuge) 2,865,000 LS 1 2,865,000
Chemical Feed and Storage Facilities 237,000 LS 1 237,000
Site Work b 11,827,000 LS 1 11,827,000
Electrical 3,562,000 LS 1 3,562,000
Neuse 2 Pump Station Upgrades 770,000 LS 1 770,000
Neuse 2 Force Main to LCWRF(16-inch-diameter PVC) 245 LF 9,915 2,426,000
Neuse 2 Force Main to LCWRF(16-inch-diameter DI pipe) 271 LF 735 199,000
Neuse 2 Gravity Main to LCWRF(24-inch-diameter DI pipe) 355 LF 3,725 1,321,000
LCWRF Effluent Pump Station Upgrades 2,610,000 LS 1 2,610,000
Outfall Pipe Force Main to Neuse River(24-inch-diameter PVC) 238 LF 4,310 1,026,000
Outfall Pipe Gravity Main to Neuse River(36-inch-diameter DI
pipe) 433 LF 4,420 1,914,000
Outfall Pipe Gravity Main to Neuse River(42-inch-diameter DI
pipe) 513 LF 5,030 2,581,000
Outfall Pipe Gravity Main to Neuse River(48-inch-diameter DI
pipe) 238 LF 2,380 567,000
Administrative and Maintenance Facility 2,373,000 LS 1 2,373,000
Diffused Re-aeration 367,000 LS 1 367,000
5-47

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-21. Estimated Construction Cost—Expand Little Creek Water Reclamation Facility to 6 MGD
Component Unit Cost($) Unit Quantity Total Cost($)a
Total Construction Cost: 67,096,000
Construction Contingency Cost: 6,710,000
Project Administration Cost c'd: 22,687,000
Total Capital Cost: 96,493,000
a 15%markup applied to component cost to address cost estimate uncertainty at Conceptual Design Phase.This markup is in
addition to the construction cost markups.
b Site work estimate includes construction of a flood wall.
c Project administration includes permitting,engineering,services during construction,commissioning,and startup.
d Includes$8,938,678 for nitrogen credit purchase.
Table 5-22 provides a summary of the total present worth cost.
Table 5-22. Present Worth Cost Summary—Expand Little Creek Water Reclamation Facility to 6 MGD
Cost Item Total Cost($)
Capital Costs 96,493,000
Replacement Cost Present Worth a-b 5,223,577
O&M Costs Present Worth—Annual c 30,448,241
O&M Costs Present Worth—Intermittent d 1,914,743
O&M Costs Present Worth—Total 32,362,984
Total Present Worth 134,079,561
a Replacement costs are based on the capital cost of major equipment components for each treatment system presented in
Table 5-21 for the expanded plant rather than the total capital cost for a treatment system.
b First year of operation of the expanded plant is 2023.
c Annual O&M includes 3 years of O&M for the existing LCWRF and 17 years for the expanded plant from 2023—2040.
d Intermittent O&M includes 3 years of O&M for the existing LCWRF and 17 years for the expanded plant from 2023—2040.
5.2.2.4 Alternative 5: Construction of a New Water Reclamation Facility, and Use of Land
Application
The estimated total present worth cost of the new WRF using land application is$225,201,816.This cost
includes 6-MGD treatment capacity, as described for Alternative 2a.The cost was estimated by
eliminating cost of the tertiary treatment system, the supplemental carbon system, and outfall upgrades
presented for Alternative 2a.Table 5-23 provides a summary of the construction costs for this
alternative. Costs are expressed in 2020 dollars. A 10 percent factor is applied to estimated construction
costs for contingencies.
Table 5-23. Estimated Construction Cost—Land Application
Component Unit Cost($) Unit Quantity Total Cost($)a
IPS 2,361,000 LS 1 2,361,000
Headworks(Screening and Grit Removal) 5,753,000 LS 1 5,753,000
5-48

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-23. Estimated Construction Cost—Land Application
Component Unit Cost($) Unit Quantity Total Cost($)a
Flow Equalization(Tank and Pump Station) 4,268,000 LS 1 4,268,000
Five-stage BNR 7,661,000 LS 1 7,661,000
Secondary Clarifiers 3,744,000 LS 1 3,744,000
RAS and WAS Pump Station 3,165,000 LS 1 3,165,000
Blowers 4,589,000 LS 1 4,589,000
Disinfection(UV) 3,170,000 LS 1 3,170,000
Solids Treatment(RDT,Aerated Holding Tank,Screw Press) 8,370,000 LS 1 8,370,000
Chemical Feed and Storage Facilities 588,000 LS 1 588,000
Site Work 17,053,000 LS 1 17,053,000
Electrical 5,109,000 LS 1 5,109,000
Access Road 370 LF 3,950 1,462,000
LC Pump Station 4,338,000 LS 1 4,338,000
LC Force Main to Neuse 2 Pump Station Site(24-inch-
diameter PVC) 238 LF 4,310 1,026,000
LC Gravity Main to Neuse 2 Pump Station Site(36-inch-
diameter DI pipe) 443 LF 4,420 1,959,000
LC Gravity Main to Neuse 2 Pump Station Site(42-inch-
diameter DI pipe) 433 LF 5,030 2,179,000
LC Gravity Main to Neuse 2 Pump Station Site(48-inch-
diameter DI pipe) 513 LF 2,380 1,221,000
Reclaimed Water Storage and Pump Station 4,522,000 LS 1 4,522,000
Transmission Pipe to three Application Sites(24-inch-
diameter concrete-lined DI) 218 LF 132,000 28,737,000
Land Application Site Storage Reservoir and Distribution
Pump Station(total for three sites) 15,244,000 LS 1 15,244,000
Irrigation Pipes(16-inch-diameter PVC)(total for three sites) 113 LF 15,000 1,694,000
Irrigation Sprinklers(total for three sites) 8,855,000 LS 1 8,855,000
Administrative and Maintenance Facility 2,373,000 LS 1 2,373,000
Total Construction Cost: 139,441,000
Construction Contingency Cost: 13,945,000
Project Administration Cost b: 33,414,000
Total Capital Cost: 186,800,000
a 15%markup applied to component cost to address cost estimate uncertainty at Conceptual Design Phase.This markup is in
addition to the construction cost markups.
b Project administration includes permitting,engineering,services during construction,commissioning,and startup.
5-49

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-24 provides a summary of the total present worth cost.
Table 5-24. Present Worth Cost Summary—Land Application
Cost Item Total Cost($)
Capital Costs 186,800,000
Replacement Cost Present Worth a'b 7,866,222
O&M Costs Present Worth—Annual c 29,103,735
O&M Costs Present Worth—Intermittent d 1,431,859
O&M Costs Present Worth—Total 30,535,594
Total Present Worth 225,201,816
a Replacement costs are based on the capital cost of major equipment components for each treatment system presented in
Table 5-23 rather than the total capital cost for a treatment system.
b First year of operation of new plant is 2023.
c Annual O&M cost is over a 17-year period from 2023—2040.
d Intermittent O&M cost is over a 17-year period from 2023—2040.
5.2.2.5 Alternative 7: Construction of New Water Reclamation Facility—Alternative Secondary
Treatment Process
The estimated total present worth cost of the new 6-MGD WRF with a four-stage BNR and chemical
phosphorus removal is$152,238,474.The following project components are included in this estimate:
• Conversion of LCWRF to a pump station
• New and upgraded transmission mains to convey flow to the Neuse 2 Pump Station site
• Upgrades to the ECIA Pump Station
• Nitrogen credit purchase
Table 5-25 is a summary of the construction costs for this alternative. Costs are expressed in
2020 dollars. A 10 percent factor is applied to estimated construction costs for contingencies.
Table 5-25. Estimated Construction Cost—Alternative Secondary Treatment
Component Unit Cost($) Unit Quantity Total Cost($)a
IPS 2,361,000 LS 1 2,361,000
Headworks(Screening and Grit Removal) 5,753,000 LS 1 5,753,000
Flow Equalization(Tank and Pump Station) 4,268,000 LS 1 4,268,000
Four-Stage BNR 11,199,000 LS 1 11,199,000
Secondary Clarifiers 3,744,000 LS 1 3,744,000
RAS and WAS Pump Station 3,165,000 LS 1 3,165,000
Blowers 4,589,000 LS 1 4,589,000
Cloth Filters 3,973,000 LS 1 3,973,000
Disinfection(UV) 3,170,000 LS 1 3,170,000
Solids Treatment(RDT,Aerated Holding Tank,Screw Press) 8,407,000 LS 1 8,407,000
Chemical Feed and Storage Facilities 636,000 LS 1 636,000
5-50

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-25. Estimated Construction Cost—Alternative Secondary Treatment
Component Unit Cost($) Unit Quantity Total Cost($)a
Cascade Re-aeration 367,000 LS 1 367,000
Site Work 11,835,000 LS 1 11,835,000
Electrical 4,761,000 LS 1 4,761,000
Access Road 370 LF 3,950 1,462,000
LC Pump Station 4,338,000 LS 1 4,338,000
LC Force Main to Neuse 2 Pump Station Site(24-inch-diameter PVC) 238 LF 4,310 1,026,000
LC Gravity Main to Neuse 2 Pump Station Site(36-inch-diameter DI
pipe) 443 LF 4,420 1,959,000
LC Gravity Main to Neuse 2 Pump Station Site(42-inch-diameter DI
pipe) 433 LF 5,030 2,179,000
LC Gravity Main to Neuse 2 Pump Station Site(48-inch-diameter DI
pipe) 513 LF 2,380 1,221,000
Administrative and Maintenance Facility 2,373,000 LS 1 2,373,000
Total Construction Cost: 82,786,000
Construction Contingency Cost: 8,279,000
Project Administration Cost b,c: 25,473,000
Total Capital Cost: 116,538,000
a 15%markup applied to component cost to address cost estimate uncertainty at Conceptual Design Phase.This markup is in
addition to the construction cost markups.
b Project administration includes permitting,engineering,services during construction,commissioning,and startup.
c Includes$8,938,678 for nitrogen credit purchase.
Table 5-26 provides a summary of the total present worth cost.
Table 5-26. Present Worth Cost Summary—Alternative Secondary Treatment
Cost Item Total Cost($)
Capital Costs 116,538,000
Replacement Cost Present Worth a'b 7,472,701
O&M Costs Present Worth—Annual c 26,942,638
O&M Costs Present Worth—Intermittent d 1,285,135
O&M Costs Present Worth—Total 28,227,773
Total Present Worth 152,238,474
a Replacement costs are based on the capital cost of major equipment components for each treatment system presented in
Table 5-25 rather than the total capital cost for a treatment system.
b First year of operation of new plant is 2023.
c Annual O&M cost is over a 17-year period from 2023—2040.
d Intermittent O&M cost is over a 17-year period from 2023—2040.
5-51

SECTION 5—ALTERNATIVES ANALYSIS
5.2.2.6 Alternative 8: Construction of New Water Reclamation Facility—Alternative Biosolids
Strategy
The estimated total present worth cost of the new WRF with a Class A biosolids treatment is
$155,869,749.This cost includes 6-MGD treatment capacity, as described in Alternative 2a.The cost was
estimated replacing the cost for aerated holding presented for Alternative 2a with the equivalent
aerated holding cost for this alternative.Table 5-27 is a summary of the construction costs for this
alternative. Costs are expressed in 2020 dollars. A 10 percent factor is applied to estimated construction
costs for contingencies.The cost for solids treatment may increase if additional storage is required due
to the seasonality of land application of Class A biosolids.
Table 5-27. Estimated Construction Cost—Alternative Biosolids Strategy
Component Unit Cost($) Unit Quantity Total Cost($)a
IPS 2,361,000 LS 1 2,361,000
Headworks(Screening and Grit Removal) 5,753,000 LS 1 5,753,000
Flow Equalization(Tank and Pump Station) 4,268,000 LS 1 4,268,000
Five-Stage BNR 11,199,000 LS 1 11,199,000
Secondary Clarifiers 3,744,000 LS 1 3,744,000
RAS and WAS Pump Station 3,165,000 LS 1 3,165,000
Blowers 4,589,000 LS 1 4,589,000
Cloth Filters 3,973,000 LS 1 3,973,000
Disinfection(UV) 3,170,000 LS 1 3,170,000
Solids Treatment(RDT,Aerated Holding Tank,
LystekTHP) 8,407,000 LS 1 8,407,000
Chemical Feed and Storage Facilities 636,000 LS 1 636,000
Cascade Re-aeration 367,000 LS 1 367,000
Site Work 11,835,000 LS 1 11,835,000
Electrical 4,761,000 LS 1 4,761,000
Access Road 370 LF 3,950 1,462,000
LC Pump Station 4,338,000 LS 1 4,338,000
LC Force Main to Neuse 2 Pump Station Site(24-inch-
diameter PVC) 238 LF 4,310 1,026,000
LC Gravity Main to Neuse 2 Pump Station Site(36-inch-
diameter DI pipe) 443 LF 4,420 1,959,000
LC Gravity Main to Neuse 2 Pump Station Site(42-inch-
diameter DI pipe) 433 LF 5,030 2,179,000
LC Gravity Main to Neuse 2 Pump Station Site(48-inch-
diameter DI pipe) 513 LF 2,380 1,221,000
Administrative and Maintenance Facility 2,373,000 LS 1 2,373,000
5-52

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-27. Estimated Construction Cost—Alternative Biosolids Strategy
Component Unit Cost($) Unit Quantity Total Cost($)a
Total Construction Cost: 82,786,000
Construction Contingency Cost: 8,279,000
Project Administration Cost b'c: 25,473,000
Total Capital Cost: 116,538,000
a 15%markup applied to component cost to address cost estimate uncertainty at Conceptual Design Phase.This markup is in
addition to the construction cost markups.
b Project administration includes permitting,engineering,services during construction,commissioning,and startup.
c Includes$8,938,678 for nitrogen credit purchase.
Table 5-28 provides a summary of the total present worth cost.
Table 5-28. Present Worth Cost Summary—Alternative Biosolids Strategy
Cost Item Total Cost($)
Capital Costs 123,400,000
Replacement Cost Present Worth a'b 7,524,499
O&M Costs Present Worth—Annual c 23,725,294
O&M Costs Present Worth—Intermittent d 1,219,956
O&M Costs Present Worth—Total 24,945,250
Total Present Worth 155,869,749
a Replacement costs are based on the capital cost of major equipment components for each treatment system presented in
Table 5-27 rather than the total capital cost for a treatment system.
b First year of operation of new plant is 2023.
c Annual O&M cost is over a 17-year period from 2023—2040.
d Intermittent O&M cost is over a 17-year period from 2023—2040.
5.2.3 Total Present Worth Summary
Present worth cost was developed for the 20-year planning period and assumes the project will be in
service by 2023. Annual O&M costs for the new or expanded plant do not occur until year 2023. Costs
related to maintaining and rehabilitating the existing LCWRF treatment systems from 2020—2023 were
included in Alternative 3. For the feasible alternatives evaluated,Table 5-29 provides the total present
worth summary in 2020 dollars.
5-53

SECTION 5—ALTERNATIVES ANALYSIS
Table 5-29.Total Present Worth for Feasible Alternatives
Replacement O&M Costs Present Worth
Alternative Capital Cost Costs Present Total Present
Number Alternative ($) Worth($) Annual($) Intermittent($) Total($) Worth($)
Construction of New WRF,and Continued Use
2a of a Surface Water Discharge(at Neuse 2 Pump
Station site) 120,198,000 7,524,499 25,538,423 1,226,479 26,764,902 154,487,401
2b Construction of New WRF,and Continued Use
of a Surface Water Discharge(at ECIA Site) 133,089,000 8,757,577 30,244,316 1,226,479 31,470,795 173,317,373
3 Expansion of LCWRF,and Continued Use of a
Surface Water Discharge 96,493,000 5,223,577 30,448,241 1,914,743 32,362,984 134,079,561
5 Construction of New WRF,and Use of Land
Application 186,800,000 7,866,222 29,103,735 1,431,859 30,535,594 225,201,816
7 Construction of New WRF—Alternative
Secondary Treatment Process 116,538,000 7,472,701 26,942,638 1,285,135 28,227,773 152,238,474
8 Construction of New WRF—Alternative
Biosolids Treatment Strategy 123,400,000 7,524,499 23,725,294 1,219,956 24,945,250 155,869,749
5-54

SECTION 6
Proposed Project Description
6. 1 General
Section 5 evaluated a range of alternatives to meet the Town's treatment needs. Based on that
evaluation,the Town's Preferred Alternative is Construction of a New WRF at the Neuse 2 Pump
Station Site, and Use of a Surface Water Discharge.This alternative was selected as the best fit to meet
the Town's purpose and need for additional wastewater capacity for the following reasons:
• New facility construction best supports the Town's long-term goals for treatment and capacity
needs up to 10 MGD.
• New facility construction provides the Town with resilience while retiring existing LCWRF
infrastructure that is at or near the end of its useful life.
• Site location maximizes use of Town-owned land with existing infrastructure, including the Neuse 2
Pump Station and Neuse River outfall.
• Site location is next to the Neuse River outfall, limiting conveyance of treated effluent to maximize
effluent DO into the Neuse River.
• Facility cost-effectively treats effluent to the NPDES permit requirements.
• Facility footprint at Neuse 2 Pump Station site avoids impacts to environmental resources on the
property, including Neuse River floodplain, wetlands, streams, and stream buffers.
Other factors that influenced the selection include the Town's elimination of environmental liability
associated with the previous law enforcement firing range and an analysis of environmental justice
considerations.This site did not raise any environmental justice concerns (Appendix H).
Each alternative presented in Section 5 was assessed for feasibility, and if feasible, was assessed against
the evaluation criteria:the potential for environmental impacts and cost considerations.The No Action
alternative does not meet the Town's purpose and need to provide additional treatment capacity but, as
described earlier, provides a basis of comparison for the Preferred Alternative. Alternatives to use
regional partnerships, land application, and reuse are also not feasible or cost-effective.
6.2 Proposed Project
The Town is proposing to meet future wastewater treatment capacity needs through 2040 via the
construction of a new WRF using a phased approach,while maintaining conveyance connections with
regional partners for resiliency.To maximize the use of existing infrastructure investment, the Town is
proposing that the new WRF be built on Town property currently housing the Neuse 2 and Clayton to
Raleigh Pump Stations and LCWRF discharge to the Neuse River.The initial treatment capacity will be
6 MGD.
This project will include:
• A 6-MGD BNR treatment facility at the Neuse 2 Pump Station site
• Conversion of LCWRF to a pump station and associated force main to convey raw wastewater to the
Neuse 2 Pump Station site
• Expansion of the ECIA Pump Station, and construction of a new force main to convey flows from the
ECIA to the Neuse 2 Pump Station site
6-1

SECTION 6-PROPOSED PROJECT DESCRIPTION
• Expansion of the existing Neuse River outfall
• Construction of an access road from O'Neil Street to the proposed WRF site, with a parallel water
main along the existing utility transmission easement
The proposed WRF would be located on a 79-acre site currently owned by the Town and located
adjacent to the existing permitted effluent discharge within the Clayton ETJ. Approximately 42 acres of
that site would be disturbed, including for the WRF and linear infrastructure.The project area will be
graded based on the hydraulic profile of the WRF and generally be sloped from west to east to facilitate
the wastewater flow. Initially, a grading plan will provide a gently sloped area,with mass grading of
approximately 150,000 cubic yards (yd3) of material. Figure 6-1 depicts the proposed project site.
6.2.1 Environmental Impacts
This section provides a general discussion of environmental impacts for components of the Preferred
Alternative. Section 7 provides a detailed evaluation and discussion of potential environmental impacts.
Construction and operation of the proposed WRF, its access road, and associated transmission mains are
not expected to significantly impact the environment.The proposed WRF site layout was planned to
avoid streams and wetlands on the parcel and keep new site infrastructure out of the floodplain.The
developed area on the site would remain under the maximum allowable developed area under the
Water Supply Watershed Rules(15A NCAC 02B.0621). Other project infrastructure was also planned to
avoid and minimize impacts.The current outfall into the Neuse River would be expanded to make use of
existing infrastructure and easement.Transmission mains from the LCWRF and the ECIA would be
routed to maximize use of existing, maintained easement to the extent practicable.
Potential environmental impacts are summarized as follows:
• Approximately 24 acres of forest lands would be cleared at the WRF site; approximately 70 percent
of forested area on the site would remain, including stream buffers. Along the LC Transmission Main
route,forest impacts and Zone 1 stream buffers are minimized by using the existing LCWRF
discharge line easement where possible.
• The biological phosphorous removal process reduces environmental impacts associated with
chemical use, namely the chemicals themselves and chemical delivery vehicles,when compared to a
chemical phosphorous removal process.
• Temporary impacts associated with construction will be minimized by using ESC measures as
approved through a Major Land Disturbance permit acquired from the Town and ESC permits
administrated by the County.
• Most stream and wetland impacts associated with the LC Transmission Main will be temporary.
Impacts would be minimized by using the existing easement for the LCWRF discharge line to the
outfall into the Neuse River; five perennial and two intermittent stream crossings would be
required. Approximately 0.024 acre of wetlands at a total of three locations along the route would
be impacted. Potential impacts would be minimized by following general and regional conditions
included in CWA Sections 401 and 404 NWPs. Specifically, NWP 7 is applicable for the outfall
structure upgrade into the Neuse River, and NWP 12 is applicable for linear infrastructure.
• Temporary impacts to the Neuse River from turbidity would occur during construction of the outfall
expansion but would be minimized by using a cofferdam system.The streambank would also be
stabilized after construction, with no floodplain impacts. Increased discharge into the Neuse River is not
expected to impact the environment. Water quality will be protected by complying with the facility's
NPDES permit.The additional flow volume is minimal compared to the flows in the Neuse River.
6-2

IIIIIIII\
- 1 I111\' ' 20 O.7/ O1g `��
.., . : • • C414 , I
• (9(- 09
0250500I 26 %
flit® $31 0
&2• a
Feet ‘ \111-1111111°.' •
15 9
___ ___ _ _ 16 19' . — 111%
17 g �14 D2 /21. J3 •
• 3
Fig.No. name 17 29 30 J ��
1 Administration/Maintenance Building
2 Electrical and Backup Power 03 Influent Pump Station •� 11 - -
4 Headworks 16
5 EQ Tanks I 1 i O 1 •
•
6 Secondary Pump Station 1, 222 v0) i '
,
7 BNRs - T t, •� ��y 4
8 Blowers _ �T� V 180 C �`,rrell l
9 Secondary Clarifiers -
10 Chemical Feed&Storage - ;, ♦4 I
11 Filters
12 UV Disinfection -,.. iiliP$1 10
13 Post-Aeration
I
14 RAS)WAS Pump Station Legend
15 Thickening Building "r- _ • � _ - - _ .- g
16 Dewatering Building
I-16 MGD Proposed WRF
17 Aerated Sludge Holding Tanks
18 Influent Junction Box 10 MGD Future WRF
19 Odor Control Facility
20 Septage Receiving I CI Expansion �'
21 Plant Water Pump Station
22 Drain Pump Station Pavement
23 Effluent Splitter Box c Proposed Manhole
24 Expanded Outfall -
25 Future EQ Tanks --• Proposed Force Main
26 Future Primary Clarifiers Split/Junction Box
27 Future Primary Clarifier — Proposed Gravity Main
28 Future BNRs
29 Future Aerated Sludge Holding Tanks --• Existing Force Main
30 Future Secondary Clarifiers
31 Future Odor Contra!Facility —Existing Gravity Main
a' _
-
Figure 6-1
0 500 1,000 N New Water Reclamation Facility Site Layout
ch 1 1,.. I I IA Water Reclamation Facility Expansion
Feet Town of Clayton, NC
The treatment systems depicted on this conceptual layout represent conservative footprints,and may be revised as the design develops.

SECTION 6—PROPOSED PROJECT DESCRIPTION
• The Sam's Branch and Neuse Riverwalk greenways would be temporarily closed during construction
of linear infrastructure and the outfall expansion.They would be restored to existing conditions
after construction is completed and reopened. A native seed mix will be used to reestablish
vegetation within the LC Transmission Main alignment adjacent to Sam's Branch at the WRF site.
This will provide habitat for pollinator species and provide an educational opportunity for greenway
users.
• The Neuse River waterdog and Carolina madtom are proposed for federal protections. Habitat for
the Neuse River waterdog is likely present in the lower reaches of Sam's Branch and the Neuse River
near the outfall.To limit potential impacts to these species, and state-listed mussels that may also
be in the vicinity, ESC measures beyond those typically required will be used to minimize sediment
loading into waterways. Impacts to these species are not expected.
• Habitat for the federally protected Michaux's sumac was also identified along maintained utility and
power easements associated with the project. A growing season survey was conducted, and the
species was not located (WithersRavenel, 2020a, 2020b, 2020c).Therefore, the project is unlikely to
affect protected species.
6.2.2 Project Costs
The estimated construction cost for the proposed project is$120,198,000 (including administrative and
contingency costs).Total present worth costs for the Preferred Alternative accounts for O&M and
lifecycle replacement costs.The estimated total present worth of the proposed project is$154,487,401.
Table 6-1 summarizes the cost components of total present worth.
Table 6-1.Total Present Worth—NeW Water Reclamation Facility at the Neuse 2 Pump Station Site
Cost Item Total Cost($)
Capital Costs 120,198,000
Replacement Cost Present Worth a-b 7,524,499
O&M Costs Present Worth—Annual c 25,538,423
O&M Costs Present Worth—Intermittent d 1,226,479
O&M Costs Present Worth—Total 26,764,902
Total Present Worth 154,487,401
a Replacement costs are based on the capital cost of major equipment components for each treatment system presented in
Table 5-29 rather than the total capital cost for a treatment system.
b First year of operation of new plant is 2023.
c Annual O&M cost is over a 17-year period from 2023—2040.
d Intermittent O&M cost is over a 17-year period from 2023—2040.
Several alternatives for expanding the Town's wastewater treatment capacity to meet future demands
and Neuse River discharge requirements are not feasible because they do not meet the purpose and
need; therefore, cost evaluation was not conducted for these alternatives. Costs were evaluated for
feasible alternatives that could meet the Town's objectives. Project cost was not the only factor
considered when selecting the preferred solution; cost-effective use of the Town's funds, ability to meet
near-and long-term capacity needs, and minimization of environmental impacts were factored into the
recommendation.
6-4

SECTION 6—PROPOSED PROJECT DESCRIPTION
6.3 Proposed Project Details
This section details the new treatment systems and conveyance system changes recommended in the
Preferred Alternative. Figure 6-1 provides the proposed site layout.
Construction of a new WRF would include the following elements:
• IPS
• Odor control
• Headworks (screening and grit removal)
• Flow equalization
• Five-stage biological treatment for nitrogen and phosphorus removal
• Chemical phosphorous removal for polishing
• Cloth (disc)tertiary filtration
• UV disinfection
• Cascade re-aeration
• Solids treatment, including:
— Thickening with RDTs
— 30-day aerated sludge holding
— Dewatering with screw press
• Effluent outfall to Neuse River
Figure 6-2 provides a generalized process flow diagram (PFD) of the proposed processes for the new
6-MGD WRF. Appendix I provides details about the process model.
Secondary
Preliminary Treatment Tertiary Cloth UV
Treatment Filtration Disinfection
g Aeration Basin d_3 Secondary
Pumping Clanfer
Screening Gnt EQ
Station ...
Rem � �ti _ r��� .. r. �• _
Neuse River
Municipal
Nov
Gr fols
Landfill Landfill
WAS
Thickening
5eptage
Receiving ;lb;lb V.::
1 Aerobic
Holding Dewatering
-�.. solids to Disposal
Solids Handling
Figure 6-2.New Water Reclamation Facility Proposed Processes
6.3.1 Little Creek Pump Station
LCWRF will be converted to pump station and serve as collection point for the western side of Clayton
(WithersRavenel, 2020d).The converted site will also serve as a receiving station for emptying Town
collection system vacuum trucks. The proposed LC Pump Station includes a headworks (redundant
helical screw screens and vortex grit removal units), odor control, and 16,570 LF of new transmission
pipe. The pumps are sized to meet peak flow and ADF for the new 6-MGD WRF. For residential and
commercial flows at this capacity, the MM ADF is 3 MGD, the ADF is 2.6 MGD, and the peak hour flow is
calculated at 7.6 MGD. The pump station's firm capacity is 8.6 MGD, which is above the peak hour flow
and is based on a pump size that allows for the operational and maintenance benefit of expansion with
similar-sized pumps.
6-5

SECTION 6—PROPOSED PROJECT DESCRIPTION
The transmission pipe is sized to accommodate flows for the expansion to 10 MGD. For the 10 MGD
expansion,the nominal size of the LC Pump Station is 5 MGD on a maximum month average daily flow
basis, with an associated ADF of 4.25 MGD and peak hourly flow of 12.5 MGD.This flow was used to
determine the size of the transmission mains.The actual pumping capacity of the LC Pump Station for a
future WRF expansion will be determined at the time of the expansion.
Table 6-2 presents the design criteria for the IPS. Appendix I provides additional details.
Table 6-2. Little Creek Pump Station and Force Main Design Criteria
Component Value
Screening
Screen Type Mechanical step screen
No.of Screens(duty and standby) 1 and 1
Screen Opening 6 mm
Design ADF,MGD a 5
Design PHF per Screen,MGD a 13
Grit Removal
Type Vortex
No.of Units(duty and standby) 1 and 1
Capacity per Unit,MGD 13
Design ADF,MGD a 5
PHF per Unit,MGD a 13
Grit Pumps
No.of Pumps(duty and standby) 2 and 2
Type Centrifugal suction lift
Capacity each,gpm 250
Grit Classifier
No.of Units 2 and 0
Type Screw classifier
Pumps
Type Submersible
No.Duty Pumps 2
Standby Pumps 1
Flow per Pump,MGD 4.3
TDH,ft 151
Dry-Prime Diesel Backup Pump
No.Standby Pumps 2
Flow per Pump,MGD 4.3
6-6

SECTION 6—PROPOSED PROJECT DESCRIPTION
Table 6-2. Little Creek Pump Station and Force Main Design Criteria
Component Value
TDH,ft 151
Force Mains
No. 1
Diameter,inches 24
Length, LF 16,570
Material Epoxy-lined DI pipe
a Little Creek Pump Station screening and grit systems sized to accommodate flows for the expansion of the
WRF to 10 MGD.
6.3.2 Influent Pumping
The proposed influent pumping station is a submersible pump station with dry-prime diesel backup.The
pump station will be designed for firm capacity at peak flows with provisions for expansion.The dry-
prime diesel backup pump will provide redundancy at peak flows. Flows from the LC Pump Station and
the Town's other gravity sewer pipes will meet at junction box upstream of the IPS, and then the
combined raw sewage will gravity flow from the junction box into the IPS wet well.The IPS will convey
the combined raw sewage to the headworks system.Table 6-3 provides the design criteria for the IPS.
Table 6-3. Influent Pumping and Force Mains Design Criteria
Component Value
Electric Pumps
Type Submersible
No.Duty Pumps 4
Flow per Pump,MGD 4.4
TDH,ft 105
Firm Capacity,MGD 17.6
Dry-Prime Diesel Backup Pump
No.Standby Pumps 2
Flow per Pump,MGD 6.6
TDH,ft 105
Influent Force Mains
No. 2
Diameter,inches 24
Material Epoxy-lined DI pipe
6-7

