NC0085359_Environmental Assessment_20120809

NPDES DOCUHENT SCANNING COVER SHEET
NPDES Permit:
NC0085839
Twelve Mile Creek WWTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Owner Name Change
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
:„.
Document Date:
August 9, 2012
Thies document is printed on reuse paper - ignore any
content Cln the resterse aside

ATA
NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Charles Wakild, P.E. Dee Freeman
Governor Director Secretary
Memorandum
To: Hannah Headrick, SEPA
NPDES Permit File NC0085359
Thru: NA
From: Tom Belnick, NPDES
Date: August 9, 2012
Subject: Review of SEPA EA for Union County Twelve Mile Creek WWTP Expansion
The following NPDES comments pertain to a proposed expansion of the Union County Twelve Mile Creek WWTP from
6 MGD to 12 MGD.
Wastewater Flow Projections
• The NPDES Unit concurs with the requested 20-year flow projection of 12 MGD based on reasonable population
growth estimates and wastewater flow assumptions.
Alternatives Analysis
• The NPDES Unit concurs with the EA conclusion that the most environmentally sound, reasonably cost-effective
option is expansion of the existing Twelve Mile Creek WWTP. The 20-year present worth costs for the selected
alternative ($97 Million) is significantly less than non -discharge options (land application, $199 Million; Reuse
Spray Irrigation, $235 Million) as well as alternative discharge options (Discharge to Catawba River in SC, $117
Million).
Other Comments
• The EA states that Union County stopped routing wastewater flow to the Hunley Creek WWTP (NC0072508) in
May 2006, and currently pumps that wastewater to either Twelve Mile Creek WWTP or Crooked Creek WWTP
for treatment. Since that wastewater flow is accounted for in the Twelve Mile Creek flow projections, the
Division anticipates that Union County will request permit rescission of the Hunley Creek NPDES permit prior to
any permitting request for expansion of the Twelve Mile Creek WWTP. Elimination of the Hunley Creek WWTP
discharge permit will also be consistent with the set of management rules adopted by the Environmental
Management Commission in 2009 for protection of the federally -endangered Carolina heelsplitter in the Goose
Creek watershed. Please provide an update on this action.
1617 Mail Service Center, Raleigh, North Carolina 27699-1617
Location: 512 N. Salisbury St. Raleigh, North Carolina 27604
Phone: [phone] l FAX: [phone] l Customer Service: 1-877-623-6748
Internet www.ncwaterquality.org
An Equal Opportunity 1 Affirmative Action Employer
One
NorthCarolina
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Environmental Assessment for
Twelve Mile Creek Wastewater Treatment
Plant Expansion
Union County, North Carolina
Lead Agency Contact:
Ms. Hannah Headrick
NCDENER Division of Water Quality
Planning Section
1617 Mail Service Center
Raleigh, NC 27966-1617
""'' [phone]
Client Contact:
Mr. Scott Honeycutt
Assistant Director, Water
Union County
500 North Main Street, Suite 500
Monroe, NC 28112
[phone]
Consultant Contact:
Ms. Mary Sadler, P.E.
Associate
Hazen and Sawyer
4011 WestChase Blvd. Suite 500
Raleigh, NC 27607
[phone]
[e-mail]
July 2012
IIAZENAND SAWYER
Environmental Engineers & Scientists
4011 WestChase Boulevard, Suite 500
Raleigh, NC 27607
NC License C 0381
32167-001-CV01.cdr

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
r-P Executive Summary
EXECUTIVE SUMMARY
This project consists of a North Carolina State Environmental Policy Act (SEPA) Environmental
,11'1 Assessment (EA) to allow Union County to apply for a National Pollutant Discharge Elimination System
(NPDES) permit for an expansion of the Twelve Mile Creek Wastewater Treatment Plant (WWTP) from 6 to
12 million gallonper day Pursuant to SEPA, an expansion of an existingdischarge facility
9 P 9 by
500,000 gallons per day (gpd) or greater requires an EA to be completed and a Finding of No Significant
Impact (FONSI) to be issued before the Department of Water Quality (DWQ) will issue permits and
approvals. Union County is requesting this project to address the wastewater capacity needs in the service
area for the 20-year planning period. Stream modeling efforts have indicated that assimilative capacity is
` available in Twelve Mile Creek and improved water quality will be a likely outcome as a result of the
expanded surface water discharge.
Union County is located in the southern piedmont region in North Carolina. It is bordered by six counties:
Mecklenburg, Stanly, Cabarrus, and Anson Counties in North Carolina and Chesterfield and Lancaster
figN Counties in South Carolina. The Twelve Mile Creek service area is located in the central and western parts
of Union County west and south of the City of Monroe. The service area covers approximately 167 square
miles. The service area is bounded by the City of Monroe city limits to the east, the South Carolina state
line. to the west, Six Mile Creek and the Mecklenburg County line to the north, and the Town of Waxhaw
town limits to the south. The Twelve Mile Creek service area includes in whole or in part the Town of
tits Waxhaw, the Town of Mineral Springs, the Village of Wesley Chapel, the Town of Weddington, the Village
of Marvin, the Town of Stallings, the Town of Indian Trail, the Village of Lake Park, and the Town of Hemby
Bridge. The majority of the near -term growth in Union County is expected in watershed areas located in the
Twelve Mile Creek service area, such as Poplin Road, Crooked Creek, Twelve Mile, and the Lake Lee area
south of the City of Monroe. The watershed areas located outside of the Twelve Mile Creek service area
are anticipated to develop in a timeframe closer to the 2030 in conjunction with the timing of the proposed
Monroe Connector Bypass.
"16-
The Catawba / Yadkin River basin boundary divides the county almost in half. Union County provides wa
and sewer to areas located in both the Catawba and the Yadkin River basins. The County has a
grandfathered interbasin transfer (IBT) amount of 5 mgd that allows water transfer from the Catawba-
Wateree basin to the Rocky River subbasin in the Yadkin River basin. The IBT calculations demonstrate
that Union County will not exceed the grandfathered IBT amount due to the expansion of the Twelve Mile
Creek WWTP. Water supply and the potential for corresponding interbasin transfers for the longer -term
growth areas will be addressed in a separate permitting process.
An expansion of the Twelve Mile Creek WWTP will meet the long-term growth needs in the Twelve Mile
Creek service area. Five project alternatives and five effluent disposal alternatives were evaluated in the
engineering alternatives analysis. An expansion of the surface water discharge to Twelve Mile Creek was
selected for the positive environmental impact to Twelve Mile Creek, less economic impact than other
eaks evaluated project and effluent disposal alternatives, and the most feasible technical solution.
Hazen and Sawyer Project No. 30831-030 HAZEN AND SAWYER
ER
Environmental Engineers & Scientists

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Executive Summary
An expansion of the Twelve Mile Creek WWTP surface water discharge will not impact water quality. The
QUAL2E water quality modeling results indicate that assimilate capacity is available in Twelve Mile Creek
for the expanded discharge. Field reconnaissance was performed for 12.5 miles of stream channel to verify
and calibrate the scoping level water quality model. The model was refined in the spring of 2012 to reflect
comments from the South Carolina Department of Health and Environmental Control (SCDHEC) regarding
sediment oxygen demand (SOD) rates. The refined model is well -calibrated and shows an overall
improvement in Twelve Mile Creek DO concentration during the critical months. The expanded discharge
will improve water quality and protect the Class C designated use by providing an increase in velocity and
re -aeration.
Direct impacts may be caused by construction and operation of the project. Direct impacts will be mitigated
with erosion and sedimentation control measures and stormwater BMPs. Construction activities related to
the Twelve Mile Creek WWTP expansion will not directly impact water resources, floodplains, soils, aquatic
and wildlife habitat and resources, forest resources, air quality, or noise levels. Two archaeological
resources are located on the Twelve Mile Creek WWTP project site but will not be impacted by the
expansion of the facility.
Minimal indirect and cumulative impacts resulting from the proposed project are anticipated to occur from
continued development in the Twelve Mile Creek service area. Federal, state, and local programs and
ordinances will help to offset potential direct, indirect, and cumulative impacts resulting from the proposed
project. These programs include land use planning, open space preservation, erosion and sedimentation
control, stormwater, and floodplain management.
Hazen and Sawyer Project No. 30831-030
HAZ NAND&WEI
Environmental Engineers & Scientists
II

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Table of Contents
Table of Contents
Executive Summary
1. Proposed Project Description 1-1
1.1 Existing Wastewater Infrastructure 1-2
1.2 Existing Water Supply and Infrastructure 1-4
1.3 Proposed Project Scope 1-5
1.4 Service Area 1-5
2. Need for the Project 2-1
2.1 Growth Trends and Population Projections 2-1
2.2 Wastewater Flow Projections 2-3
2.3 Interbasin Transfer 2-5
3. Alternatives Analysis 3-1
3.1 No Action Altemative 3-2
3.2 Purchase Additional Capacity at Charlotte Mecklenburg Utilities McAlpine Creek WWMF 3-3
3.3 Build and Purchase Capacity at Lancaster County Water and Sewer District Indian Land WWTP in
South Carolina 3-5
3.4 Partner with Lancaster County Water and Sewer District to Build a New Wastewater Treatment
Plant 3-7
3.5 Land Application 3-9
3.6 Non -Conjunctive Reuse 3-11
3.7 Surface Water Discharge to Catawba River 3-14
3.8 Expand the Twelve Mile Creek WWTP and Surface Water Discharge to Twelve Mile Creek
(Selected Altemative) 3-16
4. Existing Environmental Characteristics 4-1
4.1 Topography 4-1
4.2 Soils 4-2
4.3 Land Use 4-3
4.4 Wetlands 4-3
4.5 Prime or Unique Agricultural Lands 4-4
4.6 Public Lands and Scenic, Recreational, and State Natural Areas 4-4
Hazen and Sawyer Project No. 30831-030
nAl N Alsb ► 4W ER
Environmental Engineers & Scientists
jji

(1"N
Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion �►
Table of Contents r'tia'
r°"'°)
4.7 Areas of Archaeological or Historical Value 4-5 /'�
4.8 Air Quality 4-5
4.9 Noise Levels 4-6 ("R'
4.10 Water Resources 4-7
4.11 Forest Resources 4-11
rwq
4.12 Shellfish or Fish and Their Habitats 4-11
(1°N
4.13 Wildlife and Natural Vegetation 4-12
5. Predicted Environmental Effects- 5-1 r"')
5.1 Topography 5-1 tda'N
5.2 Soils 5-1
5.3 Land Use 5-2
5.4 Wetlands 5-2
5.5 Prime or Unique Agricultural Lands 5-2
eRN
5.6 Public Lands and Scenic, Recreational, and State Natural Areas 5-3
5.7 Areas of Archaeological or Historical Value 5-3
5.8 Air Quality 5-3 rd°'
5.9 Noise Levels 5-4 r'm`N
5.10 Water Resources 5-5
el:1\
5.11 Forest Resources 5-6
5.12 Shellfish or Fish and Their Habitats 5-6
5.13 Wildlife and Natural Vegetation 5-7 �..�
5.14 Introduction of Toxic Substances 5-17 /dIP,
6. Mitigative Measures 6-1 ('"'\
7. Summary of Local Programs and Ordinances 7-1
7.1 Land Use Planning and Environmental Resource Protection Initiatives 7-1
7.2 Zoning 7-4
tar
7.3 Open Space Plans/Initiatives, Greenways, and Riparian Buffers 7-10 f•"
7.4 Erosion and Sedimentation Control 7-19 f.N,
7.5 Stormwater Programs and Impervious Surface Limitation 7-21 ("1'►
Hazen and Sawyer Project No. 30831-030 HAZE \ AND SkYWIER IV
Environmental Engineers a Scientists

7.6 Floodplain Development Regulations
7.7 Water Conservation
8. State and Federal Permits Required
9. References
10. Qualifications of Preparers
11. Figures
Figures
Figure 1-1:
Figure 3-1:
Figure 3-2:
Figure 3-3:
Figure 4-1:
Figure 4-2:
Figure 4-3:
Figure 4-4:
Figure 4-5:
Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Table of Contents
Twelve Mile Creek Service Area
Wastewater Capacity Altematives for Twelve Mile Creek Service Area
Proposed Upgrade and Expansion Improvements to Twelve Mile Creek WWTP
Effluent Disposal Altematives for Twelve Mile Creek WWTP Expansion
Floodplains in Twelve Mile Creek Service Area
National Wetlands Inventory Wetlands in Twelve Mile Creek Service Area
U.S. Geological Service Topographic Map of Twelve Mile Creek Service Area
Watersheds in Twelve Mile Creek Service Area
Surface Waters in Twelve Mile Creek Service Area
7-28
7-34
8-1
9-1
10-1
11-1
11-2
11-3
11-4
11-5
11-6
11-7
11-8
11-9
11-10
Hazen and Sawyer Project No. 30831-030
HAM AND Sk\WER
Environments{ Engineers & Scientists

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Table of Contents
Tables
Table 1-1: NPDES Permit Limits for the Twelve Mile Creek WWTP (NC0085359) 1-3
Table 2-1: Planning Year Summary of Watershed Areas Designated For Significant Growth in Union
County 2-2
Table 2-2: Historic Population and Projections for Union County and Twelve Mile Creek Service Area 2-3
Table 2-3: Maximum Month and Average Day Wastewater Flow Projections for Twelve Mile Creek
Service Area 2-5
Table 2-4: Interbasin Transfer Calculations for Twelve Mile Creek Service Area in the Rocky River
Subbasin of the Yadkin 2-6
Table 3-1: Summary of Effluent Limits Associated with Discharge Altematives
Table 3-2: Present Worth Analysis for Purchasing Additional Capacity at Charlotte Mecklenburg Utilities
McAlpine Creek WWMF
Table 3-3: Present Worth Analysis for Purchasing Capacity at Lancaster County Water and Sewer District
Indian Land WWTP
Table 3-4: Present Worth Analysis for Partnering with Lancaster County Water and Sewer District to Build
a New WWTP
Table 3-5: Present Worth Analysis for Land Application
Table 3-6: Present Worth Analysis for Non -Conjunctive Reuse System
Table 3-7: Present Worth Analysis for Surface Water Discharge to Catawba River
Table 3-8: Present Worth Analysis for Expanding Union County's Twelve Mile Creek WWTP
Table 4-1: Summary of Classified Streams in Twelve Mile Creek Service Area
Table 4-2: State and Federal Protected Species for Union County, North Carolina
Table 5-1: Summary of Impacts to Rare and Protected Species
Table 6-1: Summary of Resource Impact Mitigative Measures
Table 7-1: Density Limits in Union County Land Use Ordinance
Table 7-2: Density Limits in Town of Waxhaw Zoning Ordinance
Table 7-3: Density Limits in Mineral Springs Zoning Ordinance
Table 7-4: Density Limits in Village of Wesley Chapel Zoning Ordinance
Table 7-5: Density Limits in Town of Weddington Code of Ordinances
Table 7-6: Density Limits in Town of Indian Trail Zoning Ordinance
Table 7-7: Density Limits in Town of Stallings Land Usage Ordinance
Table 7-8: Summary of Union County Water Supply Triggers for Conservation
3-1
3-4
3-6
3-8
3-10
3-13
3-15
3-17
4-8
4-15
5-8
6-1
7-5
7-6
7-7
7-7
7-8
7-9
7-9
7-34
Hazen and Sawyer Project No. 30831-030
HAZEN AND SUM
Environmental Engineers 41 Scientists
vi

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Table of Contents
Appendices (on CD)
A Speculative Limits / Wasteload Allocation for Proposed Catawba River Surface Water Discharge in
Lancaster County South Carolina, South Carolina Department of Health and Environmental
Control, January 2008
B Speculative Effluent Limits Letter for a Union County Twelve Mile Creek WWTP Expansion, North
Carolina Department of Environment and Natural Resources, Division of Water Quality, September
2010
C Scoping Level Assessment of Assimilative Capacity in Twelve Mile Creek Below the Union County
WWTP, Tetra Tech, April 2010
D QUAL2 Model Update for Twelve Mile Creek below the Union County WWTP
E Memorandum of Personal Communication with Office of State Archaeology, November 2011
F Comprehensive Water and Wastewater Master Plan for Union County, Final Report, Black and
Veatch, December 2011
G Correspondence with South Carolina Department of Health and Environmental Control on
QUAL2E Model Review and Calibration
H Response to Agency Comments (pending review)
Hazen and Sawyer Project No. 30831-030
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Environmental Engineers & Scientists
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Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Table of Contents
List of Acronyms
7Q10 The lowest volume of stream expected to occur on a particular stream for
7 consecutive days once every 10 years.
BFE Base flood elevation
BOD5 Biochemical oxygen demand
BMP Best management practice
CA Critical area
CBOD5 Carbonaceous biochemical oxygen demand
CFR Code of Federal Regulations
CMU Charlotte Mecklenburg Utilities
CO Carbon monoxide
CWA Clean Water Act
DAQ North Carolina Division of Air Quality
DENR North Carolina Department of Environment and Natural Resources
DNRCD United States Department of Natural Resources and Community Development
DLR North Carolina Division of Land Resources
DO Dissolved oxygen
DWQ North Carolina Division of Water Quality
E Endangered
EA Environmental Assessment
EIS Environmental Impact Statement
EMC North Carolina Environmental Management Commission
EPA U.S. Environmental Protection Agency
ESA Endangered Species Act
ESC Erosion and Sedimentation Control Plan
FEMA Federal Emergency Management Agency
FSC Federal species of concern
FONSI Finding of No Significant Impact
gpcd Gallon per capita per day
gpd Gallons per day
GIS Geographic Information System
HQW High quality water
lb Pound
IBT Interbasin transfer
Ill Infiltration and inflow
Hazen and Sawyer Project No. 30831-030
HAZEN AND SAWYER
Environmental Engineers 6 Scientists
vlll

List of Acronyms
kW
LCWSD
LDO
mgd
mg/I
ml
MSL
NAAQS
NCAC
NCGS
NHP
NOX
NPDES
NRCS
NRHP
NTU
NWI
OSA
03
ORW
OSBM
Pb
PER
PM-10
ppm
RAS
SC
SCDHEC
SEPA
SHPO
SNHA
SOD
SOX
T
Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Table of Contents
Kilowatt
Lancaster County Water and Sewer District (South Carolina)
Land Development Ordinance
Million gallons per day
Milligrams per liter
Milliliter
Mean sea level
National Ambient Air Quality Standards
North Carolina Administrative Code
North Carolina General Statutes
North Carolina Natural Heritage Program
Nitrogen oxides
National Pollutant Discharge Elimination System
National Resources Conservation Service
National Register of Historic Places
Nephelometric turbidity unit
National Wetland Inventory
Office of State Archaeology
Ozone
Outstanding resource water
North Carolina Office of State Budget and Management
Lead
Preliminary Engineering Report
Particulate matter less than 10 micrometers in diameter
Parts per million
Return activated sludge
Species of special concern
South Carolina Department of Health and Environmental Control
State Environmental Policy Act
State Historic Preservation Office
Significant natural heritage area
Sediment oxygen demand
Sulfur oxides
Threatened
Hazen and Sawyer Project No. 30831-030
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Environmental Engineers & Scientists
ix

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Table of Contents
List of Acronyms
TAZ Traffic analysis zone
TMDL Total maximum daily Toad
TSP Total suspended particles
TSS Total suspended solids
UCPW Union County Public Works
UDO Unified Development Ordinance
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
UT Unnamed tributary
UV Ultraviolet
VOC Volatile organic compound
WAS Waste activated sludge
WET Whole effluent toxicity
WRF Water reclamation facility
WTP Water treatment plant
WWMF Wastewater Management Facility
WWTP Wastewater treatment plant
Hazen and Sawyer Project No. 30831-030
HAZEN AND SAWYER
Environmental Engineers & Scientists

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
1. Proposed Project Description
Union County is located on the border of South Carolina approximately 15 miles southeast of Charlotte and
is home to fourteen municipalities. Union County Public Works (UCPW) is responsible for the management,
Proposed Project Description
operation and maintenance of the wastewater collection and treatment system for unincorporated Union
est., County and all County municipalities with the exception of the City of Monroe and the Town of Marshville.
The County's wastewater system is comprised of five extended aeration activated sludge wastewater
treatment plants (WWTPs) with a combined rated treatment capacity of 8.1 million gallons per day (mgd).
The Twelve Mile Creek WWTP was originally constructed in 1997 as a 2.5 mgd facility and is currently the
largest treatment facility in the County with a capacity of 6 mgd.
The County has contractual agreements for 2.65 mgd and 3.0 mgd of purchased wastewater treatment
✓ capacity at the City of Monroe WWTP and Charlotte Mecklenburg Utilities (CMU) McAlpine Creek
Wastewater Management Facility (WWMF), respectively. The agreement with the City of Monroe was
executed in 1979 for the treatment of up to 1.95 mgd at the Monroe WWTP. This agreement was amended
in 2005 to increase diverted flow by 700,000 gallons per day (gpd) to a total average flow of 2.65 mgd.
✓ Wastewater flow is diverted to the Monroe WWTP through a series of force mains and three pump stations.
The agreement with CMU was signed in 1996 for a total treatment allocation of 3.0 mgd at the McAlpine
Creek WWMF. Flow is transferred to CMU via the Six Mile Creek Pump Station and force main. This
infrastructure is owned and operated by CMU. The County is currently sending approximately 1.3 mgd to
the McAlpine Creek WWMF.
The North Carolina Department of Environment and Natural Resources (DENR) placed a sewer
moratorium on the Twelve Mile Creek WWTP in January 2007. The moratorium was put in place to
flits address the wastewater over -allocation that occurred during the area's growth period. The moratorium
prohibited any applications to the Division of Water Quality (DWQ) for sewer line extensions in the Twelve
Mile Creek service area. An interim plant rerating study in 2007 (Hazen and Sawyer, 2007) determined that
the facility could be re -rated from 2.5 to 3.0 mgd, thereby enabling the moratorium to be lifted. During the
ro°' timeframe of the sewer moratorium, the plant was also in the process of a capacity expansion from 3 to
6 mgd. Construction was completed in early 2008.
The Count co missioned a Comprehensive Water and Wastewater Master Plan (Black and Veatch, _4(0
-2011) to act____IALessfutura-gmxth and infrastructure needs in the County. The Comprehensive Master Plan
fitie•c provided an assessment of water supply, water treatment and distribution, wastewater treatment and
disposal, and residuals/biosolids management facilities and systems. The Comprehensive Master Plan
established population, water demand projections, and wastewater production estimates through the year
2030. The evelopment of the ompre ensive Master Plan included participation from elected officials,
✓ County staff, and leadership from each of the communities served by Union County.
Hazen and Sawyer Project No. 30831-030
HAZEN AND SOUR
Environmental Engineers i Scientists
1-1