SECTION 6—PROPOSED PROJECT DESCRIPTION
6.3.3 Flow Equalization
Flow equalization is provided downstream of the headworks facility to reduce peak flows and limit load
variability experienced by the secondary process. Flow equalization will reduce the incoming PHF to
peak day flow for the secondary and tertiary treatment systems.A covered circular tank was selected
for influent flow equalization.The equalization will be mechanically mixed and unaerated with odor
control provisions.The entire basin will be epoxy coated to provide corrosion control. A pump station
will be included to convey equalized flow from the tanks to follow-on treatment processes, and yard
valving will be included to enable bypassing of the equalization tank.Table 6-4 provides the flow
equalization design criteria.
Table 6-4. Flow Equalization Design Criteria
Component Value
Equalized Peak Flow to Downstream Processes,MGD 9.7
Estimated Volume Required,MG 1.39
Safety Factor on Sizing 1.15
Total Estimated Volume Required, MG 1.60
No.of Tanks 2
Diameter,ft(each) 90
Maximum Water Depth,ft 17
Freeboard,ft 3
Cover Aluminum
Mixing System Wall-mounted propeller
No.of Equalization Pumps(duty and standby) 2 and 1
Type Submersible
Flow per Pump,gpm 520
6.3.4 Septage Receiving
A septage receiving station will be provided at the headworks facility for the Town to discharge vactor
trucks. Substantial septage receiving from sources outside of the Town is not anticipated.The septage
receiving station will not meter flow or store hauled volumes.The station will be located upstream of
screening and grit removal.
6.3.5 Headworks Facility
The headworks facility includes screening and grit removal.These processes will be located upstream of
the influent equalization tank and will be sized for design PHFs.
6.3.5.1 Influent Screening
The screening technology selected was the inclined cylindrical screen.The technology was selected
because it as an integral washer and compactor with low maintenance requirements. Two screens will
be provided, each with capacity for PHFs to provide 100 percent redundancy with a unit out of service.
The screening facility will be constructed with one bypass channel equipped with manual bar screen
6-8

SECTION 6—PROPOSED PROJECT DESCRIPTION
sized to pass the entire peak flow for emergency use. An additional channel will be provided, but not
populated with a screen, for the future Phase 2 expansion.Table 6-5 provides the influent screening
design criteria.
Table 6-5. Influent Screening Design Criteria
Component Value
Screening
Screen Type Inclined cylindrical with integral washer and compactors
No.of Screens(duty and standby) 1 and 1
Screen Opening 6-mm perforated plate
Design ADF,MGD 6.6
Design PHF per Screen,MGD 15
Installation Angle 35°
Notes:
=degree(s)
6.3.5.2 Grit Removal
A stacked tray(for example, HeadCell)grit removal process was selected for the Town.Two parallel
stacked tray systems will be provided,with the combined system sized for PHF. Each HeadCell unit will
have a dedicated grit washer and classifier to improve reliability.
The stacked tray units will initially be populated with enough trays for peak flow.The grit basins will be
constructed at a depth capable of receiving three additional trays per basin to make future expansions
more cost effective. Table 6-6 provides grit removal design criteria.
Table 6-6.Grit Removal Design Criteria
Component Value
Grit Removal
No.of Units 2
Type Stacked tray
Tray Diameter,ft 9
Minimum No.Trays per Unit 5
Spare Tray Spaces per Unit 3
Capacity per unit,MGD 5.6
Average Day Hydraulic Loading Rate(one unit out of service),gpm/ft2 11.5 a
Average Day Hydraulic Loading Rate(each,two units in service),gpm/ft2 5.7
Peak Hour Hydraulic Loading Rate(each,two units in service),gpm/ft2 15
Grit Washer and Compactors
No.of Units 2
Type Conical(e.g.,Grit Clense)
6-9

SECTION 6—PROPOSED PROJECT DESCRIPTION
Table 6-6.Grit Removal Design Criteria
Component Value
Grit Pumps
No.of Units(duty and standby) 2 and 1(shelf spare)
Type Recessed impeller
Capacity each,gpm 400
a Average day hydraulic loading rate for single grit unit,with second unit out of service.
6.3.6 Secondary Treatment
For both phosphorus and nitrogen,the base secondary treatment process is BNR that uses conventional
secondary clarification.
6.3.6.1 Bioreactors
The process will be configured into a five-stage Bardenpho process. Figure 6-3 shows a generalized PFD.
The main bioreactor will be partitioned into the following zones:
• Anerobic zone
• Pre-anoxic zone
• Swing zone
• Three aerobic zones
• Postanoxic zone
• Re-aeration zone
The process includes a nitrified mixed liquor recycle from the end of the aerobic zone to the pre-anoxic
zone to enhance nitrate removal.There will be multiple locations for supplemental metal salt (for
example, ferric chloride) or carbon addition to enhance nutrient removal performance.The unaerated
zones in the bioreactor will include hyperboloid mixers, while aerobic and swing zones will use diffused
aeration via membrane disc diffusers. Biomass can be wasted from the system either through surface
wasting, which is included to provide operational flexibility to manage settleability concerns, or through
wasting of the settled sludge.
,-e-p4
m g
o
r7 m
Post-
Anaer.Ilitnosic Swing Aerobic snosiCReseretion
'� rg,. ,.d,3-
I i i
�i ,� r 1 �� To Tertiary
FromEC!� � 1 � 7 iy � `
-V w +-•Y r s o0o a c�,- 1 r�r,
v
SWAS WAS
Figure 6-3.Secondary Treatment Process
6-10

SECTION 6—PROPOSED PROJECT DESCRIPTION
Table 6-7 provides bioreactor design criteria.
Table 6-7. Bioreactor Design Criteria
Component Value
Basins
Process Five-stage Bardenpho
No.of Basins 3
Basin Volume each,MG 2.45
No.of Zones 6
Anaerobic Zone Volume,MG 0.37
Anoxic Zone Volume,MG 0.25
Swing Zone Volume,MG 0.12
Aerobic Zone Volume,MG 1.32
Postanoxic Zone Volume, MG 0.25
Postaerobic Zone Volume,MG 0.14
No.of Diffuser Grids 5
Average Day MLSS(all units),mgTSS/L 2,000
MM MLSS(all units),mgTSS/L 3,500
Nitrified Recycle
Type Propeller pumps with VFD
No.of Units(duty and standby) 3 and 1 shelf spare
Capacity per Unit,MGD 8(400%of MM flow)
Surface Wasting Pumps(biofoam removal pumps)
Type Horizontal centrifugal nonclog with VFD
Location Bioreactor effluent MLSS channel
No.of Units(duty and standby) 3 and 1
Diffused Aeration
Type Membrane disc diffusers
Estimated No.of Diffusers per Basin 1,970
Notes:
mgTSS/L=milligram(s)total suspended solids per liter
MLSS=mixed liquor suspended solids
6.3.6.2 Secondary Clarifiers
Three conventional secondary(final) clarifiers are included.The clarifiers are center-feed type with a
flocculating feed well.The clarifiers will include energy-dissipating inlet baffles used to promote
6-11

SECTION 6—PROPOSED PROJECT DESCRIPTION
flocculation, and peripheral density-gradient baffles to limit solids from discharging into the secondary
effluent.Table 6-8 provides secondary clarifier design criteria.
Table 6-8.Secondary Clarifier Design Criteria
Component Value
Final Clarifiers
No.of Clarifiers 3
Geometry Circular
Diameter each,ft 75
Side Water Depth,ft 18
Sludge Withdrawal Hydraulic suction
Influent Feed Arrangement Center-column,energy-dissipating inlet and hydraulic flocculating feed well
Effluent Collection System Single outboard launder with v-notch weirs
Design Sludge Volume Index,mL/g 150
Solids Loading Rate,IbTSS/d/ft2
Peak 35
Average 12
Surface Overflow Rate,gpd/ft2
Peak 730
Average 430
RAS
Type Horizontal centrifugal nonclog with VFD
No.of Units(duty and standby) 3 and 1
Capacity per Unit,MGD 2(100%of MM flow)
WAS
Type Horizontal centrifugal nonclog with VFD
No.of Units(duty and standby) 3 and 1
Notes:
IbTSS/d/ft2=pound(s)of total suspended solids per day per square foot
mL/g=milliliter(s)per gram
6.3.6.3 Aeration Blowers
Air will be supplied to the bioreactors with the use of with high-speed turbo (HST) blowers. HSTs were
selected because of their low lifecycle costs, high turndown efficiency, and comparably low maintenance
requirements.Table 6-9 provides aeration blower design criteria.
6-12

SECTION 6—PROPOSED PROJECT DESCRIPTION
Table 6-9.Aeration Blower Design Criteria
Component Value
Type HST
No.of Units(duty and standby) 2 and 1
Peak Total Air Flow,scfma 9,000
MM Total Air Flow,scfm 7,300
Average Air Total Flow,scfm 4,500
a Assumed at 2 x ADF.
6.3.7 Tertiary Treatment
Standalone cloth filters were selected for the tertiary treatment.A total of three filters will be provided,
each capable of handling 50 percent of the equalized peak day design flow.The filters will be located
outdoors beneath a canopy, and all exposed piping less than 3 inches in diameter will be insulated and
heat traced to prevent freezing.Table 6-10 provides tertiary treatment design criteria.
Table 6-10.Tertiary Treatment Design Criteria
Component Value
Type Disc filtration
No.of Units(duty and standby) 2 and 1
Average Capacity per Unit,MGD 2.7
Total Average Capacity,MGD(two units in operation) 6.2
Peak Capacity per Unit,MGD 4.9
Total Peak Capacity,MGD(two units in operation) 9.8
Disc Surface Area,ft2 1,398 total(53.8 per disk)
Minimum No.of Discs per Unit 13
Spare Locations per Unit 2
Average Hydraulic Loading(2 units),gpm/ft2 2.7
Peak Hydraulic Loading(2 units),gpm/ft2 4.8
Notes:
ft2=square foot(feet)
6.3.8 Disinfection
A UV disinfection system will be provided.The UV disinfection system has a small footprint and does not
use chemicals. In accordance with NCDEQ minimum design criteria (NCDEQ, 2017c), the UV system will
provide adequate disinfection at the PHF with one bank out of service. In addition, the following will be
provided as part of the UV system:
• Audible and visible alarms to notify operators and the control room of lamp and unit failures
• Automatic controls to switch to backup units in case of failure
• Spare lamps will be kept onsite
6-13

SECTION 6—PROPOSED PROJECT DESCRIPTION
Table 6-11 provides UV disinfection design criteria.
Table 6-11. Ultraviolet Disinfection Design Criteria
Component Value
Type Open channel LPHO UV
Weekly Fecal Coliforms,No./100 mL 400
Monthly Fecal Coliforms,No./100 mL 200
No.Trains 2
Capacity each,MGD 5
UV Transmittance,% 60
No.of Banks(duty,standby,and future) per Channel 1,1,and 1
6.3.9 Postaeration
Postaeration is provided through cascade aeration.The permitted daily average DO concentration in the
outfall is 6.0 mg02/L.Table 6-12 provides postaeration design criteria.
Table 6-12. Postaeratioh Design Criteria
Component Value
Type Cascade aeration
Minimum DO,mg02/L 6.0
6.3.10 Residuals Treatment
6.3.10.1 Thickening
RDTs will be used for thickening WAS. WAS flow will be pumped to the RDTs, and the discharged solids
will be sent to aerobic sludge holding.Two RDTs will be provided with a firm capacity capable of treating
peak week solids productions. Solids productions greater than peak week will be equalized in WAS
holding prior to thickening.Table 6-13 provides RDT design criteria.
Table 6-13.Thickening Design Criteria
Component Value
Type Rotary drum
Minimum No.of Units(duty and standby) 1 and 1
Feed Solids,%TSS 0.2-1%
Target Thickened Solids Concentration,%TSS 5%
Solids Loading Rate(total),IbTSS/h
Average 420
MM 700
Peak a 840
6-14

SECTION 6—PROPOSED PROJECT DESCRIPTION
Table 6-13.Thickening Design Criteria
Component Value
Hydraulic Loading Rate(Total),gpmb
Average b 140(0.6%)
MM b 200(0.7%)
Peak a,c 670(0.25%)
aPeak day assumed at 2 x average day production.
bUnderflow wasting.
cSurface wasting.
Notes:
IbTSS/h=pound(s)of total suspended solids per hour
6.3.10.2 Aerated Sludge Holding
Solids from the RDT are discharged to the aerobic sludge holding tank,which will provide 30 days of
storage at average solids production. Coarse bubble diffusers will be installed to keep the sludge
aerated, preventing septic, odorous conditions, and to keep the sludge mixed. Airflow requirements for
the sludge holding tank will either be provided by the Aeration Blower Building or with a dedicated
blower facility. Decanting capabilities will also be provided.Table 6-14 provides aerated sludge holding
design criteria.The stated volume provides 30-days retention time without the use of decanting. Use of
the decanting capabilities provides operational flexibility and would lead to an increase in the effective
number of days of storage available during normal operations or maintenance activities.
Table 6-14.Aerated Sludge Holding Design Criteria
Component Value
Type Holding
Average Retention Time,days 30
No.of Tanks 2
Volume,gallons 670,000
Diameter,ft 80
Maximum Water Depth,ft 17
Freeboard,ft 2
Cover Aluminum
Mixing and Aeration Ceramic coarse bubble diffusers
Average Air Demand,scfm 2,600
6.3.10.3 Dewatering
Following aerobic sludge holding, screw presses will be used to dewater the solids effluent from aerobic
sludge holding. On average, screw presses will produce effluent solids at 18 percent cake solids. In
addition, screw presses are low cost, low maintenance, and long-lasting.Table 6-15 provides dewatering
design criteria.
6-15

SECTION 6—PROPOSED PROJECT DESCRIPTION
Table 6-15. Dewatering Design Criteria
Component Value
Type Screw press
No.of Units(duty and standby) 1 and 1
Feed Solids Concentration,%TSS 4-6
Target Dewatered Cake Concentration,%TSS 18%
Solids Loading(total),IbTSS/h
Average 1,010
MM 1,750
Peaka 2,020
Hydraulic Loading(total),gpmb
Average 10.7(6%TSS)
MM 21(5%TSS)
Peaka 30(4%TSS)
a Peak day assumed at 1.5 x average day production,operating.
b Assumes dewatering schedule of 10 hours per day,5 days per week.
Notes:
IbTSS/h=pound(s)of total suspended solids per hour
Dewatered cake will discharge (drop)to a truck container located below each dewatering unit.Two
truck bays will be provided for redundancy, with a conveyor allowing for the either unit to discharge to
either bay.
6.3.10.4 Solids Disposal
The Preferred Alternative's residuals treatment approach will produce a dewatered cake at a target
solids concentration of 18 percent. Given an estimated annual solids production of 1,300 dry tons, this
target concentration would result in approximately 7,200 wet tons per year.The intended disposal
options are composting or landfill, with the Town holding contracts for multiple disposal options.
Residuals handling is not designed for land application of a classified product (for example, Class B per
503 regulations).
To this end, the Town contacted McGill Environmental Systems (McGill),who indicated their willingness
and capability to accept the estimated 7,200 wet tons of dewatered residuals annually (McGill, 2020)
(Appendix J). McGill further indicated that, beyond extreme conditions such as hurricanes or snow,they
would be able to accept solids throughout the year. In addition, landfill would be maintained as a
disposal option. Given the planned disposal options, and concerns about odor generation, dewatered
cake storage is not proposed. If cake storage became necessary for the short term, then temporary
storage could be used.
6.3.11 Chemical Feed System
Chemical feed systems for ferric chloride dosing and supplemental carbon dosing into the secondary
treatment process are included in the plant expansion. Fiber-reinforced plastic(FRP)tanks will be used
for chemical storage, and peristaltic pumps will pump from the bulk chemical feed tank to the proper
6-16

SECTION 6—PROPOSED PROJECT DESCRIPTION
zone of the bioreactors.Table 6-16 provides metal salt feed design criteria, and Table 6-17 provides
supplemental ferric chloride feed design criteria.
Table 6-16. Metal Salt Feed Design Criteria
Component Value
Type Ferric chloride
Solution Strength 38%
Type of Feed Pumps Peristaltic
No.of Feed Pumps(duty and standby) 3 and 1
No.of Feed Locations 3(influent,secondary clarifier feed,clarifier effluent)
Average Feed Rate per Pump(if used),gph 5.9
Maximum Feed Rate Per Pump(if used),gph 8.5
No.of Storage Tanks 1
Storage Tank Material FRP
Storage Days(Average Flow) 36
Minimum Storage Tank Volume,gallons 3,800
Table 6-17.Carbon Feed Design Criteria
Component Value
Type Methanol a.
Solution Strength 99.85%
Type of Feed Pumps Peristaltic
No.of Feed Pumps(duty and standby) 3 and 1
No.of Feed Locations 3(bioreactor influent,postanoxic zones)
Average Feed Rate Per Pump(if used),gph 2.15
Max Feed Rate Per Pump(if used),gph 3.31
No.of Storage Tanks 1
Storage Tank Material FRP
Storage Days(Average Flow) 30
Minimum Storage Tank Volume,gallons 2,700
Supplemental carbon to be selected during detailed design
6.3.12 Odor Control
A biotrickling filter system will be used for odor control at the proposed facility. Odor control will be
provided for the following systems:
• IPS
• Headworks Building
6-17

SECTION 6—PROPOSED PROJECT DESCRIPTION
• Influent equalization tank
• Aerobic holding
• Thickening and dewatering
Table 6-18 provides odor control design criteria.
Table 6-18.Odor Control Design Criteria
Component Value
Type Biotrickling filter
Target H2S Removal,% 99.5
Target Odor Removal,% 85
Notes:
H2S=hydrogen sulfide
6.3.13 Electrical
The existing Town-owned Northside Substation will deliver primary power to the site at 13.2/23 kilovolts
(kV), routed overhead to a power pole near the facility entrance. Primary power will transition
underground over to a Town-owned, pad-mounted service transformer with advanced metering
infrastructure metering on the secondary.
The electrical distribution system will be a 480-volt (V), three-phase,four-wire system that is
wye-connected at the secondary of the service transformer. A neutral conductor will be provided
throughout the entire distribution system, with the neutral switched between utility and the backup
power generator via four-pole, open transition, automatic transfer switch.
Uninterruptible power supplies (UPSs)will be provided for critical loads that require continuous power,
such as:
• Plant control system panels
• Network interface panels
• Instruments
• Plant control workstations
UPS runtime will be 15 minutes at design load.
In accordance with 15A NCAC 02T.0505(I), power reliability will be provided, consisting of automatically
activated onsite standby power supply capable of powering all essential treatment units under design
conditions. Standby generators will be diesel-powered with tanks sized to accommodate a minimum of
72 hours of continuous operation at full load.
6.3.14 Administrative Facility
The WRF is anticipated to be continuously occupied and operated: 24 hours per day, 7 days per week
and 365 days per year.The Town projects a total of 10 full-time staff will be assigned to the WRF.The
buildings at the WRF will include an Administration and Laboratory Building and a Maintenance Facility.
The Administration Building is estimated to be approximately 5,000 ft2, and the Maintenance Facility is
estimated to be approximately 2,500 ft2.
The Administration and Laboratory Building will include:
• Control Room
• Operator's Laboratory (one fume hood)
• Conference Room
6-18

SECTION 6-PROPOSED PROJECT DESCRIPTION
• Break Room
• Men's Restroom and Locker Room (5 lockers, 1 shower)
• Women's Restroom and Locker Room (5 lockers, 1 shower)
• Offices: total of three (Plant Manager, O&M Supervisor, Laboratory Supervisor)
• Server and Telecom Room
• Office Storage
• Janitor's Closet
• Mechanical Room
The Maintenance Facility will include two maintenance bays with roll-up doors.
The Administration and Laboratory Building will be designed as accessible in accordance with the
requirements of the Americans with Disabilities Act (ADA). All other buildings and facilities within the
WRF are not intended for access by the general public.These spaces are assumed to be accessed only by
service personnel for maintenance, repair, or monitoring of equipment, and are not designated as ADA-
compliant accessible spaces.
A paved parking area for eight employee vehicles and a minimum of two visitor spaces will be provided.
6-19

SECTION 7
Environmental Impact Document
The Town has initiated the State Environmental Policy Act (SEPA) environmental review process to
expand its wastewater treatment capacity. Appendix K includes details about agency coordination,
including the Scoping Document used to start this process.The project study area includes the Town's
expected service area comprising the Town's current ETJ area (Figure 7-1).The ECIA is also within the
study area.The ECIA is part of a state-created RTZ where these biopharma facilities partner with the
Johnston County Workforce Center to provide biotechnology education opportunities.This boundary
captures the Town's current customers, as well as areas expected to be served within the 20-year
planning window of this assessment.The study area also includes the site for a proposed WRF and
expansion of the existing surface water discharge point (outfall) along the Neuse River, associated
conveyance infrastructure, and a facility access road.This defines an area that will provide for a
comprehensive evaluation of environmental impacts. Figure 7-1 provides a map of the study area.
Data used to develop the existing conditions information discussed in Section 7.1 were gathered
through literature reviews and research, geographic information system (GIS) queries, input provided by
the Town and WithersRavenel, and correspondence with various agencies.
Direct impacts are discussed in Section 7.2. Potential secondary and cumulative impacts (SCIs) on the
study area from the proposed WRF and associated infrastructure, including conveyance from the
R. Steven Biggs Regional Pretreatment Facility to the new WRF, are also discussed in Section 7.2.
Mitigative programs are discussed in Section 7.3.
7. 1 Existing Environmental Conditions
This section describes the existing environment for the study area (Figure 7-1) and in the vicinity of the
project components (Figure 5-1). Baseline environmental conditions are necessary for the analysis of
potential environmental effects related to the following activities:
• Construction of the proposed WRF
• Expansion of the existing surface water discharge point (outfall) along the Neuse River
• Conversion of the LCWRF to a pump station
• Construction of associated conveyance infrastructure
• Construction of a facility access road
Conveyance from the R. Steven Biggs Regional Pretreatment Facility to the new WRF is being permitted
separately under a separate funding mechanism; therefore, existing environmental conditions are not
discussed for the ECIA Transmission Main and Pump Station upgrade. Details are included in the Town's
EDA Environmental Narrative (Town, 2020f) and Appendix K provides the Finding of No Significant
Impact(FONSI) for the project.
7.1.1 Topography and Floodplains
The study area is in the Piedmont region, sloping down toward the Coastal Plain.The study area includes
areas within the U.S. Geological Survey(USGS) Clayton, Garner, Edmondson, and Powhatan 1:24,000
scale topographic maps (USGS, 2019). Elevations in the study area range from about 130 feet to about
370 feet amsl.The proposed WRF site elevations range from 140 feet along the Neuse River to 220 feet
amsl in the center of the parcel (Figure 5-1).
7-1

89.' n -- v i v"-- 4, tr
I '' /
1‘ ti yf -
N,:'
'J ./'
Village r S)' .a. ., , -.4);,1,'
f
, . o' 1 . - 1 i----_ �� `- Wake
_ _ ':
ti • \ 8 Raleigh
— N . / r �. � Count'
',
\:4
> nr Johnston
i. s, 4� ` Ilk County
J-V ..-.r�,. )~r T Clayton
\ \ \lin ' .ab 1, ,1 4 10--L,
��� � Proposed >4(1eo ��,
1. �► _ WRF Site se• t Little Creek 95 ; f
�} •`- 86°.1_ .4 WRF Outfall - `_ _
��1�`') 1,"^ 7: vr�W Jiw. .r 1,
L. Vti �6' C .-,. ;
• A
., ,
: , L ,,:t. , ,
�0 Clayton on
0
r �" Little Creek �� •
/ �, WRFAL •
�. Se• age, �pnd,r
Little Creek
\ ; Transmission ' ;
�,�,n �� Main Legend
3- .� . t= reek v ' -- c ___ Interstate
�' `c ao ECIA Highway
i
Ni — Major Road
0'� *� � l - - � v, ECIA -� ' �- Transmission j
6 ` l — Main - Major Hydrology
Store w 5: Study Area
J — :7 r 1 i County Border
2 �' f Copyright:0✓013 National Geographic Society,i-cubed
0 1 2 N Figure 7-1
Ch I I I A Study Area
Water Reclamation Facility Expansion
Miles
sM Town of Clayton, NC

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
Important topographical features in the study area include floodplains.These riparian floodplain areas
provide multiple functions, including:
• Flood storage
• Sediment depositional areas
• Wildlife habitat
• Corridors for wildlife movement
• Water quality functions, such as infiltration zones and surface water filtering
Floodplains within watersheds more than 1 mi2 are regulated by the Federal Emergency Management
Agency (FEMA). Most open water and floodplain areas occur along the Neuse River and Little Creek,
with the Neuse River comprising 1.6 mi2 and Little Creek comprising 0.4 mi2 (Figure 7-2). Flood Insurance
Rate Maps (FIRMs)for most of the County area are dated June 20, 2018.Those FIRMs bordering Wake
County are being updated, with preliminary mapping done in 2020(North Carolina Floodplain Mapping
Program, 2020).
The FIRMs for the proposed WRF site are dated June 20, 2018, and the floodplains at the site are shown
on Figure 2-4. Floodplains in the study area often include wetland areas, such as those along the Neuse
River and along the northeastern and southeastern sides of the proposed WRF site adjacent to the
Neuse River and Sam's Branch, respectively.
Portions of linear project infrastructure within the proposed WRF site and the outfall will be located
within the Special Hazard Flood Areas (SHFAs) along Sam's Branch and the Neuse River.These SHFAs are
defined in the Town's Flood Damage Prevention Code, Chapter 151 of the Town's Code of Ordinances
(Town, 2018b).
The access road does not cross floodplains (Figure 7-3).
The existing LCWRF site is partially in the floodplain of Little Creek. As a result, some infrastructure is
prone to flooding (Figure 4-2).The site was graded for construction of the LCWRF, and elevations range
from 230-326 amsl (USGS, 2019).
Appendix L provides details about the topographic conditions for the access road and the
LC Transmission Main.
The pump station to be installed at the LCWRF for the LC Transmission Main will be sited to align with
incoming wastewater collection system infrastructure and to avoid existing treatment infrastructure.The
proposed location for the building slightly infringes on the 100-year and 500-year floodplains. Structures
will be built up above the 100-year flood elevation and electrical equipment above the 500-year flood
elevation.The LC Transmission Main route parallels the existing LCWRF discharge line to work within
existing easements to the extent practicable. As such, the lower reach of the alignment along Sam's
Branch falls within the floodplain, designed an SHFA by the Town (Town, 2018b) (Figure 7-3).
7-3

1V, En�reld ji '
j 8 1 , / '1.. 1, 111 I Q ''` O ,
e. 1 — o
1
' a -- . 1 ' ' ' r'V\2, -.. \ a jlif , __.,.. ..,.. - N , ' ,,,' ' \. .4' - ,
'';111%
��. /�`= S
sE, `+ �_� I \ • n , ,,Arc 1 t•
' i ,t-, 0 '40* k
. ___---11441111k , _ 0 _.,, ' -,N 1 ,:-Oki .-,, f, - ,
1471N% ,r #
c q-�, Race, w_. ` ..._95
\((. g
Lf J , rion :Cl> `G�O+.��Ss 4„.... ife,t.. r •��r `� ! i
1' O Cr F
i , ,./,
Set'age. ,t v sA►+� - �S (`,A f ,4,n,i,nq'Surp
nsmissiOnU 'NSW
t'ft '� Legend
I� •
I. A Little Creek VVRF
,. :. �, �O.• A Proposed VVRF
•
ti. ��� • .••r•• Johnston County Limits
;� `o�
i I Interstate
+- /
Major Road /
1 * .1p t Stream or River
. •... Proposed Force Main 0
4s.•or,
- . ,�; Proposed Gravity Main -�
J Water Supply
i
' -- _01 Q W?u! S
ed 40 C. 1111,_ - � N. , Y rea
tglIS
Al �. I ttcn
�) ,c �.I �\ - Copyright:©2013 National Geograpni• o Society,• j oul5,e!'�d�
c• s , A . > .• f •C
Figure 7-2
all0 1.5 3 N Water Supply Watershed Overlay
�M Water Reclamation Facility Expansion
Miles
Town of Clayton, NC
Existing ECIA Pretreatment Facility footprint shown.