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Proposed Project Description
1.1 Existing Wastewater Infrastructure
UCPW is responsible for the management, operation, and maintenance of the wastewater collection and
treatment system for unincorporated Union County and all County municipalities with the exception of the
City of Monroe and the Town of Marshville. UCPW operates and maintains five active wastewater
treatment facilities and operates and maintains approximately 65 wastewater pump stations and over
600 miles of sewer line and force main.
The County has ongoing programs to identify and correct deficiencies associated with the wastewater
collection system, such as sewer line cleaning, maintenance inspections, point repairs, and manhole
rehabilitations. In 2010, there were 23 sanitary sewer overflows with a combined volume of approximately
193,400 gallons. These overflows were less than 0.01 percent of the total flow conveyance (2.6 billion
gallons) and equaled an overflow -to -mile -of -pipe ratio less than 1:25.
The Twelve Mile Creek WWTP is permitted for an NPDES discharge of 6 mgd (NC0085359) Twehtel iie
Creek in the Catawba River basin. Table 1-1 provides a summary of the current NPDES permit limits. The
originarfacultative lagoon plant was replaced in 1997 with an extended aeration activated sludge
wastewater plant with biochemical oxygen demand (BOD5) removal, nitrification, and phosphorus removal.
The facility consists of screening and grit removal, oxidation ditches, secondary clarification, tertiary
filtration, ultraviolet (UV) disinfection, and cascade aeration. In 2010, the average flow treated at the plant
was 3.8 mgd. A sewer moratorium in January 2007 resulted in the plant being re -rated from 2.5 to 3 mgd
during the construction project for the plant expansion to 6 mgd. The re -rating was based on a review of
historical operational data, wastewater characteristics, and permit limits. Construction for the capacity
expansion to 6 mgd was completed in 2008.
Solids treatment at the Twelve Mile Creek WWTP includes gravity belt thickening and aerobic digestion to
Class B standards with final biosolids disposal onto permitted agricultural farmland. Biosolids are managed
and disposed of in accordance with Permit WQ0007486. Biosolids can be stored at both the Crooked
Creek and Twelve Mile Creek WWTPs. If volatile solids reduction cannot be achieved with aerobic
digestion, then alkaline stabilization is utilized to ensure permit compliance.
Several projects have been initiated by the County to improve plant performance at the Twelve Mile Creek
facility. The Plant Reliability Improvement project was completed in 2010 and included many miscellaneous
improvements at the plant to enable better control of monitoring and operation. Additionally, process and
operational changes were successfully implemented to control phosphorus effluent concentrations. An odor
control project was completed in 2010 to treat foul air from four aerobic digesters.
Hazen and Sawyer Project No. 30831-030
HON AND SAWYER
Environmental Engineers & Scientists
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Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Proposed Project Description
Table 1-1: NPDES Permit Limits for the Twelve Mile Creek WWTP (NC0085359)
Parameter
CBOD5(summer), mg/I
CBOD5(winter), mg/l
Total Suspended Solids, mg/I
Monthly Average Weekly Average
5.0 7.5
10.0 15.0
30.0 45.0
Ammonia as N (summer), mg/I
1.0 3.0
Ammonia as N (winter), mg/I
2.0 6.0
Fecal coliform, colonies per 100 ml
200 400
Total nitrogen N/A
Total phosphorus Monthly Average: 41.70 lb/day
12 Month Average: 20.85 lb/day
Dissolved oxygen, mg/I 1 6
' Daily average minimum concentration.
In addition to the Twelve Mile Creek WWTP, the County operates the following treatment facilities:
• The Crooked Creek WWTP (NC0069841) is a 1.9 mgd activated sludge facility
implementing tertiary filtration and UV disinfection. The facility's effluent discharges into
North Fork Crooked Creek.
• The Olde Sycamore Water Reclamation Facility (WRF) is an activated sludge facility with
tertiary filtration and UV disinfection. The facility is permitted to discharge up to 0.150 mgd
of treated wastewater onto the Olde Sycamore Golf Course as a source of irrigation.
• The Tallwood Estates WWTP (NC0069523) is an activated sludge facility with tertiary
filtration and UV disinfection. The facility is permitted to discharge up to 0.05 mgd to Clear
Creek.
• The Grassy Branch WWTP (NC0085812) is an activated sludge facility with tertiary filtration
and UV disinfection. The facility is permitted to discharge up to 0.05 mgd to Crooked Creek.
• The Hunley Creek WWTP was removed from service in May 2006 and replaced with a
transfer pump station that ultimately routes flow to either the Twelve. Mile Creek WWTP or
the Crooked Creek WWTP.
1.1.1 Six Mile Creek Pump Station
re re-ii
Prior to the diversion of flow to the CMU's McAlpine Creek WWMF, the area around the Village of Marvin
and along the northeast portion of Six Mile Creek was served by two package treatment plants. By 1996,
both plants were operating near capacity. To meet future capacity in the service area, the County elected to
Hazen and Sawyer Project No. 30831-030
HHAzEN AND SAYER
Environmental Engineers & Scientists
1-3

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Proposed Project Description
purchase wastewater capacity at the McAlpine Creek WWMF. The topography in this area allowed for
gravity flow to CMU's Six Mile Creek Pump Station, which was constructed in 1992. In the summer of 2010,
a maximum month flow of 1.3 mgd was diverted to the McAlpine Creek WWMF via a gravity line to the Six
Mile Creek Pump Station and a force main from the pump station to the McAlpine Creek WWMF influent
sewer. CMU is currently expanding the Six Mile Creek Pump Station from a firm capacity of 6 mgd to a firm
capacity of 18 mgd. The pump station is being expanded to accommodate growth in Mecklenburg County.
1.1.2 Diversion Pump Station
Union County is in the process of constructing a diversion pump station on the Twelve Mile Creek WWTP
site to divert additional flow to the McAlpine Creek WWMF. The expected 2030 flow from the Six Mile
Creek service area is 1.8 mgd. Union County intends to use the remaining 1.2 mgd (3.0 mgd contracted
amount less 1.8 mgd) of available purchased capacity for near -term growth in the Twelve Mile Creek
service area. The growth associated with the 1.2 mgd of wastewater production is not included in the 2030
flow projections for the Twelve Mile Creek service area. The pump station has been designed for an
1 average day flow of 1.2 mgd and a firm capacity of 3.0 mgd for peak flow.
1.2 Existing Water Supply and Infrastructure
Union County's primary water source is the Catawba River in South Carolina downstream of Lake Wylie.
The Catawba River Water Treatment Plant (WTP) is a 36 mgd facility that is jointly owned and operated
under a Joint Venture Agreement between Union County and the Lancaster County Water and Sewer
District (LCWSD). The County and LCWSD are each allocated 18 mgd. Average annual water demands
for Union County range between 9 and 11 mgd. In January 2012, Union County negotiated with LCWSD to
lease an additional 3 mgd of capacity in the Catawba River WTP until 2018. Therefore, the total water
supply from the Catawba River WTP to Union County is 21 mgd.
The Catawba River WTP is operated under a Class I Interbasin Transfer (IBT) Permit in South Carolina
that allows withdrawals up to 100 mgd from the Catawba-Wateree River basin and transfers up to 20 mgd
into the Lynches and Pee Dee River basins. The County also has a grandfathered North Carolina IBT
amount of 5 mgd to allow transfers from the Catawba-Wateree basin to the Rocky River subbasin in the
Yadkin River basin.
Water supply for Union County also includes the purchase of finished water from Anson County. Anson
County owns and operates a 16 mgd WTP at Blewett Falls on the Yadkin River in the Yadkin River basin.
Water is provided to Union County through a wholesale water agreement with Anson County. This contract
was executed in 1992. The agreement allows Union County to purchase up to 4 mgd from Anson County,
which supplies the eastern portion of Union County with finished water.
Hazen and Sawyer Project No. 30831-030
IIAZEN AND SAWYER
Environmental Engineers & Scientists
1-4

fresieN
elittN
1.3 Proposed Project Scope
Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Proposed Project Description
Ant-, This project consists of an Environmental Assessment (EA) to allow Union County to apply for a National
Pollutant Discharge Elimination System (NPDES) permit for an expansion of the Twelve Mile Creek WWTP
from 6 to 12 mgd. Pursuant to the North Carolina State Environmental Policy Act (SEPA), an expansion of
an existing discharge facility by 500,000 gpd or greater requires an EA to be completed and a Finding of No
Significant Impact (FONSI) to be issued before DWQ will issue permits and approvals. Union County is
requesting this expansion project to address the wastewater capacity needs in the service area for the 20-
year planning period. Stream modeling efforts have indicated that assimilative capacity is available in
Twelve Mile Creek and improved water quality will be a likely outcome as a result of the expanded surface
water discharge.
This EA documents the need for the project, provides an analysis of the project alternatives and effluent
discharge, and describes the existing environment, predicted environmental impacts, and mitigative
measures. This EA includes evaluations of the general environmental issues related to the project, as well
as the impact of specific infrastructure components of the Twelve Mile Creek WWTP expansion from 6 to
12 mgd.
1.4 Service Area
Union County is located in the southern piedmont region in North Carolina. It is bordered by six counties:
Mecklenburg, Cabarrus, Stanly, and Anson Counties in North Carolina and Chesterfield and Lancaster
Counties in South Carolina. The Twelve Mile Creek service area is located in the central and western parts
of Union County west and south of the City of Monroe. The service area covers approximately 167 square
miles. The service area is bounded by the City of Monroe city limits to the east, the South Carolina state
/, line to the west, Six Mile Creek watershed and the Mecklenburg County line to the north, and the Town of
Waxhaw town limits to the south. The Twelve Mile Creek service area includes in whole or in part the Town
of Waxhaw, the Town of Mineral Springs, the Village of Wesley Chapel, the Town of Weddington, the
Village of Marvin, the Town of Stallings, the Town of Indian Trail, the Village of Lake Park, and the Town of
Hemby Bridge.
The Catawba / Yadkin River basin boundary divides the county almost in half. The eastern half of the
County is in the Rocky River watershed of the Yadkin Pee Dee River basin. The southern portions of the
County cross the Lynches, Lower Pee Dee, and Upper Pee Dee watersheds of the Yadkin Pee Dee River
basin. The western portion of the county is in the Lower Catawba watershed of the Catawba River basin.
The Twelve Mile Creek WWTP and the majority of its service area is located in the Lower Catawba
watershed along with most of the City of Charlotte; however, a few areas in the eastern portions of the
eye, service area are located in the Rocky River watershed.
OWN
tleN
,
Figure 1-1 provides an illustration of the Twelve Mile Creek service area with respect to town limits, river
basins, and county and state jurisdictions.
Hazen and Sawyer Project No. 30831-030
HAzEN AND S5MYER
Environmental Engineers & Scientists
1-5

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Proposed Project Description
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Hazen and Sawyer Project No. 30831-030
HAZEN ANDEI
Environmental Engineers & Scientists
1-6

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Need for the Project
2. Need for the Project
est, The following sections address growth trends, wastewater demand projections, the existing infrastructure in
the Twelve Mile Creek service area, and the interbasin transfer from the Catawba to the Yadkin Pee Dee
River basin. Section 2.1 evaluates growth trends, Section 2.2 provides an explanation of wastewater
demand projections, and Section 2.3 discusses interbasin transfer compliance.
2.1 Growth Trends and Population Projections
Since 2000, Union County has ranked several times as one of the fastest growing counties in North
eitN Carolina. The County has had its highest residential growth rate over the last decade, most of which has
taken place in western Union County due to its proximity to the Charlotte metropolitan area. Three new
communities have incorporated in the western portion of the County in the past decade to accommodate
this growth: the Village of Lake Park, the Village of Marvin, and the Town of Weddington. The eastern
`fit
areas of the County are primarily rural but are expected to develop, particularly with the completion of the
Monroe Connector/Bypass. The County has maintained a strong agricultural economy and is also home to
efoN many commercial retail and personal service businesses.
The North Carolina Office of State Budget and Management (OSBM) estimated Union County's population
ega41
at 202,592 persons in 2010. This is a 64 percent increase from the 2000 estimate of 123,834 persons. The
feN County has grown steadily for the past several decades, with the majority of growth occurring in
incorporated towns. The highest average annual growth rate occurred between 2000 and 2009 when the
County population grew an average of 5.25 percent per year, in comparison to the average annual growth
eses
Hof 3.3 percent between 1970 and 2009.
Population, water demand projections, and wastewater flow projections have been completed for the entire
r county via the Comprehensive Master Plan (Black and Veatch, 2011 . 1� e.projeGtiQns were prepared using
recently updated Geographic Informall9.0 data for existing water and sewer infrastructure.
Parcel information in GIS, traffic analysis zones (TAZ), and land use planning information from the local
communities were used to determine the spatial distribution of population for the 2010 base year and the
planning years of 2015, 2020, and 2030.
Table 2-1 provides a summary of the areas of significant water and sewer growth for the 2015, 2020, and
2030 planning years. The majority of the near -term growth in Union County is expected in watershed areas
r'I°\ located in the Twelve Mile Creek service area, such as Poplin Road, Crooked Creek, Twelve Mile Creek,
and the Lake Lee area south of the City of Monroe. The Richardson (5 to 8), Lake Twitty, and Lanes
watershed areas are located in the eastern portion of the County and are anticipated to develop in 2030 in
row
conjunction with the timing of the proposed Monroe Connector/Bypass.
rA1
Hazen and Sawyer Project No. 30831-030 HAZEN AND SOWER 2-1
Environmental Engineers 3 Scientists

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Need for the Project
Table 2-1: Planning Year Summary of Watershed Areas Designated For Significant Growth in
Union County
Planning
Year
Significant
Growth in
2015
Catawba
East Twelve Mile *
Six Mile *
Twelve Mile *
Water
Yadkin
Crooked Creek *
Lake Lee 1, 2, 3 *
Poplin Road *
Richardson 1 to 4 *
Sewer
Catawba
East Twelve Mile *
Six Mile *
Twelve Mile *
Yadkin
Crooked Creek *
Lake Lee 1, 2, 3 *
Poplin Road *
Richardson 6
Significant
Growth in
2020
East Twelve Mile *
Six Mile *
Twelve Mile *
Crooked Creek * East Twelve Mile *
Lake Lee 1, 2, 3 * Six Mile *
Poplin Road * Twelve Mile *
Richardson 1 to 4 *
Crooked Creek*
Lake Lee 1, 2, 3 *
Poplin Road *
Richardson 1 to 4 *
Richardson 7 *
Significant Southwest County
Growth in
2030
Crooked Creek *
Poplin Road *
Lake Lee 1 *
Lake Twitty
Richardson 5 to 8
Lanes
Southeast County
Southwest County
Crooked Creek *
Poplin Road *
Lake Lee 1 *
Lane
Lake Twitty
Southeast County
* Denotes watershed areas in Twelve Mile Creek Service Area.
The Comprehensive Master Plan took into account information from past water and sewer master plans
along with the County's Draft 2025 Comprehensive Plan (Union County 2010a) planning projections
✓ 2010 to 2020, an annual population growth rate of 2.3 to 2.4 • ercent was used. This growth rate was based
on OSBM projections and a June 17, 2008 presentation to the Union County 2025 Comprehensive Plan
t/ Committee. From 2021 to 2030, an annual growth rate of 1.85 percent was used for consistency with the
overall county population projections from the OSBM. Table 2-2 provides the historic county population and
projection estimates in addition to the Twelve Mile Creek service area total and served population
projections. The projections also account for the expected growth in the Crooked Creek and Poplin Road
service areas.
Hazen and Sawyer Project No. 30831-030
HAZEN AND &MYER
Environmental Engineers & Scientists
2-2

✓ 1
Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Need for the Project
Table 2-2: Historic Population and Projections for Union County and Twelve Mile Creek
>
Service Area
County Historic Total Twelve Mile Served Twelve Mile
rattN Population or Average Annual Creek Service Area Creek Service Area
Year Projection I Percent Growth Population 2 Population 3
earN
1970 54,714
1980 70,436 2.56
1990 84,210 1.80
2000 123,834 3.93 (4) (4)
2009 196,322 5.25 (4) (4)
2010 202,592 3.19 92,895 51,969
2015 228,141 2.40 1 04, 005 61,996
2020 253,693 2.15 116,314 71,056
2030 304,790 1.85 141,023 91,657
1 From NC Office of State Budget and Management as reported in Comprehensive Water and Wastewater
Master Plan (Black and Veatch, 2011).
2 The total population in the Twelve Mile Creek service area includes the population on public sewer and septic
systems.
MA1 3 Population currently served by sewer in Twelve Mile Creek service area and Poplin Road service area.
Crooked Creek is a future service area and is expected to be served in approximately 2018.
4 Data not readily available.
(01
eiwN
2.2 Wastewater Flow Projections
The Comprehensive Master Plan evaluated wastewater flow projections separately for residential and non-
residential flow in all service areas of the County. The non-residential flow fraction includes commercial,
institutional, and existing industrial development. A residential wastewater production rate of 80 gallons per 100,4
capita per day (gpcd) was used. A maximum month to average month flow ratio of 1.3 was used in the -
EARN analysis based on historic flow data from the Twelve Mile Creek WWTP, the Crooked Creek WWTP, and
, the Six Mile Creek Interceptor. The projections for the service area are based on several factors, as follows: - 1C taw
• The Crooked Creek WWTP is expected to reach its existing capacity of 1.9 mgd by theesit r
�h�
year 2018. A plant expansion is not planned due to environmental limitations. AdditionalEst
14
�x
flow above the current plant capacity will be routed to the Twelve Mile Creek WWTP. ��`
• Wastewater flow from the Poplin Road Pump Station will continue to be routed to the
Twelve Mile Creek WWTP in addition to future flow from this subbasin.
• Wastewater flow from the Six Mile Creek subbasin will continue to be routed to CMU's
McAlpine Creek WWMF.
• The 3 mgd flow allocation at CMU's McAlpine Creek WWMF has been accounted for in the
Six Mile Creek subbasin and near -term developments in the Twelve Mile Creek service
r
Hazen and Sawyer Project No. 30831-030 HAZEN AND & l'21R 2-3
Environmental Engineers & Scientists

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Need for the Project
area. The wastewater flow allocation for near -term developments (approximately 1.2 mgd)
will be diverted from the Twelve Mile Creek WWTP to the McAlpine Creek WWMF via the
County's new Diversion Pump Station and force main.
The analysis in the Comprehensive Master Plan considered the conversion of existing septic systems to
public sewer in the flow projections. Residential Tots with septic systems built prior to 1989 are of the most
concern to the County Environmental Health Department, as these systems were not mandated to have a
repair area on the property. The Comprehensive Master Plan divided the conversion of septic to public
sewer into two stages. It was assumed that 50 percent of existing pre-1989 septic systems would be
converted in 2015 and the remaining 50 percent would be converted in 2020.
The projections in the Comprehensive Master Plan do not provide an allocation for industrial reserve. The
majority of the near -term industrial growth is expected in the City of Monroe's service area; however, the
County is in the process of preparing Small Area Plans to address industrial growth in other parts of the
county, including the Twelve Mile Creek WWTP service area. Therefore, a minimum industrial reserve of
3 percent of the residential and commercial flow has been include in the flow projections.
Infiltration and inflow (1/1) was not considered in the Comprehensive Master Plan.t A nominal allowance for
•
non -excessive Ill from future sewer lines was added in the projections. The allowance was calculated using
aflow rate of 100 gpolinch-mile of sewer. Data from surrounding and similarly sized municipalities was
analyzed to determine an average value of 0.096 inch -miles per person for construction of new sewer.
Table 2-3 provides the projected maximum month and average day influent wastewater flow to the Twelve
Mile Creek WWTP. The 2030 average annual daily flow for the Twelve Mile Creek service area is
anticipated to be approximately 9.0 mgd. The maximum month flow between 2030 and 2032 is anticipated
to be between 11.4 mgd and 12.5 mgd, respectively. The Twelve Mile Creek WWTP will be designed for a
maximum month flow of 12 mgd.
Hazen and Sawyer Project No. 30831-030
HAZEN AND S&WYER
Environmental Engineers & Scientists
2-4

able 2-3: Maximum Month an
Creek Service Area
Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Need for the Project
astewater Flow Projections for Twelve Mile
Flow Category 1, 2
Residential, Commercial, and Industrial,
and Institutional, mgd 4
Incremental Infiltration and Inflow for New
Sewer Lines, mgd 4
Industrial Reserve Allocation, mgd 4
Total Wastewater Flow to Twelve Mile
Creek WWTP, mgd 4' 5
' The flow projections include the Poplin Road and Crooked Creek subbasins in the Rocky River watershed and the
Richardson (1 to 4) and Lake Lee areas south of the City of Monroe in the Rocky River watershed.
2 From Comprehensive Water and Wastewater Master Plan (Black and Veatch, 2011).
esigned for a maximum month flow of 12 mgd.
2015
4.5
(3.4)
2020 2025 20303
7.0 8.9 10.8
(5.4) (6.9) (8.3)
0.2 0.3 0.3
(0.14) (0.18) (0.22)
0.2 0.3 0.3
(0.2) (0.2) (0.2)
3 The Twelve Mil
4 Maximum flow(Average day flow in (").
5 The wastewater floWTRUIDVIons repre nt t e quantity of wastewater influent to the Twelve Mile Creek WWTP and
do not include existing or future flow from th Six Mile Creek subbasin (1.8 mgd in 2030) or the remaining flow
allocation with CMU (1.2 mgd) that will be pu ped from the Twelve Mile Creek WWTP via the Diversion Flow Pump
Station.
0.1
(0.07)
0.1
(0.1)
4.7
(3.6)
7.4 9.4
(5.7) (7.2)
(8.8)
PIRA- lflfv Kut
2.3 Interbasin Transfer
et' rktcb WIA4
The Catawba / Yadkin River basin boundary divides the county almost in half. Currently, Union County's
primary water source is the Catawba River in South Carolina; however, the County serves communities in
the Rocky River subbasin of the Yadkin Pee Dee River basin. The County has a grandfathered IBT of
5 mgd that allows water transfer from the Catawba-Wateree basin to the Rocky River subbasin in the
Yadkin River basin. The County through its partnership in the CRWSP also has a Class I IBT Permit in
South Carolina that allows withdrawals up to 100 mgd from the Catawba-Wateree River basin and transfers
up to 20 mgd into the Lynches and Pee Dee River basins. Union County's secondary water source is the
wholesale purchase of finished water from Anson County. Union County may purchase up to 4 mgd of
finished water per a contract executed in 1992.
Table 2-4 provides the calculations for the anticipated interbasin transfer as a result of the expansion of the
Twelve Mile Creek WWTP. The majority of the near -term growth is anticipated to occur in the Twelve Mile
Creek service area, whereas areas outside the Twelve Mile Creek service area are long-term growth areas
(e.g., 2030) that will coincide with the timing of the proposed Monroe Connector/Bypass. Additional water
supply will be required to serve these longer -term growth areas; therefore, the water demand for the Yadkin
watershed areas outside of the Twelve Mile Creek service area will remain constant at the 2010 demand
until an additional water supply from the Yadkin -Pee Dee River is developed and/or additional Catawba
River capacity and a corresponding interbasin transfer is obtained. The IBT calculations demonstrate that
Hazen and Sawyer Project No. 30831-030
HAZEN AND SOWER
Environmental Engineers 8 Scientists
2-5