1 • illigal"4/.
o a ,` ` < PROPOSED ACCESS ROAD "�FLOODWAY wstirs , ., Y;.
100 YR FLOODPLAIN `� x GsF
�'2 _i ,
;
500 YR FLOODPLAIN d ..
PROPOSED ACCESS ROAD
ii44; 1 i
PROPOSED TRANSMISSION MAIN '"� �
•
r''' ',.-1:1/2:‘:r4::-....' ,,,,r --, --,1111.'11.7.•. ' P.., k*, f
e ' i
�h; • r f 500 YR FLOOD ¢ �/ • " � .
° ti r
,It
MANHOLES IN THE 100 YEAR FLOODPLAIN e�;``Xz , 4 bT^«r•� t , , V. ' 111‘ 7'..)
°, i ,,,^ '4 100 YR FLOOD r" ..WILL EITHER BE v.' . , '` e
1 RAISED 2 FT ABOVE THE 100 YEAR FLOOD xr »'
ELEVATION OR ° '� ` ; ,h=• .
(2) WATER TIGHT WITH VENT 2 FT ABOVE THE ' ''-•« "4,f �".: :� C'''.11 '' 4
100 YEAR FLOOD ELEVATION .. y,. TO. , ;f, r r
R 5 :
ya ' {
\'` ,4 y a`!:, ,jr, v g \
N
p • ° , ■ +hw 1 a: i `
//i
Lir 1 ,I,..'....g to.
'- :♦ A "lam
I `
r . 4 . \
., \ (/s+ C. ;.,r . •-s• ., 7 z J n ✓ �, 1 ! —ice �w
V`i
70
ei
{ V y °
�^ � :'-:.�.- ..
It
c Al*` 4 4 -,.. ',a', ....Ssne,„ ' --', • 14 ,, - \
y+ w
$ : ' ✓� .-, - - 'w... A IC i"
fie' --�r'``�
..- \ c44:::-. ,..161.410.14,,
il
r
PROPOSED LITTLE CREEK I� - :, . ,
�" + r , / s a�`? YR FLOOD • / •`�r ',. ., . . a r�
10o D a10
TRANSMISSION MAIN ;
/ i
SSI
,,-, .., 1
y • �1 .0
17 .ttlif.,1----, - ,-
, , , _ R
r ���1{i��
i ar: . ... ..' .:; 4')41;40: ' ',1' :.." —*AL*, s.a'.,-,-. .-.ail...-. -.,.._ ;h��t.�.^3... %'6''r -. ,.. "i'' ' . .J`I slh _� _�,�. .."".' ��t 1`+ _�--ti.
s
s N a ;s;nn DateBy Des;gner a`eASNOTED FIGURE 7-3 ACCESS ROAD AND �� WithersRavenel
s Drawn ByDate C LAYTO N W R F 10 Engineersy
Planners Surveyors
Checked By No. TRANSMISSION MAIN WITH FEMA 115 MacKenan Drive Cary NC 27511
t:919 469 33401 license#:C-0832 I www.w'thersravenel.corn

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
7.1.2 Water Resources
7.1.2.1 Surface Water
The study area is in the Neuse River watershed, and the river is the northeastern boundary of the
proposed WRF site. Little Creek also flows through the study area and is adjacent to the existing LCWRF
(Figure 7-1).
The Neuse River is classified into two sections within the study area, as shown on Figure 7-2 (NCDEQ,
2020c):
1. 27-(36)from the mouth of Beddingfield Creek to a point 0.2 mile downstream of the County State
Road (SR) 1700 (North O'Neil Street); Classification WS-V; Nutrient Sensitive Water(NSW).
2. 27-(38.5) adjacent to the proposed WRF site to a point 1.4 miles downstream of the County SR 1908;
Classification WS-IV; NSW.
The LCWRF outfall into the Neuse River will continue to be used as the discharge location.The river's
classification there is WS-IV. As defined by NCDEQ, WS-IV waters are:
"Waters used as sources of water supply for drinking, culinary, or food processing purposes
where a WS-I, II or III classification is not feasible. These waters are also protected for Class C
uses. WS-IV waters are generally in moderately to highly developed watersheds or Protected
Areas."
(NCDEQ, 2020c)
The Neuse River is classified as NSW, which is defined as follows:
"Supplemental classification intended for waters needing additional nutrient management
due to being subject to excessive growth of microscopic or macroscopic vegetation."
(NCDEQ, 2020c)
Little Creek Section 27-43-12 flows through the study area, and its classification is C; NSW (Figure 7-2).
These waters are not used for drinking water and are defined as follows:
"Waters protected for uses such as secondary recreation,fishing, wildlife,fish consumption,
aquatic life including propagation, survival and maintenance of biological integrity, and
agriculture.Secondary recreation includes wading, boating, and other uses involving human
body contact with water where such activities take place in an infrequent, unorganized, or
incidental manner."
(NCDEQ, 2020c)
Section 27-(38.5)of the Neuse River, adjacent to the proposed WRF site, currently supports its surface
water classification designated uses. Other portions of the study area are included in North Carolina's
Section 303(d) List. Section 303(d) of the CWA requires that states develop a list of waters that do not
meet water quality standards or that have impaired uses.The State must prioritize these water bodies
and prepare a management strategy or total maximum daily load (TMDL). Section 27-(36) of the Neuse
River is listed for impairments related to copper and zinc, while Section 27-43-12 of Little Creek is listed
for impairments related to benthos.
The hydrology of the river is used to calculate NPDES permit limits.The Neuse River within the study
area is influenced by the upstream release of water from Falls Dam.The U.S. Army Corps of Engineers
(USACE) requires a minimum flow release of 100 cubic feet per second (cfs) (or 64.6 MGD) during
the summer and 65 cfs (42 MGD) during the winter as measured at the Smithfield USGS gage
(USGS 02087570), which is the closest downstream gage to the study area. At Smithfield, these
minimum releases plus other watershed inputs equate to flow targets of 254 cfs in the summer and
7-7

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
184 cfs in the winter.The 7Q10, or the 7-day, 10-year low-flow statistic at the Clayton gage, 181 cfs, is
just met using the Falls Dam minimum flow release criteria of 184 cfs (Dewberry Inc., 2020).
The presence of streams, riparian buffers, and wetlands at the proposed WRF site was evaluated by
WithersRavenel as part of a field review conducted on October 29, 2019 and March 30, 2020. Stream 1
is perennial and enters the parcel along its northern boundary and discharges into Sam's Branch
(Stream 3) at the parcel's southern boundary(Figure 7-4). Stream 2 was delineated as two segments of
an intermittent stream that flows through the floodplain to the Neuse River in the northeastern portion
of the parcel. Stream 3, Sam's Branch, is a perennial stream that runs along the southeastern site
boundary and discharges into the Neuse River just downstream of the LCWRF outfall (WithersRavenel,
2020a). Because the proposed WRF site is within the Neuse River basin, all four of these stream
segments and the Neuse River are subject to the 50-foot buffers specified in the Neuse River Riparian
Buffer Rules (NCDEQ, 2020d).This evaluation is further discussed in the Clayton Water Reclamation
Facility— Wetland, Stream& Riparian Buffer and Threatened& Endangered Species Assessment Report
(WSBTE Report) included in Appendix L(WithersRavenel, 2020a).
WithersRavenel evaluated the access road alignment for the presence of streams, buffers, and wetlands
during a field review on March 26, 2020. No streams or riparian buffers were identified within the access
road alignment.This evaluation is shown on Figure 3 in the Potential Access Alignments WSBTE Report
included in Appendix L(WithersRavenel, 2020d).
WithersRavenel also evaluated the LC Transmission Main alignment for streams and riparian buffers
during a field review on March 26, 2020. Planned surface water crossings include 10 perennial streams
and 6 intermittent streams. All are subject to buffer rules but are exempt when within existing, cleared
easements.This evaluation is further shown on Figure 3 in the LC Transmission Alignment WSBTE Report
included in Appendix L(WithersRavenel, 2020d).
7.1.2.2 Groundwater
The North Carolina Piedmont region, including the study area, is hilly, intertwined with waterways, and
is predominately underlain by igneous and metamorphic rock initially formed during the Precambrian
and Paleozoic eras. Most of the study area, including the proposed WRF site, is geologically located in
the Raleigh Belt; areas along Little Creek are within the Coastal Plain Belt (NCDEQ, 1985).The Raleigh
Belt is composed of metamorphic rocks of injected gneiss, biotite gneiss, and schist intruded by
numerous sills and dikes of granite, pegmatite, aplite, and hornblende gneiss (Froehling & Robertson,
2020).The Coastal Plain Belt along Little Creek is composed of undifferentiated crystalline basement
rocks of igneous and metamorphic origin overlain unconformably by sedimentary sands, gravels, clays,
and marine deposits (NCDEQ, 1985). Public drinking water sources in the area typically rely on surface
water sources, not groundwater, due to the nature of the geology.
7-8

4.
GRAPHIC SCALE r -�"` I , ,' 4R.- " � ' *
0 200 400
J11 ......... i y (NEUSE RIVER)
1 inch = 400 ft. _ Q PERENNIAL
111
STREAM 2 2 S�
INTERMITTENT
l F9 50'RIPARIAN
- ` BUFFERS
REVIEW AREA
BOUNDARY WETLAND C
Or 50'RIPARIAN
STREAM 1 BUFFER
PERENNIAL `
4' _ WETLAND A
WETLAND B �1' /
Ilk
r, \.,'
'RIPARIAN
„..4411r......o.
"„ / BUFFERS /
4 fi _ .
s `� P- STREAM 3
BOUNDARY •.- .'_. a�400 I / s SAMES BRANCH
G
p O < 5 � � /Q Crye o / '
e `
3 a C \ 0
Ia
g - �? I NOTES:
cs
1) DELINEATION PREFORMED BY WR ON 10/29/2019&3/30/2020.
' 2) WETLAND/STREAM/BUFFER/FEMA LOCATIONS ARE APPROXIMATE,BASED ON GPS LOCATION,
/f JOHNSTON CO.GIS DATA AND TOPOGRAPHIC INTERPRETATION.
_ 3) BUFFER SUBJECTIVITY VERIFIED BY NCDWR BUFFER DETERMINATION LETTER DATED 5/11/2020
1 4.4-- xi. ` (RRO#20-131).
y,... 4) JURISDICTIONAL DETERMINATION REQUEST HAS BEEN SUBMITTED TO THE USACE TO VERIFY
1 WETLAND DELINEATION AND JURISDICTIONAL STATUS.
FA
CLAYTON WRF FIGURE 7-4-WETLAND/BUFFER DELINEATION EXHIBIT
%. WithersRavenel
m1/ Engineers I Planners I Surveyors
i CLAYTON JOHNSTON COUNTY NORTH CAROLINA

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
Froehling & Robertson, Inc. (Froehling & Robertson) conducted a Preliminary Geotechnical Engineering
Evaluation at the proposed WRF site to explore the subsurface conditions in the area of the proposed
WRF. Groundwater measurements were collected from 18 borings where, after stabilization,
groundwater was encountered in each of the borings at depths ranging from 14.3-37.3 feet.
Groundwater measurements were also collected from two temporary wells where stabilized
groundwater levels were measured to be 14.3 feet and 9.4 feet below ground surface (bgs) (Froehling &
Robertson, 2020).
Groundwater is expected to be encountered during construction of the pump station at the LCWRF site
and will be addressed by temporary dewatering as needed. Shallow groundwater tables along the LC
Transmission Main route are likely to be encountered near stream crossings and within wetlands.
Wetlands typically have shallow groundwater within 12 inches of the surface.
7.1.2.3 Wetlands
In general, wetlands share three important characteristics:wetland hydrology, hydric soils, and
hydrophytic plants (USFWS, 2020). Wetlands and vegetated riparian areas are biologically productive
natural ecosystems that:
• Provide wildlife habitat
• Protect water quality
• Control erosion
• Reduce flood damage
The type and area of wetlands in the study area were determined using the U.S. Fish and Wildlife Service
(USFWS) National Wetland Inventory(NWI) maps in GIS format (USFWS, 2013). Although the NWI does
not map all wetlands, it is useful in classifying types of wetlands and their approximate locations in the
study area.
In the study area, NWI wetlands cover approximately 1,850 acres (approximately 5.9 percent of the
study area). Approximately 70 percent of wetland area in the study area is freshwater forested and
shrub wetland (USFWS, 2013).
The presence of wetlands at the proposed WRF site was evaluated by WithersRavenel as part of a field
review conducted on October 29, 2019 and March 30, 2020.This review identified three wetlands (A, B,
and C) in the proposed WRF site (Figure 7-4). Wetland A is within the floodplain of the Neuse River along
the northeastern boundary of the site and is classified as a bottomland hardwood forest wetland.
Wetland B is adjacent to a section of Sam's Branch Greenway near the southwestern boundary of the
site, primarily within the existing transmission main easement, and is maintained as an herbaceous
wetland. Wetland C is in the northeastern corner of the site along an intermittent stream draining
toward the Neuse River floodplain and is classified as a headwater forest wetland.This evaluation is
further discussed in the WSBTE Report included in Appendix L(WithersRavenel, 2020a).
WithersRavenel evaluated wetlands within the access road alignment during a field review on March 26,
2020. No wetlands were identified.This evaluation is further discussed in the Potential Access
Alignments WSBTE Report included in Appendix L(WithersRavenel, 2020e).
WithersRavenel evaluated wetlands along the LC Transmission Main alignment during a field review on
March 26, 2020. Five wetlands are within the alignment.They are within the existing sewer easement
and have been maintained as herbaceous wetlands through regular mowing and maintenance. One
jurisdictional ditch is also connected to two of the wetlands.This evaluation is further shown on Figure 3
in the LC Transmission Main Alignment WSBTE Report included in Appendix L(WithersRavenel, 2020d).
7-10

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
7.1.3 Soils
According to the County Soil Survey, "...a soil association is made up of two or more geographically
associated soils that are shown as one unit on the maps" (USDA, 1994). Most of the soil types within the
study area can be summarized by their broader soil association categories.
The major soil associations in the study area are as follows:
1. Wedowee, sandy loam
2. Pacolet, loam
3. Norfolk, loamy sand
4. Cecil, loam
Soil types within floodplains and adjacent to streams include Wehadkee and Chewacla. Some of the
other soil types present in smaller areas include Marlboro, Rion, and Varina (USDA, 2020). Soils
throughout the study area have been impacted by development, grading activities, and other soil
disturbances. Figure 7-5 shows the soils across the proposed WRF site.
The soils along the access road alignment, mostly Cecil loam soils, were likely disturbed during
installation of the aerial high-voltage transmission line. Wedowee sandy loam soils are also present
along less than 15 percent of the alignment (USDA, 2020).
The soils at the LCWRF site were previously disturbed during construction of the existing facility. Soil
associations include Wehadkee close to Little Creek, and Pacolet and Cecil loams in upland areas
(USDA, 2020). Most of the LC Transmission Main runs along existing utility easements and in existing
roadways;therefore, the soils have already been disturbed in these areas.
7.1.4 Wildlife Resources and Natural Vegetation
The study area primarily includes forested cover, low-density residential areas, higher-density
residential areas in the historic part of Clayton, and industrial and commercial areas. Corridors for
wildlife movement or migration include protected stream buffers, floodplain areas, and forested
uplands. Within the study area, natural vegetation is typical of Piedmont upland and bottomland
communities and some Coastal Plain communities. However, smaller, unique ecosystems are also
present (WithersRavenel, 2020a).
Natural communities typical of those found in the study area are present at the proposed WRF site.
Mixed hardwood and mixed pine and hardwood forests cover most of the site, while maintained areas,
including the access road alignment within the transmission easement, provide travel corridors for
wildlife, including white-tailed deer(WithersRavenel, 2020a).
Upland wildlife communities are home to the following animals:
• White-tailed deer(Odocoileus virginianus)
• Virginia opossum (Didelphis virginiana)
• Raccoon (Procyon lotor)
• Eastern cottontail (Sylvilagus floridanus)
• Gray squirrel (Sciurus carolinensis)
• Red fox (Vulpes vulpes)
• Gray fox(Urocyon cinereoargenteus)
• Eastern mole (Scalopus aquaticus)
• Several species of shrews and mice
Amphibians and reptiles are abundant and diverse. Frogs, turtles, and water snakes inhabit wetlands
and the perimeters of ponds and streams.
7-11

..),,c I 111 \__ - _
•
.../ 1,.....,/,AmiN.- 11/# ♦ % 1 1110 I Wa B
• Legend
, i` e♦% drab 10-ft Contour
River ♦ 0 Parcel Boundary
/A ,��� �i�. �� 100-year FEMA
-D
�i�/ '�� Floodplain
Soils
//� � ���i�'' AaA-Altavista fine
/ � - sandy loam,0 to 2%
_ 7
/ / slopes,occasionally
(10%11:e
����� �/ flooded
CB � '►/ - °4
0110 CeB ��� 6/o slopes
JJ,4�, CeC-Cecil loam,6 to
//� ��/ . /.i� 10%slopes
CeBV i ,��� Ch-Chewacla loam,0 to
,7'
j/ �I 2%slopes,frequently 1
/ / I flooded
\ / GeB-Gilead sandy
\ $ loam,2 to 8%slopes
+. /// complex,
Marlboro-Cecil
.D (11111,111111111111
complex,2 to 8/o slopes
a , kki PaD-Pacolet loam, 10
re 4or 15%slopes
PaE Pacolet loam, 15to 25%slopes
riao
/ 0 WaB Wagram loamy
�I7,10F ////////� sand,0 to 6%slopes
// Wt-Wehadkee loam,0
o........_ _L
to 2/o slopes,frequently
Airiii°7 ///„�� , , / Iflooded
/�� � //�/ �/� w-Water
....._
-- ,
0 500 1,000 N Figure 7-5
A Soils
Feet Water Reclamation Facility Expansion
5M Town of Clayton, NC

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
Typical bird life that make their homes in the backyard habitats and forests of the area includes the
following species:
• Northern cardinal (Cardinalis cardinalis)
• American robin (Turd us migratorius)
• Carolina chickadee (Poecile carolinensis)
• Eastern bluebird (Sialia sialis)
• Eastern towhee (Pipilo erythrophthalmus)
• Wild turkey (Meleagris gallopavo)
• Various sparrow and warbler species
• Other songbirds
Hawks, owls, and vultures are predator and scavenger species known to inhabit the area. Additional
migratory birds and waterfowl also pass through the area.
Specific regulations exist at the state and federal levels to protect endangered and threatened species
and their habitats from impacts due to public or private projects and land-disturbing activities. North
Carolina Natural Heritage Program (NCNHP) Natural Heritage Element Occurrence (NHEO) data were
also reviewed for the project site and within a 1-mile radius; no state or federally listed species are
known to be present in the study area (WithersRavenel, 2020a) (Appendix L).
Information obtained from the USFWS list of Endangered and Threatened Species and Species of
Concern within the County(updated June 27, 2018) was analyzed to identify protected species with the
potential to be present in the study area (Table 7-1) (USFWS, 2018). Federally listed aquatic species and
Significant Natural Heritage Areas (SNHAs) are discussed in Section 7.1.5.
Table 7-1. Federally Listed Terrestrial Wildlife and Plant Species Potentially Occurring Within the StUdy Area
Common Name Scientific Name Federal Status Record Status
Vertebrate
Bald eagle Haliaeetus laucocephalus BGPA Current
Red-cockaded woodpecker Picoides borealis E Current
Vascular Plant
Bog spicebush Lindera subcoriacea ARS Current
Carolina bogmint Macridea caroliniana ARS Current
Michaux's sumac Rhus michauxii E Historic
Source: USFWS,2018
ARS=at-risk species
BGPA=Bald and Golden Eagle Protection Act
E=endangered
WithersRavenel evaluated the potential for protected species at the proposed WRF site, the access road
alignment, and the LC Transmission Main alignment and conducted pedestrian surveys to identify
potential habitat for these species within or immediately adjacent to the site. Potential habitat and
continually disturbed herbaceous areas were observed for Michaux's sumac at each of the locations
listed in Table 7-2. Further details are included in the environmental conditions reports included in
Appendix L(WithersRavenel, 2020a, 2020d, 2020e).
7-13

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
Table 7-2. Habitat for Federally Listed Terrestrial Wildlife and Plant Species in the Project Area
Habitat Present?
Proposed WRF LCWRF Site and
Common Name Scientific Name Site Access Road LC Transmission Main
Haliaeetus Yes,
Bald eagle laucocephalus no nests No No
Red-cockaded woodpecker Picoides borealis No No No
Bog spicebush Lindera subcoriacea No No No
Carolina bogmint Macridea caroliniana No No No
Michaux's sumac Rhusmichauxii Yes Yes Yes
Source:WithersRavenel 2020a,2020d,2020e
7.1.5 Aquatic Resources
Water resources within the study area provide aquatic habitat for various species of fish, freshwater
mussels, and other aquatic organisms. Streams provide free-flowing, warm-water habitats with
moderate gradients; generally alternating pools and riffles; and substrates consisting mainly of rocks,
gravel, sand, and mud. Ponds also provide warm-water habitat. Sportfish species may include bass,
bluegill, and crappie, among others.The Neuse River basin is also home to a variety of other, nongame
species of fish, including several species of catfish and carp (Hook and Bullet, 2020).
NCNHP NHEO data were also reviewed for the project site and within a 1-mile radius. Freshwater mussel
species were identified, as listed in Table 7-3 (WithersRavenel, 2020a) (Appendix L). None of these
species is federally protected at this time; Green floater is an at-risk species.
Table 7-3. NHEOs documented within the Proposed WRF site
Common Name Scientific Name
Triangle floater Alasmidonta undulata
Roanoke slabshell Elliptio roanokensis
Eastern lampmussel Lampsilis radiata
Green floater Lasmigona subviridis
Source:WithersRavenel,2020a (Appendix L)
Table 7-4 presents the list of federally protected aquatic species with records in the study area (USFWS,
2018).There is one aquatic Natural Heritage Natural Area (NHNA) occurring partially within the study area
and partially within Wake County.The Swift Creek Aquatic Habitat follows Little Creek along a portion of
the study area boundary to the south and covers approximately 3.3 acres within the study area. Some of
the species that this habitat supports include the following (NCNHP, 2003):
• Mussels, such as:
— Dwarf wedgemussel
— Green floater
— Yellow lance
— Atlantic pigtoe
— Others
• Fish, including the Carolina madtom
7-14

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
Table 7-4. Federally Listed Aquatic Species Potentially Occurring Within the Study area
Common Name Scientific Name Federal Status Record Status
Vertebrate
Carolina madtom Noturus furiosus ARS,proposed E Current
Neuse River waterdog Necturus lewisi ARS,proposed T Current
Invertebrate
Atlantic pigtoe Fusconaia masoni ARS,proposed T Current
Dwarf wedgemussel Alasmidonta heterodon E Current
Green floater Lasmigona subviridis ARS Current
Tar River spinymussel Elliptio steinstansana E Current
Yellow lance Elliptio lanceolata T Current
Source: USFWS,2018
T=threatened
WithersRavenel evaluated the potential for protected species at the proposed WRF site and conducted a
pedestrian survey on October 29, 2019, to identify potential habitat for these species. No habitat survey
of the Neuse River was conducted due to its depth and lack of water clarity. No habitat for the protected
aquatic species was identified in Streams 1 or 2. Potential habitat was identified in Stream 3 and the
Neuse River(Table 7-5). Figure 7-4 shows these streams.The proposed WRF is also outside the known
ranges for the Tar River spinymussel and yellow lance. Further discussion is included in the WSBTE
Report included in Appendix L(WithersRavenel, 2020b). Coordination with USFWS and NCWRC is
included in Appendix K.
Table 7-5. Habitat for Federally Listed Aquatic Wildlife and Plant Species In the Project Area
Habitat Present?
LCWRF Site and
Common Name Scientific Name Proposed WRF Site Access Road LC Transmission Main
Carolina madtom Noturus furiosus Yes No No
Neuse River waterdog Necturus lewisi Yes No Yes
Atlantic pigtoe Fusconaia masoni No No Yes,Stream 3
Dwarf wedgemussel Alasmidonta heterodon No No Yes,Stream 3
Green floater Lasmigona subviridis No No No
Tar River spinymussel Elliptio steinstansana No No Yes,Stream 3
Yellow lance Elliptio lanceolata No No Yes,Stream 3
Source:WithersRavenel,2020b,2020c,2020d;Appendix K
Additionally, the Neuse River provides habitat for anadromous fish, including the Atlantic surgeon
(Acipenser oxyrinchus) and the American shad (Alosa sapidissima).These species move between
freshwater and the ocean during their life cycles. After dam removal projects on the Neuse River,these
species have access to the river at the outfall location and can travel farther upstream. Atlantic sturgeon
are born in rivers along the east coast and migrate to the ocean, returning upriver to spawn.The Neuse
River is included in designated critical habitat for this species (NOAA, 2020).The American shad have a
similar range, using east coast rivers to spawn. Spawning has been recorded in the Neuse River,
designated as an Inland Primary Nursery Area for the species,farther upstream than the outfall location
(NCDMF, 2014; NCWRC, 2020a).
7-15

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
No streams cross the access road alignment, as observed during the WithersRavenel pedestrian survey
on March 26, 2020;therefore,there is no potential for protected aquatic species (Appendix L)
(WithersRavenel, 2020d).
WithersRavenel evaluated the potential for protected species along the LC Transmission Main
alignment, as well as conducted a pedestrian survey on March 26, 2020, to identify potential habitat for
these species. Habitat was identified in the largest of the streams, Sam's Branch (Stream 3), for the
following species:
• Atlantic pigtoe
• Dwarf wedgemussel
• Tar River spinymussel
• Yellow lance
The proposed alignment crosses Sam's Branch two times. Figure 7-6 shows these areas. Details are
included in the LC Transmission Main Alignment WSBTE Report included in Appendix L(WithersRavenel,
2020c).
With habitat for protected species identified in Stream 3, and the NCNHP's response to project scoping
(Appendix K) noting that other freshwater mussels were found in surveys near the WRF site,
WithersRavenel requested additional details from NCNHP and North Carolina Wildlife Resources
Commission (NCWRC).Their database includes survey results for the Neuse River at bridges immediately
upstream (Covered Bridge Road) and downstream (NC 42) of the proposed WRF site.Table 7-6
summarizes survey results over the last 10 years for the Neuse River near the LCWRF outfall.
Table 7-6.Survey Results for the Neuse River near the Little Creek Water Reclamation Facility Outfall
Common Name Scientific Name Year(s)Found(last 10 years)
Box spike Elliptio cistellaeformis 2018
Carolina slabshell Elliptio congaraea 2014,2018
Eastern elliptio Elliptio complanata 2014,2018
Eastern lampmussel Lampsilis radiata 2014,2018
Green floater Lasmigona subviridis 2014
Roanoke slabshell Elliptio roanokensis 2014,2018
Triangle floater Alasmidonta undulata 2014,2018
Variable spike Elliptio icterina 2014,2018
Source:NCWRC,2020a
7-16

111.‘
r i. y�1 ' .,,• _ /1Ir h.,, ...4
yy ��'wL '‘' -, ? { y .; yy • r , 1; GRAPHIC SCALE
�� + �s ^l'�ti ry1k.y �% .• \ ` .l;rFr _ ;:_ u, 0 600 1200
i, _ y�:a ar 4 L'.��r�•..,,, r{; ;��it %.t` is :�,, •'Yr.:•r- !•� - ''53-• .,i,. m
• 6a "-�+y '� v x a 1i '". -\y '•i, t •vi'.`Y, r ?� .• 1 Inch = 1200 ft.
J.
irriv
a ..:s'..., !ti; �• iti Syr..,r n � '[ O F
i;w ^' r �a•�: Y} �' y' r r +i?. (A� L: }4'' •
Z. C':' ii.�'::a: it
9 R '! �'. r"
•
s.ei• f a- m Vr = ,'''d • r'1•:.. '$� : -.Tr:,4 rr/r) STREAM 1 i
,� `� ..r.- S- ! °tic
u., , `�Z � r A'� €�,^ a•` >4 / '`�•1 I' R `e j
• PERENNIAL PROPOSED CLAYTON t y •
t. �c'C{ y . •�Y �/'y ,: �, '�k,s�+ r�L'/ iY, ' 1� ,i ads 4 - f I WRF SITE
, OD Iti.41r-
/ `�ti y �.' r�p z.� ?It,t i r } VF r 1� t E
ry • ~�� � r ::,:. hC y 14• .�,.^ { STREAM 14 +I -
'► '• t '. ``e t,;^ r.- • INTERMITTENT - / ..
* � STREAM 12 - „cli .L ..,.4, .
F. - a;' -• ' �4�.� t_. 1 ... - I INTERMITTENT
4, �•` r * ' STREAM 15
fIr
• ii + +^ ��• _ INTERMITTENT STREAM 6 i I '-�•
Y' �'" • •• • •� �. - - INTERMITTENT , .,. •
•
.• x2r'" .!' , 410t .WyRi a - [tr-r' - 17 M1 '� - .- - O. ., ar '.L.
q �. ✓ •' n (r �y "y- STREAM 16 STREAM 13 4 r
• . •. + y ;,fit :'+ ti`12.'IV,.
.• �y fi" INTERMITTENT :�
,Y_ r - yr.�7�.. l � .. R�• �`"p{. -ae'`�'y° - L•' .��•. -1•-,.,7dt'{ PERENNIAL�' LI w.,�
r :I"•,' , _ _ A .0-y ^o. �3b' ..• tt!` er:• .: 4'A_ 4,. , •* STREAM17 t R 'F ±1�
• $ • � ti - .'rY.'•, A�. s ,.Y A -,1 f: ti .R. ,f- _ -'. PERENNIAL a --N
;ir a .. •a ► iT $ �y . ' a• STREAM 19 y i'
° f �- r� ,� L' *•_:'.:C�' /. y ."y __ s' c'. y-- - PERENNIAL
•
V ,. ! ,. A • ""' 5, •'M1 ",.0 .{ �4. ' STREAM 18
.�• _ 1L� �•'r:, ��'. .��►'Clf' ' .. r .ya r �% `�� ^���.: - ,. * IPERENNIAL _��• rt•?.._ c
0: N, ': •Aot . STREAM 20 .• A
i r
dr '�:' • T'c a "1i. 9 . • Yc PERENNIAL _ •i ''�". _ ..�[e e
,-V ,\ fi "� 5 T t :- :sl STREAM 24 a, ■ ,' �'
a;a'i' ±,' {` �� LOCATION OF POTENTIAL HABITAT (SAM'S - '. '4 .• t
' '� (.1 , "y yR*.7.'.'::' : .pm\ .. '• r:�'•.'.L: PERENNIAL 0' ■� -
'.. r* ' ',+~ yam G ' ��y s� ` � ° c#+ w , . ' �'`• sti NDr PNCOVa1 + STREAM 3 BRANCH CROSSING)FOR THE FOLLOWING ee L:._.
d'`�:,-^* .. '' N. r, .• EI .-' .r` . :RA,i� ■ (SAM'S BRANCH) AQUATIC SPECIES: �'.,• ;
,r` ay -0
F • PERENNIAL
:. . r+ ' � ,. :•1`'t_ cL. ■ ''• i • DWARF WEDGEMUSSEL o
-' i y Ycc 0
• TAR RIVER SPINYMUSSEL
'h L. ,\ :;. `.'• f � 1r,r-"'•`\ .,,,g , ..,.-4, t., 1 ?/.;v. i_ - �. STREAM 21 • YELLOW LANCE cc
F .; • ' .��. +t a�' L► !-. i -r PERENNIAL • a
.. k i', t0.6 ' F', r �. • ATLANTIC PIGTOE _.
fir^ ..•; r, y. - : -•.• .F W
� _ . _ , . .. 46.' . ,41I* y
14
3 . ',:-` V` x' LOCATION OF POTENTIAL HABITAT (SAM'S '; r�
•'• .• "."y,iia, ik �' _ 4•I''' ' 1 '' r ;'' .. ;t. r, l ; m BRANCH CROSSING)FOR THE FOLLOWINGIlif °�
a` �L ri R} q�� � � � Y�,- n� •, aZ n �1yt1v`d SPECIES: y =�;
a • -�� .. ✓ .r.. -r i r '` v� 'a"` • DWARF WEDGEMUSSEL �,. .; •''
yr. _,�r� ` .��` " � ;. .. 4* N'. .. '="�±� • TAR RIVER SPINYMUSSEL a _
....4'-4:.. ',Il,,..A
s e -y p' ;';P -: ''" r • YELLOW LANCE +
/ -, . LITTLE CREEK TRANSMISSION I'" m
`� r~.•• a • ATLANTIC PIGTOE ^�►a'1�+�
• A '* I• t' MAIN REVIEW AREA i '
• a.
a ia. F y T# STREAM 3 t' _ x ��� r i010
{ . �
12. •!• •` 1 Te• s (SAM'S BRANCH) �p r�� _ _
'tr.- f j �•. rk•', "^• EXISTING LCWRF PERENNIAL •
- ,' :'1. + -F..it. !►� R i.- FACILITIES + _ � -
.4N 711 fr-C-'-' 4
I -0: '.4 - -:At .; ,..."„ if, .„. . ,..-, -' I, - • - - - ,..„.„.„ ..-,.. ( , . -._, - 0
v �.. = �i ;.'....lesi., � �. .4' .)4.
STREAM 23 T� `. •+.^�f F
++ • y INTERMITTENT' _ 90 �r ,5y [}'- �+•). _ -
E rk r Y. _rr• 4C� , _ ')'T - II r �� - i-- 'a
-Iv If.. SIIW.1.. EIMEIMIll
E -\ ` •�- � ' _ Eke
_ ^�^ a 1Z'f•r{e , Fop: . .5':547. , :u' f' V ti vt 4�d
t. �,�►+.� STREAM 22 p I i �. �.x
" URy PERENNIAL r .,C.a.r. ��...,. - U 1•• i 1
s �' EXISTING LCWRF 4ryj /a }
~�' FACILITIES STREET ,'* !A. '•,, !; l �� �. p•R — lr•�s• �yRy�
u • _ .dam ..f et •s, •x •"� ;�,,� •+, -, r }-
4
�P51gnef Ii WithersRavenel
s0, CLAYTON WRF - LITTLE CREEK TRANSMISSION MAIN FIGURE 7-6 - AQUATIC SPECIES HABITAT 1No
o�w ev oar
.. ouwnmo
mchecked By lob No. 1/ Engineers Planners Surveyors
i •O 02120241m CLAYTON JOHNSTON COUNTY NORTH CAROLINA

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
7.1.6 Land Cover
Existing land cover and land uses for the study area and proposed WRF site are summarized from the
2016 National Land Cover Database (NLCD).Table 7-7 presents the land cover classifications and
respective acreage and percentage in the study area (USGS, 2016). Land cover in 2020 is likely
somewhat changed, as development has been occurring in the study area.
Table 7-7. Land Cover Classifications by Area and Percentage of the Study Area
NLCD Grid Code NLCD Classification Area(acres) %of Study Area
11 Open Water 312 1.1
21 Developed,Open Space 5,046 17.0
22 Developed,Low Intensity 2,363 8.0
23 Developed,Medium Intensity 854 2.9
24 Developed,High Intensity 266 0.9
31 Barren Land(Rock/Sand/Clay) 55 0.2
41 Deciduous Forest 4,218 14.2
42 Evergreen Forest 3,391 11.4
43 Mixed Forest 4,760 16.0
52 Shrub/Scrub 243 0.8
71 Grassland/Herbaceous 1,025 3.4
81 Pasture/Hay 3,054 10.3
82 Cultivated Crops 2,372 8.0
90 Woody Wetlands 1,683 5.7
95 Emergent Herbaceous Wetlands 59 0.2
TOTAL 29,701 100
Source: USGS,2016
Approximately 29 percent of the study area is developed, mostly developed open space and low-density
development.A portion of this developed area is the ECIA, which has a strong pharmaceutical customer
base that continues to invest and expand their capabilities, increasing wastewater capacity demands.
Approximately 46 percent of the study area is currently forested, grassland, shrubland, or barren.
Of these classifications, mixed forest is the largest cover type, at 16 percent of the study area.
Approximately 7 percent of the study area is wetland or open water(USGS, 2016).
Approximately 24 percent of the study area is located within a water supply watershed, WSW-IV, as
shown on Figure 7-3.This area has developed area restrictions, with developed land covers in the low-
to medium-density development categories.
The proposed WRF site includes greenways along Sam's Branch and the Neuse River.The greenway
along the Neuse River, the Clayton Riverwalk, is part of the Mountains-to-Sea Trail (Figure 7-7).
The proposed WRF site also includes the Neuse 2 and Clayton to Raleigh Pump Stations,the LCWRF
outfall to the Neuse River, and easements for conveyance lines paralleling these greenways. An
electrical substation and associated power line easement are also on the property,visible along the
western property line on Figure 5-1.
7-19

�?Et AO
y 'a x3 FYd4 n �i# F
_- - - iVit Pik _: .vvr-"' PY .''�` ,.;
1
-' '''';-: TT 4-;•..7-414:4; -,' ',/:,';•:?P'-,7 :0•40.,„ -—,, -0,4,..',,1",*; imk
/ k *'FYI• F _,j�
4'Y'�° xfv� `" `; ' * x Neuse 2/Clayton to Raleigh y Y"y ` Little Creek ,� `
u Stations�� ',� � � Pump St ns �, �� W utfall
•
#. • s'° h 't �.' �.,�' • 4 •'�N„ ea 'gyp' i .;"'�` .'• Ww .4" y h'` `�,`° .+'
. - ^ d ._x • x�" ar� h f Kiu r' " e� Max �r�
u " �':-` ° - '+;�inC .�k.w ad y:: t„ .. �i- - = a ° C: r g�1 ', 4 �.' �a''' 5 �� '"r.
,\A
`.. a .' �'���w J/ ,�rY* n :� s!,4,-4 4„ { 04;%,; -a :i• fi . ►{ '^i 4
n,ost. ..i-,r - i J + ' .:r', p, Y t G. "„ .. `'�"Y�,§^=.1+` �+ °,, .,_.a ', s y2`. `�R a r` '?s "a" f't
. x •. - '. V 't' . � �� t - ,' �3. _ wr. 11Ii 7 r f k�' 1 � s k - ' -_ ,�fi. . ,„--it ti�Eq.
1
s \ Q`l # a" «
/f
per,
.: � .. �.K.' w.. •.
. fs �' s �,x��+sumYxt .t� '�* _ � r'.'#,. '� s � t'A,. of p;��•�
a
: ,tom ,�cr ,�� .Y. , �h.y ' - •fir y°•.,- aJPti{ � 1 ,x`. ;.',,�'tfQ'`„. fi r- �,
e
ti r `;pt � 7.A..�"3.wn� kt r � 4, V h �GJv � „`,fit .\. }'�
� '.+cyt - '�}vr ��' ,.�•.• +,t4 � "R� � ;,. � *S r.e*+�P.^„ '{�yy � 7� � K �l k �� u, n u
•" ` • °�' 1 �„'t ,ram":,gyp
N'e
� A 0 ;} �, " Legend
Greenway
' ■■�■�,, Proposed WRF
"meµ.' ■■■ Site
W �w . ,: A-,,,,,,....
Source: kNC;,Orthoimagery Program (2017)
Figure 7-7
0 500 1,000 N Proposed WRF Site
di •
I I I Water Reclamation Facility Expansion
Feet Town of Clayton, NC

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
The existing LCWRF, future site of a pump station, is also included in the developed land cover category.
The LC Transmission Main alignment is within an existing utility easement for most of its alignment.The
access road alignment runs along an existing aerial high-voltage transmission easement that includes a
mix of maintained vegetation and borders forested area.
7.1.7 Agricultural Land and Prime Farmland
The U.S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) has classified
farmland into three categories based on suitability for agricultural uses (USDA, 1981):
1. Prime farmland is of major importance for meeting the nation's short- and long-range needs for
food and fiber with minimal input of energy and economic resources and the least damage to other
environmental resources.
2. Unique farmland is land other than prime farmland used for production of specific high-value food
and fiber crops.
3. Farmland, other than prime or unique farmland, is land of statewide or local importance for the
production of food feed, fiber, forage, or oilseed crops.
An analysis of cultivated areas was conducted using the 2016 NLCD satellite imagery(USGS, 2016).
Currently, agriculture comprises a small portion of land cover(18 percent) in the study area.These lands
are dispersed throughout the study area, with a higher concentration in the southwestern portion of the
county.These agricultural areas include pockets of cultivated row crops and pasture areas. Some major
crops include (USDA, 2020):
• Corn
• Cotton
• Peanuts
• Soybeans
• Tobacco
• Wheat
Prime farmlands are present in portions of the study area with loamy soils.The major soil types in the
study area are (USDA, 2020):
• Wedowee
• Pacolet
• Norfolk
• Cecil
Of the major soil types within the study area, the classifications are as follows (USDA, 2020):
• Prime Farmland: Wedowee with 2-8 percent slopes, Norfolk loamy sand, and Cecil with 2-6 percent
slopes
• Farmland of Statewide Importance (those with steeper slopes): Wedowee with 8-15 percent slopes,
Pacolet with 10-15 percent slopes, and Cecil with 6-10 percent slopes
• Not Prime Farmland: Steeper sloped soils, Pacolet with 15-25 percent slopes, and likely disturbed
soils within the Norfolk urban land complex; Chewacla soils must be drained to be used for
agriculture
Of the other soils mentioned in Section 7.1.3 and minimally present in the study area, Marlboro and
Varina are listed as prime farmland, and Rion is not prime farmland (USDA, 2020).
Many of these soils throughout the study area have been affected by development and other soil
disturbances and are not currently being used for agriculture.
7-21

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
No agricultural uses are present at the proposed WRF site (Figure 7-7); however, soils are listed as
farmland of statewide importance. Approximately 35 percent of the soil types within the proposed WRF
site are listed as prime farmlands.These include Altavista and Cecil with 2-6 percent slopes.
Approximately 10 percent of the soils are Cecil with 6-10 percent slopes and are listed as farmland of
statewide importance (USDA, 2020).The remainder of the site, 55 percent, is not prime farmland and is
steep or in the floodplain. Figure 7-5 shows the soil types at the proposed WRF site.
The soils along the access road alignment are primarily rated as prime farmland.The LC Transmission
Main alignment has some soils rated as prime farmland, but most are not. No cultivated agricultural
uses are currently occurring where these soils are present along either alignment (WithersRavenel,
2020d, 2020e).
7.1.8 Forested Resources
Forested areas may provide wildlife habitat and timber, and may be buffers that protect water quality in
local streams by slowing stormwater runoff and removing nutrients, sediment, and other pollutants.
These areas can also be used as a buffer or screen between incompatible land uses. Forested areas, if
large enough, can provide economic value through harvesting.
Approximately 41.6 percent of the study area (12,369 acres) is in forested land use (USGS, 2016).The
North Carolina Gap Analysis Program (NCGAP),which describes forested resources within the study
area, was used to further detail the types of forests. NCGAP is based on land cover data and not land use
data, which are limited by parcel boundaries.These data provide a better understanding of the types of
forest resources present within the study area.The most dominant forest type within the study area is
Southern Piedmont Dry Oak-(Pine) Forest; others include (Table 7-8) (USGS, 2011):
• Managed Pine
• Atlantic Coastal Plain Dry and Dry-Mesic Oak Forest
• Southern Piedmont Mesic Forest
Table 7-8. Forest Types within the Study Area
of Study
Type Area Typical Species
Southern Piedmont Dry Oak-(Pine)Forest 26 Upland oaks,hickories,pines,red maple,sweetgum,and tulip poplar
Managed Pine and Harvested Forest 15 Loblolly and other pines, poplar
Atlantic Coastal Plain Dry and Dry-Mesic
Oak Forest 0.2 Upland oaks,water oak,laurel oak,hickories
Southern Piedmont Mesic Forest 0.2 American beech,northern red oak,tulip poplar,and red maple
Source: USGS,2011;NatureServe,2020
There is one NHNA occurring partially within the study area. NHNAs include sites that exhibit
biodiversity significance because these areas are home to rare plant or animal species, high-quality
natural communities, or important animal assemblages.These include spaces within public lands or
private conservation lands held by nonprofit organizations; the most important sites are protected
through partnerships.The sites included in the list are the best representatives of the natural diversity
of North Carolina;therefore, they have priority for protection. However, inclusion in the list does not
imply that any protection or public access exists.
7-22

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
The Neuse River (Clayton) Forests occur in sections along the Neuse River and cover approximately
369 acres within the study area. Some of the natural communities that the entirety of this habitat
supports include the following (NCNHP, 2003):
• Piedmont/Mountain Levee Forests
• Piedmont/Mountain Bottom land Forest
• Mesic Mixed Hardwood Forest
• Dry-Mesic Oak-Hickory Forest
• Piedmont/Coastal Plain Heath Bluff
Some larger parcels of forested area could be used for silviculture use. Forested areas being converted
to other land uses provide a one-time source of wood products.
Vegetative communities at the proposed WRF site were characterized as part of a field review
conducted on October 29, 2019 and March 30, 2020.Three distinct vegetative communities are present
(Appendix L) (WithersRavenel, 2020a):
1. Mowed and maintained grasses and landscaping areas
2. Mixed hardwood forests
3. Mixed hardwood and pine forest
This forested area is further described as primarily Southern Piedmont Dry Oak-(Pine) Forest, which
covers approximately 68 percent (54 acres) of the parcel (USGS, 2011). Figure 7-7 provides an aerial
(2017)view of the site showing the forested areas.
Vegetative communities along the access road alignment and the LC Transmission Main alignment were
characterized as part of a field review conducted on March 26, 2020. Most of these areas are mowed
and maintained grass, with early successional and mixed hardwood and pine forest communities also
present (Appendix L) (WithersRavenel, 2020d, 2020e).
7.1.9 Public Lands and Scenic and Natural Areas
This section discusses public or conservation lands; federal, state, and local parks; and other scenic and
recreational areas, including recreation areas, greenways, and gamelands. Figure 7-8 shows the Town's
mapped public lands.
Open spaces provide scenic and recreational opportunities for residents.The NCNHP maintains data on
public land and scenic and natural areas. Managed Areas (MAREAs) are sites with management goals
that include natural resource conservation.The MAREAs in the study area include a portion of the
Clemmons Educational State Forest and the North Carolina Department of Agriculture &Consumer
Services Central Crops Research Station to the northwest.Throughout the study area, there are also
several sites and easements for mitigation and conservation managed for biodiversity, including a
Triangle Land Conservancy Preserve (NCNHP, 2020a).These MAREAs contribute to protecting the
NHNAs discussed in this section. Although there are no state parks within the study area,there are
several local parks and greenways throughout (Town, 2020b).
The proposed WRF site includes greenways along Sam's Branch and the Neuse River, as shown on
Figures 7-7 and 7-8. Sam's Branch Greenway includes an art walk and picnic area.The greenway along
the Neuse River, the Clayton Riverwalk, is part of the Mountains-to-Sea Trail (WithersRavenel, 2020a).
Gamelands provide the public with recreational opportunities, including hunting. Gamelands were
reviewed using NCWRC interactive maps, and there are no gamelands within the study area (NCWRC,
2020b).
There are two NHNAs occurring partially within the study area.The Neuse River(Clayton) Forests occur
in sections along the Neuse River and cover approximately 369 acres within the study area.The
7-23

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
NEU/Swift Creek Aquatic Habitat follows Little Creek along a portion of the study area boundary to the
south and covers approximately 3.3 acres within the study area (NCNHP, 2020b). Neither of the NHNAs
occur within the proposed WRF site or other associated project infrastructure.
7.1.10 Archaeological and Historic Resources
Archaeological sites are important because they contain the only material remains of Native American
cultures dating back 12,000 years throughout North Carolina.The Neuse River basin contains many
archaeological sites that have been surveyed. Several of these sites have significant archaeological
resources from many native groups that lived in the region up until 200 years ago. Because of the size of
the study area, preparation of an archaeological survey was not completed for this project.
A desktop review of resources at the proposed WRF site was performed by the State Historic
Preservation Office (SHPO), as documented in the letter included in Appendix L. No historic resources
are known to occur at proposed WRF site (WithersRavenel, 2020a). Given previous land disturbances at
the LCWRF and along the existing easements of the transmission easement access road alignment and
LC Transmission Main, it is not expected that archaeological resources are present at shallow depths.
The National Register of Historic Places (NRHP) is the formal repository of information pertaining to
historic structures and districts, as well as cemeteries and archaeological sites, and is the official list of
the United States' (U.S.'s) historic places worthy of preservation.The study area contains many listings,
including the downtown Clayton Historic District (Table 7-9) (NPS, 2020). With over 300 homes and
buildings, the Town's Historic District is bounded primarily by Mulberry Street, W. Barnes Street, Mill
Street, Lombard Street, and Blanche Street. Across U.S. 70 Business from this historic area is the
Maplewood Cemetery,which includes Smith Street access to the LCWRF (Figure 7-8) (Town, 2020b).
There are no historic places at the proposed WRF site or the LCWRF or along the LC Transmission Main
route (Figure 7-8) (NPS, 2020).
Table 7-9. National Register Historic Places in the Study Area
Listing
Clayton Banking Company Building
Clayton Graded School and Clayton Grammar School—Municipal Auditorium
Clayton Historic District
Ellington-Ellis Farm
Stallings-Carpenter House
Source: NPS,2020
7.1.11 Air Quality
The U.S. Environmental Protection Agency (EPA) uses the Air Quality Index(AQI)to report ambient air
quality conditions.The AQI includes these classifications:
• Good
• Moderate
• Unhealthy for sensitive groups
• Unhealthy
• Hazardous
7-24

Appendix B: Maps
Context Features 7:4•7•07,, E.'D
�'•'� jp� �¢ p ° •
e
Clayton ETJ o= o °�, . e� ° :° -�
. Pe' 1 ' ''tE .,1 ,,,rt.6.,„.67..''41 2
County Boundaries 8a ,, ,, .
J ( c o- I • I
l — .° fla
J Town Limits o/D •�o. '11,
r `�` -1: it*
.e� ®�ji -' ' o/ • `Bq
Highways MRD .r • j.-.ram' i •�,-°- Emia
o ° 2� ' ,
Clemmon -t . ational )'
I ,. - V gig Arm Creek
Local Roads State For: 1NP a 10 '' l ` •
. ,.,r Creek .��1 1 ARCHER
mii
Natural and Historic Features* -Y 0 a;,`j'--�-.�r, w "- �� % LODGE )6,40
1 CaWetlands \ �� \ ��' ? 4 ���ro" •
r:+ • 'fir li
• Floodplam , °,� IFOA_TO
, ` ,
Streams j a o .° �. �,`.ei° ° ' I - PI
CI)
Parks and Open Space �o �, kl a 0oi , 4° ! \`
NHP Natural Area �a I Go, �oio . , ...
�"� -� � North Clayton ,�°
Areas Important to Biodiversity* j iI,� �� al
► "y� �* / �� :j Community Park,,, s ,, ��,.°
Tree Canopy _.. z/f, (Planned)
��$ Steep Slopes (>15%) 04i°. i f2� tl fitoii,il lit-. 1:).
l
o „„
w . (I I Leg in .� ix r �. IfAivar
qiiii Historic Structures � % I -,i • i• i Parl — 1. _ � { 4e
4... v_ : :::,... , ,. . „... ..)„,
... ..., i ,„ ., r, A, .
.. , , • ,, t, • , Alto Emia
fills ,
`L..1 tif it... _, 4 . --L-,,,,4 1
• i r . ,-,, .I , .J !( - t e.- CI
.: '---7----1---; •.
i it,. i ,zi / .,
, % ' fp, . , .., mii
•
r r / _ �`�. °, "Adie or! po• - -Nm -
_ Pant Clay 1rV
sili leis ',a.. :
- i - !N 'Mk 54.ai 0
0 ,�.A .=°, _Park U .. �J
° i Clayton f :�yrRp oMgPR ` . i" �' I NE S�S'i,.
` tr il9munity '.N . -�..' .a , 't F'F"orvr "F... mri
61 s al)
- ,.- " i Park i ^ ��'7 1 �� �" ? ��� ter- —•.�f' - r'
RD l . 7 Y s° Imo, �� 0 II L6 N ffi
Ir ' iii. 1616. , \ ,�I ',�_ b/ �� •
.- 1 ON RD it 41 r .
, a
.,"- ci'4)14 Ci)
' • iliiifillib, imia
) e ,, I „It ,
. v.- pi-- _iii. . ‘ L, 40PP '141:41 _*t4I, _,it 'i
k. L} "'' . tollihN ,i,...1, -.a 7 im....--..„ ._,.:._,,o)
AL. Ahati4 •N, 40, `S 0 <,,, - •,.., ...., . ,
0.!..i ie 10 • -Ile ---A0 ti .0 di
I ' 1111/ WI- - jk_. ,,,, ..,: " I'ir ° si , \I-i_._ `, g i i. . v •_-.7,.," ' . .. .
al)
` c u 1 l,i- �P
46
Fielegj
sct
ilfr _...... <5
t . p
? 10,0 1,11 r :11 . ,, : en
0'20
s OP
e 44-41 sk,.0 .
m d A • I c,
lior.. 0,-4,-*.N
A Figure 7-8
_ o F Natural and Historic Features
0 0.5 1 *Areas important to biodiversity based on �. � �° ° Water Reclamation
ti�J� Miles NCDENR Biodiversity and Habitat Assessment dataib
o, iz° • , Facilit EX ansion
. y p
° R S 7 ° -. • WILSON'? Town of Clayton, NC
l �� ' 13w IT 1 � ° °. ° ,va l r— f + r MILLS
Comprehensive Plan 2040 : 63

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
The index is based on levels of pollutants and includes:
• Ozone
• Particulate matter
• Carbon monoxide
• Sulfur dioxide
• Nitrogen dioxide
• Lead
In 2019, the median AQI in the County was 40, or good.There were 69 days considered moderate. No
days were considered unhealthful or unhealthful for sensitive populations (EPA, 2020a).
To minimize odors from their collection system, the Town installed odor control systems on an outfall
line that crosses NC 42. Prior to that, community complaints or staff observations about odor occurred
multiple times a week.The Town also installed odor control inserts on manholes along the Clayton to
Raleigh Transmission Main, as odor complaints from the community were also frequent due to minimal
flow and water age. Since that system was installed in June 2019, only two complaints have been
received (Poelman, pers. comm., 2020).
7.1.12 Noise Levels
Within the study area, noise is created primarily by development along the U.S. Highway 70(U.S. 70)
and NC 42 corridors, rural residential activities, and agricultural activities. Construction activities that
occur with development are temporary.Typical residential noise sources include lawn mowers, leaf
blowers, and barking dogs.This noise is generally concentrated during daylight hours. Noise is also
associated with agricultural activities.
The proposed new WRF site includes greenways along Sam's Branch and the Neuse River. Adjacent
properties include industrial uses, such as Caterpillar, which also generates noise that may be heard on
the proposed WRF site and at the greenways.The proposed WRF site also includes the Neuse 2 Pump
Station, the LCWRF outfall to the Neuse River, and easements for conveyance lines paralleling these
greenways. Public activity on the trails is not hindered by noise from current Neuse 2 Pump Station
operations and adjacent industrial land uses.
The LCWRF site includes current treatment operations, generating a minimal amount of offsite noise
mainly from truck traffic entering and existing the site. Properties adjacent include Maplewood
Cemetery to the northeast and residential neighborhoods surrounding the other sides.
7.1.13 Toxic Substances and Hazardous Wastes
Prior to the 1970s, few controls were in place to control the discharge of hazardous wastes into the
environment.Toxic substances and their cleanup are enforced by EPA regulations under the Resource
Conservation and Recovery Act (RCRA) and the Comprehensive Environmental Response, Compensation,
and Liability Act (CERCLA). Permit-requiring activities within the study area include:
• Treated water discharge permits
• Dry cleaners
• Pharmaceutical manufacturing
• Industrial activities
Permit-requiring activities near the proposed WRF site include the LCWRF outfall to the Neuse River. An
Environmental Data Resources (EDR) report was generated for the project area (WithersRavenel, 2020e)
(Appendix L). No superfund sites are within the study area (EPA, 2020b). Other existing sources include
those materials disposed of from agricultural and household activities.
7-27

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
Previous activities at the proposed WRF site related to the Town's law enforcement firing range resulted
in lead contamination of soil. Use of the area as a firing range was discontinued in 2019, and
remediation activities are underway to remove lead soil contamination.These activities are further
discussed in a WithersRavenel report (2020e).
The access road alignment runs along an existing aerial high-voltage transmission easement that may
use chemicals such as herbicides and defoliants during maintenance. No known sources of
contamination were identified along the access road route (WithersRavenel, 2020e).
The LCWRF currently uses UV in the disinfection process, avoiding the use of chlorine gas. Fuel for the
emergency generator is stored onsite using best management practices (BMPs).
Along the LC Transmission Main alignment, four sites with a potential moderate risk of contamination or
higher were identified (WithersRavenel, 2020e).Two of these sites are at the intersection of Durham
Street and U.S. 70. One of these four sites, Clayton Spinning Mill Brownfields,was also identified by the
Division of Waste Management during project scoping as being a recorded brownfield site (Appendix K).
7.1.14 Environmental Justice
The guidance provided in Executive Order 12989 and the EPA's Final Guidance for Incorporating
Environmental Justice Concerns in EPA's NEPA Compliance Analyses were applied.The goal of this
process was to support the "...fair treatment and meaningful involvement of all people..." during project
planning (EPA, 1998).Three sites were compared for this analysis:
1. The preferred site at the Neuse 2 and Clayton to Raleigh Pump Stations property
2. The existing LCWRF
3. The R. Steven Biggs Regional Pretreatment Facility in the ECIA
Appendix H provides the full analysis.
Johnston County, including the Town's wastewater service area, has been experiencing a high rate of
growth in the last decade.To address this growth not being fully reflected in the 2010 Census data, both
2010 Census data and future projections as captured in the NC Capitol Area Metropolitan Planning
Organization (CAMPO) dataset were reviewed as part of this analysis (CAMPO, 2019). Household income
and demographic statistics for the areas surrounding the alternatives were calculated using data from
the Census' 2017 American Community Survey(ACS) for Johnston County(Census, 2019). Each of the
three sites were assessed using a 0.5-mile buffer, with data summarized for all Census blocks or block
groups falling partially or completely within that buffer.
Table 7-10 shows a characterization of residential populations within the 0.5-mile buffer of the sites,
both in 2010 and under future projected conditions (Census, 2020; CAMPO, 2019). Comparing the
dwelling units between the LCWRF site and the proposed WRF site, there is a marked decrease in the
number of neighboring dwelling units from the LCWRF to the proposed WRF site.
Table 7-10. Number of Dwelling Units within a 0.6-Mile Buffer of Site Boundaries
Location 2010 Complete Census Blocks Future Projections Using CAMPO Data
LCWRF 2,363 2,972
Proposed WRF 298 1,785
R.Steven Biggs Regional Pretreatment Facility 283 190
Sources:Census,2020;CAMPO,2019
Household income data are included in Census statistics only at the Census block group level.These block
groups are relatively large and cover a wide area; with this analysis, the 0.5-mile buffers for the three sites
overlap. When comparing the WRF sites,there is no discernable difference between the sites.
7-28

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
Information on racial demographics was available at the Census block level,which represents a smaller
area than the block groups used for determining poverty status (Census, 2019). Nearly 46 percent of the
population within a 0.5-mile buffer of the LCWRF is considered minority, which is greater than the
Johnston County value of 30 percent. In comparison within a 0.5-mile buffer at the R. Steven Biggs
Regional Pretreatment Facility location, 23 percent of the population is considered minority. Only
9 percent of the population within a 0.5-mile buffer of the proposed WRF location is considered minority.
7.2 Environmental Effects and Mitigation
This section analyzes the potential resource impacts in the study area (Figure 7-1) and project footprint
as a result of the Town's proposed wastewater treatment expansion study.The potential for direct
impacts (temporary and permanent)to resources is discussed first, followed by the potential for SCIs to
result from the additional wastewater treatment capacity.
Direct impacts have been assessed for the 6-MGD WRF planned facility footprint and associated
conveyance infrastructure described in Section 6. It is expected that no additional direct impacts will
occur when the Town incrementally increases wastewater capacity from 6 to 10 MGD over the next
20 years.The facility footprint used in this assessment includes enough previously disturbed area to add
capacity to 10 MGD.Additionally,the LC Transmission Main is being sized for these future flows, so
additional modifications to the transmission mains will not be needed if the WRF capacity increases.
Table 7-11 provides a summary of potential temporary and permanent direct impacts associated with
the proposed project.This section also identifies relevant, existing federal, state, and local regulations
and programs that guide development in the Town's ETJ (in this case, also the project study area).
Overall, the potential for direct impacts will be minimized and avoided to the extent practicable.
Remaining temporary and permanent direct impacts will be addressed through environmental
permitting and environmentally sensitive construction practices. Section 7.3 provides further description
of the regulations and programs and how they will mitigate anticipated direct impacts and SCIs of
expanded wastewater treatment capacity.
Direct impacts associated with construction of the ECIA Transmission Main are being permitted and
potentially funded separately and are not discussed here.This additional infrastructure is considered in
the discussion of potential SCI as a result of the Town's increase in wastewater treatment capacity. A
cumulative impact includes environment impacts resulting from incremental project impacts when
added to other past, present, and foreseeable future projects, including the ECIA Transmission Main.
Secondary(or indirect) impacts occur after a project is completed and would occur in the study area.
Often,these impacts occur as a result of growth and development facilitated, in part, due to the project.
7.2.1 Direct Impacts
7.2.1.1 Topography
Development of the proposed WRF site will result in permanent direct but not significant impacts to
topography at the site from grading and fill during construction. Approximately 42 acres of the site will
be graded or disturbed for installation of linear infrastructure; the WRF footprint will require grading of
approximately 25 acres. Approximately 70 percent of the site will remain in its present elevations after
installation of linear infrastructure.The grading and fill activities are limited to upland areas of the site
for the new WRF footprint, primarily at the highest point of the site.This approach protects and
preserves the Neuse River floodplain, stream buffers, and wetlands at the site.The design layout of the
proposed WRF avoids floodplain impacts. Stormwater management measures and the decreased site
slope will also minimize changes to sheet flow into natural areas, limiting erosion potential. Additionally,
siting the facility well above the floodplain provides the positive benefit of facility resiliency from flood
risks.This limits the potential for unexpected flood-related overflows to the Neuse River.
7-29

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
Table 7-11.Summary of Proposed Project Potential Direct and Indirect Impacts
Environmental Outfall Area within Neuse 2 Pump
Resource Neuse 2 Pump Station Site Station Site WRF Access Road LCWRF PS and LC Transmission Main
Permanent direct impacts to"30%of site, Temporary impacts only to 50 LF of Limited grading along 4,000 LF of Temporary construction impacts at site and
avoiding floodplain,stream buffers,and Neuse River bank;will be returned to access road adjacent to existing along 16,500 LF of underground transmission
wetlands. existing slope.No net fill in the utility easement resulting in alignment.Pump station will be outside
Topography No Significant Impact. floodplain. minor permanent changes.Route floodplain.LC Transmission Main installation
No Significant Impact. does not cross floodplains. within floodplain areas but no net fill in
No Significant Impact. floodplains.
No Significant Impact.
Water Resources
Permanent direct impacts not expected Temporary direct impacts during No temporary or permanent Five perennial and two intermittent stream
because site layout and construction construction will be minimized by use of direct impacts expected. No crossings will be included in NWP permitting.
activities avoid disturbing stream and cofferdam and limited to potential short- streams within alignment. Stream 3 crossings are planned for use of
buffer areas.Temporary construction term increase in turbidity. No Significant Impact. trenchless technologies where practical but
impacts to be controlled by ESC. Permanent direct impacts not expected open-cut impacts are included if trenchless
Stormwater management and buffer will from increased discharge operations. technology is not practical.Approximately 0.2
minimize operational impacts. Permanent direct impact of 10 feet of acre of Zone 1 stream buffers will be
discharge pipe,and the outfall structure permanently impacted.Approximately 400 LF of
Surface Water No Significant Impact.
placed into the Neuse River is not stream will be impacted during the installation if
significant.Modified NPDES permit limits trenchless technologies used;if open-cut is
will be set based on water quality needed,an additional 60 LF of impacts may
criteria,and nitrogen credits were occur.Stream buffer variances may be necessary
purchased. for those crossings not currently within utility
easements.Impacts are not significant and will
No Significant Impact. be addressed through the NWP.
No Significant Impact.
Temporary impacts during construction None expected. Minimal permanent impacts due No direct impact from construction of pump
from dewatering activities. No Significant Impact. to addition of impervious area of station at LCWRF.
Minor permanent impacts from addition of access road.No temporary No Significant Impact.
Groundwater impervious surface and grading,limiting impacts expected during
groundwater recharge on a portion of the construction.
site. No Significant Impact.
No Significant Impact.
7-30

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
Table 7-11.Summary of Proposed Project Potential Direct and Indirect Impacts
Environmental Outfall Area within Neuse 2 Pump
Resource Neuse 2 Pump Station Site Station Site WRF Access Road LCWRF PS and LC Transmission Main
Direct impacts avoided with site layout. No direct or indirect impacts expected. No direct or indirect impacts Temporary direct impacts during construction
Natural buffer will help avoid indirect No riparian wetlands at streambank expected.No wetlands within to five herbaceous wetlands(0.03 acre total)
impacts to onsite wetlands. adjacent to outfall. alignment. and one jurisdictional ditch within existing
No Significant Impact. No Significant Impact. No Significant Impact. sewer easement.Permanent direct impacts of
Wetlands approximately 0.025 acre are expected due to
additional easements needed.Wetland soils
will be replaced per NWP conditions.
No Significant Impact Expected.
Disturbance of 1/3 of the site.Soils will be Temporary impacts along 50 LF of Neuse Temporary impacts during Temporary impacts during construction.
stabilized per ESC plan and reseeded within River bank.Soils and river bank will be construction.No net soil loss Existing grades will be returned.Soils will be
Soils 7 days after grading completed. stabilized per ESC plan.No soil loss expected.Soils will be stabilized stabilized per ESC plan and use of additional
No Significant Impact. expected. per ESC plan. BMPs to limit soil loss into adjacent streams.
No Significant Impact. No Significant Impact. No Significant Impact.
Permanent wildlife displacement due to Temporary displacement during Michaux's sumac habitat present; Michaux's sumac habitat present; none located
construction and loss of"22 acres of construction.Refer to Table 7-13. none located during growing during growing season survey.Refer to
forested habitat.Native herbaceous seed No Significant Impact. season survey.Refer to Table 7-15.
Wildlife mix to be used to revegetate disturbed Table 7-14. No Significant Impact.
Resources and easement along Sam's Branch at Neuse 2 No Significant Impact.
Natural Pump Station site,supporting pollinator
Vegetation species.Michaux's sumac habitat present;
none located during growing season survey.
No effect expected.Refer to Table 7-13.
No Significant Impact.
7-31