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Need for the Project
Union County will not exceed the grandfathered IBT amount due to the expansion of the Twelve Mile Creek
WWTP.
Union County is actively planning for additional water supply capacity for the next planning period including
a Catawba River water supply expansion, increased capacity from Anson County, and the development of
a new supply from the Yadkin -Pee Dee River. An increase in water supply capacity will require that the
County obtain an IBT certificate. The County will initiate the permitting process to obtain additional water
supply and address the corresponding IBT issues.
Table 2-4: Interbasin Transfer Calculations for Twelve Mile Creek Service Area in the Rocky River
Subbasin of the Yadkin
Water Demand
Catawba Demand, Average Day
Catawba Demand, Maximum Day (PF 1.9)
Yadkin Demand, Twelve Mile Creek Service Area,
Average Day
Yadkin Demand, Twelve Mile Creek Service Area,
Maximum Day (PF 1.7)
Yadkin Demand 2010, Other, Average Day
Yadkin Demand, Other, Max Day (PF 1.7)
Total Max Day Yadkin
Yadkin Supply
Yadkin Demand - Supply, Max Day
Wastewater Return
2010 2015 2020 2025 2030
(Al! units in mgd)
5.6 7.0 8.1 9.1 10.2
10.6 13.3 15.4 17.3 19.4
3.3 3.8 4.7 5.5 6.3
5.6 6.5 8.0 9.3 10.7
1.7 1.7 1.7 1.7 1.7
2.9 2.9 2.9 2.9 2.9
8.5 9.4 10.9 12.2 13.6
4.0 4.0 4.0 4.0 4.0
4.5 5.4 6.9 8.2 9.6
Poplin Road Transfer to Catawba, Max Month 1.2 1.4 2.4 3.2 3.2
Crooked Creek Transfer to Catawba, Max Month 0 0 0.4 0.6 0.8
Richardson Creek Transfer to Catawba, Max Month 0 0 0.3 0.3 0.3
Lake Lee Transfer to Catawba, Max Month 0 0 0.7 0.7 0.7
Interbasin Transfer
Grandfathered Transfer 1
3.3 4.0 3.1 3.4 4.6
5.0 5.0 5.0 5.0 5.0
1 Letter correspondence on Grandfathered Interbasin Transfer to Mr. Fransen, Division of Water Resources,
October 19, 2000.
Hazen and Sawyer Project No. 30831-030
H ZEN AM) &MIR
Environmental Engineers d Scientists
2-6

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Alternatives Analysis
3. Alternatives Analysis
The following section presents the evaluation of project and discharge alternatives for addressing Union
County's wastewater infrastructure needs in the Twelve Mile Creek service area. The project expansion
alternatives that were considered for the Twelve Mile Creek WWTP expansion include the following:
• No Action Alternative
• Purchase Additional Capacity at the CMU McAlpine Creek WWMF
• Build and Purchase Capacity at the LCWSD Indian Land WWTP in South Carolina
• Partner with LCWSD to Build a New WWTP
11
The effluent disposal alternatives considered in this EA include the following:
• Land Application •
• Non -conjunctive Reuse
• Surface Water Discharge to Catawba River
• Expand the Twelve Mile Creek WWTP and Surface Water Discharge to Twelve Mile Creek
1
Table 3-1 summarizes the effluent limits associated with the effluent discharge alternatives for reference in
this section. This table provides the current NPDES limits to Twelve Mile Creek, land application and
reclaimed water criteria, speculative limits to the Catawba River, and speculative limits to Twelve Mile
Creek at a discharge flow of 12 mgd. Figure 3-1 provides an illustration of the proposed infrastructure for
each of the project alternatives. Figure 3-3 provides an illustration of the discharge alternatives.
Table 3-1: Summary of Effluent Limits Associated with Discharge Alternatives
Parameter
BOD5 (summer)
BOD5 (winter)
Total Suspended Solids
Ammonia (summer)
Ammonia (winter)
Fecal Coliform,
coliform / 100 ml
Total Nitrogen
Total Phosphorus
Maximum Turbidity
Current
NPDES Limits
to Twelve Mile
Creek 1
55 mg/I
<_10 mg/I
G30 mg/I
<_1 mgll
mg/I
�100
Monitor
41.7 Ibs/day
NA
Land Reclaimed
Application Water
Design Criteria
Criteria 2 (2T Rules) 2
5_30 mg/I 5_10 mg/I
s30 mg/I s10 mg/I
G30 mg/I s4 mg/I
s15 mg/I s4 mgll
<_15 mg/I 5_4 mg/I
�200 <_14
NA NA 5
NA NA
NA 10 NTU
Speculative
Limits for
Discharge to
Catawba River 3
s5 mg/I
s10 mg/I
s30 mg/I
s1 mg/I
s2 mg/I
�00
Report
41.7 Ibs/day
NA
Speculative
Limits for
Discharge to
Twelve Mile
Creek 4
s5 mg/I
<_10 mg/I
<30 mg/I
<_1 mg/I
s1.9 mg/I
�00
Monitor
41.7 Ibs/day 6
Monitor
Hazen and Sawyer Project No. 30831-030
HAZEN AND &WM
Environmental Engineers & Scientists
3-1

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Alternatives Analysis
Table 3-1: Summary of Effluent Limits Associated with Discharge Alternatives
Parameter
Current
NPDES Limits
to Twelve Mile
Creek 1
Land Reclaimed
Application Water
Design Criteria
Criteria 2 (2T Rules) 2
S eculative
Li its for
Discharge to
Catawba River 3
Speculative
Limits for
Discharge to
Twelve Mile
Creek 4
1 Monthly average limits, NPDES Permit No. NC0085359 (DENR 2006).
2North Carolina Administrative Code, Title 15A 2T, Department of Environment and Natural Resources
3Per South Carolina DHEC Speculative Limits Letter, Wasteload Allocation Discharge to the Catawba River, Union
County, North Carolina, issued January 29, 2008 (SCDHEC 2008). Limits provided in this table are for a 6 mgd
wasteload allocation.
4 Per DWQ speculative effluent limits letter issued September 1, 2010 for a discharge of 12 mgd (DENR 2010d).
5 Altemative design criterion is s4 mg/1 per DWQ memo dated October 27, 2006.
6 The total phosphorus load allocated to Union County was maintained to comply with the South Carolina lake standard
of 0.06 mg/I.
3.1 No Action Alternative
The no -action alternative is the Twelve Mile Creek WWTP continuing to discharge into the Twelve Mile
Creek receiving stream at the permitted capacity of 6 mgd. The County would continue to send flow to
CMU McAlpine Creek WWMF and the City of Monroe up to the existing allocations of 3 mgd and 2.65 mgd,
respectively. Union County would be able to ireat_flow in the service area until approximatel6.
Privately owned wastewater treatment package systems and septic systems will proliferate in the service
area in the absence of a centralized sewer expansion. The permitting of package plant and septic systems
would continue without a sustainable effluent disposal method. The soils in the County are marginally
suitable for septic systems. According the County's Environmental Health Department, septic systems can
be a viable wastewater alternative. However, as septic systems age, the incidence of failure will increase,
resulting in ground and surface water contamination and potentially posing a threat to the environment and
to public health and safety. The County is in the process of planning for the conversion of pre-1989 septic
systems on the verge of failure to public sewer. This septic replacement effort will contribute 0.75 mgd of
wastewater flow to the existing system. Septic systems currently account for 25 percent of the total
wastewater disposal in the County.
The no -action alternative does not address the need for the proposed project, which includes an
environmentally sustainable solution for managing wastewater effluent disposal in the service area. Growth
will continue in the Twelve Mile Creek service area leading to a strong probability of degradation of area
water quality (and public health) from underperforming septic systems and the proliferation of privately
owned wastewater package plants. The no -action alternative does not address the Tong -term growth needs
in the service area. Therefore, this alternative was eliminated from further consideration.
Hazen and Sawyer Project No. 30831-030
HAZENAND S4VVYER
Environmental Engineers & Scientists
3-2

towk
Environmental Assessment for
Twelve Mile Creek Wastewater
`mt, Treatment Plant Expansion
Alternatives Analysis
3.2 Purchase Additional Capacity at Charlotte Mecklenburg Utilities McAlpine Creek WWMF
Union County has a contractual agreement for 3 mgd of purchased wastewater capacity with CMU. The
cAla, County is currently sending 1.3 mgd to the McAlpine Creek WWMF via the Six Mile Creek Pump Station
and force main. The Six Mile Creek infrastructure was constructed in 1992 and is owned and operated by
CMU. The 3 mgd flow allocation has been accounted for in the growth projections in the Six Mile Creek
' subbasin and in near -term developments in the Twelve Mile Creek service area via the County's new
Diversion Pump Station on the Twelve Mile Creek WWTP property.
Union County has considered purchasing additional 6 mgd of capacity at the CMU McAlpine Creek WWMF
to address the growth needs in the Twelve Mile Creek service area. There are several issues associated
with this alternative. The first issue is the availability of existing capacity at the McAlpine Creek WWMF.
The McAlpine Creek WWMF is currently rated at 64 mgd. Between November 2009 and February 2010,
the monthly average flow to theplant has ranged between.48.8 mgd and 59.2 mgd, which are 76 percent
and 92 percent, respectively, of available plant capacity during a conservative wet weather condition. In
2010, the annual average flow was 47 mgd and the maximum month flow was 78 mgd. It is highly probable
fizz that McAlpine Creek WWMF will be close to the rated design capacity as Union County continues to use
their current 3 mgd purchased allocation and as growth continues in Mecklenburg County.
CMU does not plan to consider an expansion or additional wastewater flow allocations at the McAlpine
WWMF until final decisions are made regarding the proposed Long Creek WWTP near the Town of
eir\ Belmont. The capacity of the proposed facility is not yet known, as it will serve the western area of
,B, Mecklenburg County. The Environmental Impact Statement (EIS) is expected to be completed by the end
of 2013 followed by a NPDES discharge permit application. It is not known whether CMU will divert
wastewater flow from the McAlpine Creek WWMF to the proposed Long Creek WWTP. The anticipated
completion date for the proposed Long Creek WWTP is near the end of 2015. Therefore, an expansion of
sc, the McAlpine Creek WWMF would be required for this alternative to be feasible.
The second issue is the capacity of the existing collection system infrastructure to handle the increased
wastewater flow. The County's Diversion Pump Station and force main capacity will not be adequate for an
increase in wastewater flow above the average day flow of 1.3 mgd. Expansion of this pump station and a
fitN new parallel force main is required to convey an additional 6 mgd to the Six Mile Creek Interceptor. The Six
Mile Creek Pump Station is currently being expanded from 6 mgd to a firm capacity of 18 mgd to
accommodate growth in Mecklenburg County. It is anticipated that the Six Mile Creek Pump Station and
force main would require an expansion beyond the current 18 mgd expansion to accommodate an
additional 6 mgd from the Twelve Mile Creek service area.
The total present worth analysis for the purchase of additional capacity at CMU's McAlpine Creek WWMF
are provided in Table 3-2. Costs include a capacity expansion of the Twelve Mile Creek Diversion Pump
Station, a capacity expansion of Six Mile Creek Pump Station, a parallel force main and a gravity sewer
line, and an expansion of the McAlpine Creek WWMF. The cost per gallon to expand the McAlpine Creek
SAWYER
Hazen and Sawyer Project No. 30831-030 HAZEN AND 3-3
PlitS Environmental Engineers & Scientists

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Alternatives Analysis
WWMF was estimated based on the construction cost of the previous plant expansion from 48 mgd to
64 mgd and several post -construction projects related to performance reliability and regulatory compliance.
A future expansion at the McAlpine Creek WWMF would likely increase rated capacity from 64 mgd to
80 mgd. The net present worth of this alternative is $95,590,000.
Purchasing capacity at the McAlpine Creek WWMF does not address long-term growth needs in the
Twelve Mile Creek service area. CMU will not be able to allocate an additional 6 mgd of capacity at the
McAlpine Creek WWMF to Union County. Additional capacity may be available at the McAlpine Creek
WWMF in the future, but the timing of a plant expansion is not known at this time. It is also not known
whether the proposed Long Creek WWTP will significantly reduce influent wastewater flow to the McAlpine
Creek WWMF, thereby opening up capacity. Therefore, this project alternative was removed from
consideration.
Table 3-2: Present Worth Analysis for Purchasing Additional Capacity at Charlotte Mecklenburg
Utilities McAlpine Creek WWMF
Salvage Value
Salvage Useful Life
Component Project Cost 1'2'3 Amount t 4
Union County Infrastructure
New or Expanded Diversion Pump Station $5,438,000 $0
Force Main to Six Mile Creek Interceptor $11,809,000 $3,800,000
Mecklenburg County Infrastructure
Gravity Sewer to Six Mile Creek Pump Station
Six Mile Creek Pump Station Expansion
Parallel Force Main to McAlpine Interceptor
McAlpine Creek WWMF Expansion
Expansion from 64 to 80 mgd 5
$2,098,000
$9,323,000
$2,983,000
$46,614,000 $8,571,000
Subtotal $78,265,000
$12,371,000
20
40
28
(*)
Project Cost
Present Worth
of O&M 6' 7
Present Worth
of Salvage
$78,265,000
$22,100,000
$4,775,000
Total Present Worth for Purchasing Additional Capacity $95' 590,000
at Charlotte Mecklenburg Utilities McAlpine Creek WWMF:
Note: Time Period = 20 years, Interest Rate = 4.875% per DENR DWQ Guidance for Preparing Engineering Reports.
Costs developed by Hazen and Sawyer (2011).
2 Ai! costs in 2011 dollars.
3 Project cost includes contingencies, overhead, profit, insurance, mobilization, bonds, and engineering costs.
Useful life of structures, piping, and electrical equipment is 40 years, mechanical equipment is 20 years, hybrid of
electrical and mechanical is 28 years.
Hazen and Sawyer Project No. 30831-030
HAZE AND S \WER
Environmental Engineers & Scientists
3-4
Oft
r
Adak
Jim
041,
114
0144

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Alternatives Analysis
Table 3-2: Present Worth Analysis for Purchasing Additional Capacity at Charlotte Mecklenburg
Utilities McAlpine Creek WWMF
Salvage Value
Salvage Useful Life
Component Project Cost 1,2,3 Amount (years) 4
Capital costs are presented as Union County's portion (6 mgd) of overall expansion cost: Unit expansion costs were
estimated using the construction cost of the previous plant expansion from 48 mgd to 64 mgd and several post -
construction projects related to performance reliability and regulatory compliance.
6 O&M costs include pumping to McAlpine Creek WWMF (Diversion Pump Station and Six Mile Creek Pump Station)
and treatment costs at the McAlpine Creek WWMF.
' The treatment costs at the McAlpine Creek WWMF are based on a letter from Charlotte -Mecklenburg Utilities (2010)
describing the unit cost to be billed to Union County.
3:3 Build and Purchase Capacity at Lancaster County Water and Sewer District Indian Land WWTP
in South Carolina
Union County has considered entering into a partnership with LCWSD in South Carolina to build and buy
treatment capacity at the existing Indian Land WWTP. The Indian Land WWTP was constructed in 2001 as
a 2 mgd advanced secondary treatment facility. The facility serves the Indian Land community of Lancaster
County. This service area is located in the northern portion of Lancaster County. The Indian Land WWTP is
permitted for an NDPES discharge of 2 mgd to the Catawba River (SC0047864). The NPDES,permit is a
phased permit with an ultimate discharge capacity of 15 mgd with intermediate phases of 1.2, 2.0, 4.0, and
7.5. The facility would need to be expanded to accommodate an additional 6 mgd from Union County.
Informal discussions have taken place between the County and LCWSD regarding the purchase of
additional capacity at the Indian Land WWTP. LCWSD and the County have partnered on drinking water
treatment and infrastructure; however, LCWSD has been reluctant to formally discuss wastewater options
with Union County for several reasons. First, wastewater flow to the Indian Land WWTP is less than 1 mgd,
so Lancaster County is not under immediate pressure to expand the facility. Second, LCWSD's approved
208 Water Quality Management Plan does not explicitly state that LCWSD can accept wastewater flows
generated in the State of North Carolina. The 208 Plan would need to be amended, which is initiated
through a letter of intent outlining an agreement that LCWSD is willing to accept wastewater flow from
Union County. The letter must also indicate that other alternatives were evaluated and that this alternative
was recommended. A 30-day public notification period for public comment would also be required once the
208 Amendment has been accepted by South Carolina Department of Health and Environmental Control
(SCDHEC). Following this process, a construction permit could be issued for the Indian Land WWTP
expansion and the force main from the Twelve Mile Creek WWTP (i.e., the section of the force main in
South Carolina).
Capital improvements for this project alternative would include the construction of a new pump station at
the Twelve Mile Creek WWTP to convey up to 6 mgd to the Indian Land WWTP. This pump station would
be integrated into the Diversion Pump Station structure such that one wet well is shared but individual
Hazen and Sawyer Project No. 30831-030
H►ZEN AND S&WYER
Environmental Engineers 8 Scientists
3-5

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Alternatives Analysis
pumps are dedicated to route influent wastewater flow to either the Six Mile Creek Pump Station or the
Indian Land WWTP. This alternative would also require a new force main between the Twelve Mile Creek
WWTP and the Indian Land facility. Table 3-3 provides the total present worth analysis for this alternative.
The net present worth of this alternative is $137,810,000.
A partnership with LCWSD to expand the Indian Land WWTP is not a viable alternative for Union County.
LCWSD has not indicated a willingness to allocate Indian Land WWTP capacityto the County. The timing
associa a with the regulatory process followed by construction is also a concern for meeting Union
County's wastewater capacity needs in the Twelve Mile Creek service area. Therefore, this alternative was
removed from consideration as a viable project alternative.
Table 3-3: Present Worth Analysis for Purchasing Capacity at Lancaster County Water and
Sewer District Indian Land WWTP
Component
Union County Infrastructure
Pump Station at Twelve Mile Creek WWTP
Force Main to Indian Land WWTP
Indian Land WWTP Expansion
Expansion from 2 to 15 mgd 5
Subtotal
Salvage Value
Salvage Useful Life
Project Cost 1'2'3 Amount (years) 4
$9,300,000 $0
$13,500,000 $4,350,000
$65,300,000
$88,100,000
$12,000,000
20
40
28
(*)
Project Cost
Present Worth
of O&M 6
Present Worth
of Salvage
. $88,100,000
$56,020,000
$6,311,000
Total Present Worth for Purchasing $137,810,000
Capacity at Indian Land WWTP:
Note: Time Period = 20 years, Interest Rate = 4.875% per DENR DWQ Guidance for Preparing Engineering Reports.
1 Costs developed by Hazen and Sawyer (2011).
2 All costs in 2011 dollars.
3 Project cost includes contingencies, overhead, profit, insurance, mobilization, bonds, and engineering costs.
4 Useful life of structures, piping, and electrical equipment is 40 years, mechanical equipment is 20 years, hybrid of
electrical and mechanical is 28 years.
5 Capital costs are presented as Union County's portion (6 mgd) of overall expansion cost. Unit expansion costs were
estimated at $7 per gallon (prior to contingencies, overhead, profit, etc.).
6 O&M costs include pumping and treatment costs. For pumping energy costs, the required head was estimated using
the approximate static and friction losses for the force main route between the Twelve Mile Creek WWTP and the
Indian Land WWTP.
Hazen and Sawyer Project No. 30831-030
HkzEN AND SAWYER
Environmental Engineers & Scientists
3-6

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Alternatives Analysis
flPN
3.4 Partner with Lancaster County Water and Sewer District to Build a New Wastewater Treatment
Plant
Union County has also considered a partnership with LCWSD to construct a new WWTP. Union County
has had brief and informal discussions with LCWSD regarding this altemative. Similar to the partnership
with the Indian Land WWTP, Lancaster County has also expressed reluctance to enter into formal
`sari discussions. Lancaster County would need to develop an appropriate service area and wastewater flow
projections to supplement Union County's Twelve Mile Creek service area. Currently, LCWSD has
,,ne\ indicated that there may not be sufficient wastewater flow to justify construction of a new treatment facility.
The proposed WWTP would ultimately discharge into the Catawba River.
rek\
Lancaster and Union Counties would need to identify a location for the proposed facility. The facility was
preliminarily located on Van Wyck Road in Lancaster County. The proposed location of the new plant was
exittN estimated based on the following:
,,� • Wastewater generated in Lancaster County south of Highway 5 would be transferred to the
City of Lancaster's existing wastewater treatment facility.
• The Indian Land WWTP would continue to serve the northern portion of Lancaster County.
, • SCDHEC has previously declined to give speculative permit limits for a new NPDES
discharge to Twelve Mile Creek in South Carolina.
rst's The present worth analysis for this project alternative is provided in Table 3-4. The unit cost for construction
�► of the new plant is higher than that of the expansion of the Indian Land WWTP to account for additional
costs associated with a new facility, such as administration facilities and the purchase of land. Other capital
improvements would include a pump station at the Twelve Mile Creek WWTP and a force main to the
proposed facility. The net present worth of this alternative is $150,850,000.
rya,
The complexities involved in permitting a new WWTP, particularly a plant jointly owned by counties in two
r� states, could result in a lengthy environmental review, permitting, design, construction, and financing
process. The environmental documentation and permitting for establishing a new WWTP site and NPDES
rik-N discharge may require 8 to 12 years. Furthermore, the expected growth in the Lancaster County portion of
the proposed service area has decreased significantly over the past few years. LCWSD doesipot r_urrPntly
AteN have sufficient wastewater flow to justify construction of a new treatment facilit . For the aforementioned
reasons, th' ' ct alternative is not a technically feasible alternative for Union County to address the
growth needs in the Twe ve ree ice area.
elaN
Hazen and Sawyer Project No. 30831-030
eltA
HAZEN AND S4\WER
Environmental Engineers 8 Scientists
3-7

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Alternatives Analysis
Table 3-4: Present Worth Analysis for Partnering with Lancaster County Water and Sewer District
to Build a New WWTP
Component
Union County Infrastructure
Pump Station at Twelve Mile Creek WWTP
Force Main to New WWTP
New WWTP Construction
Construct 10 mgd WWTP 5
Subtotal
Salvage Value
Salvage Useful Life
Project Cost 1'2'3 Amount (years) 4
$9,323,000 $0
$18,347,000 $5,904,000
$74,582,000
$102,250,000
$13,714,000
$19,618,000
20
40
28
(*)
Project Cost
Present Worth
of O&M 6
Present Worth
of Salvage
$7,572,000
$102,250,000
$56,170,000
Total Present Worth for Partnering with $150,850,000
LCWSD to Build a New WWTP:
2 All costs in 2011 dollars.
3 Project cost includes contingencies, overhead, profit, insurance, mobilization, bonds, and engineering costs.
a Useful life of structures, piping, and electrical equipment is 40 years, mechanical equipment is 20 years, hybrid of
electrical and mechanical is 28 years.
5 Capital costs are presented as Union County's portion (6 mgd) of overall expansion cost. Unit costs were estimated at
$8 per gallon (prior to contingencies, overhead, profit, etc.) to account for additional costs of a greenfield facility, such
as land purchase and administration facilities.
6 O&M costs include pumping and treatment costs. For key O&M Costs, the pumping head was estimated based on
approximate static and friction losses for the force main route between the Twelve Mile Creek WWTP and the
proposed WWTP.
Note: Time Period = 20 years, Interest Rate = 4.875% per DENR DWQ Guidance for Preparing Engineering Reports.
1 Costs developed by Hazen and Sawyer (2011).
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Hazen and Sawyer Project No. 30831-030
HAZEN AND SAWYER
Environmental Engineers 8 Scientists
3-8
ook

,a,
reoN
r
Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Alternatives Analysis
3.5 Land Application
The land application of wastewater effluent was evaluated as a discharge alternative. Land application
systems include individual or community onsite subsurface systems, drip irrigation, and spray irrigation.
Land application systems generally do not require advanced secondary treatment processes prior to
irrigation per North Carolina Administrative Code (NCAC) 15A 02T, Waste Not Discharged to Surface
Water. Typically, only preliminary treatment is used. Land application systems also do not facilitate other
options for effluent disposal, such as reuse or high rate infiltration. Secondary effluent limits for land
application include BOD5 and total suspended solids (TSS) Tess than 30 mg/I, ammonia less than 15 mg/I,
and fecal coliform Tess than 200 colonies/100 ml. The effluent criteria for land application are summarized
in Table 3-1. Influent pumping, screening, and equalization for the additional 6 mgd to be land applied
would be located on the treatment plant site.
Suitable property for disposal of land application effluent must be acquired to dispose of the additional
6 mgd. A conservative land application rate of 1 inch •er acre •er week w. -w.-c ed_ba •. •. 1.. ar
systems in North Carolina an publis a crt eria (EPA, 2006). Including land for the 60-day storage pond,
wetlands, buffers, and access roads, nion ount would need to acquire approximately 2 700 acres of
land for effluent disposal of 6 mgd. The closest suitable and contiguous land application sites with adequate
capacity for a flow of 6 mgd was found approximately 7 miles from the Twelve Mile Creek WWTP. These
properties were selected based on size, zoning classification, and proximity to the treatment plant. Detailed
investigations were not performed to determine the suitability of the land for application or the availability of
the properties. The site evaluation was limited to Union County. Per North Carolina General Statute
(NCGS) 153A-15, Union County cannot purchase land outside the County without the consent of the Board
of Commissioners of the county in which the land is located. Figure 3-3 illustrates the location of the
potential land application sites relative to the Twelve Mile Creek WWTP.
Research suggests that land application of secondary treated effluent may reduce the porosity of soil
(i.e. clogging) and the infiltration rate over time (Clanton and Slack 1987). Therefore, more land may be
required to dispose of the same quantity of effluent as the system ages. Additionally, land application
systems do not maximize the value and service of the property due in part to the large buffer areas that are
required.
Table 3-5 summarizes the total present worth for the land application disposal alternative. Costs include
land acquisition, spray field infrastructure, effluent pumping and force main, and preliminary treatment at
/se> the Twelve Mile Creek WWTP. The total present worth for this alternative is approximately $199,100,000.
emN.
The land a lication alternative has been removed from consideration for several reasons. First, this
a ternative isirgoLgcole. The total present worth cost is approximately twice as high as the
selected alternative. Furthermore, the acquisition of 2,700 acres of land would require four to five years to
accomplish prior to design and bidding. The Twelve Mile Creek WWTP will require an expansion before all
Hazen and Sawyer Project No. 30831-030
HAZEN AND Wm
Environmental Engineers & Scientists
3-9

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Alternatives Analysis
of the land could be acquired to dispose of the additional 6 mgd. Therefore, this effluent disposal alternative
was removed from consideration.
Table 3-5: Present Worth Analysis for Land Application
Component
Twelve Mile Creek WWTP Expansion
Influent Pumping, Coarse Screening, and Flow
Equalization
Land Application Infrastructure
Five -Day Onsite Storage
Return Pump Station
Reuse Pump Station to Storage
Equalization Storage Reservoir
Effluent Pump Station from Storage to Land
Application Site
Land Acquisition for Spray Irrigation 5
Piping
Force Main from WWTP to Reservoir
Force Main from Reservoir to Land Application
Site
Project Cost 1'2,3
$10,099,000
$6,992,000
$3,107,000
$9,322,000
$41,950,000
$27,967,000
$79,950,000
$31,137,000
$1,119,000
Salvage
Amount
Salvage Value
Useful Life
(years) a
$1,857,000 28
$2,250,000
$0
$0
$13,500,000
$0
$79,950,000
$10,020,000
$360,000
40
20
20
40
20
40
40
Subtotal
$211,643,000
$107,937,000
(*)
Project Cost
Present Worth
of O&M 6
Present Worth
of Salvage
$211,643,000
$29,110,000
$41,661,000
Total Present Worth for Land Application: $199,100,000
2 All costs in 2011 dollars.
3 Project cost includes contingencies, overhead, profit, insurance, mobilization, bonds, and engineering costs.
' Useful life of structures, piping, and electrical equipment is 40 years, mechanical equipment is 20 years, hybrid of
electrical and mechanical is 28 years.
5 Land was assumed to have a 100% salvage value.
6 O&M costs include pumping and treatment costs.
Note: Time Period = 20 years, Interest Rate = 4.875% per DENR DWQ Guidance for Preparing Engineering Reports.
1 Costs developed by Hazen and Sawyer (2011).
Hazen and Sawyer Project No. 30831-030
HAZEN AND SAWYER
Environmental Engineers & Scientists
3-10
to"
IBA
Onk
/I\
Area

emN Environmental Assessment for
Twelve Mile Creek Wastewater
1 Treatment Plant Expansion
Alternatives Analysis
evAk
3.6 Non -Conjunctive Reuse
eieN
In addition to land application, a non -conjunctive reuse system was evaluated as a discharge alternative for
the expansion of the Twelve Mile Creek WWTP. Reuse is the beneficial reuse of tertiary treated
wastewater effluent. DWQ defines non -conjunctive reuse as a wastewater treatment system that relies on
reclaimed water uses to account for all of the generated wastewater (i.e., zero direct discharge to surface
water). Design criteria for reclaimed water systems in which an irrigation system is required' to meet the
needs of the facility are more stringent than for land application systems. Per NCAC 15A 02T, Waste Not
Discharged to Surface Water, effluent criteria for reclaimed water systems include BOD5 less than 10 mg/I,
TSS less than 5 mg/I, ammonia less than 4 mg/I, fecal coliform less than 14 colonies/100 ml, and a
maximum turbidity of 10 NTU (refer to Table 3-1).
Aft, This alternative involves the development of a non -conjunctive reuse system to land apply the 6 mgd of
expanded treated effluent from the Twelve Mile Creek WWTP onto suitable land within a 3 to 7 mile radius
of the treatment plant. This alternative would require the expansion of the Twelve Mile Creek WWTP as
well as additional disinfection to meet reclaimed water standards. Treated effluent would be pumped from
✓ the Twelve Mile Creek WWTP to a 60-day storage pond at the reuse application site. Refer to Figure 3-3
for a general location of the potential dedicated spray irrigation sites.
In addition to treatment design criteria, NCAC provides design criteria for distribution lines and reclaimed
(IN water utilization. Setback requirements for irrigation and utilization areas are less stringent than for land
application systems. The required setbacks for treatment and storage facilities in reclaimed water systems
riot are identical to those for land application systems.
Production of reuse quality effluent allows a greater range of options for land application other than a
tors dedicated land application site. These effluent disposal options include golf courses, residential lawns,
ra, parks and school grounds, athletic fields (e.g., soccer, baseball, football), irrigation of crops, and industrial
uses (such as cooling and wash down water). Additionally, beneficial reuse is considered by many
communities as a supplement to the NPDES discharge, particularly to offset potable water demand in the
ra° hot summer months. Water reuse systems in the Piedmont region of North Carolina are generally
landscape irrigation -based systems that experience high demands during the hot, dry summer season and
little to no demands during the cool, wet winter season. As an example, data collected by the Town of Cary
in its Northeast Reclaimed Water Service Area indicated that reclaimed water customers used the same
MAN
amount of potable water in winter as non -reclaimed water users, but used less potable water in the
summer.
A cost effective reduction of a surface water discharge requires commercial and industrial users on a year-
round basis. The County commissioned a Twelve Mile Creek Reuse System Preliminary Engineering
Report (PER) to evaluate beneficial reuse options (HDR, 2005) to help offset high potable water demands
during the spring and summer seasons when residential irrigation and other demands peak. The PER
r focused on the installation of water reuse infrastructure at the Twelve Mile Creek WWTP and the potential
Olt\ Hazen and Sawyer Project No. 30831-030 HAZE1, AND Sr► TLJ 3-11
Environmental Engineers & Scientists

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Alternatives Analysis i'""'
reuse demand within a 2-mile radius of the plant. The PER did not find a significant demand reuse watertalkIN
applications near the plant. The following is a summary of the PER findings:
• Two potential irrigation sites were identified, including a development adjacent to the plant '1'1)`
owned by G.S. Carolina Property and two unidentified tracts of land in a 2-mile radius of the
plant. fa",
• Significant industrial and agricultural reuse opportunities do not exist near treatment plant. r+ft,
• Plant effluent quality will generally meet reuse requirements for monthly average and daily (�
maximum BOD5, TSS, and ammonia limits. Additional disinfection would be required to �►,
meet reclaimed water fecal coliform standards.
eth
• The average reclaimed water flow for the identified properties was determined to be
630,000 gpd. The infrastructure would be designed to deliver this flow rate over an 8-hour
per day irrigation schedule.
tiab
Table 3-6 summarizes the total present worth for the non -conjunctive reusedisposal alternative. Costs riaN
include land acquisition, spray field infrastructure, effluent pumping and force main, and expansion of the
Twelve Mile Creek WWTP. The total present worth for this effluent disposal option is approximately ebs
$234,960,000. The capital and total present worth costs are more than double the cost of the selected
alternative. eig°'
I4"'
Water reuse is not considered a reliable effluent disposal option. The extreme seasonal variation in non -
potable water demand requires large contiguous dedicated properties for spray irrigation. The challenge of
land acquisition for reuse is similar to the land application altemative. The Twelve Mile Creek WWTP will
require an expansion before all of the land could be acquired to dispose of the additional 6 mgd. Therefore, tdhN
this effluent disposal alternative was removed from consideration in this EA.
r`'hN
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eas
eatal►
raaN
Hazen and Sawyer Project No. 30831-030 i]AZ N AND SOWER J 3-12
Environmental Engineers & Scientists

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Alternatives Analysis
Table 3-6: Present Worth Analysis for Non -Conjunctive Reuse System
Salvage Value
Salvage Useful Life
Component Project Cost 1,2,3 Amount (years) a
Twelve Mile Creek WWTP Expansion
Twelve Mile Creek WWTP Expansion 5 $47,678,000 $14,512,000 40
Reuse Infrastructure
Five -Day Onsite Storage $6,992,000 $2,250,000 40
Return Pump Station $3,108,000 $0 20
Reuse Pump Station from WWTP to Storage $9,323,000 $0 20
Reservoir
Storage Reservoir $13,984,000 $4,500,000 40
Effluent Pump Station from Storage $27,968,000 $0 20
Reservoir to Irrigation Sites
Additional Disinfection System $622,000 $200,000 40
Land Acquisition for Spray Irrigation 6 $79,200,000 $79,200,000
Piping
Force Main from WWTP to Reservoir $31,137,000 $10,020,000
Force Main from Reservoir to Irrigation Sites $1,119,000 $360,000
40
40
Subtotal $221,130,000
$111,042,000
(*)
Project Cost
Present Worth
of O&M'
Present Worth
of Salvage
$221,130,000
$56,690,000
$42,860,000
Total Present Worth for Non -Conjunctive Reuse System: $234,960,000
Note: Time Period = 20 years, Interest Rate = 4.875% per DENR DWQ Guidance for Preparing Engineering Reports.
1 Costs developed by Hazen and Sawyer (2011).
2 All costs in 2011 dollars.
3 Project cost includes contingencies, overhead, profit, insurance, mobilization, bonds, and engineering costs.
4 Useful life of structures, piping, and electrical equipment is 40 years, mechanical equipment is 20 years.
5 Costs for the plant expansion cost includes influent pumping, screening, flow equalization, preliminary treatment
facility, biological treatment, filtration, disinfection, post aeration, sludge thickening, digesters, sludge storage, odor
control, and standby power.
6 Land was assumed to have a 100% salvage value.
O&M costs include pumping and treatment costs.
Hazen and Sawyer Project No. 30831-030
HAZEN AND SAWYER
Environmental Engineers 8 Scientists
3-13