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
Table 7-11.Summary of Proposed Project Potential Direct and Indirect Impacts
Environmental Outfall Area within Neuse 2 Pump
Resource Neuse 2 Pump Station Site Station Site WRF Access Road LCWRF PS and LC Transmission Main
No temporary or permanent,direct or Temporary direct displacement impacts Aquatic resources not present; Protected aquatic bivalves and species proposed
indirect impacts to aquatic resources due to use of cofferdams during therefore,no temporary or for listing are not likely to be present in Stream 3
expected from WRF construction because construction.Temporary indirect permanent impacts. where crossed by the transmission line.
construction avoids stream resources. sediment impacts may result during No Significant Impact. Trenchless technologies are proposed where
Refer to Table 7-16. cofferdam installation. No protected feasible for two crossings of Stream 3.By
No Significant Impact. species likely in Neuse River adjacent to avoiding impacts,these protected species,if
Aquatic existing outfall location.Impacts to present,are not likely to be adversely affected.
Resources habitat of species proposed for listing Zone 1 impacts to riparian buffers,which help
minimized through use of BMPs. limit sedimentation into the stream,are avoided
Modified NPDES permit will be to the extent practicable by the project.No
protective of aquatic resources and DO. impacts from LCWRF decommissioning and
Refer to Table 7-16. conversion to pump station.Refer to Table 7-17.
No Significant Impact. No Significant Impact.
Permanent impacts within cleared 25 acres No change. Use of transmission easement for Future project will return LCWRF site to open
of facility footprint.Consistent with other No Significant Impact. access road limits permanent land space,except for pump station footprint."200
onsite land uses,including Neuse 2 Pump cover changes.Some clearing LF of the transmission alignment to be
Land Cover Station,linear infrastructure,and power may be necessary to widen converted from forest to maintained
substation. easement for road. vegetation.
No Significant Impact. No Significant Impact. No Significant Impact.
No disturbance to agricultural activities. No direct impact to prime farmland soils. No disturbance to ongoing No impacts to soils at LCWRF,as soils
Permanent impacts will occur to prime No Significant Impact. agricultural activities.Temporary previously impacted with LCWRF construction.
Agricultural farmland soils of"12.5 acres and farmlands impacts to prime farmland during Temporary impacts to 4.3 acres of prime
Land and Prime of statewide importance of approximately 6 construction. farmland soils along transmission alignment.
Farmland acres.
No Significant Impact. No Significant Impact.
No Significant Impact.
Permanent impacts of"22 acres.Other Few trees in vicinity of outfall location. Some permanent clearing may be Zone 1 riparian zone impacts limited to the
forests within parcel will remain. No Significant Impact. necessary to widen easement for extent practicable.Loss of mixed hardwood
Forested No Significant Impact. road,although use of and pine forest of"1 acre.
Resources transmission easement limits No Significant Impact.
forest impacts.
No Significant Impact.
7-32

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
Table 7-11.Summary of Proposed Project Potential Direct and Indirect Impacts
Environmental Outfall Area within Neuse 2 Pump
Resource Neuse 2 Pump Station Site Station Site WRF Access Road LCWRF PS and LC Transmission Main
No temporary or permanent direct impacts Temporary direct impacts due to closure No temporary or permanent No temporary or permanent impacts at LCWRF.
to public greenways on parcel. of greenway during construction; direct impact because these areas Temporary impacts to Sam's Branch greenway
Public Lands No Significant Impact. alternative access to be provided during are not present along the route. with closure during construction of transmission
and Scenic and construction.Will restore greenways to No Significant Impact. line.Will restore greenways to existing
Natural Areas existing conditions,resulting in no conditions,resulting in no permanent impact.
permanent impact. No Significant Impact.
No Significant Impact.
No direct impacts expected per SHPO No direct impacts.Construction in None expected. Positive permanent direct impact resulting
Archaeological coordination. previously disturbed area. No Significant Impact. from less traffic passing through the cemetery
and Historic No Significant Impact. No Significant Impact. and residential area once the LCWRF is
Resources converted to a pump station.
No Significant Impact.
Temporary direct air quality impacts during Temporary direct impacts during Temporary direct impacts during Temporary direct impacts during conversion to
construction only.WRF would have odor construction only. construction only; limited pump station.Pump station would have odor
Air Quality control measures. because no adjacent residences. control;therefore,no change expected.
No Significant Impact.
No Significant Impact. No Significant Impact. No Significant Impact.
Temporary direct increase in ambient noise No direct impacts from construction Temporary direct impacts during Temporary direct impacts to neighbors from
from construction to users of greenway, because greenway will be temporarily construction;temporary direct construction and associated traffic.Long-term
reduced by forested buffer.No permanent closed.Operations will not cause direct and indirect impacts limited direct impacts of pump station expected to be
direct impacts-users of public spaces have impacts to greenway users. because no adjacent residences. less than current LCWRF operations.
Noise Levels noise from current Neuse 2 Pump Station No Significant Impact. No Significant Impact. No Significant Impact.
site operations and adjacent industrial land
uses,and operational levels are not
expected to increase.
No Significant Impact.
No impacts expected.Previous site No direct or indirect impacts expected No impacts expected. More detailed review is needed of the four
activities generating hazardous materials with operations under modified NPDES No Significant Impact. locations identified as having a risk of
Toxic have been discontinued,and the area is permit. contamination before construction to limit risk.
Substances and being remediated.Will disinfect using UV, Line items will also be added to the bid
Hazardous No Significant Impact.
avoiding use of chlorine gas onsite. schedule to address any identified areas of
Wastes
No Significant Impact. contamination.
No Significant Impact.
Notes:
yd3=cubic yard(s)
7-33

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
Temporary impacts will occur to the topography at the Neuse River outfall, but the Neuse River bank
and floodplain will not be permanently affected by construction of the outfall upgrade because the
riverbank will be returned to existing grade and stabilized with riprap after construction, resulting in no
net fill. Preliminary planning for construction limits the disturbed riverbank area to approximately 50 LF.
Infrastructure associated with the outfall into the Neuse River will be constructed within the 100-year
flood plain, and a Floodplain Development Permit will be obtained to prevent impacts to elevations in
this area after construction (Town, 2018b). Obtaining the permit also supports the Town's tracking of all
development within SHFAs.
Minor permanent changes to topography will result from construction associated with the access road
along the preferred transmission easement access alignment. Preliminary planning for approximately
4,000 LF of road includes a 50-foot-wide ROW with two undivided lanes and paved shoulders. Heavy
equipment and truck traffic will use this access road with low speeds anticipated. Minimal grading will
be required to achieve the necessary grade for truck use (WithersRavenel, 2020e).The access road does
not cross floodplain areas; therefore, no floodplain impacts will occur.
Decommissioning activities at the existing LCWRF site and conversion to a pump station will result in
temporary impacts to topography, with the site returned to existing grade and stabilized after
demolition.The pump station to be installed at the LCWRF for the LC Transmission Main will be sited to
align with incoming wastewater collection system infrastructure and to avoid existing treatment
infrastructure.The proposed location for the building will be sited outside the 100-year floodplain.The
Little Creek floodplain at the LCWRF site will not be significantly impacted. Construction of the
associated approximately 16,500 LF of LC Transmission Main from the new pump station to the
proposed WRF site will result in temporary impacts to topography and floodplains; areas will be
returned to existing grade and stabilized after construction. With much of the LC Transmission Main
constructed within the SHFA of Sam's Branch, a Floodplain Development Permit will be obtained to
prevent impacts to elevations in this area after construction (Town, 2018b).
No net fill in floodplains will occur. No direct impacts to topography or floodplains are expected.
7.2.1.2 Water Resources
Surface Water
Construction of the proposed WRF will not result in permanent direct impacts to surface waters.The
preliminary site plan was developed to avoid existing water resources. In addition, implementing the
ESC plan during construction and a stormwater management plan during operation, and maintaining a
buffer around the WRF footprint will prevent temporary impacts associated with soil and pollution
discharging to the surface waters.
Additionally, the proposed WRF is being sited on the parcel well above the Neuse River floodplain, and
the Neuse 2 and Clayton to Raleigh Pump Station was constructed with flood protections.This approach
provides resiliency from flood risks, limiting the potential for unexpected untreated discharges to the
Neuse River.The proposed WRF will also include flow equalization, further limiting the potential for
unexpected untreated discharges to the Neuse River during significant wet weather events, such as
hurricanes.These measures limit risk to the Neuse River from surges of Escherichia coli(E. coli) and
other environmental contaminants during wet weather events.
Discharge into the Neuse River will increase from the permitted flow of 2.5 MGD to 6 MGD with the
initial expansion. Future discharge of up to 10 MGD is planned.
Operation of the new WRF with its increased discharge is not expected to impact water quality in the
Neuse River.The facility will operate under a modified NPDES permit for 6 MGD, awarded after
evaluation of potential water quality impacts to the river and subsequent determination of speculative
limits by NCDEQ(Appendix B).The permit is also expected to include an option for operation at 10 MGD,
7-34

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
with the only difference being no increase in TN loading beyond that permitted at 6 MGD. Other limits
are carried forward from the existing permit, also included in Appendix B.The facility will be designed to
reliably meet these permit requirements. Modeling was conducted to determine treatment approaches
needed to address seasonal variations of DO and other parameters in the river.
A request for speculative limits was submitted to the NCDEQ NPDES Unit for expanded discharges of
6 MGD and 10 MGD, with 6 MGD being the initial capacity expansion.Table 2-19 summarizes NCDEQ's
determination of speculative limits, and Appendix B provides the full response. Appendix B provides the
subsequent modified draft NPDES permit.
The speculative limit for TN is equivalent to a 3.5-mg/L TN concentration at the permitted capacity of
6 MGD and 2.1-mg/L TN at 10 MGD.The Town will achieve the TN limit through a combination of readily
available treatment technologies and nitrogen credit purchases. In addition, nitrogen offset credits
equivalent to 6 MGD have been purchased to meet nutrient reduction requirements of the Neuse& Tar-
Pamlico Nutrient Strategy Rules(NCDEQ, 2020d), and treatment processes are being designed to
achieve effluent quality needed to meet the requirements set forth in 15A NCAC 02B.0713 and the
Neuse River Compliance Association's NPDES Permit NC000001(NCDEQ, 2018) (Appendix B).The Town's
updated draft NPDES permit reflects these nitrogen credit purchases (Appendix B).The Town is abiding
by these rules to limit nitrogen and phosphorus loading into the Neuse River.
These limits are protective of aquatic life in the river.The location of the facility adjacent to the
discharge location also helps protect the DO discharged into the river,taking advantage of the
topography fall from the WRF to the river to aerate the treated effluent so that the discharged DO
remains greater than 6 mg/L. Maintaining DO in the discharge is important for the survival of fish and
other aquatic organisms in the Neuse River.
The TSS water quality limit will remain the same as the current permit.TSS can include a variety of
suspended material, such as bacteria, silt, salts, and metals. Under the expected NPDES permit,TSS
concentrations in the discharge to the Neuse River would not increase.This protects water clarity in the
river, as well as limits loading of other measurable parameters, such as metals.
The outfall upgrade will include installation of an outfall pipe and outlet structure that extends into the
river approximately 10 feet, parallel to and mirroring the current structure.This permanent impact is
not considered significant, given the existing outfall structure, and will be permitted with a USACE
NWP 7. Construction of the outfall upgrade will result in temporary impacts to surface waters during
construction. Construction at the Neuse River bank will occur within the existing easement,with no
additional stream buffer impacts.
However, a cofferdam system is planned to allow outfall construction to occur under dry conditions to
minimize increases in turbidity.The cofferdam and pipe installation is anticipated to occupy
approximately 2,500 ft2 of the river.This impact is not anticipated to be significant, given the short time
period the cofferdam system will be in place and the dilution capabilities of the Neuse River. Use of this
construction approach also limits turbidity impacts for the full construction period. No wetlands are
present along this segment of stream bank; therefore, no wetland impacts will occur with construction
or operation of the upgraded outfall.
The addition of 6 MGD of treated effluent into the Neuse River is an increase in flow from the current
permitted amount of 2.5 MGD.The Neuse River in this vicinity has a 7Q10 of 181 cfs, or 116 MGD.This is
an increase of 3 percent during low flows and is not a measurable increase during normal and higher
flows.This is not expected to lead to bank erosion or otherwise change the hydrology of the river
downstream of the outfall.
No direct impacts to surface waters will occur from construction of the access road along the
transmission easement access alignment.The proposed alignment does not cross any streams or
encroach on any riparian buffers, and features shown in the County Soil Survey were not identified
7-35

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
within the alignment evaluation area. A formal Buffer Determination by North Carolina Division of Water
Resources(NCDWR)will be required to confirm the features are not present within the review area to
comply with buffer rules (WithersRavenel, 2020e) (Appendix L).
The LC Transmission Main will require CWA Sections 401 and 404 permitting to authorize permanent direct
impacts once final alignment and construction methods are selected. Surface water crossings within
existing easements include five perennial streams and two intermittent streams (Figure 7-9,Table 7-12).
Stream 3, locally known as Sam's Branch, has potential freshwater mussel habitat; and construction
methods for this stream will likely be open-cut, but measures will be taken to reduce direct impacts.
Streams will be crossed using diversion or bypass pumping. Appendix M provides additional detail on
stream crossing methods.
A formal buffer determination is not required because all streams were depicted on the USGS quadrangle
map. All are subject to the 50-foot buffer requirements but exempt when within existing, cleared
easements.Any activities other than perpendicular crossings resulting in permanent buffer impacts in
Zone 1 areas not within existing utility easements, expected to total approximately 0.2 acre, are allowable
with mitigation from NCDWR (WithersRavenel, 2020d) (Appendix L).Vegetation will be allowed to
regenerate in disturbed temporary construction areas.
Table 7-12.Little Creek Transmission Main Stream and Wetland Crossings
Acres Impacted Acres Impacted
No.Keyed to Map Diameter and Type of Sewer Installation Method (Permanent) (Temporary)
W-1 36 inches,Gravity Open-cut 0.0018(82 ft2) 0.0047(206 ft2)
W-2 36 inches,Gravity Open-cut 0.01(440 ft2) 0.014(620 ft2)
W-3 36 inches,Gravity Open-cut 0.012(524 ft2) 0.01(454 ft2)
Total Wetland Impacts(acres): 0.024(1,046 ft2) 0.029(1,280 ft2)
LF Temporarily Impacted
5-1 48 inches,Gravity Open-cut 65
5-2 36 inches,Gravity Open-cut 65
5-3 36 inches,Gravity Open-cut 60
5-4 36 inches,Gravity Trenchless if feasible 60
5-5 24 inches,Gravity Open-cut 60
5-6 24 inches,Gravity Trenchless if feasible 60
5-7 24 inches,Pressure Open-cut 85
Total Temporary Stream Impacts(feet): 455
7-36

r,i•IllI .Ia.-•..:,l,
v, i
"'‘,i,7e.4-tI*.Pit'.tr 14r..e:.1,g 1*%4i,•e1117.__.. #
=Vc#•.,:7*v,•.-,.0..1•,%#%s.0.
••,„\,
-,,.,
loa
= = °° = W"1 ` �,' ,,\A
,k.,Ff%S.it,4,, _A 1Mw M4Il
_'
).,,_\.
,.
\,\
,1,,
r\.,,, ,> o\yam.. ..,r.„
♦)��:Vi:
_,_',a--S2
�i �.: w = � �� WETLAND D ;> ),,, \.
.\
,i, 4, �� _ •:� .,�\�� \ U :\ \fir \
� i11 ♦ ♦ � � 111
i. 111 tf �/ . ,,i" mitd411111111111
"M �, .•. I�j, . _ �►� �i„ :.\ STREAM 1.1.I.I10 42,1.s1
1
g•ea i l%al1v,,t,,.4.i,p
���i ., ■�� • ,� r �,��s tr ) \ 1♦ .� *.� . .�• •I M•.I,,T„4.Lt8s./A
oW,',k•i•
.pg_-o.,._
p
l.
, , STREAM 14
: :"4" ,,,,,,,
., '
Ail AVM% ,/,
e#S •
�♦♦� ♦Q � ♦ `•.♦�♦`�i ♦ . ♦y.� I ������rfroirr:.....un.�.♦ \ STREAM 16
6 -
S-3• �;� kg /
S 4
• • tts
HS l'41"-■ S7 STREAM 3
�i ♦ . ♦ �� iti �4 �♦♦•�•r� WETLAN D J ,�� Elf4Pr \4%.��,•��� �����..�, \y #.,o .s.-;.'� l/ V STREAM 21
.•.AI MI
S-7 ar
'. WETLAND K * S6
STREAM 23 �\ :Ill
STREAM 3 Ohk
.0001W mi
404 - -**
bo _ , s v, 'I%
• s, # gA 1
i ***s 4 a, ; •of'.4s# 7 2011 11
til II
R . 0 ,' atiik
` , 0% ... ma * P
-,; ,�.• _' s, 500
GRAPHIC SCALEA 4,No 1
t It
A ta%li.p•tia,r 414--D)
No. Revision Date By Designer 5ca1e CLAYTON WRF AND
�• WithersRavenel Sheet No.
Drown By Da Figure 7-9
CAC ^°G° 2020 TRANSMISSION MAIN STREAM AND WETLAND EXHIBIT 1� EngineerslPannersISorveyors
Checker!By ]°M1 N°.
ou9oza� CLAYTON JOHNSTON NORTH CAROLINA
11s MacKenan Dme rY.NC 2Js11 t 919.4b9.3340 license#:C-0832 www.wilM1ersravenel.c°m

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
Groundwater
Development of the proposed WRF site will result in minor permanent impacts to groundwater from
addition of impervious surface, minimally limiting groundwater recharge.The water table at the site was
recorded at depths from 9-37 feet bgs during geotechnical investigation (Froehling & Robertson, 2020).
Minor, localized, and temporary impacts to the groundwater table may be caused by dewatering
necessary for the excavation planned for the facility footprint.
Groundwater is not expected to be directly affected by the outfall upgrade.
Groundwater is not expected to be directly affected by construction associated with the access road
because addition of impervious area is minimized by the selection of a simple roadway cross section
(WithersRavenel, 2020e).
Decommissioning activities at the LCWRF site and conversion to a pump station will result in positive
direct impacts to groundwater. Impervious surface area will be removed with future site restoration
activities.The pump station will be constructed so that groundwater intrusion does not occur.
Groundwater is not expected to be directly affected by construction of the associated transmission line;
USACE general regional permit conditions will be followed to limit groundwater changes in wetlands
crossed by the alignment.
Wetlands
Development of the proposed WRF site will not result in direct impacts to wetlands. Indirect impacts
have been minimized by conducting most grading activities in the center portion of the site, away from
wetlands, and will be further minimized by implementing the ESC plan and maintaining a buffer around
the construction site to prevent soil from settling in wetlands.The site's existing natural forested buffers
protect wetlands from stormwater runoff, which will help avoid indirect impacts to wetlands.
No wetlands exist at the outfall being upgraded; therefore, there are no direct impacts.
WithersRavenel evaluated the access road alignment during a field review on March 26, 2020, and did
not locate any wetlands (WithersRavenel, 2020e).Therefore, no direct impacts to wetlands will occur
from construction of the access road along the transmission easement.
No wetlands are present within the footprint of the LCWRF decommissioning activities and pump
station; therefore, no impacts to wetlands will occur. Construction of the associated LC Transmission
Main is estimated to temporarily impact 0.03 acre and permanently impact 0.025 acre of wetlands along
the alignment (Table 7-12). WithersRavenel evaluated wetlands along the LC Transmission Main
alignment during a field review on March 26, 2020. Five wetlands are within the alignment.They are
within the existing sewer easement and have been maintained as herbaceous wetlands through regular
mowing and maintenance. One jurisdictional ditch is also connected to two of the wetlands
(WithersRavenel, 2020d). Wetlands soils will be stockpiled and returned to wetlands areas after
construction to support wetland restoration. A detailed delineation will be completed as part of
environmental permitting to determine final temporary and permanent impacts.
7.2.1.3 Soils
Development of the proposed WRF site will result in minor permanent impacts to soils at the site from
grading, including cut and fill during construction. Approximately 25 acres of soil will be disturbed
(approximately one-third of the site), and soil losses from the site are minimized with the preliminary
site plan. Figure 6-1 shows the area to be graded for construction of the WRF footprint. Approximately
150,000 yd3 of soil will be moved. To prevent soil loss during construction, additional ESC measures,
such as use of a double row of silt fence along the three sloped sides of the WRF footprint,will be used.
Disturbed areas will be reseeded within 7 days of completed work.The Town will also increase
7-39

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
inspections of this measure to support proper functionality during all construction activities.These
losses are not considered significant.
Soils impacts of approximately 1.1 acres (included in the total site disturbance of 25 acres)from the
outfall upgrade construction will be temporary in nature because the bank of the Neuse River will be
returned to existing grade and stabilized after construction. No net soil loss is expected.To minimize the
potential for long-term stream bank erosion, the stream bank will be restored using a mix of hard and
natural restoration methods. Around the outfall pipe, riprap will be used to fill the portion of the trench
below the normal water elevation. Upslope of the normal water elevation, the bank will be
reconstructed to match surrounding grades using a bioengineered approach, such as vegetated
geogrids. Vegetated geogrids, soil encapsulated lifts, or wrapped earth lifts, will be constructed of high-
velocity and shear-stress-tolerant woven coconut fiber (coir)fabric filled with topsoil. During vegetated
geogrid construction, a native grass blend will be seeded.
Temporary and permanent soils impacts are expected as a result access road construction along the
transmission easement access alignment.The transmission easement is currently maintained and
traveled for inspections, limiting the grading necessary for the access road. As a result of the previous
disturbance, the impacts will be minor. No net soil loss is expected.
Decommissioning activities at the LCWRF site and conversion to a pump station will result in permanent
but not significant impacts to soil from future regrading and excavation of the pump station.
Construction of the associated transmission line will result in temporary impacts to soils along the
alignment,which will be returned to existing grade.
7.2.1.4 Wildlife Resources and Natural Vegetation
Wildlife resources inhabiting the site may be temporarily impacted by construction noise and activities,
and permanently affected by the loss of habitat. However, most wildlife resources are mobile and
expected to relocate to adjacent areas, resulting in minimal effects. Forested habitat loss of
approximately 22 acres will occur. As mentioned in Section 4.4, habitat was identified for Michaux's
sumac,which is a federally endangered species. A pedestrian survey was conducted by WithersRavenel
on June 2, 2020, during its growing season, and Michaux's sumac was not located.The biological opinion
documented is that the proposed project activities will have no effect on this species.Table 7-13
summarizes present habitat and biological opinions for listed wildlife species at the proposed WRF site
(WithersRavenel, 2020b, 2020c, 2020d).
A NCNHP Project Review letter listing element occurrences, natural areas, and managed areas within the
project area and within a 1-mile radius of the project area is attached to the WSBTE Report included in
Appendix L(WithersRavenel, 2020b). Only aquatic species were included, and these are discussed in
Sections 7.1.5 and 7.2.1.5.
Table 7-13. Proposed Water Reclamation Facility USFWS Biological Opinion for Federally Listed Terrestrial Wildlife
and PlantSpecies for Johnston County, North Carolina
Common Name Scientific Name Federal Status Habitat Present Biological Opinion
Bald eagle Haliaeetus laucocephalus BGPA No No effect
Red-cockaded woodpecker Picoides borealis E No No effect
Michaux's sumac Rhus michauxii E Yes No effect
Source:WithersRavenel,2020a
Linear infrastructure easements are typically mowed on a regular schedule to limit woody vegetation
growth that could damage infrastructure.This mowing schedule can limit the viability of native
vegetation and flowering,which benefits pollinator species. Linear infrastructure on the WRF parcel
parallels Sam's Branch Greenway.The Town plans to use construction as an opportunity to create a
7-40

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
corridor of native vegetation along the greenway by reseeding after construction with a native seed mix.
The Town will also modify its mowing protocol within this zone to avoid mowing during the flowering
spring and summer seasons to promote pollination and natural reseeding for long-term viability of the
area.This will also provide an educational opportunity for the community using the greenway.
Construction of the outfall upgrade will temporarily displace but not impact wildlife resources, such as
birds, at the existing outfall location.The portion of discharge conveyance from the proposed WRF to
the Neuse River will take approximately 3 weeks to construct and will cover approximately 1.1 acres,
with 40 percent of that currently in maintained easement.
Wildlife resources may be temporarily displaced during construction of the access road along the
transmission easement access alignment due to noise and construction activities.The linear access road
corridor is approximately 50 feet wide and will not directly impact the general wildlife community.
Habitat was identified as present for Michaux's sumac along the access road alignment. A pedestrian
survey was conducted by WithersRavenel during its growing season, and no Michaux's sumac were
located.The biological opinion documented is that the proposed activities will have no effect on this
species.Table 7-14 summarizes present habitat and biological opinions for listed wildlife along the
access road alignment(WithersRavenel, 2020d) (Appendix L).
Table 7-14. Potential Access Road USFWS Biological Opinion for Federally Listed Terrestrial Wildlife and
Plant Species for Johnston County, North Carolina
Biological
Common Name Scientific Name Federal Status Habitat Present Opinion
Bald eagle Haliaeetus laucocephalus BGPA No No effect
Red-cockaded
woodpecker Picoides borealis E No No effect
Michaux's sumac Rhus michauxii E Yes No effect
Source:WithersRavenel,2020d
Wildlife resources are not expected to be directly affected by decommissioning activities at the LCWRF
site and conversion to a pump station. Little wildlife habitat is present because the site is currently an
operating treatment facility. Wildlife may be temporarily displaced during construction of the associated
transmission main.These activities are not expected to directly impact the general wildlife population.
During onsite field surveys, habitat was identified for Michaux's sumac.A pedestrian survey was
conducted by WithersRavenel and did not identify a presence of Michaux's sumac.The biological
opinion documented is that the proposed activities will have no effect on the species.Table 7-15
summarizes present habitat and biological opinions for listed wildlife species (WithersRavenel, 2020c)
(Appendix L).
Table 7-15. Little Creek Transmission Main USFWS Biological Opinion for Federally Listed Terrestrial Wildlife and
Plant Species for Johnston County, North Carolina
Common Name Scientific Name Federal Status Habitat Present Biological Opinion
Bald eagle Haliaeetus laucocephalus BGPA No No effect
Red-cockaded woodpecker Picoides borealis E No No effect
Michaux's sumac Rhus michauxii E Yes No effect
Source:WithersRavenel,2020c
7-41

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
7.2.1.5 Aquatic Resources
Aquatic resources will not be directly affected by construction at the proposed WRF site.The proposed
facility footprint avoids aquatic resources on the site.
No significant direct, permanent impacts to aquatic resources are expected with expansion of the outfall
to the Neuse River. Construction associated with the outfall upgrade will temporarily impact and
displace aquatic resources at the existing outfall location. Cofferdams will be used during construction
and are likely to be in place for approximately 3 weeks.The impacted area will cover approximately
2,500 ft2.The impacted area leaves approximately two-thirds of the river width unimpeded so that
passage of flow and movement of wildlife, including migration of species such as the sturgeon, are not
impacted for the brief construction window. Prior to installation of the cofferdam system, a mussel
survey will be performed within the planned construction area (Figure 7-10). Any mussels will be
relocated upstream of the outfall area in the Neuse River reach adjacent to the WRF site.This will avoid
a potential take of a protected species, and relocation upstream will avoid any temporary impacts from
turbidity associated with construction.
During installation of the cofferdam system, turbidity in the area will rise, although the net effect of the
cofferdam is expected to be a reduction in turbidity in the river during construction.The addition of a
parallel outfall structure will extend into the river the same distance, approximately 10 feet from the
bank as the current structure.
During operations, the proposed WRF will discharge treated effluent as specified in the draft NPDES
permit, protective of aquatic resources and DO (Appendix K). Disinfection will be achieved by UV, avoiding
the discharge of chlorine residuals into the Neuse River and the potential for chlorine-related impacts.
A field assessment was not performed for the Neuse River; data reviews and inquiries were used, and
details are included in Appendix K.
NCWRC records for mussel surveys in the area are included in Appendix K. Additionally,the creeper is
known to occur within a 1-mile radius of the project site.The habitats of some of these freshwater
bivalve species are limited enough to warrant state status. Given that these species are currently living
in the vicinity of the operating LCWRF outfall into the Neuse River, impacts to freshwater bivalves are
not expected with continued, increased discharge of improved quality effluent compared to what is
currently discharged.The instream waste concentration of effluent in the Neuse River is not significantly
increasing. Discussion of measures to limit sediment loading into the Neuse River, and therefore limit
the potential for impacts to aquatic habitat, is included in Section 7.2.1.3.
During field surveys, no habitat for the listed aquatic species was identified as present in perennial
streams, including Sam's Branch, within the WRF parcel. Potential habitat for species proposed for
listing, the Neuse River waterdog and Carolina madtom, may be present in the Neuse River and the
lower reaches of Sam's Branch. Impacts to aquatic habitat will be minimized through the strengthening
of ESC measures. After any rough grading, reseeding will be expected to occur within 7 days. After
installation of linear infrastructure, restabilization will be expected to occur within 7 days. In addition,
The Town is committed to increasing the frequency of its inspections of ESC measures, such as silt
fences and basins,to promote proper maintenance.Table 7-16 summarizes present habitat and
biological opinions for listed aquatic species (WithersRavenel, 2020a) (Appendix L). Appendix K provides
details about coordination with USFWS and NCWRC.
7-42

r ' . :�'
r. C �r
,„•••-i•\\'
y. _ . . ..t' no -°,.w_= - � -# . Existing
•1'' ',] Neuse 2/Clayton to Raleigh �;+ ,, �- Outfall .;,�
Fa -\. ,/ 'oil Pump Stations ,- /. . -, •.7.rt: �q
11.
,..-. •
' ., f, _. ` •,-...:
. Proposed
7.� '` - Legend
,`� 1 ��O _ ,,+fit '" , ^ ;�r;...I' :: f . \• \„;00._i.`,.,,,,5,1-'-, — lisy i Existing Gravity
� - 1 ' P
f '' ,• tia1 +�►` • +I 1(� ,, ' ' r ,P, _.` - . , - a Main
O • a _ ExistingForce
' + �� ti, h t ` r is _ e , 'fir Main
',�, .. 0, ` • } fr .1, " _ , Proposed Force
` Main
r y� ti,; ���i Proposed Gravity
;.�. ;� ' :,� � t ` f,. e, Main
' .� •
": 1 ;: � _ �ti 4 �� . Proposed
•, �� s. �•
r i 1,4
:'1 41 ,' Manhole
: ' - •pi: . - ', VO Proposedt. ? * • t' ' " , ,j Construction
1,.• 1' ` Splitter Box , y i �` - Area
�I +`" v.- Source: NC Orthoimagery Program (2017)
Figure 7-10
0 80 160 N Expanded Outfall Construction Area
elk 2/111f• I I I Water Reclamation Facility Expansion
Feet Town of Clayton, NC

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
Table 7-16. Proposed Water Reclamation Facility USFWS Biological Opinion for Federally Listed Aquatic Wildlife and
Plant Species for Johnston County, North Carolina
Common Name Scientific Name Federal Status Habitat Present Biological Opinion
USFWS Federally Listed Species for the County
Dwarf wedgemussel Alasmidonta heterodon E Yes Not likely to be affected
Tar River spinymussel Parvaspina steinstansana E No No effect
Yellow lance Elliptio lanceolata T No No effect
USFWS Proposed Federally Listed Species for the County
Atlantic pigtoe Fusconaia masoni PT No No effect
Neuse River waterdog Necturus lewisi PT Yes Not likely to be affected
Carolina madtom Noturus fuiosus PE Yes Not likely to be affected
Source:WithersRavenel,2020a;Coordination with USFWS and NCWRC included in Appendix K
PE=proposed endangered
PT=proposed threatened
No aquatic resources are present within the transmission easement access road alignment.Therefore,
no aquatic species will be impacted by the planned access road to the proposed WRF.
No aquatic resources are present within the LCWRF site.Therefore, no aquatic species will be impacted
by the decommissioning activities at the LCWRF site and conversion to a pump station.
Aquatic resources may be directly and permanently affected by construction of the associated
LC Transmission Main. With 10 perennial and 6 intermittent stream crossings expected, aquatic habitat
within the easement crossings will be temporarily directly impacted. Many of the crossings will be within
existing, maintained easements, limiting additional impact at these locations. Environmental permitting
will be conducted, and general regional conditions followed to limit and mitigate impacts.
WithersRavenel conducted pedestrian surveys on March 26 and June 2, 2020,to identify potential
habitat for federally listed species within or immediately adjacent to the LC Transmission Main
alignment. Habitat was identified in larger perennial streams along the transmission alignment for the
following species:
• Dwarf wedgemussel
• Tar River spinymussel
• Yellow lance
• Atlantic pigtoe
• Neuse River waterdog
Surveys were not conducted to identify a presence of these species.The biological opinion was that
traditional open-cut construction activities may affect the Dwarf wedgemussel and Atlantic pigtoe; and
may affect, but are not likely to adversely affect,Tar River spinymussel,Yellow lance, and Neuse River
waterdog.To avoid these direct impacts to Stream 3, locally known as Sam's Branch, the Town will use
trenchless technologies where feasible at the crossings shown on Figure 7-6.Table 7-17 summarizes
present habitat and biological opinions for listed aquatic species at the crossing locations identified on
Figure 7-6.These crossings are farther upstream than the reach nearest the confluence with the Neuse
River where agencies suspect habitat may be present (WithersRavenel, 2020b) (Appendixes K and L).
7-44