3.7 Surface Water Discharge to Catawba River (311U
Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Alternatives Analysis
CeA44.4-v..)
An alternate surface water discharge was considered in this analysis. A surface water discharge into the
Catawba River immediately downstream of the jointly owned LCWDS and Union County WTP was
preliminarily identified as a feasible location. Figure 3-3 provides an illustration of the proposed location.
This discharge alternative would require that the Twelve Mile Creek WWTP be expanded from 6 to 12 mgd.
Treated effluent would continue to be discharged to Twelve Mile Creek under the existing permit, and the
additional 6 mgd would be pumped and discharged to the Catawba River.
Speculative limits for the proposed surface water discharge to the Catawba River were issued by SCDHEC
in January 2008 (Appendix A). The letter outlined a wasteload allocation for 3, 6, and 9 mgd. The limits
proposed by SCDHEC are identical to the current NPDES permit limits for the Twelve Mile Creek WWTP
(refer to Table 3-1). SCDHEC also included a requirement that the Twelve Mile Creek WWTP be assigned
a reliability classification of Class I. The location of the proposed discharge into the Catawba River is in a
water supply intake area as defined by SCDHEC. Reliability Classification I requires specific redundancies
and backup components for most of the treatment processes at the plant. These requirements are
described in Section 67.400 of SCDHEC's Standards for Wastewater Facility Construction (May 2002).
The infrastructure required for this alternative includes an expansion of the Twelve Mile Creek WWTP with
current treatment technology and pumping the additional 6 mgd of treated effluent to the Catawba River.
Parallel 42-inch and 24-inch high service water mains currently route finished drinking water from the WTP
to Union County. The 24-inch water main may not be needed to meet current and near -term water supply
demands. The cost for this alternative factors in re -purposing the 24-inch high -service water main for
effluent disposal. A summary of the total present worth for this alternative is provided in Table 3-7. The
present worth of this alternative is $117,170,000.
The complexities involved in permitting a new surface water discharge in South Carolina will result in a
lengthy environmental review, permitting, design, construction, and financing process. SCDHEC would
require a 208 Amendment and a public comment period. The amendment must indicate that other
discharge alternatives were evaluated and the reasoning for the recommended alternative. Furthermore,
this alternative may not meet the long-term growth goals of the Twelve Mile Creek service area. A plant
expansion may be needed before the permits and approvals for a Catawba River surface water discharge
could be obtained. Therefore, this alternative has been removed from consideration in this EA.
Hazen and Sawyer Project No. 30831-030
HAZEN AND SAWYER
Environmental Engineers & Scientists
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Environmental Assessment for
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Treatment Plant Expansion
Alternatives Analysis
Table 3-7: Present Worth Analysis for Surface Water Discharge to Catawba River
Salvage Value
Salvage Useful Life
Component Project Cost 1,2,3 Amount (years) a
Twelve Mile Creek WWTP Expansion
Twelve Mile Creek WWTP Expansion 5 $47,679,000 $14,512,000 40
Effluent Pump Station and Piping
Effluent Pump Station
Effluent Force Main
Conversion of Existing Water Main to
Wastewater Service
$9,323,000 $0
$10,814,000 $3,480,000
$388,000
20
40
Subtotal
$68,204,000
$17,992,000
(*)
Project Cost
Present Worth
of O&M 6
Present Worth
of Salvage
$6,944,000
$68,204,000
$55,910,000
Total Present Worth for Surface
Water Discharge to Catawba River:
$117,170,000 �a if r{/✓/
P 0I0HRhrc
Note: Time Period = 20 years, Interest Rate = 4.875% per DENR DWQ Guidance for Preparing Engineering Reports.
1 Costs developed by Hazen and Sawyer (2011).
2 All costs in 2011 dollars.
3 Project cost includes contingencies, overhead, profit, insurance, mobilization, bonds, and engineering costs.
4 Useful life of structures, piping, and electrical equipment is 40 years, mechanical equipment is 20 years.
s Twelve Mile Creek project expansion cost includes influent pumping, screening, flow equalization, preliminary
treatment facility, biological treatment, filtration, disinfection, post aeration, sludge thickening, digesters, sludge
storage, odor control, and standby power.
6 O&M costs include pumping and treatment costs.
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Environmental Assessment for
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Treatment Plant Expansion r^
Alternatives Analysis el"'N
3.8 Expand the Twelve Mile Creek WWTP and Surface Water Discharge to Twelve Mile Creek
(Selected Alternative)
The expansion of Union County's Twelve Mile Creek WWTP from 6 mgd to 12 mgd was identified as the
most favorable project alternative to accommodate the long-term growth needs in the Twelve Mile Creek
service area. No additional land will be required for this project alternative as all modifications will be
restricted to plant property. This alternative has been selected by Union County to be the most technically e*,
feasible, the most economical, and the most protective of water quality in the Twelve Mile Creek receiving
stream. Speculative limits were issued by DWQ in September 2010.
An expansion of the Twelve Mile Creek WWTP requires major plant improvements necessary to achieve a
rated plant capacity of 12 mgd and meet the speculative effluent limits. The facility is an extended aeration flgIC
activated sludge wastewater plant with CBOD5 removal, nitrification, and phosphorus removal. The facility
consists of screening and grit removal, oxidation ditches, secondary clarification, tertiary filtration, UV
disinfection, and cascade aeration. BioWin© process modeling indicates that modifying the existing plant
processes will be successful in achieving the speculative limits. The proposed site plan is provided in
Figure 3-2. The improvements required to meet the speculative permit limits are summarized as follows:
• Parallel influent pump station, replace existing screens, add a fine screenings facility, and ems
add influent flow equalization.
• Modify existing oxidation ditches with new blowers, diffusers, air piping, and blower taN
building.
• Additional activated sludge aeration basins to accommodate expanded flow.
• Additional secondary clarifiers and associated return activated sludge pumping facilities.
• Additional tertiary sand filters.
• Additional two UV channels with four UV banks and cascade aerator.
• A new gravity belt thickener and an additional 3 million gallons of sludge digester volume.(4111.
• Expand the odor control facility.
• One 1,000 kilowatt (kW) standby generator and a 1,000 kW standby generator for the
influent pump station and coarse screenings facility.
The total present worth analysis for the plant expansion to .12 mgd is summarized in Table 3-8. The net
present worth for the selected alternative is approximately $97,250,000. This project alternative is
29 percent less than the project alternative to build and buy additional capacity at the Indian Land WWTP.
ems
Hazen and Sawyer Project No. 30831-030 HAZFli AM) Sol 3-16
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Environmental Assessment for
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Treatment Plant Expansion
Alternatives Analysis
Table 3-8: Present Worth Analysis for Expanding Union County's Twelve Mile Creek WWTP
Salvage Value
Salvage Useful Life
Component Project Cost 1,2,3 Amount (years) 4
Twelve Mile Creek WWTP Expansion
Influent Pump Station, Equalization Tanks, $12,430,000 $4,000,000 40
Coarse Screens, and Preliminary
Treatment Facility
Biological Treatment (Diffusers, Blowers, Blower $16,796,000 $5,405,000 40
Building, Nitrified Recycle Pumps/Piping, Additional
Aeration Volume, Secondary Clarification and
Pumping)
Tertiary Filtration and Disinfection $6,022,000 $1,107,000
Sludge Storage, Thickening, and Digestion $7,769,000 $2,500,000
Odor Control and Standby Power $4,661,000 $1,500,000
28
40
40
Subtotal 5
$47,678,000
$14,512,000
(*)
Project Cost 6
Present Worth
of O&M 7
Present Worth
of Salvage
$47,678,000
$55,170,000
$5,601,000
Total Present Worth for Twelve Mile Creek WWTP Expansion: $97,250,000
Note: Time Period = 20 years, Interest Rate = 4.875% per DENR DWQ Guidance for Preparing Engineering Reports.
Costs developed by Hazen and Sawyer (2011).
2 AlI costs in 2011 dollars.
3 Project cost includes contingencies, overhead, profit, insurance, mobilization, bonds, and engineering costs.
4 Useful life of structures, piping, and electrical equipment is 40 years, mechanical equipment is 20 year, hybrid of
electrical and mechanical is 28 years.
5 Capital costs equal approximately $8 per gallon (prior to contingency, overhead, profit, insurance, etc.).
6 The project cost for the plant expansion is used in the discharge alternatives presented in this EA.
O&M costs include pumping and treatment costs.
A surface water discharge to Twelve Mile Creek was identified as the most favorable effluent discharge
alternative to accommodate the Tong -term growth needs in the Twelve Mile Creek service area. This
alternative has been selected by Union County to be the most technically feasible, the most economical,
and the most protective of water quality in Twelve Mile Creek. Scoping meetings with DWQ staff in the
spring of 2010 indicated that the County would need to demonstrate that assimilative capacity is available
in Twelve Mile Creek and the expanded discharge will provide a benefit to water quality in the stream.
Speculative effluent limits for the proposed surface water expansion from 6 to 12 mgd in Twelve Mile Creek
were issued by DWQ in September 2010 (Appendix B). DWQ noted that Twelve Mile Creek is listed as
impaired for copper and turbidity from the headwaters of the creek to the North Carolina / South Carolina
state line. Furthermore, DWQ noted that historic data has shown low dissolved oxygen (DO) concentrations
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Environmental Assessment for
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Treatment Plant Expansion
Alternatives Analysis
upstream and downstream of the discharge point during summer low flow conditions. The speculative
effluent limits are identical to the existing Twelve Mile Creek NPDES effluent limits. These limits are
summarized in Table 3-1. DWQ maintained the total phosphorus load originally allocated to Union County
to comply with the South Carolina lake standard of 0.06 mg/I.
3.8.1 Water Quality Modeling to Support the Expanded Surface Water Discharge
Tetra Tech conducted a scoping level model assessment of assimilative capacity in Twelve Mile Creek in
2010. The scoping report is provided in Appendix C. Tetra Tech compiled and reviewed existing
information and water quality data to establish how assimilative capacity had been determined prior to the
scoping level study. Tetra Tech also performed field reconnaissance and surveys to obtain channel cross
section information, longitudinal elevation data, and visual inspection of the receiving stream downstream
of the Twelve Mile Creek WWTP discharge. A QUAL2E model of Twelve Mile Creek from the existing
outfall to the Catawba River was constructed using the field reconnaissance data and available survey
information.
The scoping level assessment concluded that the expanded Twelve Mile Creek WWTP discharge would
not cause DO concentrations to decline downstream of the discharge. Conversely, the scoping level model
results indicated that the expanded discharge would increase DO concentrations due to increased stream
velocity and re -aeration. An increase in stream velocity also decreases sediment oxygen demand (SOD) in
the receiving stream. A presentation was made to DWQ staff on the scoping level analysis in the -fall of
2010. DWQ staff pointed out a few areas of concern where the slope of Twelve Mile Creek flattens and
velocity decreases. DWQ suggested that the County collect site -specific data in Twelve Mile Creek to
validate and recalibrate the QUAL2E model specifically to verify the areas of concern.
In response to DWQ input, Tetra Tech performed field reconnaissance of the entire downstream section of
Twelve Mile Creek in the spring of 2011. The reconnaissance identified access points, noted substantive
changes in channel characteristics, and any obstacles or debris that may affect the DO profile during warm
low flow periods. A detailed channel survey of representative sections was performed along with site -
specific water quality data. A total of 90 detailed transects were surveyed in the upper section in addition to
the 113 initial survey points over 12.5 miles of stream channel. The scoping level QUAL2E model was
recalibrated with the site -specific field data. The QUAL2 Model Update for Twelve Mile Creek (Tetra Tech)
is provided in Appendix D.
The results of the recalibrated QUAL2E model supported the scoping level model and indicated that the
expanded effluent discharge from 6 to 12 mgd would not cause further decrease in DO downstream of the
outfall. The increased discharge significantly increases downstream DO concentrations over what would be
expected without the effluent flow present in the channel. Therefore, the expanded discharge will protect
the Class C designated use in Twelve Mile Creek. The increased stream velocity and re -aeration due to the
expanded discharge also would decrease the sensitivity of the stream to bio-available nutrients.
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Environmental Assessment for
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Treatment Plant Expansion
Alternatives Analysis
SCDHEC provided input into the revised and updated QUAL2E Model in April 2012. The Water Quality and
Monitoring Section of SCDHEC made several comments with respect to the modeling parameters that
were used in the model, including temperature, estimated stream slopes, CBOD ultimate values, and high
SOD rates. All of the comments were addressed with informal correspondence between SCDHEC and
Tetra Tech; however, the response to the SOD issue required a model adjustment. Tetra Tech checked the
sensitivity of the model's SOD rates and consequently used a lower SOD ceiling, which then required a
calibration adjustment to the model. In May 2012, Tetra Tech formally documented all of the responses to
SCDHEC's comments, including the refined model adjustments. On July 6, 2012, SCDHEC issued a letter
stating that the refined model is well calibrated and better reflects the actual conditions in Twelve Mile
Creek. SCDHEC also stated that the refined model is suitable to be used in assessing compliance with
South Carolina's water quality standards, specifically the 0.1 mg/I DO Deficit Rule (SC Regulation 61-68,
Water Classifications and Standards, Section D). The refined model shows an overall improvement in
Twelve Mile Creek DO concentration during the critical months. All of the correspondence related to
comments from and responses to SCDHEC are provided in Appendix G.
3.8.2 Conclusion
An expansion of the surface water discharge to Twelve Mile Creek was selected for the positive
environmental impact to Twelve Mile Creek, less economic impact than the other evaluated project and
effluent disposal alternatives, and the most feasible technical solution. An expansion of the Twelve Mile
Creek WWTP will meet the long-term growth needs in the Twelve Mile Creek service area. The water
quality modeling results indicate that assimilative capacity is available in Twelve Mile Creek for the
increased effluent discharge and water quality will improve by providing an increase in velocity and re -
aeration.
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4. Existing Environmental Characteristics
The Twelve Mile Creek service area is located in the western part of Union County. The service area is
described in detail in Section 1.3. The project site consists of the existing parcel within which the Twelve
Mile Creek WWTP and outfall in Twelve Mile Creek are located. Construction activities associated with the
selected alternative will be confined to the project site. The facility has been in operation at its current
location since 1997. Information pertaining to the existing environment in the project site and service area is
provided in the following sections.
4.1 Topography
Union County, North Carolina is situated in the Piedmont Physiographic Province in the south-central
portion of the state. The County borders the North Carolina / South Carolina state line. The geography of
the region is the typical rolling terrain of the Piedmont Province, except for the broad flat areas between
streams and some stream valleys with steep side slopes. The northwestern portion of the service area is
located in the Charlotte Belt, and the southeastern portion of the service area is located in the Carolina
Slate Belt.
The majority of the service area is underlain by metamorphic rocks, with intrusive rocks present in the
southwestern corner and in a small area in the northwestern portion of the service area. In the portion of
the service area located in the Charlotte Belt, the metamorphic rock formations are. underlain by phyllite,
schist, and metavolcanic rock, and the intrusive rock formations are underlain by granite of the Salisbury
Plutonic Suite. In the portion of the service area located in the Carolina Slate Belt, metamorphic rocks are
underlain by the Cid formation and felsic metavolcanic rock, and the intrusive rocks consist of
metamorphosed granitic rock (United States Department of Natural Resources and Community
Development [DNRCD], 1985).
The Twelve Mile Creek service area is depicted on the Bakers, Catawba Northeast, Matthews, Midland,
Mint Hill, Monroe, Waxhaw, Weddington, and Wingate, North Carolina U.S. Geological Survey (USGS)
7.5—minute topographic quadrangle maps. Elevations range from approximately 495 feet above mean sea
level (MSL) in the southeastern portion of the service area at Lake Monroe to approximately 780 feet above
MSL in the northern portion of the service area. Elevations in the Twelve Mile Creek WWTP site range from
approximately 540 to 560 feet above MSL.
The 1 percent Annual Chance Flood information was obtained from the Federal Emergency Management
Agency (FEMA) in 2008 (Figure 4-1). According to the floodplain information, portions of the service area,
mainly floodplains associated with perennial streams, are in the 100-year flood zone. Base flood elevations
(BFEs) have not been generated for the Twelve Mile Creek service area. The existing WWTP facility is
located above the 100-year floodplain; however, portions of the property are located in the 100-year
floodplain.
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Environmental Assessment for
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Treatment Plant Expansion
Existing Environmental
Characteristics
4.2 Soils
The process of soil development depends upon both biotic and abiotic influences. These influences include
past geologic activities, nature of parent material, environmental and human influences, plant and animal
activity, time, climate, and topographic position. A soil association is defined as a landscape that has a
distinctive proportional pattern of soils consisting of one or more major soils and at least one minor soil. The
soils in an association may vary in slope,. depth, stoniness, drainage, and other characteristics (USDA
1996). The soil associations described herein are based on information obtained from the U.S. Department
of Agriculture (USDA) (USDA 1996).
The soil associations present in the service area are the Cecil-Appling, Tatum, Cid-Badin-Goldston, Badin-
Cid-Goldston-Tatum, and Goldston-Badin-Cid associations.
• The Cecil-Appling association's soils are gently to strongly sloping, well drained soils that
have a loamy surface layer and a dominantly clayey subsoil. The Cecil-Appling association's
soils are formed in material weathered from felsic crystalline rocks on uplands.
• The Tatum association's soils are gently sloping to steep, well drained soils that have a loamy
surface layer and a dominantly clayey subsoil. The Tatum association's soils are formed in
material weathered from Carolina slates on uplands.
• The Cid-Badin-Goldston association's soils are nearly level to steep, excessively drained to
somewhat poorly drained soils that have a loamy surface layer and a loamy or clayey subsoil.
The Cid-Badin-Goldston association's soils are formed in material weathered from Carolina
slates on uplands.
• The Badin-Cid-Goldston-Tatum association's soils are nearly level to steep, excessively
drained to somewhat poorly drained soils that have a loamy surface layer and a loamy or
clayey subsoil. The Badin-Cid-Goldston-Tatum association's soils are formed in material
weathered from Carolina slates on uplands.
• The Goldston-Badin-Cid association's soils are nearly level to steep, excessively drained to
somewhat poorly drained soils. The surface layer is loamy, and the subsoil may be loamy or
clayey. The Goldston-Badin-Cid association's soils are formed in material weathered from
Carolina slates on uplands.
The soils on the project site are of the Tatum and the Badin-Cid-Goldston-Tatum associations. The project
site is underlain by Badin channery silt loam, Badin channery silty clay loam, Chewacla silt loam, Goldston-
Badin complex, and Wynott gravelly loam (USDA 2011).
• Badin channery silt loam is a well drained, moderately permeable soil that formed in
residuum weathered from metavolcanic rocks and/or argillite. These soils are found on
convex upland ridges and side slopes adjacent to intermittent drainage ways. Badin soils
are fine, mixed, semiactive, thermic Typic Hapludults.
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Environmental Assessment for
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Treatment Plant Expansion
Existing Environmental
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• Badin channery silty clay loam is a well drained, moderately permeable soil that formed in
residuum weathered from metavolcanic rocks and/or argillite. These soils are found on
convex upland ridges and side slopes adjacent to intermittent drainage ways. Badin soils
are fine, mixed, semiactive, thermic Typic Hapludults.
• Chewacla silt loam is a somewhat poorly drained, moderately permeable soil that formed in
loamy alluvium derived from igneous and metamorphic rock. These soils are found on
broad flats along the major streams and on narrow flats along minor creeks and drainage
ways. These soils are frequently flooded for brief periods, particularly from November to
April. Chewacla soils are fine -loamy, mixed, active, thermic Fluvaquentic Dystrudepts.
• Goldston-Badin complex map unit represents areas of Goldston and Badin soils that are so
intricately mixed that it is not practicable to separate them at the scale used for the soil
survey. These soils are well drained to excessively drained, and permeability is moderately
rapid in the Goldston soil and moderate in the Badin soil. These soils are found on ridges in
the uplands. Goldston soils are loamy -skeletal, siliceous, semiactive, thermic, shallow Typic
Dystrudepts, and Badin soils are fine, mixed, semiactive, thermic Typic Hapludults.
• Wynott gravelly loam is well drained with slow permeability. This soil is found on uplands in
the piedmont and formed in residuum from gabbro, diorite, and other dark colored mafic
rocks. Wynott soils are fine, mixed, active, thermic Typic Hapludalfs.
4.3 Land Use
Land use in the Twelve Mile Creek service area varies from residential development to undeveloped
forestland. Approximately 4 percent of the service area consists of residential development, which ranges
from high -density (multiple -unit structures or urban cores) to low -density (houses on lots of more than an
acre) development. Approximately 0.4 percent of the service area is under the commercial and services
land use category, which includes urban central business districts, shopping centers, and commercial strip
developments. Areas used for agricultural operations comprise approximately 47 percent of the service
area and includes confined feeding operations, cropland, and pastureland use designations. Approximately
48 percent of land in the Twelve Mile Creek service area is classified as undeveloped, which includes
forested land, lakes, and reservoirs. The remaining 0.9 percent of the land in the service area is comprised
of transitional and industrial land use categories (USGS 2010). The WWTP site is zoned residential.
4.4 Wetlands
Wetlands, as defined by federal regulations [40 Code of Federal Regulations (CFR) 230.3(t)] and the N.C.
Environmental Management Commission (EMC) rules [15A NCAC 2B .0202(71)], are "...areas that are
inundated or saturated by an accumulation of surface or groundwater at a frequency and duration sufficient
to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted
for life in saturated soil conditions." The U.S. Army Corps of Engineers (USACE) requires the presence of
three parameters (hydrophytic vegetation, hydric soils, and evidence of hydrology) in support of a
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Environmental Assessment for
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Treatment Plant Expansion
Existing Environmental
Characteristics
jurisdictional wetland determination (Environmental Laboratory, 1987). The boundary between wetlands
and deepwater habitat is defined as the maximum depth where rooted emergent vegetation may be found.
Rooted emergent vegetation is generally present at depths less than six feet below mean low water during
the growing season. Riparian wetlands are those areas that border streams and other water bodies.
Wetlands are located throughout the service area and are mainly present in low floodplain areas adjacent
to streams and creeks. Figure 4-2 provides the location and types of wetlands in the Twelve Mile Creek
service area, as depicted by the National Wetland Inventory (NWI) mapping. One wetland area is depicted
by NWI on the Twelve Mile Creek WWTP site (Figure 3-2). Onsite assessments or verification of the
mapping has not been performed for the proposed project.
4.5 Prime or Unique Agricultural Lands
In North Carolina, two categories of important farmlands are recognized. These consist of prime farmland
and unique farmland. The categories are based on mapped USDA Natural Resources Conservation
Service (NRCS) soil series. The 167 square mile Twelve Mile Creek service area includes soils listed as
prime or unique farmland, some of which have been impacted by development or other soil disturbances.
The project site is underlain by Badin channery silt loam, Badin channery silty clay loam, Chewacla silt
loam, Goldston-Badin complex, and Wynott gravelly loam. Of these soils, Chewacla silt loam is a prime
farmland soil if it is drained and either is protected from flooding or is not frequently flooded during the
growing season. The portion of the site that is underlain by Chewacla silt loam does not meet these criteria •
and therefore is not a prime farmland. No unique agricultural lands are present on the project site.
4.6 Public Lands and Scenic, Recreational, and State Natural Areas
One area of land managed for conservation or open space is located in the south-central portion of the
service area: the Mineral Springs Barrens Preserve. The Preserve is owned by The Nature Conservancy
and covers approximately 41 acres. No parks or game lands owned or managed by the municipality,
county, state, or federal government are located in the Twelve Mile Creek service area. No other state or
federally owned lands are located in the Twelve Mile Creek service area.
The North Carolina Natural Heritage Program (NHP) designates significant natural heritage areas (SNHA)
if those areas contain rare or protected species, high quality examples of relatively undisturbed natural
communities, or unusual geological features (2009). SNHAs may be on public or private land and their
designation as a natural area by NHP does not confer protection. Five SNHAs are located in the service
area. The Mineral Springs Barrens site and the Waxhaw Sunflower Site are located approximately 4.2
miles east-southeast of the project site. The Mineral Springs Barrens SNHA encompasses approximately
120 acres, and the Waxhaw Sunflower Site SNHA covers approximately 35 acres. The three remaining
SNHAs are the East Fork Twelve Mile Creek Aquatic Habitat, Crooked Creek Aquatic Habitat, and Goose
Creek/Duck Creek Aquatic Habitat. The East Fork Twelve Mile Creek SNHA includes 127 acres of habitat
in Twelve Mile Creek and its tributaries across the service area and continuing in Twelve Mile Creek
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Environmental Assessment for
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Existing Environmental
Characteristics
downstream of the project site. The reach of Twelve Mile Creek that is located adjacent to the project site is
included in this SNHA. The Crooked Creek Aquatic Habitat SNHA includes a total of 117 acres in Union
County. The upstream -most portion of the SNHA along Crooked Creek is located in the service area. This
SNHA follows Crooked Creek as it flows northeastward out of the service area. The Goose Creek/Duck
Creek Aquatic Habitat SNHA includes a total of 100 acres of habitat in Union County and crosses the
northernmost portion of the service area extending to the northeast.
4.7 Areas of Archaeological or Historical Value
Pursuant to Section 106 of the National Historic Preservation Act of 1966, as amended, the State Historic
Preservation Office (SHPO) and Office of State Archaeology (OSA) files were reviewed to determine the
potential presence of historic or archaeological resources located within a one -mile radius of the project
site. Resources of interest are those in or eligible for inclusion in the National Register of Historic Places
(NRHP).
There are no historic resources of interest in a one -mile radius of the project site. Two historic districts that
are listed on the NRHP are located in the service area. The Waxhaw Historic District is located
approximately 2 miles south of the project site, and the Pleasant Grove Camp Meeting Grounds Historic
District is located approximately 4.5 miles east of the project site. Between 3.8 and 4.5 miles north of the
project site and within the service area are two historic structures that have a Determination of Eligibility for
listing on the NRHP.
Two archaeological resources are located on the Twelve Mile Creek WWTP project site (personal
communication with D. Hall, OSA, 2011). One of these two onsite resources has been assessed by OSA
and determined not to be intact. The other onsite resource is identified as 31UN218 by the OSA and has
not been studied sufficiently to determine whether it is eligible for listing on the NRHP. An additional site is
located on the adjacent property, abutting the project site to the north and along the bank of Twelve Mile
Creek (personal communication with D. Hall, OSA, 2011). The resource located on the adjacent property is
identified as 31 UN203 by OSA and has been determined to be eligible for listing on the NRHP. A summary
of personal communication with SHPO and OSA is located in Appendix E.
4.8 Air Quality
The N.C. Division of Air Quality (DAQ) monitors compliance with National Ambient Air Quality Standards
(NAAQS). The principal air quality pollutants emitted are particulates (total suspended particles [TSP] and
[PM-10j), sulfur oxides (SO„), nitrogen oxides (NO,), volatile organic compounds (VOCs), carbon monoxide
(CO), and lead (Pb). The major emission sources are fuel combustion for transportation and heating, power
generation, industrial processes, waste incineration, forest fires, open burning of yard waste particulate
matter less than 10 micrometers in diameter and construction debris, and non -industrial solvent use
PIN (EPA, 1990). Ground -level ozone (03) is created by the photochemical reaction of hydrocarbons (including
VOCs) and NO, with ultraviolet sunlight.
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Environmental Assessment for
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Treatment Plant Expansion
Existing Environmental
Characteristics
The DAQ and EPA have established ambient air quality standards for each pollutant based on hourly, daily,
quarterly, or annual averages, depending on the pollutant's physical properties, chemical dynamics, human
physiological responses, and monitoring technology. Primary air quality standards are those established for
protection of public health. For some pollutants, secondary standards are established to protect against
adverse effects on soil, water, crops, vegetation, animals, materials, climate, visibility, and personal
comfort.
A new 8-hour ambient ozone standard of 0.075 parts per million (ppm) was adopted in 2008 by DAQ, as
compared to the former standard of 0.085 ppm. DAQ has one monitoring site in Union County. The
monitoring site is reported by DAQ as having attained the 1997 8-hour ambient ozone standard of
0.085 ppm from 2007 through 2009 but having violated the 2008 standard of 0.075 ppm in these years.
North Carolina ozone levels in 2009 were found to be at the lowest levels since air quality monitoring began
in the state in the 1970's. During 2009, North Carolina only had six days when ozone levels exceeded the
2008 8-hour standard of 0.075 ppm. As of February 29, 2012, the northern half of Union County was listed
as being in the 8-hour ozone non -attainment boundary, which is based on the revised 2008 8-hour ozone
standard of 0.075 ppm (DENR 2010a).
A review of DAQ data summaries from 2006 through 2008 showed that all North Carolina counties are
attaining the national standard for particulate matter less than 10 micrometers in diameter (PM-2.5). In
addition, Union County has been designated as an attainment area for carbon monoxide and sulfur dioxide.
Starting in the late 1990s, Union County documented several complaints regarding odor from the Twelve
Mile Creek WWTP. In response to these complaints, the County initiated an odor control project in 2008.
The project went on-line in 2010. The County has not received any odor complaints after the project went
on-line.
4.9 Noise Levels
Noise is subject to the federal Noise Control Act of 1972 (PL-92-574) and Quiet Communities Act of 1978
(PL-95-6009), which require standards of compliance and recommend approaches to abatement for
stationary noise sources such as airports, highways, and industrial facilities. The service area consists of
developed and undeveloped areas that exhibit day-to-day normal noise conditions. The project site is
presently developed and operated as a WWTP and exhibits noise levels typical of this type of development.
Current noise levels in the service area and project site have not been quantified.
In 2001, Union County received noise complaints in response to the positive displacement blowers for the
aerobic digester at the WWTP site. In response, the County retrofitted the blower buildings, installing
acoustic baffles in the respective building intake louvers. No further noise issues have been documented at
the facility.
Hazen and Sawyer Project No. 30831-030
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Environmental Assessment for
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Treatment Plant Expansion
Existing Environmental
estN, Characteristics
(Az,
;sit.
Water Resources
,est` 4.10.1 Drainage Basins and Surface Water Supplies
The Twelve Mile Creek service area includes a portion of the Catawba River subbasin of the Catawba
River basin, USGS Hydrologic Unit 03050103, and a portion of the Rocky River subbasin of the Yadkin -
Pee Dee River basin, USGS Hydrologic Unit 03040105. The Catawba River basin is part of the headwaters
of the Santee -Cooper River system, which originates on the eastern slopes of the Blue Ridge Mountains,
flows through the piedmont, crosses into South Carolina, and continues on to the Atlantic Ocean (DENR
2010b). The Yadkin -Pee Dee River basin originates on the eastern slopes of the Blue Ridge Mountains.
The Yadkin River flows into the Uwharrie River to form the Pee Dee River, which flows through South
Carolina to Winyah Bay at the Atlantic Ocean. A USGS topographic map is 'provided on Figure 4-3.
ros
eRN The Twelve Mile Creek service area is located in four subbasins, USGS Hydrologic Units 03050103030,
03040105030, 03040105040, and 03040105070. Hydrologic Unit 03050103030 consists of three stream
`ink_ watersheds: the Six Mile Creek watershed, the Twelve Mile Creek watershed, and the Waxhaw Creek
watershed (USDA 1998). The Twelve Mile Creek WWTP is located in the Twelve Mile Creek watershed.
Hydrologic Unit 03040105 includes six stream watersheds that are partially located in the Twelve Mile
Creek service area. These six watersheds are Goose Creek (03040105030), Crooked Creek
(03040105070), Bearskin Creek, Lake Lee, Richardson Creek, and Flag Branch (03040105070) (USDA
r=\ 1998). The DWQ subbasins identified for the service area are 03-07-12, 03-07-14, and 03-08-38 (USDA
1998).
(vs
Figure 4-4 provides the watershed delineations for the service area. There is one surface water supply
watershed in the Twelve Mile Creek service area. The water supply I watershed is located in the
southeastern portion of the service area and comprises the Lake Lee subbasin. A portion of the water
rsit‘ supply watershed critical area (CA) is also included in the service area.
4.10.2 Surface Water Use Classifications
The DWQ classifies surface waters of the state based on their existing. or proposed uses. The primary
classification system distinguishes the following three basic usage categories: waters used for public water
supply and food processing (Classes WS-I through WS-V), water supply (WS) waters used for frequent
swimming or bathing (Class B), and waters used for neither of these purposes (Class C). Class C waters
rAN are protected for fishing, boating, aquatic life, and other uses.
fa►
The location of streams in the Twelve Mile Creek service area is shown on Figure 4-5. A summary of the
classified streams is provided in Table 4-1. All streams in the Lake Lee and Richardson Creek subbasins
are classified as either "WS-IV" or "WS-IV, CA." All other streams in the service area are classified as "C."
rat,
f
eoth' HAM AND SHYER
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Environmental Assessment for
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Treatment Plant Expansion
Existing Environmental
Characteristics
Table 4-1: Summary of Classified Streams in Twelve Mile Creek Service Area
Name
Description
Stream
Classification River Basin
Rone Branch (Rhone
Branch)
Twelve Mile Creek
From source to North Carolina -South Carolina
state line
From source to North Carolina -South Carolina
state line
East Fork Twelve Mile
Creek From source to Twelve Mile Creek
Catawba
Catawba
Catawba
Blythe Creek
From source to East Fork Twelve Mile Creek
C Catawba
McNeely Branch
Machine Branch
Bates Branch
From source to Blythe Creek
From source to East Fork Twelve Mile Creek
From source to East Fork Twelve Mile Creek
C Catawba
C Catawba
C Catawba
Lee Branch
From source to Bates Branch
C Catawba
Little Twelve Mile
Creek
From source to East Fork Twelve Mile Creek
C Catawba
Underwood Creek
Price Mill Creek
Davis Mine Creek
Molly Branch
From source to Little Twelve Mile Creek
From source to East Fork Twelve Mile Creek
From source to Price Mill Creek
C
C
C
From source to East Fork Twelve Mile Creek C
Catawba
Catawba
Catawba
Catawba
West Fork Twelve
Mile Creek
Mundys Run
Culvert Branch
Goose Creek
From source to Twelve Mile Creek
C Catawba
From source to West Fork Twelve Mile Creek
From source to West Fork Twelve Mile Creek
C Catawba
C Catawba
Stevens Creek
North Fork Crooked
Creek
South Fork Crooked
Creek
From source to Rocky River
From source to Goose Creek
From source to Crooked Creek
C
C
Yadkin
Yadkin
Yadkin
From source to Crooked Creek
Bearskin Creek
Horsepen Creek
Camp Branch
Richardson Creek
From source to Richardson Creek
From source to Bearskin Creek
From source to Bearskin Creek
From source to a point 0.2 mile downstream
of mouth of Beaverdam Creek
Beaverdam Creek
WS-IV
Yadkin
Yadkin
Yadkin
Yadkin
Yadkin
From source to Richardson Creek WS-IV Yadkin
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Environmental Assessment for
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Existing Environmental
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Table 4-1: Summary of Classified Streams in Twelve Mile Creek Service Area
Name
Adams Branch
Little Richardson
Creek (Lake Monroe)
Description
From source to Richardson Creek
From source to a point 0.6 mile upstream of
Buck Branch
Stream
Classification
WS-IV
River Basin
Yadkin
WS-IV Yadkin
Little Richardson
Creek (Lake Monroe)
Buck Branch
From a point 0.6 mile upstream of Buck Creek
to Richardson Creek
From source to a point 0.5 mile upstream of
mouth
WS-IV; CA Yadkin
. WS-IV Yadkin
Buck Branch
From a point 0.5 mile upstream of mouth to
Little Richardson Creek
WS-IV; CA Yadkin
Rays Fork
From source to Richardson Creek
C Yadkin
Flag Branch
From source to Rays Fork
C Yadkin
Middle Fork Rays Fork From source to Rays Fork
C Yadkin
4.10.3 Existing Surface Water Quality
DWQ monitors water quality using physical, chemical, and biological sampling and rates each stream
segment or lake with respect to its designated usage classification (DENR 2008a). Biological monitoring,
including benthic macroinvertebrate (benthos) and fish community sampling, is particularly useful in
tracking water quality trends because these organisms reflect Tong -term interactions among many water
• quality and habitat parameters, including factors not detected by physical and chemical sampling.
DWQ assigns use support ratings for all monitored water bodies based on the findings of the monitoring
efforts. There is one DWQ ambient water quality monitoring site, one benthos monitoring site, and one fish
community monitoring site in Twelve Mile Creek immediately upstream of the project site (DENR 2010b).
These monitoring sites are located at, or immediately downstream of, the Highway 16 Bridge over Twelve
Mile Creek, which is approximately 0.35 mile upstream of the Twelve Mile Creek WWTP effluent discharge
location. In addition, there are five fish community monitoring sites in the service area, two in South Fork
Crooked Creek and one in each of North Fork Crooked Creek, West Fork Twelve Mile Creek, and East
Fork Twelve Mile Creek. There are also three benthos sampling sites and two ambient water quality
monitoring sites located in Goose Creek (DENR 2008b).
Per section 303(d) of the Clean Water Act (CWA), if a surface water quality standard is exceeded and the
impaired waters do not have an EPA approved total maximum daily load (TMDL), then an integrated
reporting category of "5" is assigned to those waters, and the waters are incorporated into the 303(d) list.
The 303(d) list is conveyed to the EPA and incorporated into the National Water Quality Inventory Report,
which is provided to Congress every two years.
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Per the Final 2010 303(d) list, four streams in the service area are listed as impaired. North Fork Crooked
Creek is listed as impaired due to a standard violation of turbidity limits and a fair bioclassification resulting
from the ecological and biological integrity score relative to benthos. South Fork Crooked Creek is listed as
impaired due to a fair bioclassification resulting from the ecological and biological integrity score relative to
fish community and benthos sampling. Twelve Mile Creek is listed as impaired due to a standard violation
of copper and turbidity limits and a fair bioclassification resulting from the ecological and biological integrity
score relative to the fish community sampled in 2008 (DENR 2010c). The impairment of Twelve Mile Creek
extends from the confluence of the two forks of the creek to the North Carolina -South Carolina state line.
Little Richardson Creek (Lake Monroe) is listed as impaired due to a standard violation for chlorophyll a
levels based on the results of 2008 sampling efforts.
The Draft 2012 303(d1) list includes a standard violation of the lower limit of dissolved oxygen as a source of
impairment in Twelve Mile Creek DENR 20 . Additionally, North Fork Crooked Creek is shown on he
Draft 2012 303(d) list as being impaired due to a turbidity standard violation only. The previous impairment
due to benthos sampling results is not maintained from the Final 2010 list to the Draft 2012 list.
In the Catawba River subbasin (USGS Hydrologic Unit 03050103), the major water quality issues originate
from the effects of a densely populated area with large amounts of impervious surface (DENR, 2010b). In
the Twelve Mile Creek watershed, agricultural lands are being converted to populated residential lands, and
DWQ has identified the current rate of development as a likely source of impairment. DWQ indicated that
additional water quality degradation in Twelve Mile Creek may be associated with the Twelve Mile Creek
WWTP, which has a history of NPDES permit violations prior to 2006 for BOD5, fecal coliform, discharge
flow, nitrogen, phosphorus, and TSS (DENR, 2010b). The facility underwent major process and reliability
upgrades to address the treatment issues prior to 2006.
In the Rocky River subbasin (USGS Hydrologic Unit 03040105), water quality is affected by the proximity of
the subbasin to the City of Charlotte and associated development in the area. Development involves
shifting land uses from agricultural to residential and commercial uses, resulting in stream degradation.
Ambient monitoring sites in the watershed indicate that turbidity and nutrients, primarily nitrogen and
phosphorus, are notably higher in the watershed than in other parts of the river basin (DENR, 2008b).
Additional pollutants of concern in the watershed are fecal coliform bacteria, iron, and copper.
Point -source dischargers located throughout North Carolina are regulated through the NPDES program
and are required to register for a permit. There are two major NPDES dischargers in the Twelve Mile Creek
service area, the Twelve Mile Creek WWTP in the Catawba River basin and the Crooked Creek WWTP in
the Rocky River subbasin of the Yadkin River basin (DENR 2010b; DENR 2008b). The Twelve Mile Creek
WWTP currently has a permitted flow of 6 mgd into Twelve Mile Creek adjacent to the WWTP site. The
Crooked Creek WWTP currently has a permitted flow of 1.9 mgd into East Fork Stewarts Creek.
Seven streams in the service area have been designated as significant aquatic endangered species
habitat. Three of the streams are in the Goose Creek watershed and include Goose Creek, Stevens Creek,
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Environmental Assessment for
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and an unnamed tributary (UT) to Goose Creek. These streams are home to numerous rare species of
mussels, including the Carolina heelsplitter (federal and state -listed endangered [E]), Carolina creekshell
ese` (federal species of concern [FSC] and state -listed E), Atlantic pigtoe (FSC and state -listed E), creeper
(state -listed threatened [T]), and notched rainbow (state -listed SC). The four remaining streams are Davis
Branch and three UTs to Waxhaw Creek. These four streams are tributaries to Waxhaw Creek upstream of
eiRN
documented populations of Carolina darter (FSC and state -listed SC), and of Carolina heelsplitter (federal
and state -listed E). Reaches of both Goose Creek and Waxhaw Creek have been designated as critical
habitat for the Carolina heelsplitter outside the service area. Additional information regarding rare species is
discussed in Section 5.14.
No wild and scenic rivers are listed in the Twelve Mile Creek service area. No anadromous fish spawning
!ow\ areas, fish nursery areas, High Quality Waters (HQWs), or Outstanding Resource Waters (ORWs) are
listed in the Twelve Mile Creek service area.
tist
4.10.4 Groundwater Supplies
raN The principal aquifer in the Piedmont and Blue Ridge provinces of North Carolina is the crystalline rock
riN aquifer (USGS 1985). In the Piedmont province of North Carolina, aquifers are localized and consist of
complex fractured metamorphic, igneous, and sedimentary rocks from the Triassic Basin. Regolith overlies
most of the rocks and consists of soil, saprolite, alluvium, and colluvium. In Union County, groundwater is
11011 held in the regolith-fractured crystalline rock aquifer system. The fractured crystalline igneous and
?"t- ) metamorphic rock generally has low porosity and therefore little storage capacity. As a result, the majority
caw of the groundwater is located in the regolith that sits atop the bedrock and recharges the water -holding
fractures in the underlying bedrock. Variations in the geology across the county result in different rates of
infiltration and recharge.
EA\ There are several private well systems in the service area. All of the private well systems also utilize septic
for wastewater disposal.
eixN
4.11 Forest Resources
+•� Natural forested communities are scattered throughout the undeveloped and developed portions of the
Twelve Mile Creek service area. The forested areas include conifer forests, bottomland forests, and mixed
oft,
hardwood forests. The project site consists of developed land with small wooded areas (e.g. mature soft
rre\ and hardwoods) primarily located along riparian corridors.
ra- ts
4.12 Shellfish or Fish and Their Habitats
Aquatic habitats in the service area include streams, which provide free-floating, warm -water habitats, and
ponds, which also provide warm -water habitat. Several perennial streams are located in the Twelve Mile
Creek service area, including Twelve Mile Creek, East Fork Twelve Mile Creek, Blythe Creek, Machine
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Environmental Assessment for
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Treatment Plant Expansion
Existing Environmental
Characteristics
Branch, Bates Branch, Little Twelve Mile Creek, Underwood Creek, Molly Branch, Price Mill Branch, Mine
Creek, West Fork Twelve Mile Creek, Mundys Run, Culvert Branch, Goose Creek, Stevens Creek, North
Fork Crooked Creek, South Fork Crooked Creek, Bearskin Creek, Horsepen Creek, Camp Branch,
Beaverdam Creek, Richardson Creek, Adams Branch, Little Richardson Creek, Buck Branch, Flag Branch,
Middle Fork Rays Fork, and Rays Fork. Numerous perennial, intermittent, and ephemeral watercourses are
tributary to the aforementioned major streams within the service area. The streams in the service area
provide habitat for various species of fish and other aquatic organisms.
In general, the larger streams in the project area provide suitable habitat for fish such as bluehead chub
(Nocomis leptocephalus), redlip shiner (Notropis chiliticus), sandbar shiner (Notropis scepticus), gizzard
shad (Dorosoma cepedianum), Eastern mosquitofish (Gambusia holbmoki), yellow perch (Perca
flavescens), and tessellated darter (Etheostoma olmstedi). As part of the DWQ Stream Fish Community
Assessment Program, more than 875 sites across North Carolina have been assessed by the wadeable
stream fish community assessment program since 1990 (2011). An assessment of West Fork Twelve Mile
Creek and East Fork Twelve Mile Creek was performed in 2007, and an assessment of Twelve Mile Creek
was performed in 1997 and 2002. North Fork Crooked Creek and South Fork Crooked Creek were
assessed in 1995. Richardson Creek was assessed in 2001 and 2006, and Bearskin Creek was evaluated in
2006. Based on review of data collected by DWQ, no anadromous fish species have been found in these
streams. A total of nine species of fish for which construction moratoria apply were identified in the seven
assessed streams. Habitat for mussels is present in the service area and the outfall site.
4.13 Wildlife and Natural Vegetation
Terrestrial communities in the service area and treatment plant site are typical of urbanized areas in the
piedmont and are represented by three major community types, which include hardwood and mixed
hardwood forest, pine -dominated forest, and disturbed lands. General descriptions of the flora and fauna in
the aforementioned community types are provided as follows.
Hardwood and Mixed Hardwood Forest
Hardwood and mixed hardwood forest communities represent approximately 47 percent of the service
area. Mixed hardwood forests include areas that have been disturbed in the past and are in the process of
regenerating. These forests may be in the process of reverting to a hardwood forest and may contain up to
50 percent coverage by pines. Hardwood forests occur on both floodplains and uplands. The canopy is
dominated by hardwoods with some loblolly and shortleaf pine (Pinus taeda and P. echinata), particularly in
areas of past disturbance. Hardwoods in the canopy consist of a variety of oaks (Quercus rubra, Q. alba, Q.
nigra, Q. phellos), tuliptree (Liriodendron tulipifera), sweetgum (Liquidambar styraciflua), red maple (Acer
rubrum), American beech (Fagus grandifolia), green and American ash (Fraxinus pennsylvanica and F.
americana), and mockernut and pignut hickories (Carya alba and C. glabra). These canopy trees are also
present in the subcanopy. The understory and herbaceous layers are populated with privet (Ligustrum
sinense), dogwood (Comus flbrida), black cherry (Prunus serotina), American holly (Ilex opaca), Virginia
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Environmental Assessment for
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Treatment Plant Expansion
Existing Environmental
eft Characteristics
creeper (Parthenocissus quinquefolia), Japanese honeysuckle (Lonicera japonica), poison ivy
(Toxicodendron radicans), Christmas fern (Polystichum acrostichoides), running cedar (Lycopodium
flabelliforme), and ebony spleenwort (Asplenium platyneuron).
Wildlife in hardwood and mixed hardwood forests may be more diverse in woods that are less disturbed
and that have greater stratification. The spotted (Ambystoma maculatum), white -spotted slimy (Plethodon
es4, cylindraceus), and marbled (Ambystoma opacum) salamanders may be found in the service area. The five-
" lined skink (Eumeces fasciatus) and eastern worm snake (Carphophis amoenus amoenus) are found in
hardwood forests. The multi -strata structure of mixed hardwood and bottomland hardwood forests typically
support high densities and diversities of neotropical migrant birds such as wood thrush (Hylocichla
mustelina), ovenbird (Seiurus aurocapillus), Swainson's warbler (Limnothlypis swainsonii), worm -eating
warbler (Helmitheros vermivora), prothonotary warbler (Protonotaria citrea), hooded warbler (Wilsonia
citrina), and white -breasted nuthatch (Sitta carolinensis). Mammals such as the white -tail deer (Odocolleus
(AN virginianus), raccoon (Procyon lotor), eastern cottontail (Sylvilagus floridanus), gray squirrel (Sciurus
carolinensis), and white-footed mouse (Peromyscus leucopus) are likely to be found in the forests of the
service area.
tolo
Pine -dominated Forest
Pine -dominated forests in the Piedmont are not a persistent natural community. They occur on both
floodplains and uplands where pines have been planted or where an abandoned field adjacent to mature
pines is undergoing natural succession. In the absence of frequent fires or timber management, most such
est. areas will ultimately revert to hardwood forest. The canopy of these forests is dominated by loblolly or
shortleaf pine and may include scattered hardwood species that are typical of the hardwood or mixed
hardwood forests. The subcanopy typically includes younger individuals of the canopy species, if present.
These subcanopy trees will dominate the canopy as forest succession occurs. The understory and
herbaceous layers are typically populated with privet, dogwood, black cherry, American holly, Virginia
rat\-- creeper, Japanese honeysuckle, poison ivy, running cedar, and ebony spleenwort.
Pine forests in the Piedmont tend to support a relatively sparse animal community because of their lower
plant species diversity, compared with hardwood forest. Characteristic amphibians and reptiles are Fowler's
toad (Bufo woodhousei), eastern box turtle (Terrapene carolina), rough green snake (Opheodrys aestiva),
fence lizard (Sceloporus undulates), six -lined racerunner (Cnemidophorus sexlineatus), five -lined skink,
black rat snake (Elaphe obsoleta), kingsnakes (Lampropeltis spp.), and black racer (Coluber constrictor).
Birds of pine forests include sharp -shinned hawk (Accipiter striatus), downy woodpecker (Picoides
pubescens), yellow -bellied sapsucker (Sphyrapicus varius), pine warbler (Dendroica pinus), yellow-rumped
warbler (Dendroica coronata), white -breasted nuthatch, and several finch and sparrow species (Fringillidae
spp.). Pine forest mammals include opossum (Didelphis virginiana), raccoon, gray squirrel, woodland vole
(Microtus pinetorum), white-footed mouse, and red fox (Vulpes vulpes).
swieN
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Disturbed Land
Disturbed lands are present in portions of the service area. Disturbed land includes residential areas with
maintained grass lawns and sporadically planted hardwood trees and shrubs, industrial buildings with wide-
open cultivated grass lawns, and various rights -of -way or disturbed lands. Trees and shrubs in developed
areas include many non-native species. Common woody species include silver maple (Acer saccharinum),
Bradford pear (Pyrus calleryana), sawtooth oak (Quercus acutissima), willow oak (Q. phellos), pecan
(Carya illinoinensis), hybrid azaleas (Rhododendron spp.), privet, Russian olive (Elaeagnus angustifolia),
and crepe myrtle (Lagerstroemia indica).
Cats, dogs, and introduced species are abundant in these areas, reducing habitat suitability for native
species. Reptile and amphibian species are limited to a few small, secretive species such as the rough
earth snake (Virginia striatula), northern brown snake (Storeria dekayi), and ground skink (Scincella
lateralis). Predominant birds include the introduced house sparrow (Passer domesticus), starling (Stumus
vulgaris), and pigeon (Columba livia); and the native cardinal (Cardinalis cardinalis), robin (Turdus
migratorius), white -throated sparrow (Zonotrichia albicollis), blue jay (Cyanocritta cristata), Carolina wren
(Thryothorus ludovicianus), mourning dove (Zenaida macroura), and mockingbird (Mimus polyglottos).
Typical mammals of these areas are gray squirrel, house mouse (Mus musculus), Norway rat (Rattus
norvegicus), raccoon, opossum, and big brown bat (Eptesicus fuscus).
4.13.1 Rare and Protected Species or Habitats
Some populations of fauna and flora have been, or are, in the process of decline due to either natural
forces or their inability to coexist with humans. Federal law, under the provisions of Section 7 of the
Endangered Species Act (ESA) of 1973, as amended, requires that any action likely to adversely affect a
federally protected species be subject to review by the U.S. Fish and Wildlife Service (USFWS). Other
species may receive additional protection under separate state laws.
The service area encompasses a portion of Union County. As of September 22, 2010, the USFWS
identified three species as federally endangered and one species as a federal Candidate (C) species in
Union County. The USFWS also identified ten species as FSC, two of which are listed as
probable/potential and one of which is listed as a historic record. The NHP list as of February 13, 2012
included these federally listed species and identified 31 additional species receiving protection under state
laws. Each protected species is provided in Table 4-2 with the state and federal status of the species
provided by NHP and USFWS, respectively.
A review of NHP data available via the Natural Heritage Virtual Workroom and from natural heritage
elements shape files revealed that there are no element occurrences of federal or state endangered species
at the project site. However, 45 element occurrences are in the service area. The nearest known population
of a protected species to the project site is a population of Carolina creekshell that is approximately 2.3 miles
southeast of the WWTP site. There are six populations of Carolina darter, one population of notched
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Environmental Assessment for
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rainbow, three populations of Carolina creekshell, two populations of thick -pod white wild indigo, one
population of dwarf aster, four populations of smooth sunflower, sixteen populations of Schweinitz's
sunflower, two populations of prairie birdsfoot-trefoil, one population of Heller's rabbit -tobacco, and nine
populations of Georgia aster that have been documented in the service area.
Table 4-2: State and Federal Protected Species for Union County, North Carolina
Scientific Name
Common Name
State
Status
Federal
Status
Vertebrates
Ambystoma talpoideum
Anguilla rostrata
Crotalus horridus
Etheostoma collis collis
Lanius ludovicianus
Masticophis flagellum
Moxostoma robustum
Invertebrates
Choroterpes basalis
Fusconaia mason
Gomphus abbreviatus
Gomphus septima
Lampsilis cariosa
Lampsilis radiata
Lasmigona decorata
Strophitus undulatus
Toxolasma pullus
Villosa constricta
Villosa delumbis
Villosa vaughaniana
Vascular Plants
Baptisia alba
Boechera missouriensis
Buchnera americana
Callitriche terrestris
Cardamine dissecta
Carex impressinervia
Coelorachis cylindrica
Dichanthelium aciculare ssp. neuranthum
Eurybia mirabilis
Gillenia stipulata
Mole salamander
American eel
Timber rattlesnake
Carolina darter
Loggerhead shrike
Coachwhip
Robust redhorse
A mayfly
Atlantic pigtoe
Spine -crowned clubtail
Septima's clubtail
Yellow Iampmussel
Eastern Iampmussel
Carolina heelsplitter
Creeper