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
Table 7-17. Little Creek Transmission Main Alignment USFWS Biological Opinion for Federally Listed Aquatic Wildlife
and Plant Species for Johnston County, North Carolina
Common Name Scientific Name Federal Status Habitat Present Biological Opinion
Dwarf wedgemussel Alasmidonta heterodon E Yes Not likely to adversely affect
Tar River spinymussel Parvaspina steinstansana E Yes Not likely to adversely affect
Yellow lance Elliptio lanceolata T Yes Not likely to adversely affect
Atlantic pigtoe Fusconaia masoni PT Yes Not likely to adversely affect
Neuse River waterdog Necturus lewisi PT Yes Not likely to adversely affect
Carolina madtom Noturus fuiosus PE No Not likely to adversely affect
Source:WithersRavenel,2020d; updated conclusions with avoidance plans at stream crossing locations and coordination with
USFWS and NCWRC(Appendix K)
7.2.1.6 Land Cover
Land cover at the new WRF site currently includes:
• Forested cover
• Industrial uses, including the Neuse 2 Pump Station
• Maintained linear infrastructure easements
• A power substation
• Open space where the previous law enforcement firing range was located
Development of the proposed WRF site will result in changes to land cover at the site; approximately
22 acres of the total estimated 25 acres of facility footprint are forested and will be converted to
industrial land cover. Other natural areas will remain.
Land cover is not expected to be impacted by the outfall upgrade because the Neuse River bank and
associated conveyance easement will be restored to current conditions, including where the greenway is
crossed.
Most of the access road will be within the existing transmission line easement and will remain as
maintained land cover. Land cover will permanently change to maintained utility easement for
approximately 2.3 acres of the wooded area.
No land cover change will occur with construction of the LCWRF Pump Station; the land cover is
expected to remain as developed.The decommissioned area of the LCWRF site will be removed as part
of a future project.The associated transmission line alignment primarily occurs within existing
maintained utility easements.Trenchless technologies will be used to avoid impacts to existing
roadways and the rail line. Limited changes to land cover include conversion of less than 1 acre of
forested area to maintained utility easement.
7.2.1.7 Agricultural Land and Prime Farmland
Agricultural lands are not present in the project area. Development of the proposed WRF site will result
in permanent loss of soils classified as prime farmland from grading and fill during construction.
Approximately 12.5 acres of prime farmland and 6.0 acres of farmland of statewide importance will be
disturbed; this is not considered significant given adjacent industrial and residential land uses.
Agricultural land uses are not present in the vicinity of the project site and are not part of the Town's
2040 Comprehensive Land Use Plan (LandDesign, 2015).
No direct impacts to soils classified as prime farmland will occur from the outfall upgrade.
7-45

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
Construction of the access road along the transmission easement access alignment will result in
permanent impacts to approximately 4.3 acres of soils classified as prime farmland (WithersRavenel,
2020c).
Prime farmland soils are not expected to be directly affected by construction associated with
decommissioning activities at the LCWRF site and conversion to a pump station because the location is
currently industrial land use, and soils have been previously disturbed. Construction of the associated
transmission line will result in temporary impacts to soils classified as prime farmland in limited areas of
the alignment. Approximately 3.2 acres of prime farmland soils and 2.8 acres of farmland of statewide
importance will be disturbed. Soils will be backfilled after installation of the transmission line.These
impacts are not considered significant because much of the transmission line alignment is within existing
utility easements.
7.2.1.8 Forested Resources
Development of the proposed WRF site will result in permanent impacts to mixed hardwood forest
resources from clearing.The planned facility footprint includes approximately 24 acres of forest that will
be cleared.These lands around the WRF infrastructure will be maintained and mowed during
operations.
Few trees are present along the Neuse River bank where installation of the upgraded parallel outfall
structure construction will occur.Therefore, forested resources are not expected to be directly impacted
by the outfall upgrade.
Construction of the access road will primarily impact mowed and maintained grass and early
successional vegetative communities along the transmission easement access alignment. Permanent
impacts to approximately 2.3 acres of the mixed hardwood and pine forest communities will result from
clearing and road construction. Land adjacent to the access road and within the water line easement will
be maintained for safety.
Forested resources are not present within the LCWRF site;therefor, decommissioning activities and
conversion to a pump station will not impact forested resources. Construction associated with the
associated LC Transmission Main will result in permanent impacts to 4 acres of mixed hardwood and
pine forest,with 0.2 of those acres being within Zone 1 stream buffers (WithersRavenel, 2020c).
7.2.1.9 Public Lands and Scenic and Natural Areas
No impacts to public lands and scenic and natural areas will occur from development of the proposed
WRF site.The facility is sited away from the Sam's Branch and Neuse River greenways, and forested
buffers will limit visual and noise impacts from operations.
Construction of the outfall will temporarily close the greenways. Alternative access locations will be
used during construction to minimize impacts. Access to the Clayton River Walk on the Neuse River is
available at a parking area on Covered Bridge Road.This portion of the trail is out-and-back and can be
temporarily blocked at the northern edge of the plant site. Permanent direct impacts are not expected,
as the greenways will be restored to existing conditions and reopened. A benefit of the project will be
education opportunities afforded by the revegetation of linear infrastructure paralleling the Sam's
Branch Greenway with a native, herbaceous seed mix.This will create habitat for pollinator species.
Public lands and scenic and natural areas are not expected to be directly affected by construction of the
access road because none of these areas is along the transmission easement access alignment.
Public lands and scenic and natural areas are not present at the LCWRF site; therefore, there will be no
impact from the decommissioning activities at the LCWRF site and conversion to a pump station.
Construction of the associated transmission line will temporarily impact Sam's Branch Greenway due to
7-46

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
closures during construction. Permanent direct impacts are not expected, as the greenways will be
restored to existing conditions and reopened.
7.2.1.10 Archaeological and Historic Resources
Archaeological and historic resources are not expected to be directly affected by construction of the
new WRF. A desktop review of known resources at the proposed WRF site was conducted by SHPO,
concluding that no historic resources would be affected by the project.This letter is included in
Appendix K.
Archaeological and historic resources are not expected to be directly affected by the outfall upgrade
because no resources have been identified at the existing outfall location, which was previously
disturbed by construction.
Archaeological and historic resources are not expected to be directly affected by construction of the
access road because no resources have been identified along the transmission easement access road
alignment (NPS, 2020).
The LCWRF site is southwest of the Maplewood Cemetery. Smith Street routes through the cemetery
and is used as a secondary entrance.The primary entrance to the LCWRF site is residential Durham
Street. A permanent direct benefit of decommissioning the LCWRF and pump station conversion is less
traffic to the site through the cemetery and residential area. Archaeological and historic resources are
not expected to be directly affected by construction of the associated transmission line because no
resources are known to be present along the alignment (NPS, 2020).The Town's downtown Historic
District is avoided by this alignment.
7.2.1.11 Air Quality
Development of the proposed WRF site will temporarily impact air quality during construction. Dust
suppression will be used to minimize impacts. Permanent direct impacts are not expected, as operation
of the Neuse 2 Pump Station does not currently receive odor complaints, and odor control is proposed
for the new WRF; therefore, no change is expected.Truck traffic to and from the site during operations
is not expected to contribute to changes in local air quality.
Construction of the outfall upgrade will also temporarily impact air quality. Dust suppression measures
will be used to minimize impacts.
Construction of the access road will also temporarily impact air quality along the transmission easement
access alignment. Dust suppression measures will be used to minimize impacts. In addition, the distance
of this alignment from residential areas will further reduce the potential for the public to be affected.
Construction associated with decommissioning activities at the LCWRF site, conversion to a pump
station, and the associated transmission line construction will temporarily impact air quality. Similar to
other construction sites, dust suppression will be used to minimize impacts. Permanent direct impacts
are not expected, as the pump station would have odor control. Benefits of decommissioning the LCWRF
include less potential for odor control issues at the site.
7.2.1.12 Noise Levels
Development of the proposed WRF site will temporarily create construction-related noise. Noise
associated with operations of the WRF is not expected to change overall ambient noise levels, as other
infrastructure, including the Neuse 2 Pump Station, is present; and adjacent land uses include industrial
activities.The forested buffer that will remain between the WRF and the greenways will provide a noise
buffer for greenway users. Users are familiar with such activities because the Neuse 2 Pump Station is
immediately adjacent to the greenways.
7-47

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
Noise associated with construction of the outfall upgrade will not impact the public because the
greenways will be temporarily closed during this portion of construction. Operations will not impact
ambient noise levels given adjacent land uses and forested buffer areas separating the WRF from the
public using the greenways.
Construction of the access road will temporarily create noise; however, no public spaces or residential
areas are adjacent to this alignment.
Construction associated with decommissioning activities at the LCWRF site, conversion to a pump
station, and the associated transmission line construction will temporarily create noise. Permanent
direct impacts are not expected, as operation of the LCWRF produces more noise than the smaller
future pump station.
7.2.1.13 Toxic Substances and Hazardous Wastes
Sites with contamination from previous or current land uses could be encountered during construction
of the LC Transmission Main (WithersRavenel, 2020e).To mitigate this risk, additional assessments will
be conducted once the final detailed alignment is selected, and if needed, assessment activities will take
place during construction. Line items will be set up in the bid schedule for dewatering, pretreatment,
removal of contaminated materials, replacement with select fill, and disposal in the appropriately
permitted offsite facility.The specifications will require the contractor to coordinate with the owner's
environmental consultant prior to the construction in this area.The area of the contamination is near
the bore and jack location of the force main across U.S. 70, so the excavation will be limited in this area.
During the construction phase, field crews will be educated to identify environmental contaminants
encountered in soil and groundwater.
During construction of the proposed project,toxic substances and hazardous materials could be
introduced to the environment from construction equipment if leaks or malfunctions occur. Best
practices and regular offsite maintenance would be used to limit this potential. Stormwater pollution
prevention plans would also be used to limit indirect impacts to resources during facility operations.
Construction wastes will also be generated, and it is not expected that these solid wastes will be toxic or
hazardous. No hazardous wastes will be generated by project operations.
The LCWRF site would be decommissioned and the site converted to a pump station. All demolition
debris removed as part of a future project will be properly disposed of.The associated transmission line
construction does not introduce new toxic substances to the environment; maintenance will be
conducted to limit potential for spills.
7.2.1.14 Environmental Justice
When reviewing and comparing data, it is evident that the proposed WRF location will not adversely
affect minorities or special populations near the new facility when compared to the LCWRF located
closer to the historic downtown area.There is the expectation that the residential and industrial growth
around the proposed site, as identified with the use of the CAMPO data, will be similar in demographics
to the current population.The proposed WRF site has, and will continue to have, a lower percentage of
minorities, low income, and special populations nearby than the LCWRF site. In addition, the R. Steven
Biggs Regional Pretreatment Facility location is primarily located in an industrial area with minimum
impacts on minority or sensitive populations. In conclusion, selection of the proposed WRF site is not
likely to lead to environmental justice concerns, especially when compared to the current neighbors of
the LCWRF site.
7.2.2 Secondary and Cumulative Impacts
Secondary impacts are those that are removed in time and place from an action,while cumulative
impacts occur in combination with other projects happening in the recent past, present, and reasonably
7-48

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
foreseeable future. Included in this evaluation of potential SCIs is the construction and operation of the
ECIA Transmission Main so that the entirety of the proposed project and Town actions related to the
wastewater treatment capacity expansion are evaluated.
The Town is proposing to increase its total treatment capacity from 4.9 to 6 MGD within the next
5 years.This replacement of current contracted and LCWRF capacity and increase of 1.1 MGD is
expected to generate few secondary impacts because the first phase of this project, increasing
treatment capacity to 6 MGD, is:
• Meeting a need that already exists from approved industrial facility expansions
• Meeting a need to treat wastewater from housing units approved but not yet built (Table 2-4)
• Replacing capacity currently provided by regional agreements but not available in the near future
This expansion in capacity to 6 MGD is not facilitating future growth; rather, it will meet the needs of the
existing, allocated customer base.Therefore, no significant secondary impacts to the study area and its
environmental resources are expected with the expansion of capacity to 6 MGD.
Future incremental treatment capacity expansion beyond 6 MGD is likely within the 2040 planning
period.The availability of that capacity has the potential to support growth and trigger secondary
impacts. Potential secondary impacts associated with treatment capacity beyond 6 MGD and mitigation
programs in place are discussed in this section. With these programs in place, secondary impacts in the
study area associated with capacity increases beyond 6 MGD are not expected to be significant.
Cumulative impacts resulting from this project,the recently constructed R. Steven Biggs Pretreatment
Facility, the ECIA Transmission Main, housing units approved but not yet constructed, and other
projects, such as the future construction of the U.S. 70 Business and NC 42 intersection, may occur but
are expected to be minimized by implementation of local ordinances and processes.These cumulative
impacts, discussed in the following subsections, are not expected to be significant.
Programs and measures that limit both direct impacts and SCIs to environmental resources in the study
area are further discussed in Section 7.3.
7.2.2.1 Topography, Floodplains, and Soils
Secondary impacts to topography and soils are not expected as a result of the 6-MGD WRF capacity
expansion because the expansion is supporting existing and near-term development already in progress
rather than stimulating new development with its associated impacts. Cumulative impacts to soils and
topography as a result of the proposed project and projects listed herein are not expected to be
significant because of plans, ordinances, and regulatory requirements designed to minimize and
mitigate those impacts.
Secondary impacts associated with increases in capacity beyond 6 MGD are not expected to be
significant. Changes to topography and protection against the loss of soils are addressed in the County's
ESC program, and through federal and local floodplain protection requirements and building codes.
Structures must be built in accordance with rules that limit development in floodplains identified by
FEMA,the Town's Flood Damage Prevention Code, and Neuse River watershed stream buffer rules.
Soil disturbance is likely given the expected development in the study area; however, development
plans will follow regulations that limit such disturbance and will be consistent with other residential and
commercial development that has already occurred in the area. Cumulative impacts over time to soils
and topography from additional stormwater runoff and impervious surface areas are limited with Town
stormwater management design requirements.
In accordance with the County's Land Development Code and the Town's Unified Development Code
(UDC), new and replacement sanitary sewage systems in the study area will be designed to minimize or
eliminate infiltration of flood waters into systems and discharges from the systems into flood waters.
7-49

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
7.2.2.2 Wetlands, Groundwater, and Water Resources
Secondary impacts to wetlands, groundwater, and water resources are not expected as a result of the
6-MGD WRF capacity expansion because the expansion is supporting existing and near-term
development already in progress rather than stimulating new development with its associated impacts.
Cumulative impacts to wetlands, groundwater, and water resources as a result of the proposed project
and projects listed herein are not expected to be significant because of water supply watershed
protections; Neuse River watershed stream buffer requirements; and other plans, ordinances, and
regulatory requirements designed to minimize and mitigate those impacts.The NPDES permitting
process accounts for the potential for cumulative impacts to a waterway from the project and other
dischargers.
The potential for secondary impacts to wetlands and streams in the study area will be limited by the
continued implementation of stormwater management and programs, such as the protection of stream
buffers. Increases in both the quality and quantity of stormwater runoff as a result of development and
the addition of impervious area can alter the natural hydrology of an area. As imperviousness increases,
the more impacted surface waters become from contaminants, increased runoff, flooding potential, and
associated stream channel changes.The cumulative effects of stormwater runoff are evident in the
frequent correlation between the location of a stream and its water quality, where urban streams
overall have poorer water quality than rural streams.
Final development plans must be approved by the Town. USACE and state permitting are also required
for fill-in wetlands or streams. Wetlands adjacent to streams are also protected, in part, by stream
buffer rules and limits on floodplain development.These buffers and wetlands provide important
filtering of runoff, helping to limit SCIs from development to water resources. Implementation and
enforcement of these programs will prevent significant SCIs to wetlands and water resources in the
study area.
The Town's LCWRF currently discharges into the Neuse River. While additional treated effluent will be
discharged, the location is not changing. During the major NPDES permit modification request process,
water quality modeling of the Neuse River was conducted to confirm that this expanded discharge
would not cumulatively impact the Neuse River. Modeling was conducted far downstream of the outfall
location and considered other discharges, including the JCRWWTP, to consider cumulative impacts. DO
levels in the river are projected to be protected. In addition, the Neuse River watershed has a nitrogen
credit trading program to limit nutrient loading into the river and reduce cumulative impacts to the
Neuse River estuary.The Town has purchased the equivalent of 6 MGD of nitrogen credits. With the
granting of speculative limits, the modified NPDES permit, and the purchase of additional nitrogen
credits, SCIs to the Neuse River are not expected (Appendix B).
Land use activities and growth in the study area could impact groundwater quality by introducing toxic
contaminants into or onto the soil, where they could seep into the water table. Such pollution can
contaminate drinking water wells for communities and individual homes, making them unsuitable for
potable water use. Potential sources of groundwater contamination include:
• Solid waste disposal sites
• Storage or use of hazardous substances
• Poorly designed or maintained septic systems
• Accidental spills
• Leaking underground storage tanks
These potential SCIs resulting from land use activities would likely not be significantly different from the
No Action alternative. Overall, SCIs associated with increases in capacity beyond 6 MGD are not
expected to be significant.
7-50

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
7.2.2.3 Wildlife Resources
Secondary impacts to wildlife resources are not expected as a result of the 6-MGD WRF capacity
expansion because the expansion is supporting existing and near-term development already in progress
rather than stimulating new development with its associated impacts. Cumulative impacts to wildlife
resources as a result of displacement from the proposed project and projects listed herein are not
expected to be significant because of plans, ordinances, and regulatory requirements designed to
minimize and mitigate those impacts.
Secondary impacts to wildlife resources associated with increases in capacity beyond 6 MGD are not
expected to be significant.The Town has mapped natural and historic features to guide future land use
planning and zoning approvals. State biodiversity and habitat assessment data were used to classify
some areas as "areas important to biodiversity."This information is also guiding the Town in making
decisions on open space preservation, including planned public park space. Development is expected to
follow the Town's 2040 Comprehensive Land Use Plan (LandDesign, 2015), and this will lead to a
reduction in upland habitat.The Town's planning processes, protected areas such as stream buffers, and
open space requirements set forth in the UDC will limit SCIs to wildlife resources. SCIs are not expected
to be significantly different than the No Action alternative.
Protected birds with documented observations within the County include the bald eagle and red-
cockaded woodpecker. Development in the study area is not cumulatively expected to impact these
species. For feeding, the bald eagle prefers open bodies of water, such as the Neuse River and ponds.
Stream buffers will, in part, provide adequate nesting areas.The red-cockaded woodpecker's habitat is
specifically old growth pine forest, and if identified in the study area, should be protected (USFWS,
2018). Michaux's sumac is also not expected to be cumulatively impacted, as these projects will consider
its habitat in planning and permitting.
7.2.2.4 Aquatic Resources
Secondary impacts to aquatic resources in the study area are not expected as a result of the 6-MGD
WRF capacity expansion because the expansion is supporting existing and near-term development
already in progress rather than stimulating new development with its associated impacts.
Cumulative impacts to aquatic resources as a result of land cover and other changes from the proposed
project and projects listed herein are not expected to be significant because development trends within
the study area are likely to continue to follow the Town's 2040 Comprehensive Plan, and will continue to
implement stream buffer rules and other state and local permitting processes.
Federally listed and proposed for listing aquatic species, such as the Dwarf wedgemussel, and state-
listed species are present in the streams of the Neuse River watershed (USFWS, 2018). Both the water
quality and sensitive species aquatic habitat could be minimally and cumulatively impacted by
development; stream buffer protections and the Town's stormwater program limit this potential for
impacts.
Cumulative impacts to the Neuse River and its habitats are not expected to be significant. Buffers
including the river's floodplain limit impacts from runoff. Adding treated effluent discharge to the river is
not expected to cumulatively impact water quality, given the facility's NPDES permit and the nutrient
reduction strategy.Therefore, aquatic resources in the Neuse River are not expected to be cumulatively
impacted by the additional discharge and other nearby facilities.
Further development and growth within the study area facilitated by the availability of treatment
capacity beyond 6 MGD could have minor secondary impacts on aquatic resources. Stream buffer
requirements and stormwater management requirements outlined in the Town's UDC will minimize
impacts to aquatic resources and habitats as development occurs in the study area. Stream buffers
successfully limit sheet flow and stabilize stream banks, limiting sediment deposition in streams that
could otherwise reduce and change instream habitats for aquatic resources.Town development
7-51

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
standards and other nonpoint source pollutant management strategies, including water supply
watershed development restrictions, are also important in reducing the potential for both secondary
and cumulative impacts.
7.2.2.5 Land Cover,Agricultural Land, and Forest Resources
Secondary impacts to land cover, agricultural land, and forest resources are not expected as a result of
the 6-MGD WRF capacity expansion because the expansion is supporting existing and near-term
development already in progress rather than stimulating new development with its associated impacts.
Cumulative impacts to land cover, agricultural land, and forest resources as a result of land cover
changes from the proposed project and projects listed herein are not expected to be significant because
current land use and development trends within the study area are likely to continue to follow the
Town's 2040 Comprehensive Plan (Figures 7-11 and 7-12) (LandDesign, 2015). Clayton is the fastest
growing town in Johnston County and is expecting increases in residential, commercial, and industrial
land uses.The establishment of the ECIA and RTZ are examples of the forward-thinking planning efforts
of the Town and County to guide land use changes and prepare for public infrastructure needs.
Significant investments are underway by pharmaceutical industries in the ECIA, as reflected in
wastewater demand projections.These industrial investments cause job growth and subsequent
demand for housing and commercial developments.
The Town's UDC establishes the rules for the physical development of property, and, together with the
Town's General Design Guidelines, zoning processes, and the 2040 Comprehensive Plan, these plans
describe how the Town wants to grow and develop (Town, 2006; LandDesign, 2015).Transitions in land
cover from forested, agriculture, and open space to developed (primarily low-to medium-density
residential) are expected. Infill development in the downtown area is also expected, as the Town seeks
to promote a vibrant downtown area as described in the Downtown Master Plan (OBS, 2010). Another
example of planned, expected land use change is the Small Area Plan for an area around the County
Memorial Hospital (ETd, 2007).This commercial development area will be served by public utility
infrastructure.
These changes to land cover, including transition of forest and some agriculture remaining in the Town's
ETJ, are expected to occur regardless of the alternative chosen and are not expected to differ from the
No Action alternative.
7.2.2.6 Public Lands and Scenic and Natural Areas
Secondary impacts to public lands and scenic and natural areas are not expected as a result of the
6-MGD WRF capacity expansion because the expansion is supporting existing and near-term
development already in progress rather than stimulating new development with its associated impacts.
Cumulative impacts to public lands and scenic and natural areas as a result of land cover changes from the
proposed project and projects listed herein are not expected to be significant because development trends
within the study area are likely to continue to follow the Town's 2040 Comprehensive Plan and Parks and
Recreation Comprehensive Plan Update (LandDesign, 2015; Sage Design, 2013). Public lands and scenic and
natural areas are present throughout the study area and mapped by the Town to use as input when making
development decisions.The Town has plans to set aside additional lands from development(Figure 7-13)
(LandDesign, 2015).The Town also adopted its Parks and Recreation Comprehensive Plan Update in 2013
(Sage Design, 2013) and is encouraging outdoor activities and connectivity through implementation of its
Comprehensive Bicycle Plan (Kimley-Horn, 2006).
7-52

Appendix B: Maps
Future Land Use
1.1 Recreation and Open Space `� ` LE[I H s o= x
MIMI
Agricultural and Rural Residential t ' I z a
d I 7 U
Low Density Residential - co
4 Emil'
Medium Density Residential Mr/ 73 m
ilk
rild1111414 C
High Density Residential
��� Neighborhood Center # 0.� OLD ( i S Crete
To
7i Community Center k 3 ��� $�°�'�o S Ro / (1111)
F Downtown Residential 1°7 i (.
r
1- Downtown Core ;* } ARCHER
lkir
Employment Center I ] 4�ft
t 1 �. LODGE-
ri lia
• Context Features �.``RRa + P Y
= Clayton ETJ / '��►.* r
County Boundaries i `�1 it!444 Lr �oG�o 16
1:11L
a Highways t101. ( °�I �-
Roads de 111
4/t. ........ 1 ,
` '
4.41 . a
New Location Roads �_—��
i i i Rail �~=! .. `
i'.1.:Ilk1 1'
1 * "�% . 6 'I. Proposed WRF Site +�[
r , �� f _ 60) CID
,..17 - /e. (1\ im i
1 / ' - - (:.'_</."14:401 N\ •
IF
. .„ 0 '��/ Sri
40 itis 1 �I
_(.401.:,2.
..
„,...*, ibill--1k .
wm.ls ,.. .. ..,.
0
ja \ /� rr -Ra •
2„,
trito
.....
ip"... -- i \
\ r_. . ...
..."
, . .. . _ ....
,,,.-.
,....
...
' ...,
le// ,,./j/// oy q� c} .y
64- -HP
Zr-r.
42
1 00 lilt- I i
l9II i 111.4 70 � z ,__� � +.� �R�1.'
.tip
ii mho IF . 1 1),,/
III
�� p�� �'�•� Figure 7-11
�, Future Comprehensive Land Use Plan Map
r 0 0.5 y r Ro �� Water Reclamation Facility Expansion
AliK. ,
,��z Miles
o Rir �� Town of Clayton, NC
SIDmpoa a shin.?040 : 58

Appendix B: Maps
— �tu Br�iv�L
Future Land Use �
/0„)//ziii. ... ,----r---
Recreation and Open Space ��. 10
Agricultural and Rural Residential o co Low Density Residential `Gsy �F , •
Medium Density Residential �� •
'+`
r. High Density Residential \ ��
��� Neighborhood Center .� . 3
EMIllCommunity Center � " �`
ifi
1
- Downtown Residential ;. • -I z CI
= o l
Downtown Core - ��
PM Employment Center :: ,.
Context Features L ;
Clayton ETJ ` �J
I
County Boundaries re • f r�Highways �7 � ".�
�r PIN ELAND AVE
OMIll
R: ocation
ds ' C
4,
Roads ////,/, 4ild .... . ' '../ ' °cw°°n
I I Rail I•11,. ."�•. \,,
,� ` t -lam. mit
, _ MEL ST !
RANDO�pH �R�
C1)
RIDGE DR a
. _ .,_,.., 4 �� ci,;„, 00.- j, r
! v - �� k�N/Ij� ,..,:,.:�. p+0„.
zCili)
-, ,...„•(.:--•-s.,,,, -.?•\- -. . ::' •',":1,..'F--::-.---', --",..-, ...... ../.,'---_-:_.__ - .111,,1 z:-.:,
,v,s,
3:j 61 ; : fl 0-111:)-14,1rriVI-A-31, ...,;: -1-;.----_--IL 1 r (,/j° .0',1 .- / _.- X. . • •-.. :, .. ,..._,. .. .. „ ,... , il,„,,,,:.:::,:l...:1,,,:,cf: .. . I
F'' 1111111 ■ CIL
Cf i ��p-� ..
m Till_ �M°R •+ // Y� %
I z ¢4 :•: ly' F —�� 1
,
1 Lii• • '
rri ix ■ °�, �Q z 42 4,/ - '''-'----- .. - h. '' . ti
(11)
U y' ;
•... - /1'---„-.,-c--7,-)', -,'--s
n ?y WING4NG W �m G
T ,,(A M855 4 : � .c t0 -
�`�'' D BREEZEWO°D LN p Q P �P DI!'NQ �1
oQX °Og BREEZE dp a vG n S�F rifg F ♦ . _ -
G ,". i, w - s
cL-
RD LN a BENTWOOD LN m Fpt'� % WOG ] ��'��
Fp 4N A ��OF � 5 -CO a ,
Rp w a NUC GPI � } ��G °' \ $
��' _z E� O,�ENL� , RD " �O� yea DR ¢ '
a� qG 9-\ �� �'"� ';�!/ � * . ...
' Figure 7-12
ti�� 0 0.125 a.25 z g i a �9,R-r��'� N STER w M ,�� ���'
� Miles c o z a J / Downtown Future Land Map
o R z° Q" "zw°°� ° woe o �,��� ��@ Water Reclamation Facility Expansion
- s � ? . — / / ' o iiii�////////, Town of Clayton NC
59 :Town of Clayton Comprehensive Plan 2040 : 59

Appendix B: Maps
\;,,. . . II% %IN --. . ',.,. 1 f
1 \
.‘ ...
_ _, .
.._ .41
.., _,:_ ,
1 ,,,,., ‘
. . r e
r
Existing Mountains to Sea Trail/ /� - r._ '
/ J
/ East Coast Greenway '1111
miq
1 -IN i _ W • Triangle Land '�./_
I 1 e Conservancy ,y nR.
LOWE
41111014
Preserve u�o�
I4 i
A
�_ - proposedirati-eadand
' * 1 illCanoe/Kayak Launch J
fli)
jft.41:
16' _ 6,„,n9 L.."<.e,,
:*. .,—Igiate
S. . ,_Aiii„, I .. ,i., . .RGIBLER =
o
II
,._ 1:11L
-
isik ,/ . I 40 '
c., -t — :r
4 III ��
i resl Existing Trallhead and
..
.,.,„/„„
� z Canoe lKayak Launch
Mi
i„ )6., / .
b
•
all)
fmit,4it
ry��„I!
f!>•Hff,;',7„IINIIiNI,„„,„„„, „,,„„,„,„, • •..••• ram.. r - • �I<f -
mg
. .).):11' IP •
•
C1)
Ilk _ , ,
` •(lD1J4'1' I'% � •roposed WRF Site
,..., . ill,
1210
--ir -*IfY . .' .
I cii)
_< knillEr 's ii• . • ,
A -
/ - ' .--• 01 imil
I' '. _ ����/ '����� Planned Mountains to Sea Trail 1 Proposed Trailhead and
+��, �p . East Coast Greenway Canoe f Kayak Launch _ r
4 . 9 - O
a• - Clayton #.1: '��, .....
Community r .� % 3...y
per_
Park *i*.'i i • 4 2i 't
II
Plan • N e use fir'
in ''. '' 4.00 0.,-- . P.tr k., :.
elk V4110.1441,4 0
Cill)
4 cds 4I'.-' ,,, .,,,:: .
•
•
„..A• ,,,,, :
„Iv .... \ .
Ips. - . . , "... 1 /, .,...._ \,. . _,
L Al
,..3 Sa + Planned
`_' i- Park „f'h
Figure 7-13
6'6S:
*. '
Parks and Recreation Map
411i4, Water Reclamation Facility Expansion
°' .4...' '''''
Town of Clayton, NC
611)mmoolunel €litynd040 : 60