Savannah lilliput
Notched rainbow
Eastern creekshell
Carolina creekshell
Thick -pod white wild indigo
Missouri rockcress
American bluehearts
Terrestrial water-starwort
Dissected toothwort
Ravine sedge
Carolina jointgrass
Nerved witch grass
Dwarf aster
Indian physic
SC
SC1
SC
SC
SR 1
E2
SR
E
SR 1
SR
T
E
T
E
SC
SR
E
T
SC-V
E
SR-0
SC-V
SR-T
SC-H 2
SC-V
SR-T
T
FSC
FSC
FSC
FSC 3
E
FSC
FSC
FSC
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Environmental Assessment for
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Table 4-2: State and Federal Protected Species for Union County, North Carolina
Scientific Name
Helianthus laevigatus
Helianthus schweinitzii
Hymenocallis coronaria
Ilex longipes
Isoetes virginica
isolepis carinata
Lotus unifoliolatus var. helleri *
Paspalum dissectum
Primula meadia
Pseudognaphalium helleri
Rhus michauxii
Solidago rigida var. glabrata
Symphyotrichum georgianum
Symphyotrichum Iaeve var. concinnum
Nonvascular Plants
Orthotrichum exiguum
Common Name
Smooth sunflower
Schweinitz's sunflower
Shoals spiderlily
Georgia holly
Virginia quillwort
Keeled beakrush
Prairie birdsfoot-trefoil
Mudbank crown grass
Shooting -star
Heller's rabbit -tobacco
Michaux's sumac
Southeastern bold
goldenrod
Georgia aster
Narrow -leaf aster
State Federal
Status Status
SC-V
E E
FSC 3
SR-P
SR-L 2 FSC 4
SR-P
SC-V FSC
E2
T
SR-P
E2 E
SR-P 1
T C
T
Small wood -bark moss SR-0 2
Note:
* - Species is listed as Acmisoon helleri by NHP. Acmisoon helleri is a recognized synonym of the name used by USFWS.
Kev to State Status:
E — Endangered: "Any species or higher taxon of plant whose continued existence as a viable component of the State's flora is
determined to be in jeopardy" (NCGS 198 106:202.12).
T — Threatened: "Any resident species of plant which is likely to become an endangered species within the foreseeable future
throughout all or a significant portion of its range" (NCGS 19B 106:202.12).
SC — Special Concern: Any species of plant in North Carolina which requires monitoring but which may be collected and sold under
regulations adopted under the provisions of the Plant Protection and Conservation Act (NCGS 19B 106:202.12).
SR — Significantly Rare (only an NHP designation): Species which are very rare in North Carolina, generally with 1-20 populations in the
state, generally substantially reduced in numbers by habitat destruction. These species are generally more common
somewhere else in their ranges.
-H — Historical: Any species or higher taxon of plant that occurred in North Carolina at one time, but for which all known populations are
currently considered to be either historical or extirpated.
-L — Limited: The range of the species is limited to North Carolina and adjacent states (endemic or near endemic). These are species
which may have 20-50 populations in North Carolina, but fewer than 100 populations rangewide. The preponderance of
their distribution is in North Carolina and their fate depends largely on conservation here.
-O — Other: The range of the species is sporadic or cannot be described by the other Significantly Rare categories.
-P — Peripheral: The species is at the periphery of its range in North Carolina. These species are generally more common somewhere
else in their ranges, occurring in North Carolina peripherally to their main ranges, mostly in habitats which are unusual in
North Carolina.
-T — Throughout: These species are ram throughout their ranges (fewer than 100 populations total).
-V — Vulnerable: Any species or higher taxon of plant which is likely to become a threatened species within the foreseeable future.
' — Obscure: The date the species was last observed in the county is uncertain.
2 — Historic: The species is either extirpated or there have not been any recent surveys to verify its continued existence.
Kev to Federal Status:
E — Endangered. A taxon "in danger of extinction throughout all or a signircant portion of its range."
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Table 4-2: State and Federal Protected Species for Union County, North Carolina
State Federal
Scientific Name Common Name Status Status
FSC — Federal species of concern. A species under consideration for listing, for which there is insufficient information to support listing.
C — Candidate. A taxon under consideration for official listing for which there is sufficient information to support listing.
3 — Probable/Potential: The species is considered likely to occur in this county based on the proximity of known records (in adjacent
counties), the presence of potentially suitable habitat, or both.
`— Historic: The species was last observed in the county more than 50 years ago.
4.13.1.1 Vertebrates
Mole salamander (Ambystoma talpoideum)
The mole salamander is a small salamander that grows to approximately 4 inches in length and has a large
head. The mole salamander is usually gray or dark brown in color with darker mottling and a gray
underside. The mole salamander is nocturnal and prefers moist habitats comprised of vegetative debris
near a permanent body of water. Mole salamanders breed during the winter and lay eggs in the spring
during heavy rains.
American eel (Anguilla rostrata)
The American eel has an elongated, snakelike body with a small, pointed head. The American eel has no
pelvic fins, but has one long dorsal fin that extends more than half of the body. The dorsal fin is continuous
with the caudal and anal fin. Coloration varies with age and ranges from yellow to olive -brown during the
adult form. The adult males are dark brown and gray dorsally, with a silver to white ventral side. Adults
reach lengths up to 5 feet (Page & Burr 1991). The American eel is a catadromous species that spawn in
the Atlantic Ocean and ascends stream and rivers in North and South America. The American eel is found
in the Atlantic Ocean, Great Lakes, Mississippi River, the Gulf Basin, and south to South America.
American eel lives in freshwater as an adult, usually in larger rivers or lakes, primarily swimming near the
bottom in search of food. American eel hunts mainly at night and resides in crevices or other shelter to
avoid Tight during the day, and often buries in substrate consisting of mud, sand, or gravel (Landau 1992).
Timber rattlesnake (Crotalus horridus)
The timber rattlesnake measures 36 to 72 inches at maturity. Dorsal ground color of individuals in
southeastern Virginia and most of the Carolinas is typically brown, gray, or pinkish with a reddish or brown
middorsal stripe. The rattlesnake's favorite habitats include rocky hillsides, fields along forests, river valleys
and swamps, low pinewoods, and pocosin. Stump holes and surface cover are common hiding places. The
timber rattlesnake may be active day or night.
Carolina darter (Etheostoma corns collis)
The Carolina darter is a small fish that grows to only 2% inches in length and is endemic to the Piedmont of
Virginia and the Carolinas. It is typically found in pools and very slow runs of small upland creeks and
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rivulets. Habitats are often against the banks or in backwater areas over beds of sand, mud, or rubble
substrate covered by silt or detritus. It forages on microcrustaceans and small insect larvae. Spawning
occurs in early spring and peaks at the end of March. The fish inhabits small streams from the Roanoke
River basin in Virginia to the Santee River system in South Carolina.
Loggerhead shrike (Lanius ludovicianus)
The loggerhead shrike is a 7-inch-long bird with a heavy hooked beak, black mask, and flat head. These
birds of prey catch small rodents, insects, and other birds and often impale their catch on thorns or barbed
wire. The loggerhead shrike is found across the state. Heavily vegetated hedgerows are utilized as nesting
habitat, and foraging is conducted in nearby open fields.
Coachwhip (Masticophis flagellum)
The coachwhip is a long, slim diurnal snake that ranges from 4 to 5 feet in length. The coachwhip is a non-
venomous colubrid snake. The coloration of the coachwhip varies substantially, but most reflect a proper
camouflage for their natural habitat. The coloration of the coachwhip can also vary from head to tail with the
head and the upper half of the body being charcoal black and the lower half of the body transitioning from
black to tan with tan scales outlined in black. The coachwhip is typically found in open grasslands but is
also found in lightly forested areas. Coachwhips actively hunt and eat lizards, rodents, and small birds.
Robust redhorse (Moxostoma robustum)
The robust redhorse is a 10- to 19-inch long fish, weighing up to 10 pounds with a stout body and thick lips.
The caudal and dorsal fins are red or slate -colored, and other fins are cream or yellow to red. Preferred
habitat for this fish is medium to large creeks and rivers, usually in deep and fast water, over gravel, rock,
and boulders. Clean, silt -free, gravel beds in shallow waters are required for breeding, which occurs during
May. The name Moxostoma robustum has been misapplied in the past to the smallfin redhorse, which is
now identified as the brassy jumprock in the genus Scartomyzon. Small populations (one or two fishes) of
the true robust redhorse have been found in the Pee Dee River in North Carolina and the Savannah River
downstream of Augusta, Georgia. A large population, and potentially the only breeding population, of the
robust redhorse is found in the Oconee River south of Milledgeville, Georgia.
4.13.1.2 Invertebrates
A mayfly (Choroterpes basalis)
Adults of this species are distinguishable by the distinct costal projection located near the midpoint of the
hind wing (Bright 2003). Mature nymphs have gills on body segment Ab1 that are structured differently than
the gills on succeeding segments. The Ab1 gills may be forked or unforked linear lamellae, and those on
succeeding segments terminate in three filaments with the middle one being the longest and broadest
filament. In Union County, this mayfly is known to occur in Lanes Creek and an unnamed tributary to
Laurens Creek (NHP 2011).
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eirN
Atlantic pigtoe (Fusconaia masoni)
ems
rlirN The Atlantic pigtoe is a freshwater mussel, and the adults are essentially sessile. Some passive movement
downstream may occur. The Atlantic pigtoe inhabits relatively fast waters with high quality riverine/large
`' creek habitat. The Atlantic pigtoe is typically found in headwater or rural watersheds in sand or gravel
substrates below riffles.
elitN
/
Spine -crowned clubtail (Gomphus abbreviatus)
Clubtails are dragonflies that have an enlarged tip on the end of their abdomens, giving them a club -like
ems
appearance. Adult spine -crowned clubtails are stocky, 1.3 to 1.5 inches long, and have a yellow face. They
ems
have black legs and gray -blue to green eyes'that are separated dorsally. Males have a dark -brown thorax
efibs with thick, yellow, dorsal stripes forming a broken "U." Their sides are yellowish -gray with two narrow, black
stripes. Male spine -crowned clubtails have a black abdomen with yellow appearing on segments one
through seven and yellow lateral spots on segments eight and nine. Females are similar in appearance, but
have a less developed club, more yellow on their abdominal sides, and a dorsal spot on segment ten. The
spine -crowned clubtail inhabits clean, medium to large streams and rivers with sandy or rocky substrates
containing muck deposits.
Arks
Septima's clubtail (Gomphus septima)
Septima's clubtail is a large species of dragonfly with a moderate club. The thorax of Septima's clubtail has
wide yellow stripes, and the anterior lateral thoracic stripe is usually incomplete. The dorsal abdomen has a
series of yellow streaks, and the dorsal surface of the club is usually black, with the exception of a very
small yellow basal spot that may or may not be present. Septima's clubtail inhabits rivers with rocky
substrates.
Yellow lampmussel (Lampsilis cariosa)
ems
The yellow lampmussel is a bright yellow, medium-sized freshwater mussel with an inflated shell and
smooth periostracum with rays that are restricted to the posterior slope, if present. The shell of the yellow
eyes lampmussel is heavy with well -developed dentition. The adults of the yellow lampmussel are essentially
ems sessile, although some passive movement downstream may occur. The yellow lampmussel is typically
found in medium to large streams and rivers in areas underlain by sand, silt, cobble, and gravel and in
areas with good current.
eats
Eastern lampmussel (Lampsilis radiata)
The eastern lampmussel is an approximately 4-inch freshwater mussel with a slightly roughened, wrinkled
,a\ shell with numerous dark green rays and a periostracum that is yellowish to brownish green. The umbos of
the eastern lampmussel extend above the hinge line, and the shell is sub -ovate elliptical with an evenly
rounded margin. The eastern lampmussel has two pseudocardinal teeth in the right and left valves. The
eigiN eastern lampmussel is found in most creeks, rivers, and lakes with a wide range of flow and substrates, but
prefers coarse sand and gravel substrates.
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Carolina heelsplitter (Lasmigona decorate)
The Carolina heelsplitter is a relatively large, freshwater mussel endemic to several river drainages in North
and South Carolina. The shells are ovate to trapezoidal in shape, up to 4% inches in length and 1 % inches
in width. The outer surface is greenish brown to dark brown with faint darker rays. The interior nacre is
pearly to bluish white, grading to orange or orange mottled in the area of the umbo. The species is reported
to inhabit small to large streams and rivers. They are usually found near stable, well -shaded stream banks
in muddy sand, muddy gravel, or mixed sand and gravel. The current range is a very fragmented, relict
distribution within the known historic range. Historically, the range included the Catawba and Pee Dee
systems in North Carolina, and the Pee Dee, Savannah and possibly the Saluda River systems in South
Carolina. Only four small populations are currently known to exist: two in Union County, North Carolina and
two in South Carolina.
Creeper (Strophitus undulatus)
The creeper is freshwater mussel that can reach approximately 4 inches in length in North Carolina. The
shell of the creeper is elliptical and moderately compressed. The shell is thin when the creeper is young
and thickens and becomes somewhat inflated as the creeper matures. The periostracum is generally
smooth and shiny. The creeper ranges in color from yellowish to dark brown. Green rays may extend over
the entire surface of the shell. The creeper has been found throughout its range from headwater streams to
large rivers and lakes to a depth of 13 feet.
Savannah lilliput (Toxolasma pullus)
The savannah lilliput is a small freshwater mussel with an oval or elliptical shell and a double posterior
ridge. The ridge is usually angular but may be broadly rounded. Females have a broader, more truncated
posterior end than males of the species. The outer surface of the shell is usually blackish but may be
brownish, greenish, or olive with very fine, obscure green rays. The inner surface of the shell is bluish white
with pink to purplish iridescence at the posterior end. This mussel has been recorded from the Neuse River
in North Carolina south to the Altamaha River in Georgia. The savannah lilliput is found in shallow water
along the banks of rivers, streams, ponds, and lakes. The savannah lilliput moves up and down the banks
as the water levels fluctuate.
Notched rainbow (Villosa constricta)
The notched rainbow is a small freshwater mussel that is short and has a sub -elliptically shaped shell. The
female notched rainbow's shell has a posterior point slightly more than midway up from the base with a
small swelling along the outline. The male notched rainbow's shell is usually subrhomboid with the posterior
point generally Tess than midway up from the base. The outer shell of this mussel is yellowish -green or
green with indistinct rays, and the inner shell is bluish and may be purplish in the center. The shell of the
notched rainbow is sometimes thicker in the front. The notched rainbow is found in riffles, runs and pools of
very clean streams and large rivers with a sand or sand and gravel substrate.
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eta
Eastern creekshell (Villosa delumbis)
The eastern creekshell is a freshwater mussel with a yellow to dark golden brown periostracum and broken
green rays (NCWRC 2011). The posterior -ventral margin of the female shell becomes expanded with age,
while the ventral margin of the male remains straight. Two pseudocardinal teeth are present in each valve;
however, the posterior tooth in the left valve and the anterior tooth in the right valve may be vestigial. The
rA) lateral teeth are straight and well developed. The outer margin of the marsupium is black in this species.
The eastern creekshell is distributed from the Altamaha River Basin in Georgia, north to the Cape Fear
riaN
River Basin in North Carolina.
rot) Carolina creekshell (Villosa vaughaniana)
The Carolina creekshell is a freshwater mussel for which the shell morphology can be used to determine
gender. The male shell is elliptical and approximately 2.4 inches in length, and the female shell is ovate and
✓ approximately 2.2 inches in length. Male Carolina creekshells have a gently curved ventral margin, and the
female has a distinct posterior basal swelling and a straight ventral margin. The outer shell of the Carolina
creekshell is moderately shiny and greenish yellow to dark brownish yellow with numerous continuous
green rays. The inner surface of the shell of the Carolina creekshell is shiny iridescent white or bluish white.
The anterior margin of the shell is rounded in both sexes, and the posterior end is pointed about two-thirds
of the way from the ventral margin. The Carolina creekshell is endemic to North and South Carolina, is
found in mud or sand near stream banks, and is occasionally found in gravelly sand in the main channel of
riz\ streams and medium rivers.
4.13.1.3 Vascular Plants
Thick pod white wild indigo (Baptisia alba)
esitN
Thick -pod white wild indigo is a shrubby, drought -tolerant perennial with a deep taproot (North Creek
Nurseries 2011). Spikes of creamy white flowers bloom from May through July. The plant grows to a height
of two to six feet and is in the pea family. The leaves are trifoliate, gray -green, and arranged alternately on
upright stems. This species prefers to grow in a sunny location with rich, well drained soil, but it will thrive in
fiEN
soil that ranges from moist to dry.
Missouri rockcress (Boechera missouriensis)
'"t The Missouri rockcress is a tap -rooted biennial herb. It has a compact rosette of basal leaves; the lowest
leaves of the rosette are spatulate with dentate margins, and the remaining leaves are lyrate and
pubescent (NYSDEC 2011). A single stalk grows out of the rosette to a height of six to twelve inches and
bears flowers and leaves. The flowers appear in May to July and have four small, white petals and sepals
that are approximately half the length of the petals. Fruits are slender, elongated, and spreading or
fiaN divergent from the stem. In North Carolina, the Missouri rockcress inhabits thin soils around basic rock
outcrops.
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American bluehearts (Buchnera americana)
American bluehearts is an herbaceous plant that inhabits prairies and limestone glades. The stems have
streaks of purple and are up to two feet tall, erect, and scabrous. Leaves have few coarsely serrate teeth
and are opposite, sessile, and lanceolate. Three conspicuous main veins arise from the base of the leaf
blade. The purple flowers are borne on a terminal inflorescence from June to September and are
subtended by three scalelike bracts.
Terrestrial water-starwort (Callitriche terrestris)
The terrestrial water-starwort is a monoecious, annual plant that consists of sprawling stems with pairs of
opposite leaves. The two-inch long stems are whitish green and occasionally branch. The leaves are
medium green, ovate -oblong or obovate-oblong, and smooth along their margins. The flowers are very
small and greenish. Male flowers produce a single stamen, and female flowers produce a single pistil with a
pair of styles. Flowering may occur from late spring to mid -summer, lasting one to two months. The plant
also reproduces vegetatively by forming rootlets at the axils of the leaves. The terrestrial water-starwort
prefers light shade, moist to dry-mesic conditions, and barren soil that is devoid of competing ground
vegetation.
Dissected toothwort (Cardamine dissecta)
Dissected toothwort is a rhizomatous, perennial herb that grows to a height of approximately 16 inches.
The plant has a highly incised leaf with a glabrous rachis. There are two leaves on the stem in addition to a
cluster of basal leaves. Flowers are white or pink with four regular parts. Flowering occurs in March and
April, and fruits appear from April into early May. The plant inhabits rich to disturbed woods and wooded
stream terraces.
Ravine sedge (Carex impressinervia)
Ravine sedge is a perennial graminoid that grows in very dense tufts. The'stem is yellow -brown at the
base. Leaf blades are green and range from smooth to scaberulous. Fruits are borne in inflorescences,
forming a terminal and few lateral spikes. Fruiting occurs in spring. The ravine sedge inhabit mesic
deciduous forests, usually on gentle slopes above small streams in ravines and in shallow loams and
sandy loams over clays (FNA 2003). Fifteen populations of the plant are known from Alabama, Mississippi,
South Carolina, and North Carolina.
Carolina lointgrass (Coelorachis cylindrica)
Carolina jointgrass is a perennial plant with narrow, flat leaves and cylindric jointed spikes (Britton and
Brown 1913). Spikelets occur in pairs at each node of the hollow rachis, one sessile and perfect and the
other with a pedicel. The perfect spikelet has four scales that cover, along with the pedicel of the sterile
spikelet, the excavation in the rachis. The leaf sheaths are narrow, round, and not keeled in this species of
jointgrass. The species can also be distinguished from others by its creeping rootstock. Carolina jointgrass
grows in sandy soil at low elevations.
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Nerved witch grass (Dichanthelium aciculare ssp. neuranthum)
Nerved witch grass is a perennial graminoid that is tufted in clumps (FNJP 2011). The species produces a
grassy rosette with a vernal panicle in June and an autumnal panicle from August to September. Spikelets
mature within a month following anthesis. The grass inhabits sandy soils in xeric, open old fields or upland
oak woodlands.
Dwarf aster (Eurvbia mirabills)
Dwarf aster is a perennial plant with coarse, short, woody rhizomes (Nesom 2006). Stems are erect and
exerN
simple with stiff hairs that are proximally sparse and distally dense. The dwarf aster has dense hairs on
both surfaces of the basal and cauline leaves. Flowers are borne in three to ten loose, flat-topped,
corymbiform arrays. Ray flowers are white to lavender, and disc flowers are pale yellow with a purplish
ext tinge on the lobes. The dwarf aster inhabits deciduous or mixed deciduous woods on slopes or alluvial
plains, usually on basic or circumneutral soils.
'' Indian physic (Gillenia stipulata)
cztN
Indian physic is a small shrub with exposed semi -woody branches and deeply serrated leaves. The lower •
leaves are larger and are divided into palmately arranged leaflets. Flowers appear between May and July.
Blooms are composed of five slender white petals that are loosely arranged and typically appear slightly
twisted and limp as if wilted. Indian physic is distinguishable by the stipules at the base of the leaves that
persist throughout the life of the plant. The species is endemic to dry open woods underlain by acidic soils.
Smooth sunflower (Helianthus laevigatus)
�` Smooth sunflower is a perennial wildflower with erect, usually glabrous stems (FNA 2006). This sunflower's
leaves are glabrous underneath, cauline, and sessile or subsessile with grayish or bluish green coloration
(FNA 2006). The yellow flowers are borne in one to six cylindric involucres in late summer to fall. The
smooth sunflower is found in woodlands and along road embankments (Radford et al. 1968).
Schweinitz's sunflower (Helianthus schweinitzii)
Schweinitz's sunflower is a perennial aster arising from a cluster of carrot -like tuberous roots. Plants at
maturity may stand as tall as 10 feet and support 100 or more two-inch wide flowers. The yellow ray and
ottN disc flowers appear from late August through October. Leaves are opposite on the lower stem changing to
alternate above, narrow, and pubescent on both surfaces, which is a distinctive, diagnostic feature. The
upper leaf surface is scabrous. Schweinitz's sunflower occurred historically in Piedmont prairies in the
Charlotte geologic belt of North and South Carolina. Only 90 populations are presently known, and all occur
within 60 miles of Charlotte, North Carolina. Currently, most populations occur in dry, open, artificial
habitats, such as roadsides, utility rights -of -way, and edges of pastures (Weakley 1993). Schweinitz's
pier
sunflower is known to grow on Enon, Iredell, and Mecklenburg soils.
to,
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tArt
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Shoals spiderlily (Hymenocallis coronaria)
Shoals spiderlily is an aquatic, perennial flowering plant (LWF 2011). It grows to a height of up to three feet
from a bulb that lodges between rocks in the shoals. This spiderlily blooms from early May to late June, and
each flower blooms for one day. The shoals spiderlily requires swift, shallow water current and direct
sunlight to flourish.
Georgia holly (Ilex longipes)
Georgia holly is a deciduous species of holly that reaches a mature height of 10 to 20 feet (Radford et al.
1968). Flowers bloom from April to May. The fruits are bright red drupes that mature in September or
October and persist through winter. The leaves are dull and densely to remotely pubescent on the
underside, at a minimum along the midrib. Georgia holly inhabits upland woods and thickets.
Virginia quillwort (lsoetes virginica)
Virginia quillwort is a grass -like pteridophyte. Leaves have four longitudinal air chambers and irregular
transverse chambers, giving a segmented appearance. The base of each leaf has a large cavity with a
solitary sporangium containing numerous female megaspores (in the oldest, outermost leaves) or male
microspores (in the younger, middle leaves). Species of Isoetes are distinguished by the pattern of ridges,
tubercles, and reticulations on the megaspores (Cobb 1963; Radford et al. 1968). Virginia quillwort is found
in upland depressional swamp forests over clayey soils in North and South Carolina and Virginia.
Keeled beakrush (Isolepis carinata)
Keeled beakrush is an annual grass that reaches a mature height of up to ten inches. The sheaths of the
leaves of the plant are green to straw-colored or brown, and the distal blade is much longer than the
sheath. The inflorescences contain one to ten small spikelets with scales that are pale yellow to pale
orange in color and greenish midribs that are keeled. Fruits appear in spring. The keeled beakrush
inhabits wet, often drying, freshwater places in cultivated fields, lawns, waste places, open woods, rock
barrens, and grasslands.
Prairie birdsfoot-trefoil (Lotus unifoliolatus var. helleri)
The prairie birdsfoot-trefoil is a variety of American birdsfoot-trefoil. Prairie birdsfoot-trefoil is an annual forb
that grows from 8 to 32 inches in height and has alternate, nearly sessile, trifoliolate leaves. The leaflets are
lanceolate or ovate -lanceolate and 0.4 to one inch long. Branches and stems are glabrous to moderately
villous. Prairie birdsfoot-trefoil flowers from June through August and has one to two flowers on stalks in the
upper leaf axils. Flower color may be white, yellow, red, rose, or purple. Habitat for the prairie birdsfoot-
trefoil consists of dry woodlands, prairie plains, rocky hillsides, stream valleys, roadsides, and open or
cleared areas.
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eolt
Mudbank crown grass (Paspalum dissectum)
r Mudbank crown grass is a rhizomatous perennial plant (Allen and Hall 2002). Leaf blades are narrow, flat,
and up to 5 inches long. The plant has terminal panicles with two to six racemosely arranged branches that
are no more than 2 inches long. The culms, or flowering stems, range from four to twenty inches in length
and are decumbent. Mudbank crown grass grows at the edges of lakes, ponds, rice fields, and wet
✓ roadside ditches.
eime
Shooting -star (Primula meadia)
r
Shooting -star is a perennial flowering plant characterized by a basal rosette of large leaves. The flowers
bloom between April and June in umbellate clusters at the end of a single, 12-inch tall stem. The nodding
flowers range from purple to white with yellow and maroon spotting at the base. The shooting -star grows in
eft) prairies, meadows, hillsides, open woods, and rock outcrops.
est' plant are greenish and glandular-villous. Leaf blades are mostly oblong -lanceolate with flat margins.
Involucres are cylindric or campanulate, and bracts are white and imbricate. Flower heads are in narrow
r- panicles or corymbs. The discoid, perfect flowers are whitish to pinkish in color and are very small.
Flowering occurs in September and October, uncommonly extending into November. Heller's rabbit -
tobacco inhabits dry woods and openings over clay and sandy clay soils.
Michaux's sumac (Rhus michauxi(
Michaux's sumac is a densely pubescent, dioecious, rhizomatous shrub. It has a low stature, growing up to
r 2 feet high. The leaves are compound with 7 to 13, serrately edged, hairy leaflets on a hairy rachis. Male or
female flowers are found in the dense terminal panicles typical of the genus. Flowers bloom in June, and
seed heads are visible from August to September. Due to habitat fragmentation, colonies of this dioecious
plant, when they occur, often are only one large clone representing a single sex. Unfortunately, this quality is
r a serious limitation to the reproduction and repopulation of this species. Michaux's sumac grows in dry, open
woodlands and forest edges in scattered locations from Virginia to Georgia. In the Piedmont region, it is
usually associated with acidic to subacidic clay loam or sandy clay loam soils over granite and occasionally
found on clayey soils derived from mafic rock such as Carolina slate or gabbro.
Southeastern bold goldenrod (Solidago rigida var. glabrata)
eft-) Southeastern bold goldenrod has bright yellow flowers that appear in September and October, occasionally
✓ into November. The flower heads are usually compact, flat-topped arrays of four to fourteen flowers.
Flower stalks are sparsely to moderately hispid. The leaves are arranged basally and are lanceolate to