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
Greenway systems within stream buffer corridors allow the public access to natural areas, including within
the project area and along the Neuse River.The Clayton Riverwalk is part of the Mountains-to-Sea Trail
system, and project construction and operations will not permanently create cumulative impacts to these
trail systems. Co-location of public infrastructure and greenspaces is successful at the current project site
and is an example of how other public lands can be developed with multiple benefits in the future. In
summary, SCIs related to capacity increases beyond 6 MGD are not expected to be significantly different
than the No Action alternative.
7.2.2.7 Archaeological and Historic Resources
Secondary impacts to archaeological and historic resources are not expected as a result of the 6-MGD
WRF capacity expansion because the expansion is supporting existing and near-term development
already in progress rather than stimulating new development with its associated impacts. Appendix K
includes correspondence with NCSHPO.
Cumulative impacts to areas of archaeological or historic value as a result of land cover changes from
the proposed project and projects listed herein are not expected to be significant because development
trends within the study area are likely to continue to follow the Town's 2040 Comprehensive Plan and
Parks and Recreation Comprehensive Plan Update (LandDesign, 2015; Sage Design, 2013).Those places
already listed would be protected in accordance with current regulations.The historic downtown area is
listed on the NRHP and shown on Figure 7-8 (LandDesign, 2015).These areas would be protected
through implementation of the Town's Downtown Master Plan (Figure 7-12) (OBS, 2010).This area
would also benefit from the strong economic conditions present in the area created by the Town's
industries and location in the greater Raleigh metropolitan area.The Town's Downtown Facade
Improvement Grant Program also helps to preserve the character and resources within the historic
downtown area (Town, 2019b).
Any large development activities would require investigation of the potential for historic value, according
to current regulations. Archaeological resources may be present along the Neuse River; none are known in
the area adjacent to the project site (WithersRavenel, 2020a, 2020d, 2020e). Historic areas could be
impacted directly by future projects, creating cumulative impacts; but secondary impacts would be
unlikely. Impacts to historic resources would be assessed individually during project planning, likely at the
Town level, if properties are not listed on the NRHP. In summary, SCIs to archaeological and historic
resources from capacity increases beyond 6 MGD are unlikely to be significant and are not expected to
differ from the No Action alternative.
7.2.2.8 Air Quality and Noise Levels
Secondary impacts to air quality and noise levels in the study area are not expected as a result of the
6-MGD WRF capacity expansion because the expansion is supporting existing and near-term
development already in progress rather than stimulating new development with its associated impacts.
Cumulative impacts to air quality and noise levels as a result of traffic, land cover, and other changes
from the proposed project and projects listed herein are not expected to be significant.The land uses
around the proposed WRF parcel include industrial (Caterpillar, a heavy equipment manufacturer),
forested lands, and the Ashcroft neighborhood under development. Given that the area has been slated
for low-density development in compliance with the Water Supply Watershed Rules for years in the
2040 Comprehensive Plan, and the land uses are compatible with surrounding areas, the types of noise
and air quality changes are not expected to generate significant cumulative impacts around the WRF site
different than those expected with the No Action alternative. Additionally,the Town has attracted
industries to the ECIA that are not large air polluters. Growth in the study area, and specifically within
the ECIA, is not expected to cumulatively increase air pollution or noise levels.
Development of the currently undeveloped sections of the Town and study area will lead to additional
road traffic and associated noise and air quality concerns. As more vehicles travel within the service
7-59

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
area, levels of emitted air pollution could increase. Smog, ozone, and carbon monoxide are pollutants of
concern within the study area and are monitored.The joint planning efforts used to develop the County
Comprehensive Transportation Plan demonstrations how public infrastructure investment can both
support growth and limit associated SCIs through thoughtful planning (NCDOT, 2011).
7.2.2.9 Toxic Substances and Hazardous Wastes
Secondary impacts from the introduction of toxic substances and hazardous materials or waste in the
study area are not expected as a result of the 6-MGD WRF capacity expansion because the expansion
must comply with its NPDES permit, its stormwater pollution prevention plan, and other federal and
local programs.The main goals of RCRA and CERCLA and their associated regulations are to eliminate or
reduce toxic waste; clean up waste that has been leaked, spilled, or improperly disposed of; and protect
people from harmful wastes.These measures will limit the potential for release of toxic substances and
hazardous wastes into the environment.
As development continues in the study area supported by capacity expansions beyond 6 MGD, the
potential for releases of toxic substances from residential, commercial, and industrial sources could
increase.These substances, if improperly disposed of, could have adverse cumulative impacts on the
environment by entering the surface water and groundwater system through landfill leachate or
entering the sewer system and reaching the WRF.
As the amounts of traffic and development in the study area increase supported by capacity expansions
beyond 6 MGD, stormwater runoff will contain increasing the levels of water pollutants, some of them
toxic.Typical nonpoint source stormwater pollutants include the following:
• Sediment and silt
• Nitrogen and phosphorus from lawn fertilizers
• Oils and greases
• Rubber deposits
• Toxic chemicals
• Pesticides and herbicides
• Road salts
Neuse River watershed stream buffer requirements,Town stormwater management requirements, and
Water Supply Watershed Rules applicable in the study area will limit SCIs from toxic substances.
7.2.3 Permitting and Other Regulatory Activities
Construction and operation of an expanded WRF and associated infrastructure will require additional
permits, plans, and regulatory compliance activities to help protect the natural environment.The
following activities are either underway or will be a part of the process to bring the expansion online and
into operation:
• Sections 401 and 404 of the CWA permits will be needed for the LC Transmission Main and ECIA
Transmission Main, as well as the outfall expansion. Impacts to streams and wetlands are not
anticipated as part of the proposed WRF site construction.
• The facility's NPDES permit will need to be modified to 6 MGD.
• Nitrogen credits equivalent to 6 MGD will need to be purchased to increase the nitrogen discharge
to the Neuse River basin.
• Stream buffer variances may be required for construction of the LC Transmission Main and ECIA
Transmission Main. Alignments are proposed to be within existing easements and road ROWs to the
maximum extent practicable.
7-60

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
• A Major Site Development Plan for the WRF will need to be submitted to and approved by the Town
Planning Department.
• A Stormwater Management Plan will need to be prepared, and General Permit NCG010000 will need
to be obtained and prepared in accordance with the General Engineering Design Criteria and
stormwater rules, as follows:
— Stormwater runoff from built-upon areas will flow through wetlands at nonerosive velocities.
— Stormwater control structures must be designed for the 1.5-inch rainfall event and remove
85 percent on an annual average of TSS.
— Stormwater control structures that detain water cannot draw down the treatment volume in
less than 48 hours but also cannot take more than 120 hours.
— Vegetative buffers are to be included, with widths varying depending on the activity.
— Many of these guidelines are outlined in the Stormwater Design Manual(Town, 2010).
• A Public Water Supply Section ER will need to be prepared for the water main to the WRF and
submitted to NCDEQ for approval.
• A sewer extension permit will need to be obtained from the Town for the LC Transmission Main.
• An Authorization to Construct application for the WRF, including engineering expansion plans, will
need to be reviewed by NCDEQto verify that minimum design criteria are met.
• An air quality permit update for LCWRF will need to be obtained from the North Carolina Division of
Air Quality(NCDAQ) to reflect the generator capacity required for the new pump station.
• An air quality permit application for the new generator for the proposed WRF will need to be
prepared and submitted to NCDAQ.
• ESC permitting will need to be obtained for each project component, as administered by the County.
• Encroachment agreements will need to be obtained from the North Carolina Department of
Transportation (NCDOT) for U.S. 70 Business and secondary roads for LC Transmission Main
construction.
• An NCDOT driveway permit will need to be obtained for the WRF access road.
• A Norfolk Southern Railroad pipeline occupancy application for the LC Transmission Main will need
to be prepared and submitted to the railroad.
• There are other potential permitting requirements with other utilities, including Duke Energy and
AT&T.
• A Town Building Permit for the WRF and LC Pump Station will need to be obtained.
• A Town Floodplain Development Permit for construction activities associated with the effluent line
and outfall into the Neuse River that fall within designated the SHFA along the Neuse River and the
LC Transmission Main within the SHFA of Sam's Branch will need to be obtained.
7.3 Mitigative Measures
The proposed project, new WRF at the Neuse 2 Pump Station site with surface water discharge to the Neuse
River, will have limited direct impacts to the environment. WRF infrastructure would be located at elevations
above the floodplain and would avoid streams and their buffers.Associated conveyance infrastructure
alignments and the preferred access road alignment maximize the use of existing easements to the extent
possible. State and federal permitting programs under the CWA will be used to address the unavoidable direct
7-61

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
impacts. Discharge under a modified NPDES permit will minimize cumulative impacts to the Neuse River from
this expanded discharge and other discharges, and the river will support its designated uses.
Other state and federal programs are in place to limit the potential SCIs to environmental resources as a
result of available wastewater treatment capacity.These programs are listed in Table 7-18, and local
programs are described in this section. With these programs in effect,the impacts of this proposed
project would be minimal when compared to the No Action alternative.This evaluation focuses on the
study area as a whole and over the 20-year planning period for the Town. Within this time frame, the
Town is likely to incrementally add treatment capacity up to 10 MGD.
7.3.1 Summary of Federal and State Regulations and Programs
This section includes a brief description of selected existing regulations and programs at the federal and state
levels that may adequately mitigate the anticipated impacts of study area growth in the project area.
Table 7-18 presents an overview of the regulations and programs and the intent of each to minimize or avoid
SCIs.
The focus of this discussion is on the programs specific to those resources with the most susceptibility for
SCIs: protected species and water resources. Local programs that provide additional measures to limit SCIs
to protected species and water resources are discussed in Section 7.3.2. Land cover, including the potential
loss of forested cover and open spaces, is also susceptible from SCIs.This resource topic is best addressed
through the local programs also detailed in Section 7.3.2.
7.3.1.1 Endangered Species Act
Listed terrestrial and aquatic species are known to occur in the County(USFWS, 2018).The 1973
Endangered Species Act (ESA) conserves ecosystems threatened and endangered species of fish, wildlife,
and plants depend on, through federal action and state programs (16 United States Code [U.S.C.]
1531-1544, 87 Statute 884).The ESA:
• Authorizes the determination and listing of species as endangered and threatened
• Prohibits unauthorized taking, possession, sale, and transport of endangered species
• Provides authority to acquire land for the conservation of listed species, using land and water
conservation funds
• Authorizes establishment of cooperative agreements and grants-in-aid to states that establish and
maintain active and adequate programs for endangered and threatened wildlife and plants
• Authorizes the assessment of civil and criminal penalties for violating the ESA or regulations
• Authorizes the payment of rewards to anyone furnishing information leading to arrest and
conviction for any violation of the ESA of any regulation issued thereunder
• Requires federal agencies to ensure that any action authorized, funded, or carried out by them is
not likely to jeopardize the continued existence of listed species or modify their critical habitat
7-62

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
Table 7-18.Summary of Existing State and Federal Programs and Regulations and the Environmental Resources they Protect
Wildlife and Public Archaeological
Program or Topography Surface Ground- Aquatic Land Forested Lands and and Historic Air Toxic
Regulation and Soils Floodplains Water water Wetlands Resources Cover Farmland Resources SNHAs Resources Quality Noise Substances
ESA - - X - X X X - - X - - - -
Fish and Wildlife
Coordination Act X
CWA X X X X - - X - X - X
Section 303(d)
CWA Sections 401 X X X X X
-
and 404
SSO Regulations - - X X X X X - - X - - - X
NPDES
- X X X - X - X
Regulations
NPDES
Stormwater X - X X X X - - - - - - - X
Regulations
Safe Drinking - X X X X X - - X
Water Act
CAA - - - - - - - - - - - X - -
Floodplain
Management and X X X - X - X - X X - - - X
NFIP
Archaeological
and Historic - - - - - - X - - - X - - -
Preservation Act
National Historic
Preservation Act X X
7-63

SECTION 7—ENVIRONMENTAL IMPACT DOCUMENT
Table 7-18.Summary of Existing State and Federal Programs and Regulations and the Environmental Resources they Protect
Wildlife and Public Archaeological
Program or Topography Surface Ground- Aquatic Land Forested Lands and and Historic Air Toxic
Regulation and Soils Floodplains Water water Wetlands Resources Cover Farmland Resources SNHAs Resources Quality Noise Substances
Protection and
Enhancement of
Cultural X
Environment
Farmland
Protection Policy - - - - - - X X - - - -
Act
ESC X X X - X X X - X X - -
Neuse Nutrient
Management X X X X - X X -
Strategy,including
Buffers
Regulations for
Water Main and - X X X X X X - X
Sanitary Sewer
Extensions
Groundwater
Protection - - X - X - - - X
RCRA - - X X - - - - - - - - - X
Notes:
-=not applicable
CAA=Clean Air Act
NFIP=National Flood Insurance Program
X=protects
7-64

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
7.3.1.2 Fish and Wildlife Coordination Act
The Fish and Wildlife Coordination Act states that whenever the waters or channel of a body of water
are modified by a department or agency of the U.S., the department must first consult the USFWS, the
National Marine Fisheries Service (NMFS), and the lead state wildlife agency.The purpose of the Fish
and Wildlife Coordination Act is to prevent or minimize impacts to wildlife resources and habitat due to
water or land alterations. When modifications occur, provisions must be made for the conservation,
maintenance, and management of wildlife resources and habitat in accordance with a plan developed
with the wildlife protection agencies noted.
7.3.1.3 Clean Water Act
In 1972,the CWA(33 U.S.C. 1251 et seq.)was enacted to "...restore and maintain the chemical, physical,
and biological integrity of the Nation's water."The CWA includes a number of sections that are relevant
to the potential minimization of SCIs to streams and wetlands in the study area, including:
• Section 303(d) of the CWA established a program to identify waters that do not support their
designated uses and develop plans to address the impairments of these waters.
• Section 401 of the CWA requires certification that a project does not violate the water quality
standards as administered by each state.
• Section 404 of the CWA established a program to regulate the discharge of dredged and fill material
into waters of the United States, including wetlands.
As development such as a new subdivision occurs within the study areas, rules outlined in these CWA
sections must be followed. Other projects, such as the Town's extension of sewer lines, may also require
CWA permitting. Additionally, the CWA provides the regulatory authority for managing SSOs and NPDES
stormwater programs.
7.3.1.4 National Pollutant Discharge Elimination System Regulations
NPDES wastewater discharges are also enforced by NCDEQ under authority of the EPA and target point
source pollution into waterways. An NPDES permit is required for discharges into waterways to meet
and sustain water quality criteria. Under this proposed project, the Town will modify its NPDES permit
for its outfall into the Neuse River to cover the new WRF. Multiple facilities in the ECIA and elsewhere in
Clayton participate in the industrial pretreatment program to further support achievement of
appropriate treatment before discharge to the Neuse River.
7.3.1.5 National Pollutant Discharge Elimination System Stormwater Regulations
NPDES stormwater discharges are controlled by the federal NPDES regulations and enforced by NCDEQ.
The program regulates all major discharges of stormwater to surface waters. NPDES permits are
designed to require the development and implementation of stormwater management measures.These
measures reduce or eliminate pollutants in stormwater runoff from certain municipal storm sewer
systems and industrial activities.
The study area falls under Phase II rules for NPDES stormwater permitting.The County and the Town
have developed a postconstruction stormwater program (Town, 2010). More information regarding this
program is included in Section 7.3.2.
7.3.1.6 Erosion and Sedimentation Control
The North Carolina Division of Energy, Mineral, and Land Resources administers programs to control
erosion and sedimentation caused by land-disturbing activities on 1 or more acres of land. Control
measures must be planned, designed, and constructed to protect from the calculated peak rate of
runoff from a 10-year storm. Enforcement of the program is at the state level but may be delegated to
local governments with certified erosion control programs.The County administers the program for the
7-65

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
Town and the study area (County, 2020a).The Town is in the process of developing its own Erosion
Control and Stormwater program and is creating ordinances, policies, and procedures to support the
program once launched.The plan is for this program to be launched in early 2021 (Town, 2020e).
7.3.1.7 Water Supply Watershed Protection Rules
The study area includes area designated as WS-IV and WS-V, as described in Section 7.1.2.1 and shown
on Figure 7-3. North Carolina most recently updated its Water Supply Watershed Rules in 2019
(15A NCAC 02B.0621).These rules are meant to protect public drinking water supplies by limiting
activities and land uses that may be detrimental to surface waters. Most activities are permitted in these
watershed classifications. Limitations in WS-IV watersheds are placed on sewage and industrial waste
for those activities that have adverse impacts on human health.
Density rules are also in place in WS-IV watersheds to limit impacts from nonpoint source pollution. In
these designated WS-IV watersheds, built-upon area is limited to 24 percent, or 36 percent without curb
and gutter stormwater collection systems. Activities such as subdivision construction are considered a
singular project for this calculation. Minimum setbacks from waterways are also required. Stream
buffers specific to the study area are described in Section 7.3.1.8.These programs help to mitigate
nonpoint source impacts by limiting density and impervious area, and promoting filtering of runoff and
stability of streambanks with stream buffers.
7.3.1.8 Neuse River Nutrient Management Strategy
The entire Neuse River basin was classified as NSW in 1988. Now the strategy addresses both
phosphorus and nitrogen. New development and redevelopment that drains in whole or in part to NSW
must implement stormwater BMPs that reduce nutrient loading. NCDEQ has specified basinwide
requirements for the Neuse River basin, as described in 15A NCAC 02B.0714.
The Neuse River NSW rules require that existing riparian buffer areas be protected and maintained on
both sides of intermittent and perennial surface waters, as well as lakes and ponds. Riparian buffers
serve to stabilize stream banks with rooted systems, preventing sediment loading into the water, and
may shade waterways to moderate water temperature.They also filter nonpoint source pollutants and
serve as wildlife corridors and habitat. A 50-foot buffer consisting of 30 feet of undisturbed area
(Zone 1)and 20 feet of vegetated area (Zone 2) must be maintained.The rule does not require
restoration of buffers that no longer exist. Perennial and intermittent stream determinations are to be
based on soil survey maps prepared by the NRCS or the most recent version of USGS topographic maps
(7.5 minute quadrangle).
Nutrient loading is also reduced through the Neuse River basin nitrogen trading program.The Neuse
River Compliance Association's estuary TN limitation is 1,187,213 lb/y as part of NPDES
Permit NCC000001 (Appendix B).The Town's portion of this allocation and additional nutrient credit
purchased for this project are discussed in Sections 3.3 and 7.1.2.1.The Town's commitment and
compliance with the NSW program helps to limit cumulative impacts to the Neuse River. While this
revised strategy places more stringent nutrient removal requirements on point source dischargers, it
also addresses other sources of nutrients, including urban stormwater, agricultural sources, and nutrient
application management. In addition, the strategy includes special provisions to protect stream buffers
to prevent further degradation of the watershed's ecological integrity.
7.3.2 Summary of Local Programs
The discussion provides a general overview of the local existing regulatory and nonregulatory programs
that protect natural resources from the potential for SCIs associated with this proposed project.
Therefore,the following discussion addresses relevant regulations and programs from an environmental
management and land use policy analysis perspective. Full documents are included in Appendix N.
7-66

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
7.3.2.1 Johnston County Stormwater Management Program
The County's Stormwater Management Program covers the study area (County, 2020b).The goals of the
program are to mitigate impacts on surface water resources from development to the maximum extent
feasible by:
1. Improving and enhancing the quality of stormwater runoff from development
2. Maximizing infiltration of groundwater
3. Collecting and transmitting excess stormwater flows in a manner to protect human health and
welfare and to protect property
4. Protecting and preserving downstream natural drainage ways
With a focus on nitrogen removal as required in the Neuse River NSW watershed and water supply
watershed land use requirements,the program also addresses NPDES Phase II stormwater program
requirements for new development and existing development, including illicit discharge identification and
elimination, installation of retrofit BMPs for nutrient removal and stormwater detention, and public
education.
The program also administers the stream buffer program, promotes open space preservation, and
supports additional stream buffers and development restrictions for protection of endangered aquatic
species. Stream buffer requirements are further outlined in Section 7.3.1.7.
The Town is in the process of developing its own Erosion Control and Stormwater program and is
creating ordinances, policies, and procedures to support the program once launched.The Town's
approach is in compliance with Johnston County's program and its NPDES Phase II permit.The plan is for
this program to be launched in early 2021 (Town, 2020e).
7.3.2.2 Town of Clayton Stormwater Design Manual
The management of stormwater runoff through nonstructural controls (for example, low-density
development) is the preferred method of reducing pollution from urbanizing areas in Clayton. BMP
structures are required in cases where low density is not feasible and are to be designed in accordance
with the NCDEQ Stormwater BMP Manual(NCDEQ, 2012).
A Stormwater Management Permit is required for all new development within Clayton and ETJ limits.
The permit must be applied for by the developer or owner of the site where the development is
proposed.The developer or owner must sign the permit application and provide the required
development information (Town, 2010).
A Stormwater Management Statement is required with all plan submissions to help the Town
Stormwater Administrator determine how the stormwater management facility was designed.The
statement must meet minimum requirements as set forth in the Stormwater Design Manual and be sent
in with the preliminary subdivision plat for either commercial or residential subdivisions (Town, 2010).
The Town's Stormwater Ordinance requires new development to reduce nitrogen loading by installing
BMPs, both structural and nonstructural, or by offsetting payments to the North Carolina Division of
Mitigative Services or a local nutrient mitigation bank. NCDEQ requires that all new developments
achieve a nitrogen export of less than or equal to 3.6 pounds per acre per year (lb/ac/y). Guidance on
how to calculate TN loading is included in the Town's Stormwater Design Manual(Town, 2010).
All new developments will be held to impervious area limits. For single family residential new
development,the limit on impervious area is 15 percent; and for all other new development, the limit is
60 percent. All Stormwater Management Permit applications must include calculations documenting the
total proposed impervious area within the development (Town, 2010).
7-67

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
7.3.2.3 Town of Clayton Design Guidelines
The Town's design guidelines were prepared to pair with the Town's UDC to provide clarifying vision to
enhance the appearance of Clayton and make it more livable as development occurs.The intent is to
guide development that fits in with the scale and context of its surroundings, while also promoting the
protection of sensitive areas of the environment (Town, 2006).
7.3.2.4 Town of Clayton Unified Development Code
Chapter 155 of the Town's UDC is dedicated to zoning and development.The code allows for
development that is sensitive to the environment and encourages the preservation of open and natural
areas.These requirements include an open space area of 1,245 ft2 for each proposed dwelling unit.Tree
preservation is required where practical, and landscaping requirements include installation of trees for
both screening and tree canopy generation.
While conventional subdivisions are included in the UDC, open space(cluster)subdivision plans are
encouraged.This approach promotes preserving sensitive natural resources, can reduce erosion and
sedimentation by minimizing land disturbance,and can be used to create contiguous greenspace within and
adjacent to other parcels.These approaches promote larger protected areas and limit runoff to waterways.
Resource conservation areas must be persevered and cannot be counted toward the recreation and
open space requirements.These areas include:
• Floodplains
• Stream buffers
• Steep slopes
• Wetlands
• Other mapped areas
They cannot be used for activities such as stormwater management facilities.This designation is an
important tool for the Town to preserve unique land covers and features and limit SCIs.
Watershed protection overlay requirements include the limitation of land uses to protect the Neuse
River and stormwater measures to mitigate point source stormwater out of developments. Vegetative
swales are encouraged, for example.
7.3.2.5 Town of Clayton Floodplain Damage Prevention Ordinance
The Town's Floodplain Damage Prevention Ordinance (Chapter 151 in the UDC) includes rules to avoid
development in flood-prone areas that are subject to periodic inundation; and its jurisdiction includes
the ETJ, covering the entire study area. Coupled with the NFIP, the Town's ordinance limits impacts to
floodplains that could otherwise lead to loss of life and property while also disrupting commerce and
government services. Floodplains and other features can also be viewed in the County's online GIS
mapping tool, MapClick(County, 2020c).
The Town recognizes that limiting the cumulative effects of obstructions in floodplains can lead to
increased flood heights and velocities and seeks to avoid this through enforcement of this ordinance.
Residential and nonresidential construction must have the active use space, including basements
elevated no lower than the regulatory floodplain elevation. While most development in the floodplain is
prohibited, permitting and variance processes are included in the ordinance.
To protect water quality in a water supply watershed, the Town limits land uses within the floodplain,
such as solid waste disposal facilities, salvage yards, and chemical storage buildings. Subdivision plans
are also required to locate infrastructure, including sewer, gas, electrical, and water systems, to
minimize flood damage.The Town also seeks to limit infiltration into its sewer system and overflows by
requiring that all new and replacement sanitary sewer systems be designed to minimize or eliminate
infiltration of floodwaters into the system and discharges from the systems into floodwaters.
7-68

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
7.3.2.6 Town of Clayton Comprehensive Plan 2040
Approved in 2015,the Town's comprehensive plan has goals for Clayton to remain an active arts and
recreation community with an alive downtown, strong employment base, and quality neighborhoods
(LandDesign, 2015). Both residential growth and the ECIA are important aspects of this plan, and
investments by pharmaceutical industries are, in part, causing the purpose and need for this proposed
project.The Town uses this plan and its design guidelines as a tool to evaluate new development proposals
and direct capital investments. With implementation of this plan,the Town also seeks to promote a
multimodal transportation system with connectivity provided by sidewalks, bike facilities,greenways, and
transit facilities.
A Town survey as part of the plan development showed public interest in tree and natural area
preservation, improving water quality, and need for expansion of recreational opportunities, such as
greenways. Primary Resource Conservation Areas (PRCAs) are defined to include floodplains, protected
riparian buffers, and wetlands. Outside of these areas, land use densities and uses are planned.The
plan's future land use map shows the densest development along NC 42 and U.S. 70 Business. Medium-
density development will be guided along areas north of O'Neil Street and Covered Bridge Road and off
NC 42 west of downtown. Expansion of the ECIA industrial area is also shown,from the Caterpillar
facility south of the proposed WRF to the southern limits of the ETJ at the junction of U.S. 70 and U.S. 70
Business. Employment centers are located along the major transportation corridors to provide sufficient
infrastructure and focus commuting traffic, and commercial centers will be guided along these corridors
to encourage residents to shop locally. Other areas not along major transportation corridors will remain
low-density residential or agricultural and rural (where sewer service is not provided) (Figure 7-11)
(LandDesign, 2015).
The watershed protection overlay for the Neuse River includes these low-density land uses, with not
more than three houses per acre.The Town has also identified Secondary Resource Conservation Areas
(SRCAs), which include areas of high biodiversity, as identified in NCDEQ's Biodiversity and Wildlife
Habitat Assessment, and other unique land covers, such as mature forests and rock outcrops.The Town
seeks to protect these areas by encouraging their protection as open spaces and passive recreation
areas in the design of new developments (LandDesign, 2015).
The plan also includes the Town's goal to support innovative site and street design that reduces the
impact of the built environment on water quality, including exceeding requirements for riparian buffers
and incorporating the following elements in new developments:
• Pervious pavements
• Rain gardens
• Bioswales
• Stormwater planters
• Other features
For example, low-density housing developments can propose methods of stormwater control other than
curb and gutter to promote infiltration. Low-impact development strategies and mass grading of large
developments are discouraged.
Open space preservation areas include around the Cremmons State Forest and along the Neuse River.
Access to the river for water recreation activities is provided at the North Clayton Community Park.
Expansion of the greenway program is also included in the plan, including expansion of connectivity with
the Mountains-to-Sea Trail. Protection of these spaces and providing access to the Neuse River will also
attract recreation users to Clayton.
7-69

SECTION 7-ENVIRONMENTAL IMPACT DOCUMENT
7.3.2.7 Town of Clayton JCMH/NC 42 Small Area Plan
Development is expected along major transportation corridors and intersections.The Town developed the
JCMH/NC 42 Small Area Plan to prepare for growth at the future intersection of U.S. 70 Business and NC 42
(ETd, 2007).This road improvement project has been a part of the Town's Comprehensive Transportation
Plan (Figure 7-14)and is the location of the new regional hospital,Johnson County Memorial Hospital.The
NCDOT recently appropriated funds for the project(NCDOT, 2020).This Small Area Plan includes
institutional, commercial, and mixed-use development.This goal of this plan is to create housing
opportunities near this major employment center, promoting shorter commute times and smart,focused
growth.
7.3.2.8 Town of Clayton Parks and Recreation Plan Update
The Town desires to be the "...premier community for active families...," and the Parks and Recreation
Plan sets out areas for open space preservation and recreational opportunities (Sage Design, 2013).
Many objectives of this update were incorporated into the 2015 development of the Town's
Comprehensive Plan 2040 and are shown in its mapping (LandDesign, 2015). Both passive and active
recreation opportunities are in development.
Priorities include extension of Sam's Branch Greenway to downtown Clayton, construction of a
greenway along Little Creek, and creation of connections between spaces such as existing parks and
community centers.The extension of Sam's Branch Greenway under O'Neil Street toward downtown
Clayton is expected to open in fall 2020.This greenway will also become part of the East Coast
Greenway, a project extending from Maine to Florida. Expansion of the North Clayton Community Park
amenities is also an identified need (Town, 2020b).
7-70

Appendix B: Maps
Road Class I Improvement Bike/Ped Features •,4 (1 t .a %` � .a�a , .
Freeway, Existing Existing Greenway ff , F
s Freeway, Widening and HOT Lane Proposed Greenway a \ /=-=;- ,
. 11.111.1 Freeway, New Location Existing Sidewalks / °�
it A. _ \� ',,,,,,•:,-... eic nrm c,:,R
Boulevard, Existing Proposed Sidewalks . cA a A .
JA
® Boulevard, Widening Proposed Bike Lane ". °
a •
♦ 3 I. -. 9 - �♦ `1 - + s`a ` ' Sr ARCHER
Boulevard, New Location Clemmuna „� , r LODGE
Sale Forest SNP • I 1 °"IT''','
N .-hr Y . +3 _, .r f A �'""n� Y
. =
Major Thoroughfare, Existing e • ": ,,;.,. a e
z - 1 � 'S - , .s "
.J
Minor Thoroughfare, Existing : CI
,./...„..,,
-� '• i r( `� �� . a•�
w Max
22 Q}
--'--• Minor Thoroughfare, Streetscape
r =_� ,'�.. „ s. 4� \`; ,• g G+' ,
OMIN
----' Minor Thoroughfare, New Location C.lezens i �f ' r , �l,4 y;" ' .M ., ,r `, 'I . •.`� = •
^ Fo}est ' J s• n A4 f f,f.4,. `u_ •• ♦ :-,
ril)
O Intersection Improvement Needed M iA y
I: _ s,, :AT. _1. fit, r `.• ' r � .
Fr
•,i FS*.
I.
• GARNER • .; `# • a No• Rha r ��r
• `�,,,° t'"m ..cs.a•., #li �.., 1'. 7.�" + !�a ra * •` i' ii 4. • - Community Pa fii "`? ' �� `^o �"-c '- •�'`4. y 1 •.1. •a•w 4 1 s. y •n®Y (Planned) r - /', 3.4} y
\ CI
'c, f .`f� '�� r Ts#C�-Y+ x¢' s, J 5 "-5y-,s "' *�'+y �L ' �\`� / � —•
,,, cif 4 w •
:®• 51i Pentl+ i `v•L• _ p_ _ 441 ,i _ I��;�r 'f':' �zl J - �[..�fC -- „yF.J
:TI
•
,,,. . " f •f g ti 1 � - C �4 - . ',�,. -roposed:IIVRF Site "
NI
g \ {{Y 1 (vp \�,,� `• - ,i _ , . '. t ip,,,,, .,,,,,.. ' .i. , -. } ,.;., +� -+;•Y. � ,., 4 �'
.-- %,,„„, -1:1
•
�4I. ;{`A 1L •`� � r ,- r. ,. , , Fh 1.. -'mac , - - f`4-".
t mit
- • ~ # .� .. 'yq- 1 X ; ;•Sa' �•�' T ' c,.:,!'a .4''liC 4 : , .g , i'w ` • ^'� '' �',,-• 1 4 , .: 5', `� "�,
k •` '� '• �'4 yr>'f • :._ -y� ♦ .s -�� AVtA'� •�� ,}'�� r r � BPS � �y'
1 � � � : �' 4 ei�L�'�' q�` ••,. n�ra ' ems=' 1 ? - �
■ ,•. w '',.d t ,,k- Q1 "1 • f•,' +` Y -. �,BP-21 'ti 1 a fit.:._ •1 's• 1 •',-,: �° '� O
•
mirk
t •'�: dip' ^' '' - ' r r i 'q„
4;....; .__.:
■ ,y,..`,c _ - n ..� $
^E ,� -A i " • �, .�`' r� ,eQ a. - I q - - j
—•
.,..„.. , ,
..
. . . , . ,
,,......,. _,,,„:,,,,,,,
...,,, ,
,...,. ...
.". _0:,... ,_
, .,,,,,,,
•
■ ' -".'k' •. `- r. reu; 'F,,' 131�.` < 1. x` 1; w�". '♦ �- zR!, .� f'�, a _ .
■ v, y� '� - 1. - lP D3' �i� s V� '1 e�••;• a '1w • _ •-fp, ✓-4F.-:- !Tr." _ , - �--
■ �... � .�' i _ r �°.. Y s 4 i• �� - '' `r ¢ are ,Fae' - i, R ! °l v • �42 p""' ,""o,".-
Q.
-I:I
a° m m '•4i A� a r :-d. .. .tear. , md `� • <i- ''LhL 4
• c� ifs i �'z • , 4 -5..�.�
•
i • } ...8 �?•, _ .�*r „s}. a•1'• - 4 u V '.fi> i_'t.S.� �" ::�. q +/r.\�. :!,� i- .1( y_ ,eti �,y�
•
miq.35
•�' 112Pcne1mn \ t. 3? F8 x r+� N..- >Y f. • r -m° eoa t"'. ;r Y;� b ac,•'
•• u :21bn Lana t ds .�^• '.` '-- ,., ., } +y , '' CI
r• —I: :-i p=''' CFI. mho {�.
1 •- ■* �� _. `'4At .� xi. i*:, - -�° a llllln�rrrr. c7 ',i -. -` .i ` s r•, '� w .- .# , 1 .1'41 ' e r `.
„'> �� 's� �.� " �i Y- -A ,� ��.y �,�..a -..�,.j p ;' - :%i• --�1': 99 ',t d,' .t, f w '
,....• C1)
:-"' " N'., - f `Zr`. s '✓` VCr�as'"s- j, I., J „b t k` {,.a
.. • 'L... , •, ,,•..
:c•d '} - f r- ~ �,.._ -3 of - �� i r'. • +, •_ t' _( { ��h ' L ,I 7._ _
'it
ATAN
v� er ♦ r k! t ` ,4'.w ;z •-y ai �•,�; r Qom,.
•
fie. •a c« oa y[ I • " ...1'.... t 9 , }5 ! 'j"h' k - 4 ' %4'' - /
$ '- --_:� Cot 4'41. ; 1�. '.!
.i,j,
k.
( / ''''''''''
Wm .b:,a4' n 9 I c .�+ �'J(f • 1\. k /''^
i -+ 3. 'r 1 r .r o .1•t 'e'er+ _ •1 !`A 1•' ` •
: w
' + "� f ' ' - - 1 : '' `• r : _ • � ° -' ' �— Figure 7-14
. � T'... - ' o - r`� ..': " g- *,• , F ' Transportation Priority Projects
" ! ,Y, ' `� n� • _ Water Reclamation Facility Expansion
�� � __ •
.� I�r.• .�, ;� , : " .. Na Town of Clayton, NC
111$0;141, .' . . .- -il r _t-fir r -
®mTmeti eii i- 11 1 n040 : 62

SECTION 8
Financial Analysis
8. 1 Determination of Rates to Median Household Income
Percentage
Water and sewer rates for the Town's customers include both a base charge and volumetric charge. For
water, this volumetric charge is tiered, with the charge increasing with increased water consumption.
For sewer, a single volumetric charge applies. For a consumption of 5,000 gallons, the average monthly
bill is $83.58, based on current rates and fees (Table 8-1) (Town, 2O19c).
The median household income (MHI)for the Clayton LGU is$62,059 (Census, 2019), and as a percentage
of MHI, an average monthly bill is 1.62 percent (Table 8-1).
Table 8-1.Applicant Local Government Unit Financial Condition
Item Sewer Rate Structure Water Rate Structure
Rate Structure Uniform Uniform
Base Charges,$ 17.53 16.05
Base Charge per 1,000 gallons 0 0
Volumetric Charge per 1,000 gallons,$ 5.64 4.36a
Monthly Bill for 5,000 gallons,$ 45.73 37.85
Combined Monthly Water and Sewer Bill for 5,000 gallons,$ 83.58
MHI,$ 62,059
Monthly MHI for LGU,$ 5,172
Bill as%of MHI 0.88 0.73
Overall Bill as%of MHI 1.62
Source:Census,2019,Town,2019c
a Water rate per 1,000 gallons calculated from tiered rates.
8.2 Determination of Funding Sources
The Town contracted with Black &Veatch to prepare a 5-year financial plan for the Town's water and
sewer utilities.The resulting Water and Sewer Financial Plan (Black &Veatch, 2020) is included in
Appendix M.The financial plan was developed for the FYs 2021—2025 and was based on an analysis of
the existing revenues and revenue requirements of the Town's water and sewer utilities.The analysis
looked at expected revenues under existing rates and the water and sewer revenue requirements with
implementation of the Capital Improvement Plan (CIP), of which the new WRF was a part.
The plan reported that the costs of major capital improvements are expected to be financed through a
mix of sources that includes debt financing, existing fund balances, and annual operating revenues
available for cash financing of capital improvements (Black&Veatch, 2020).Table 8-2 summarizes the
recommended financing mix.
8-1

SECTION 8—FINANCIAL ANALYSIS
Table 8-2. Utility System Capital Improvement Plan and Capital Improvement Plan Financing a
FY 2021 FY 2022 FY 2023 FY 2024 FY 2025 Total
Line Description ($) ($) ($) ($) ($) ($)
Capital Improvement Program:
1 Water CIP 3,954,650 1,281,000 1,180,000 2,624,500 1,381,250 10,421,400
2 Wastewater 7,045,000 9,612,500 1,368,750 2,400,000 1,131,300 21,557,500
CIP—All Other
3 WWTP CIP 15,000,000 40,000,000 35,000,000 26,000,000 0 116,000,000
4 Loan Issuance 450,000 300,000 300,000 80,000 0 1,130,000
Expenses
5 Total Uses 26,449,650 51,193,500 37,848,750 31,104,500 2,512,500 149,108,900
Sources of Funds:
6 Beginning 24,300,000 12,568,544 14,007,3113 0
Balance
7 Revenue Bond 15,000,000 0 0 8,000,000 0 23,000,000
8 State Revolving 30,000,000 30,000,000 30,000,000 90,000,000
Fund
9 Cash Financed 5,749,650 9,462,044 9,287,519 9,097,187 2,512,500 36,108,900
Capital
10 Total Sources 50,749,650 63,762,044 51,856,063 31,104,500 2,512,500 149,108,900
11 Ending 24,300,000 12,568,544 14,007,313 0 0
Balance
a Table summarized from Water and Sewer Financial Plan(Black&Veatch,2020).
The Town is eligible for up to $90 million of CWSRF funding based on current status with NCDEQ DWI
and the SWIA.The Town has engaged Davenport &Co. to support them with bond issuances.
The LGC has approved $15 million, which includes funding for nitrogen credit purchases.
8.3 Determination of Loan Repayment Output
To date, one round of CWSRF funding has been approved for$30 million, at an interest rate of
1.38 percent over a 20-year period and with an administrative fee of 2 percent.The Year 1 principal and
interest on this loan is$1,914,000, as summarized in Tables 8-3a and 8-4a.Tables 8-3b and 8-4b
summarize the potential total CWSRF funding amounts.
Table 8-3a.Current CWSRF Funding Distribution
Specified Interest Repayment
Amount Rate from LOIF a Period
Funding Type Funding Source ($) Funding Type (%) (years)
Main Division Funding CWSRF 30,000,000 Loan 1.380 20
Closing and Administrative Fee 600,000
Total Funded Amount 30,000,000
Total Project Cost 30,600,000
8-2

SECTION 8—FINANCIAL ANALYSIS
a LOIF=Letter of Intent to Fund,issued by the Division
Table 8-3b. Potential Total Funding Distribution
Specified Interest Repayment
Amount Rate from LOIF a Period
Funding Type Funding Source ($) Funding Type (%) (years)
Main Division Funding CWSRF 30,000,000 Loan 1.380 20
Main Division Funding CWSRF 30,000,000 Loan 1.380 b 20
Main Division Funding CWSRF 30,000,000 Loan 1.380 b 20
Closing and Administrative Fee 1,800,000
Total Funded Amount 90,00,000
Total Project Cost 91,800,000
a LOIF=Letter of Intent to Fund,issued by the Division
b LOIF not provided.Indicated interest rate shown matching current CWSRF funding LOIF.
Table 8-4a.Year 1 Interest and Repayment on Current Funding Distribution
Year 1 Total
Total Funding Year 1 Principal Year 1 Interest Payment(Principal
Amount Payment Payment +Interest)
Funding Type Funding Source ($) ($) ($) ($)
Main Division Funding CWSRF 30,000,000 1,500,000 414,000 1,914,000
Table 8-4b.Year 1 Interest and Repayment on Potential Total Funding Distribution
Year 1 Total
Total Funding Year 1 Principal Year 1 Interest Payment(Principal
Amount Payment Payment +Interest)
Funding Type Funding Source ($) ($) ($) ($)
Main Division Funding CWSRF 30,000,000 1,500,000 414,000 1,914,000
Main Division Funding a CWSRF 30,000,000 1,500,000 414,000 1,914,000
Main Division Funding a CWSRF 30,000,000 1,500,000 414,000 1,914,000
Total 90,000,000 4,500,000 1,242,000 5,742,000
a LOIF not provided.Indicated principal and interest payments shown matching current CWSRF funding LOIF.
8.4 Determination of User Fee Increase and Impact to User
Rates
The Town conducted an analysis in 2020 to assess the impact of the proposed project on rates and fees.
One aspect of this analysis was to assess operating results under existing rates.The analysis indicated
that without any revenue adjustment, that utility system would have a negative fund balance at the end
8-3

SECTION 8—FINANCIAL ANALYSIS
of the forecast period (FY 2025).The following series of revenue increases over the forecast period was
proposed (Black and Veatch, 2020):
• FY 2021: 8.7 percent
• FY 2022: 9.2 percent
• FY 2023: 9.6 percent
• FY 2024: 6.9 percent
• FY 2025: 7.3 percent
The increases were applied differently to water and sewer rates, as presented in Table 8 of the Water
and Sewer Financial Plan (Black and Veatch, 2020) (Appendix 0).
Program costs for a new WRF and associated transmission infrastructure are currently estimated at
$120 million, based on a construction cost of$94 million and project administration costs of$26 million.
Town Council continues to support the rate increases associated with full program delivery. CWSRF and
bond capacity are available. Regardless of available funds, the LGC must approve all debt issuance.The
Town continues to work with LGC to officially approve the issuance of debt.
8.5 Determination of Impacts to Utility Bill per Median
Household Income
The Water and Sewer Financial Plan (Black and Veatch, 2020) (Appendix 0) proposed across-the-board
increases of 2 percent to water rates and 16 percent to sewer rates for 3 years. In FY 2024 and FY 2025,
there would be no further increase in water rates, but the sewer rates would increase by 12 percent.
Proposed rates for FY 2021,which have since been adopted, were included in the plan.Table 8-5 shows
the impact of these proposed changes through FY 2025.
Table 8-6. Fiscal Year 2025 Impact to Bills
Item Sewer Rate Structure Water Rate Structure
Rate Structure Uniform Uniform
FY 2025 Base Charges,$ 34.31 17.03
FY 2025 Base Charge per 1,000 gallons 0 0
FY 2025 Volumetric Charge per 1,000 gallons,$ 11.04 4.63 a
FY 2025 Monthly Bill for 5,000 gallons,$ 89.51 40.16
Combined FY 2025 Monthly Water and Sewer Bill for 5,000 gallons,$ 129.67
2019 MHI,$ 62,059
Monthly 2019 MHI for LGU,$ 5,172
FY 2025 Bill as%of 2019 MHI 1.73 0.78
FY 2025 Overall Bill as%of 2019 MHI 2.51 b
Source:Census,2019; Black&Veatch,2020
a Water rate per 1,000 gallons calculated from projected FY 2025 tiered rates.
b MHI will likely increase over the analysis period,so this percentage would likely reduce by FY 2025.
8-4

SECTION 8-FINANCIAL ANALYSIS
The projected FY 2025 overall utility bill will be over 2 percent of the MHI.The Town will work to
manage the cost and timing of capital projects to limit the impact of rates and fees to the extent
possible.
8-5

SECTION 9
Public Participation
Public participation is an important part of the development of a project because it allows the Town to
keep their citizens informed.
Based on NCDEQ guidance for the preparation of ERs and ElDs, the project will require a FONSI as the
final environmental document. Given that, a high level of public involvement is required before a FONSI
can be sent to the State Clearinghouse. The process will include the following steps:
1. Advertise a public meeting.
2. Hold the public meeting.
3. Report on the public meeting.
In addition to the requirements from NCDEQ, it is the Town's intention to hold informational meetings
before Town Council meetings to keep the public informed. To this end, a public drop-in meeting was
held at the Clayton Town Hall on July 22, 2020. The Town also has a page on its website dedicated to the
project, where information will be posted as available (Town, 2020g). Regular project updates will be
provided, and some public workshops will be conducted as the project progresses. A schedule for public
participation in being developed by the Town for publication on the website.
The proposed expansion of the discharge will require an NPDES permit modification. As part of that
process, a public hearing would be required. This would provide another opportunity for the public to be
informed, engaged, and provide input. This public hearing would be held separately from the meeting to
be held as part of the ER-EID and FONSI process.
9-1

SECTION 10
References
Black&Veatch Management Consulting LLC(Black&Veatch). 2020. Water and Sewer Financial Plan.
Prepared for the Town of Clayton, NC.
CH2M HILL North Carolina, Inc. (CH2M). 2013. Wastewater Conveyance Study. Prepared for the Town of
Clayton, NC.
CH2M HILL North Carolina, Inc. (CH2M). 2015.Sam's Branch Basin Pump Station Decommissioning
Feasibility Evaluation. Prepared for the Town of Clayton, NC.
CH2M HILL North Carolina, Inc. (CH2M). 2019a. Technical Memorandum: Water and Wastewater Asset
Inventory and Assessment Risk/Criticality Analysis and Renewal and Replacement Model Results
Summary. Prepared for the Town of Clayton, NC.
CH2M HILL North Carolina, Inc. (CH2M). 2019b. Business Case Evaluation for Little Creek Water
Reclamation Facility. Prepared for the Town of Clayton, NC.
CH2M HILL North Carolina, Inc. (CH2M). 2019c. Business Case Evaluation for Proposed Neuse River
Water Reclamation Facility. Prepared for the Town of Clayton, NC.
CH2M HILL North Carolina, Inc. (CH2M). 2020. Memorandum: Town of Clayton Wastewater Forecast
Update. Prepared for the Town of Clayton, NC.
City of Raleigh and the Town of Clayton (City and Town). 2007. Interlocal Agreement. February 27.
Dewberry Inc. 2020. Neuse River QUAL2K Model Report:Falls Dam to Smithfield. Prepared for the Town
of Clayton in support of the Little Creek WRF Expansion.
Elam,Todd, D'Ambrosi (ETd). 2007.JCMH/NC42 West Small Area Plan. Prepared for the Town of
Clayton. https://www.townofclaytonnc.org/uploads/files/Planning/JCMH%20 %20SmallAreaPlan.pdf.
Accessed May 2020.
Froehling & Robertson, Inc. (Froehling & Robertson). 2020. Report of Subsurface Exploration and
Preliminary Geotechnical Engineering Evaluation—Town of Clayton Wastewater Reclamation Facility.
Prepared for the Town of Clayton, NC.
Grifols Therapeutics (Grifols). 2020. Personal communication (email) Re: Grifols Conversation/Reuse
Water Cycle with Town of Clayton. April 29.
Hazen and Sawyer(Hazen). 2013. Nitrogen Removal Study. Prepared for Town of Clayton, NC.
Hook and Bullet. 2020. Clayton Bait Shops, Tackle Shops, Fishing Reports, and Fishing Charters(North
Carolina). https://www.hookandbullet.com/c/fishing-clayton-nc/. Accessed April 2020.
Johnston County(County). 2020a. Erosion and Sediment Control-within the jurisdictions of Johnston
County, Benson, Wilson's Mills,Archer Lodge, Pine Level, and Clayton.Johnston County Public Utilities.
https://www.johnstonnc.com/ut2/content.cfm?page desc=esc. Accessed May 2020.
Johnston County(County). 2020b.Stormwater- Within the jurisdictions of Johnston County.Johnston
County Public Utilities. https://www.johnstonnc.com/ut2/content.cfm?page desc=stormwater.
Accessed May 2020.
Johnston County(County). 2020c. MapClick Online Mapping. Geographic Information Systems.
https://www.johnstonnc.com/gis2/. Accessed May 2020.
10-1

SECTION 10-REFERENCES
Johnston County(County). 2020d. Water and Sewer Rate Adjustments for FY 20/21. Effective Date
October 1, 2020. https://johnstonnc.com/FILES/UTILS/FY20-21 Utility Rate Increases.pdf.
Johnston County and the Town of Clayton (County and Town). 2005. Interlocal Agreement for Transfer of
500,000 gpd Wastewater Allocation. October 3.
Johnston County and the Town of Clayton (County and Town). 2006.Amendment to No. 1, February 19,
2001 Bulk Wastewater Interlocal Agreement. November 20.
Kimley-Horn and Associates, Inc. (Kimley-Horn). 2006. Comprehensive Bicycle Plan. Prepared for the
Town of Clayton.
https://www.townofclaytonnc.org/uploads/files/Planning/2006%20Comprehensive%20Bicycle%20PIan.
pdf. Accessed May 2020.
Kuntz, Matthew, Novo Nordisk. 2020. Personal communication (email)with the Town of Clayton, NC.
April 23.
LandDesign. 2015.2040 Comprehensive Plan. Prepared for the Town of Clayton, NC.
McKim &Creed. 1996. Wastewater Treatment Facilities 1993 Improvements-Revisions after
construction.
McGill Environmental Systems (McGill). 2020. Letter to Jacobs Engineering Group Inc. regarding
accepting waste.June 9.
National Oceanic and Atmospheric Administration (NOAA). 2020.Atlantic Sturgeon.
https://www.fisheries.noaa.gov/species/atlantic-sturgeon. Accessed August 2020.
National Park Service (NPS). 2020. "National Register Database and Research." National Register of
Historic Places. https://www.nps.gov/subjects/national register/database-research.htm. Accessed
April 2020.
NatureServe. 2020. NatureServe Explorer. https://explorer.natureserve.org. Accessed May 2020.
NC Capital Area Metropolitan Planning Organization (CAMPO). 2019. Community Viz.
https://www.campo-nc.us/mapsdata/community-viz.Accessed March 2020.
North Carolina Department of Environmental Quality(NCDEQ). 1985. 1985 Geologic Map of North Carolina.
https://ncdenr.maps.arcgis.com/apps/MapSeries/index.html?appid=a8281cbd24b84239b29cd2ca798d4a1
Q. Accessed May 2020.
North Carolina Department of Environmental Quality(NCDEQ). 2012. DENR Storm water BMP Manual&
BMP Forms. December 5. http://www.conservation.nc.gov/web/Ir/bmp-manual.Accessed May 2020.
North Carolina Department of Environmental Quality(NCDEQ). 2015. Guidance for the Preparation of
Engineering Reports and Environmental Information Documents for Wastewater Treatment Plant
Projects.
North Carolina Department of Environmental Quality(NCDEQ). 2017a. Notice of Violation. June 19,
2017.
North Carolina Department of Environmental Quality(NCDEQ). 2017b. Notice of Deficiency. August 9,
2017.
North Carolina Department of Environmental Quality(NCDEQ). 2017c. Minimum Design Criteria for
NPDES Wastewater Treatment Facilities.
North Carolina Department of Environmental Quality(NCDEQ). 2018. "Neuse River Compliance
Association Permit(2018)." Wastewater. https://deq.nc.gov/about/divisions/water-
10-2

SECTION 10-REFERENCES
resources/planning/nonpoint-source-management/nutrient-strategies/neuse#wastewater. Accessed
April 2020.
North Carolina Department of Environmental Quality(NCDEQ). 2020a. Draft National Pollutant
Discharge Elimination System Permit for the Town of Clayton Little Creek Water Reclamation Facility.
North Carolina Department of Environmental Quality(NCDEQ). 2020b. Speculative Limits for the
Expansion of the Little Creek Water Reclamation Facility. Issued to the Town of Clayton on September 4,
2020.
North Carolina Department of Environmental Quality(NCDEQ). 2020c. Classifications.
https://deq.nc.gov/about/divisions/water-resources/planning/classification-standards/classifications/.
Accessed April 2020.
North Carolina Department of Environmental Quality(NCDEQ). 2020d. Buffer Determination Letter for
the Clayton WWTP. Letter received by Town of Clayton from Scott Vinson, Regional Supervisor, Water
Quality Operations Section Raleigh Regional Office. May 11.
North Carolina Department of Transportation (NCDOT). 2011. Comprehensive Transportation Plan.
Prepared for Johnston County, NC.
North Carolina Department of Transportation (NCDOT). 2020. N.C. 42 Widening.
https://www.ncdot.gov/protects/nc-42-widening/Pages/default.aspx. Accessed May 2020.
North Carolina Division of Marine Fisheries (NCDMF). 2014.American Shad Habitat Plan. February 6.
http://www.asmfc.org/files/ShadHabitatPlans/AmShadHabitatPlan NC.pdf. Accessed August 2020.
North Carolina Floodplain Mapping Program. 2020. "County Status."flood.NC.gov.Johnston County
Floodplain Mapping. https://flood.nc.gov/ncflood/mappingprogram.html. Accessed May 2020.
North Carolina Natural Heritage Program (NCNHP). 2003. "Executive Summary."An Inventory of
Significant Natural Areas in Wake County, North Carolina.
https://www.nrc.gov/docs/ML0907/ML090770916.pdf. Accessed April 2020.
North Carolina Natural Heritage Program (NCNHP). 2020a. April 2020 Managed Areas shapefile. Data
Download. https://ncnhde.natureserve.org/content/data-download/. Accessed May 2020.
North Carolina Natural Heritage Program (NCNHP). 2020b. April 2020 Natural Heritage Natural Area
shapefile. Data Download. https://ncnhde.natureserve.org/content/data-download/. Accessed
May 2020.
North Carolina Wildlife Resources Commission (NCWRC). 2020a. Clayton WWTP data request. Provided
June 4, 2020.
North Carolina Wildlife Resources Commission (NCWRC). 2020b. "North Carolina Game Lands." North
Carolina Portal Access to Wildlife Systems. https://www.ncpaws.org/ncwrcmaps/gamelands#/. Accessed
May 2020.
OBS Landscape Architects (OBS). 2010. Clayton Downtown Master Plan. Prepared for the Town of
Clayton, NC. October 2010, updated from August 20, 2001.
https://www.townofclavtonnc.org/uploads/files/Planning/2010%20Clavton%20Downtown%20Master%
20Plan.pdf. Accessed May 2020.
Poelman, Byron. 2020. Personal communication (email) Re: Odor Complaints Information with
J.D. Solomon,J.D. Solomon, Inc. May 28.
Ragsdale Consultants, PA(Ragsdale). 1990. Wastewater Treatment Facilities Improvements-Revisions
after construction.
10-3

SECTION 10-REFERENCES
Sage Design. 2013. Parks and Recreation Comprehensive Plan Update. Prepared for the Town of Clayton.
June.
https://www.townofclavtonnc.org/uploads/files/Parks%20%26%20Recreation/Parks%20and%20Rec%2
OComprehensive%20PIan%20June%202013.pdf. Accessed May 2020.
The Wooten Company(Wooten). 2003. Little Creek Water Reclamation Facility Improvements.
The Wooten Company(Wooten). 2007.Supplement to Operation and Maintenance Manual for Town of
Clayton Little Creek Water Reclamation Facility.
The Wooten Company(Wooten). 2018. Presentation: Wastewater Capacity Study Additional
Information. Prepared for the Town of Clayton, NC and presented to the Town of Clayton Council.
December 17.
The Wooten Company(Wooten). 2019. Presentation: Wastewater Capacity Update. Prepared for the
Town of Clayton, NC and presented to the Town of Clayton Council. February 18.
Town of Clayton (Town). 2006. Town of Clayton General Design Guidelines.A Policy Manual. Adopted
February 20, 2006.
https://www.townofclaytonnc.org/uploads/files/Planning/General%20Design%20Guidelines%202-20-
2006.pdf. Accessed April 2020.
Town of Clayton (Town). 2010.Stormwater Design Manual.June.
https://www.townofclaytonnc.org/uploads/FileLinks/7230f7ebfb6d448fb4afc8cc84731fa5/CLAYTON ST
ORMWATER MANAGEMENT AND DESIGN DRAFT.pdf. Accessed May 2020.
Town of Clayton (Town). 2015. Wastewater System Performance Annual Report Fiscal Year 2014-2015.
Town of Clayton (Town). 2016. Wastewater System Performance Annual Report Fiscal Year 2015-2016.
Town of Clayton (Town). 2017. Wastewater System Performance Annual Report Fiscal Year 2016-2017.
Town of Clayton (Town). 2018a. Wastewater System Performance Annual Report Fiscal Year 2017-2018.
Town of Clayton (Town). 2018b. Flood Damage Prevention Ordinance.
http://library.amlegal.com/nxt/gateway.dll/North%20Carolina/clavton nc/townofclavtonnorthcarolinac
odeofordinanc?f=templates$fn=default.htm$3.0$vid=amlegal:clavton nc. Accessed May 2020.
Town of Clayton (Town). 2019a. Wastewater System Performance Annual Report Fiscal Year 2018-2019.
Town of Clayton (Town). 2019b. Downtown Facade/Site Element Improvement Grant.
https://www.townofclaytonnc.org/uploads/files/Downtown%20Clayton/Downtown%20Facade%201mpr
ovement%20Grant%20Application%207-2019.pdf. Accessed May 2020.
Town of Clayton (Town). 2019c. Comprehensive Fee Listing 10-08-19.
Town of Clayton (Town). 2020a. WRF Activity and Flow Summary 2019. Data Provided February 19.
Town of Clayton (Town). 2020b. Parks& Recreation. May 2. https://www.townofclavtonnc.org/Parks-
and-Recreation/. Accessed April and August 2020.
Town of Clayton (Town). 2020c. Residential Development in the Town of Clayton Planning Jurisdiction.
Data provided on May 12.
Town of Clayton (Town). 2020d. Speculative Limits Request, NPDES NC-0025452. Submitted by the Town
of Clayton to NCDEQ on August 7.
Town of Clayton (Town). 2020e. "Clayton Launching Erosion Control/Stormwater Program." Watershed
Protection. https://www.townofclaytonnc.org/Public-Works/watershed-protection.aspx. Accessed
August 2020.
10-4

SECTION 10-REFERENCES
Town of Clayton (Town). 2020f. East Clayton Industrial Area (ECIA) Transmission Improvements
Preliminary Engineering Report and Environmental Narrative. Prepared for the Economic Development
Administration.
Town of Clayton (Town). 2020g. "New Water Reclamation Project." Public Works.
https://www.townofclaytonnc.org/Public-Works/water-reclamation-.aspx. Accessed May 2020.
U.S. Census Bureau (Census). 2019. "Clayton town, North Carolina." QuickFacts.July 1.
https://www.census.gov/quickfacts/claytontownnorthcarolina. Accessed February 2020.
U.S. Department of Agriculture (USDA). 1981. Environmental Compliance Library, Farmland Protection
Policy Act. Pub. L. 97-98 Subtitle I, Dec. 22, 1981, 95 Stat. 1341.
U.S. Department of Agriculture (USDA). 1994.Soil Survey of Johnston County, North Carolina. Prepared
by the Soil Conservation Service.
U.S. Department of Agriculture (USDA). 2020. Web Soil Survey Home. National Cooperative Soil Survey.
Natural Resources Conservation Service. http://websoilsurvey.nrcs.usda.gov. Accessed April 2020.
U.S. Environmental Policy Agency (EPA). 1998. Final Guidance for Incorporating Environmental Justice
Concerns in EPA's NEPA Compliance Analysis. April. https://www.epa.gov/sites/production/files/2015-
04/documents/ej-guidance-nepa-compliance-analyses.pdf.Accessed March 2020.
U.S. Environmental Protection Agency(EPA). 2018.40 CFR Part 503, Standards for the Use or Disposal of
Sewage Sludge.
U.S. Environmental Protection Agency(EPA). 2020a. North Carolina Nonattainment/Maintenance Status
for Each County by Year for All Criteria Pollutants(Green Book).
https://www3.epa.gov/airquality/greenbook/anayo nc.html. Accessed May 2020.
U.S. Environmental Protection Agency(EPA). 2020b. EnviroMapper.
https://geopub.epa.gov/myem/efmap//index.html?ve=13,47.236778259277344,-
122.35669708251953&pText=Fife,%20WA. Accessed May 2020.
U.S. Fish and Wildlife Service (USFWS). 2013. "Wetlands Mapper." National Wetlands Inventory.
https://www.fws.gov/wetlands/Data/Mapper.html/. Accessed April 2020.
U.S. Fish and Wildlife Service (USFWS). 2018. Endangered Species, Threatened Species, Federal Species of
Concern, and Candidate Species,Johnston County, North Carolina.
https://www.fws.gov/raleigh/species/cntylist/johnston.html. Accessed February and August 2020.
U.S. Fish and Wildlife Service (USFWS). 2020. "Wetlands and Deepwater Habitats." Classification of
Wetlands and Deepwater Habitats of the United States.
U.S. Geological Survey(USGS). 2019. The National Map. https://viewer.nationalmap.gov/basic/.
Accessed April 2020.
U.S. Geological Survey(USGS). 2011. "GAP/LANDFIRE National Terrestrial Ecosystems 2011." Land Cover
Data Download. https://www.usgs.gov/core-science-systems/science-analytics-and-
synthesis/gap/science/land-cover-data-download?qt-science center objects=0#qt-
science center objects/. Accessed May 2020.
U.S. Geographical Survey (USGS). 2016. National Land Cover Database(NLCD)2016.
https://www.mrlc.gov/national-land-cover-database-nlcd-2016/. Accessed April 2020.
WithersRavenel. 2020a. Little Creek Pump Station and Discharge Technical Memorandum. Prepared for
the Town of Clayton, NC.
WithersRavenel. 2020b. Clayton Water Reclamation Facility- Wetland, Stream & Riparian Buffer and
Threatened& Endangered Species Assessment Report. Prepared for the Town of Clayton, NC.
10-5

SECTION 10-REFERENCES
WithersRavenel. 2020c. Clayton WRF—LC Transmission Main Alignment— Wetland, Stream & Riparian
Buffer and Threatened& Endangered Species Assessment Report. Prepared for the Town of Clayton, NC.
WithersRavenel. 2020d. Transmission Easement Access Road Wetland,Stream& Riparian Buffer and
Threatened& Endangered Species Assessment Report. Prepared for the Town of Clayton, NC.
WithersRavenel. 2020e. Environmental Desktop Review, Town of Clayton Water Reclamation Facility
Potential Conveyance&Access Route Reviews. Prepared for the Town of Clayton, NC.
10-6