ovate in shape. The southeastern bold goldenrod is known to inhabit prairies, glades, savannas, dry open
rxt) areas, especially on calcareous soils.
Heller's rabbit -tobacco (Pseudognanhalium helleri)
Heller's rabbit -tobacco is a fragrant, annual herb with fibrous roots (Anderberg 2006). The stems of the
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Environmental Assessment for
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Existing Environmental
Characteristics
Georgia aster (Svmphyotrichum georgianum)
Georgia aster is a perennial dicot that can reach 39 inches in height. The leaves of the Georgia aster grow
to 3 inches in length and are alternate, elliptic, and entire. The flowers are violet, have numerous parts, and
are up to 2 inches wide. The Georgia aster blooms from early fall through mid fall. Habitat for the Georgia
aster consists of dry open areas. This species is often found on disturbed sites.
Narrow -leaf aster (Svmphyotrichum laeve var. concinnus)
Narrow -leaf aster is a perennial flowering plant with mostly glabrous stems (Pippen 2009). The leaves are
lanceolate -linear, narrow, nearly sessile, and clasping to slightly auriculate. The flowers are pale purple.
Narrow -leaf aster inhabits woodlands with high pH soils over mafic rocks.
4.13.1.4 Nonvascular Plants
Small wood -bark moss (Orthotrichum exiquum)
Small wood -bark moss has stem leaves that are erect, lanceolate -oblong to oblong with reflexed to broadly
recurved margins (Sullivant 2004). The capsule is widest at the mouth with 16 reflexed exostome teeth and
is distinctly 8-ribbed to the base when dry. The small wood -bark moss grows at the base of trees or on tree
trunks.
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Environmental Assessment for
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tot, Treatment Plant Expansion
Predicted Environmental Effects
5. Predicted Environmental Effects
This section provides an assessment of the potential direct, indirect, and cumulative impacts that may
result from the proposed project. Direct impacts are immediate impacts related to the proposed
construction associated with the expansion of the Twelve Mile Creek WWTP. Indirect effects are the result
of a specific activity that occurs later in time and are reasonably foreseeable. Cumulative effects result from
the incremental impact of the proposed activity when added to other past, present, and reasonably
foreseeable future activities regardless of the constituents originating from any other activity. The potential
,we\ for direct, indirect, and cumulative impacts of the proposed project is discussed herein.
5.1 Topography
_ The topography at the WWTP site is nearly level in the central portion of the site and decreases in elevation
along the eastern, southern, and western boundaries of the site. Proposed construction activities
associated with upgrades to the Twelve Mile Creek WWTP will occur on the plant site in areas that have
been previously graded. Placement of fill in lower elevations to provide a more level site may be necessary
for perimeter structures. However, direct impacts to the topography at the WWTP site will be minimal.
The existing developed areas at the Twelve Mile Creek WWTP are not located in the 100-year floodplain.
The site is bound by the 100-year floodplain to the south and includes the 100-year floodplain in the
western portion of the property. No construction activities will occur in the 100-year floodplain; therefore, no
direct impacts to the 100-year floodplain will occur from the proposed project.
Indirect and cumulative impacts to topography and floodplains may be possible as a result of future
development in the Twelve Mile Creek service area. Urban development is likely to lead to modification of
topography for construction and possible encroachment into the 100-year floodplain with the placement of
fill material in lower elevations bordering streams and tributaries. However, indirect and cumulative impacts
are expected to be minimal.
5.2 Soils
The Twelve Mile Creek WWTP site is currently developed, and the soils at the site have previously been
disturbed. Activities associated with construction of the proposed project are expected to have a negligible
impact to soils. Precautions will be taken to minimize direct impacts to water resources from construction to
avoid spillage and control runoff. Such measures will include the approval of an Erosion and
Sedimentation Control (ESC) Plan, provisions for waste materials and storage, and appropriate
,stA\ maintenance measures. Best management practices (BMPs) will be utilized for the protection of surface
waters, and sedimentation control guidelines will be strictly enforced during the construction of the project.
Direct impacts to soils from the proposed project will be minimal.
eatN
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Environmental Assessment for
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Predicted Environmental Effects
Indirect and cumulative effects to soils may be possible as a result of future development in the Twelve Mile
Creek service area. However, these impacts are expected to be insignificant.
5.3 Land Use
No direct impacts to land use will occur from the proposed project since the WWTP site is currently
developed for its proposed use. Potential indirect and cumulative impacts of future growth in the service
area will be land use changes in the currently open/agricultural/vacant urban areas. Impacts of land use
changes may include the direct loss of the resources from conversion to urban uses. Land use changes
may also cause indirect degradation of recreational lands by the development of incompatible land uses
along their periphery. Additionally, parks, greenways, and natural areas may be degraded through overuse
of the resource by the local population, usually resulting from limited recreational opportunities and a lack of
open space.
5.4 Wetlands
The Twelve Mile Creek WWTP site contains one wetland area consisting of approximately 0.34 acres of
PFO1 C near Twelve Mile Creek. Construction of the proposed project will not directly impact jurisdictional
wetlands at the Twelve Mile Creek WWTP site or in the Twelve Mile Creek service area.
Wetlands and vegetated riparian areas are valuable since they preserve biological diversity, protect wildlife,
provide natural open spaces, protect water quality, stabilize stream banks, control erosion, and prevent
flood damage. The acreage of wetlands impacted directly or indirectly in the service area may increase as
the level and intensity of land use changes and the number of development projects increases in the
service area. Impacts could be direct in terms of filling or draining of wetlands for construction of roads,
private or public building sites, or utilities. Urban development may also have significant indirect and
cumulative impacts to wetlands in terms of increased levels of silt and sediment from grading activities and
the increasing amount of non -point source pollutants entering the wetlands from upland development
activities and urban land uses. It is anticipated that direct, indirect, and cumulative impacts to wetlands in
the service area will be minimal.
5.5 Prime or Unique Agricultural Lands
No prime or unique agricultural lands are present at the Twelve Mile Creek WWTP site; therefore, no direct
impacts to prime or unique agricultural lands will occur from construction of the proposed project. Prime
and unique farmland soils are mapped across the service area. Indirect and cumulative impacts to prime or
unique agricultural lands are anticipated to be minimal.
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Environmental Assessment for
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Predicted Environmental Effects
5.6 Public Lands and Scenic, Recreational, and State Natural Areas
'�' No direct impacts to public, scenic, or recreational areas are anticipated to occur from the proposed project.
est. Negligible direct impacts to one SNHA, East Fork Twelve Mile Creek Aquatic Habitat, may occur as a result
esit of project construction. Direct impacts on the SNHA will be minimized to the extent possible by the
implementation of BMPs and the project ESC Plan. The increase in effluent discharge will not detrimentally
affect the habitat available in Twelve Mile Creek immediately downstream of the outfall, as discussed in
Section 4.5.
Indirect and cumulative impacts to public, scenic, or recreational areas in the service area may be possible
as a result of land use changes. Conversion of lands from a rural or forested state to denser residential and
ext) commercial uses may cause air, noise, and water pollution; increased storm flow; decreased base flow in
streams; habitat fragmentation; invasion of exotic species; and other forms of degradation. Growth in the
Twelve Mile Creek service area will likely increase the number of users of the public lands and recreational
areas in the region.
Indirect and cumulative impacts to public, scenic, or recreational areas in the Twelve Mile Creek service
area are expected to be minimal.
5.7 Areas of Archaeological or Historical Value
Based on a review of files and records available at SHPO, there are no known historic resources present at
the project site. One archaeological resource that may be eligible for listing on the NRHP is located in the
southwestern corner of the project site. Due to the distance between the proposed activities and the
archaeological resource, direct impacts to areas of archaeological or historic value are not expected to
occur from the proposed project (personal communication, J. Mintz, OSA, 2011). Indirect and cumulative
impacts to archaeological or historic sites will be insignificant.
5.8 Air Quality
An increase in airborne particulates from land clearing and exhaust emissions from construction vehicles
will occur during project construction, but the public health impacts of these emissions are anticipated to be
negligible. Proper vehicle maintenance, frequent wetting of exposed soil, and prompt soil stabilization will
minimize these impacts.
Two new on -site emergency generators are proposed as part of the expansion of the Twelve Mile Creek
,sk) WWTP to provide back-up power to the new plant equipment and to the influent pump station and coarse
screenings facility in the event of an emergency. The proposed generators will require modification of the
existing air permit for standby emergency power generation that will allow the generators to operate without
exceeding a specific number of hours per year, thereby controlling any potential criteria pollutant emission
to be under 100 tons/year. The proposed emergency generators will contribute very little additional direct
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Environmental Assessment for
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Treatment Plant Expansion
Predicted Environmental Effects
impact to air quality in the area. The minor direct impact will offset the major impacts associated with public
health and safety if power service is disrupted. Compliance with air quality standards will be required at
both the state and local level. No Tong -term impacts to air quality will occur from increasing the capacity of
the Twelve Mile Creek WWTP.
Urban growth in the service area may cause an increase in air pollutant emissions from vehicles, industrial
activities, and construction. Ozone and carbon monoxide are the primary pollutants of concern in the
service area, and the levels of ozone in the service area may be affected by increased growth. Since NO, is
the limiting factor in ozone formation and an estimated 60 percent of NO, is emitted by automobiles, the
additional vehicle miles traveled due to increased population will likely result in higher concentrations of
ozone being formed during hot, summer months. It is not anticipated that indirect or cumulative impacts to
air quality will result from the proposed project.
5.9 Noise Levels
Residents in the vicinity of the Twelve Mile Creek WWTP may experience temporary nuisance noise from
construction equipment. In order to minimize noise impacts, construction will normally be limited to Monday
through Friday between the hours of 6:00 am and 7:00 pm to the maximum extent practicable. Upon
completion of construction activities associated with the expansion of the Twelve Mile Creek WWTP, a
slight increase over existing noise levels may occur within and immediately adjacent to the Twelve Mile
Creek WWTP site; however, direct impact from the increase in noise will be negligible.
Periodic increases in noise level will occur during operation of the emergency generators; however, these
impacts will be occasional and temporary, and the increase in noise from operation of the generator will
offset the major impacts associated with public health and safety if power service is disrupted.
Growth in the service area may produce greater amounts of noise due to greater density of land uses,
more people living in the region, more businesses and industries operating in the areas, and the increase in
the number of vehicles using local roads and highways. As development occurs, existing residential
developments, once isolated in the countryside, will be joined by additional subdivision developments. The
cumulative effect of lawn mowers, leaf blowers, barking dogs, etc. will rise accordingly. Businesses and
industries will move into the area, also potentially bringing elevated noise levels to existing residential
areas. It is not anticipated that indirect and cumulative impacts to noise levels in the service area will result
from the proposed project.
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Environmental Assessment for
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5.10 Water Resources
erN
AWN 5.10.1 Surface Water Quality Impacts
The primary sources of water quality degradation in rural areas are agriculture and construction. The
construction activities associated with the proposed WWTP upgrades may cause water quality degradation
from runoff and sedimentation. Potential direct impacts to water resources may include additional substrate
destabilization, bank erosion, increased turbidity, and altered flow rates. Existing streamside vegetation will
not be impacted during construction of the proposed project.
Precautions will be taken to minimize direct impacts to water resources from construction by avoiding
spillage and controlling runoff. Such measures include an ESC plan, provisions for waste materials and
storage, and appropriate maintenance measures. BMPs will be utilized for the protection of surface waters,
and sedimentation control guidelines will be strictly enforced during construction of the project.
Oil, fuel, and emissions from construction vehicles may also create temporary, localized water quality
impacts during infrastructure construction. These impacts will be minimized by instructing contractors to
esieN perform vehicle maintenance in areas away from waters and wetlands and to collect and properly dispose
of all used vehicle fluids and containers.
Expansion of the Twelve Mile Creek WWTP will provide Union County the opportunity to offer future
sanitary sewer services to some areas presently using septic systems and will reduce new septic system
construction in the service area. Although the proposed Twelve Mile Creek WWTP expansion will increase
the NPDES effluent discharge into Twelve Mile Creek, the plant expansion will assist in reducing the overall
impact of nutrients in the watershed from failing or inefficient wastewater treatment systems. Therefore, the
proposed project will have a positive impact on water quality in the watershed over time.
Changes in land use have a major effect on both the quantity and quality of stormwater runoff. Urbanization
and land use development, if not properly planned and managed, may dramatically alter the natural
hydrology of an area. Impervious surfaces increase the volume and rate of stormwater runoff that may
affect erosion, caving, and sloughing of stream banks; erosion and scouring of streambeds; sediment and
severe flooding; and lead to degradation of water quality due to the various stormwater pollutants that wash
off impervious areas during rain events (e.g., nutrients, oils, toxics, sediments, bacteria, etc.). 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.
Historic records indicate that turbidity and copper levels upstream and downstream of the Twelve Mile
Creek WWTP site have exceeded the water quality standard. Prior to 2006, Twelve Mile Creek WWTP was
cited for permit violations for BOD, fecal coliform bacteria, discharge flow, nitrogen, phosphorus, and TSS
levels. Upgrades to the facility were implemented to address these violations and prevent them from
_ occurring again. The facility was in compliance by late 2005 (DENR 2010b). The upgrades proposed for the
Hazen and Sawyer Project No. 30831-030 llAZEN AND SWIM 1 IM 5-5
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Environmental Assessment for
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Treatment Plant Expansion
Predicted Environmental Effects
WWTP expansion and the associated modification of the NPDES discharge permit will continue to
minimize the risk of future violations, thereby improving water quality downstream of the WWTP outfall.
Refer to Section 4.5 for a detailed discussion of the water quality modeling in Twelve Mile Creek.
Historic records show that Twelve Mile Creek upstream of the WWTP site has had occasional low DO
levels, which tend to occur during periods of summer low flows in the stream. I�V ostelitlaperformed by Tetra
Tech indicates that the proposed project will have a beneficial impact on DO concentrations downstream of
the outfall in tweTirelliteRefer to Section 4.5.1 for a detailed discussion of the water quality
monitoring in Twelve Mile Creek.
Indirect and cumulative impacts to water resources due to growth will be minimal.
5.10.2 Groundwater
There will be no impacts to groundwater as a result of the proposed project.
5.11 Forest Resources
Forest resources are present along the western and southern property boundaries of the Twelve Mile
Creek WWTP site. These resources are primarily associated with the wooded riparian stream buffers that
are present along these property boundaries along Twelve Mile Creek and an UT to this stream. Twelve
Mile Creek forms the southern property boundary, and the UT is within the portion of the property that is
located across Kensington Road from the site of the proposed improvements. No construction activities are
proposed to occur outside the boundaries of the existing Twelve Mile Creek WWTP site or within existing
forested areas onsite. Therefore, no direct impacts to forest resources will occur from construction of the
proposed project. Indirect and cumulative forest resource impacts, such as the clearing of large tracts of
wooded land for development in the service area, may be possible as the service area experiences growth.
5.12 Shellfish or Fish and Their Habitats
Construction activities associated with the proposed plant upgrades and expansion will occur in the existing
facility boundaries, which is located adjacent to the northern bank of Twelve Mile Creek. Information
pertaining to the proposed increase in the effluent discharge and its effect on water quality are discussed in
Section 4.5.
No removal of streamside vegetation or placement of fill material will occur at the outfall site or in the
existing riparian buffer of Twelve Mile Creek or the UT to Twelve Mile Creek that flows through the western
portion of the site. However, the proposed construction activities at the Twelve Mile Creek WWTP site may
increase the potential for erosion and possible sedimentation. Quick re -vegetation of disturbed areas will
reduce the impacts by supporting the underlying soils. Erosion and sedimentation may carry soils, toxic
compounds, trash, and other materials into the aquatic communities. Erosion control during construction
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Emil")
oirN Environmental Assessment for
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Treatment Plant Expansion
Predicted Environmental Effects
will be important to minimize direct impacts to streams during construction. An ESC Plan will be developed
and implemented during construction associated with proposed upgrades and expansion at the Twelve
Mile Creek WWTP site.
The Twelve Mile Creek WWTP site is located adjacent to the north bank of Twelve Mile Creek. The outfall
discharges directly into Twelve Mile Creek. No anadromous fish species are known to be present in Twelve
Mile Creek. Nine species of fish for which construction moratoria have been implemented have been
identified in Twelve Mile Creek during fish community assessments in 1997 and 2002. No in -stream
construction or direct impacts to surface waters will occur during the proposed plant expansion project.
Direct impacts to fish, shellfish, or aquatic resources from construction activities at the Twelve Mile Creek
WWTP will be minimal.
Indirect and cumulative impacts to aquatic habitats may occur from growth in the service area. However,
impacts to aquatic habitat and resources from the proposed project are expected to be minimal. Indirect
and cumulative impacts may occur from loss, fragmentation, or degradation of aquatic and terrestrial
species and their habitats; degradation of water quality, aquatic resources, fisheries, and wetlands; and
'iP\ increased erosion, sedimentation, and stormwater runoff.
emit
5.13 Wildlife and Natural Vegetation
Minor direct temporary impacts to terrestrial habitats and resources will occur from the proposed project
during the construction activities. Temporary fluctuations of terrestrial species are anticipated during
construction activities. Slow moving, burrowing, and/or subterranean organisms will be directly impacted by
construction activities, while mobile organisms will be displaced to adjacent communities. Minimal direct
riEN
permanent impacts to terrestrial habitat or resources, which consist of maintained grass areas, will occur
from the proposed construction activities. No wooded areas will be disturbed during the proposed plant
expansion activities.
Indirect and cumulative impacts to terrestrial habitats may occur from growth in the service area. Indirect
impacts may occur from loss, fragmentation, or degradation of terrestrial species and their habitats. The
minimal amount of expected indirect and cumulative impacts will be insignificant.
5.13.1 Rare and Protected Species or Habitats
Table 5-1 summarizes the impacts to rare and protected species that may occur from the proposed project.
Construction activities are not expected to impact rare or protected species; however, field reconnaissance
is proposed prior to construction during the flowering season of one federal and one state -listed plant
species, Schweinitz's sunflower and thick -pod wild white indigo, respectively. Habitat for several state and
federally protected species is present in the service area. Indirect and cumulative impacts to state and
ram' federally protected species are expected to be minimal.
Hazen and Sawyer Project No. 30831-030 HAM AND SAWYER 5-7
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Environmental Assessment for
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Treatment Plant Expansion
Predicted Environmental Effects
Table 5-1: Summary of Impacts to Rare and Protected Species
Scientific Name
Common Name
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Vertebrates
Ambystoma talpoideum
Anguilla rostrata
Crotalus horridus
Etheostoma collis collis
Lanius ludovicianus
Masticophis flagellum
Moxostoma robustum
Invertebrates
Choroterpes basalis
Fusconaia masoni
Gomphus abbreviatus
Gomphus septima
Lampsilis cariosa
Lampsilis radiata
Lasmigona decorata
Strophitus undulatus
Toxolasma pullus
Villosa constricta
Villosa delumbis
Villosa vaughaniana
Vascular Plants
Baptisia alba
Boechera missouriensis
Buchnera americana
Callitriche terrestris
Cardamine dissecta
Carex impressinervia
Coelorachis cylindrica
Mole salamander
American eel
Timber rattlesnake
Carolina darter
Loggerhead shrike
Coachwhip
Robust redhorse
A mayfly
Atlantic pigtoe
Spine -crowned clubtail
Septima's clubtail
Yellow lampmussel
Eastern lampmussel
Carolina heelsplitter
Creeper
Savannah lilliput
Notched rainbow
Eastern creekshell
Carolina creekshell
Thick -pod white wild indigo
Missouri rockcress
American bluehearts
Terrestrial water-starwort
Dissected toothwort
Ravine sedge
Carolina jointgrass
X
X
X
X
X
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Environmental Assessment for
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Treatment Plant Expansion
Predicted Environmental Effects
Table 5-1: Summary of Impacts to Rare and Protected Species
Scientific Name
Dichanthelium aciculare
ssp. neuranthum
Eurybia mirabilis
Gillenia stipulata
Helianthus laevigatus
Helianthus schweinitzii
Hymenocallis coronaria
Ilex longipes
!soetes virginica
Isolepis carinata
Lotus unifoliolatus var.
helleri
Paspalum dissectum
Primula meadia
Pseudognaphalium helleri
Rhus michauxii
Solidago rigida var.
glabrata
Symphyotrichum
georgianum
Symphyotrichum Iaeve
var. concinnum
Nonvascular Plants
Orthotrichum exiguum
Common Name
Nerved witch grass
Dwarf aster
Indian physic
Smooth sunflower
Schweinitz's sunflower
Shoals spiderlily
Georgia holly
Virginia quillwort
Keeled beakrush
Prairie birdsfoot-trefoil
Mudbank crown grass
Shooting -star
Heller's rabbit -tobacco
Michaux's sumac
Southeastern bold
goldenrod
Georgia aster
Narrow -leaf aster
Small wood -bark moss
°' a m
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X x
X x
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O
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X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Hazen and Sawyer Project No. 30831-030
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Environmental Engineers i Scientists
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Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Predicted Environmental Effects
5.13.1.1 Vertebrates
Mole salamander (Ambystoma talpoideum)
Potential habitat for the mole salamander is available in some of the floodplains associated with the streams
in the service area. No documented populations of the mole salamander are reported in the service area or
at the project site. No direct impacts to the mole salamander are expected to occur from construction of the
proposed project. Indirect or cumulative impacts to the mole salamander may occur from potential
development in the service area.
American eel (Anguilla rostrata)
Potential habitat for the American eel is available in the service area. No known populations of the
American eel are documented in the service area. Direct impacts to the American eel are not anticipated to
occur due to the proposed project. Indirect or cumulative impacts to the eel may occur from construction of
the proposed project.
Timber rattlesnake (Crotalus horridus)
Suitable habitat for the timber rattlesnake is present in the service area and in the project site. No known
populations of the timber rattlesnake are documented in the service area. Direct impacts to the timber
rattlesnake are not anticipated to occur from construction of the proposed project. Indirect or cumulative
impacts to the timber rattlesnake may be possible from development in the service area.
Carolina darter (Etheostoma collis collis)
Appropriate habitat for the Carolina darter is present in small streams in the service area. Additionally,
assessment of the fish populations in West Fork Twelve Mile Creek and East Fork Twelve Mile Creek
found Carolina darter to be present in both streams. Four known occurrences of the Carolina darter have
been documented in the service area; two of the four occurrences are in an SNHA. No direct impacts to the
Carolina darter from the project construction are anticipated to occur. Indirect or cumulative impacts to the
Carolina darter may be possible from future development in the service area.
Loggerhead shrike (Lanus ludovicianus)
Potential habitat for this bird is open fields surrounded by heavily vegetated hedgerows. Habitat for the
loggerhead shrike is present in the service area but is not present at the project site. No known populations
of this species are documented in the service area. No direct impacts are anticipated to occur to this bird
from construction of the proposed project. Indirect or cumulative impacts to the loggerhead shrike may be
possible from future development in the service area.
Coachwhip (Masticophis flagellum)
Habitat for the coachwhip is available in the service area and at the project site. No known populations of
this species are documented in the service area. Direct impacts to the coachwhip are unlikely to occur
Hazen and Sawyer Project No. 30831-030
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Environmental Assessment for
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Treatment Plant Expansion
041
Predicted Environmental Effects
during construction of the proposed project. Indirect or cumulative impacts to the species may be possible
as a result of future development in the service area.
EssiN Robust redhorse (Moxostoma robustum)
Suitable habitat for the robust redhorse consists of medium to large creeks and rivers with gravel, rock, or
boulder substrate and reaches of streams that are deep and fast -flowing. Habitat for this species is present
in streams in the service area, including Twelve Mile Creek. No known occurrences of robust redhorse are
fiRN
documented in the service area. Construction of the proposed project is not anticipated to have direct
impacts to the robust redhorse. Future development in the service area may have indirect or cumulative
impacts on this species.
5.13.1.2 Invertebrates
A mayfly (Choroterpes basalis)
Little information regarding the habitat requirements of this mayfly species is available. The mayfly is known
to occur in two streams in Union County: Lanes Creek and an UT to Laurens Creek. Neither of these
streams is located in the service area. There are no known populations of the species in the service area or
r project site. No direct, indirect, or cumulative impacts to the mayfly are anticipated to occur as a result of
project implementation.
e-sh Atlantic pigtoe (Fusconaia mason)
faltN Appropriate habitat for the Atlantic pigtoe is present in the service area and may be present in the UT to
Twelve Mile Creek along the western property boundary of the project site. No known populations of the
mussel are located in the service area or the project site. Direct impacts to the Atlantic pigtoe are not
expected to occur as a result of project implementation. Indirect or cumulative impacts may be possible due
to future development in the service area.
tveN Spine -crowned clubtail (Gomphus abbreviatus)
The spine -crowned clubtail inhabits clean, medium to large streams and rivers with sandy or rocky
substrates containing muck deposits. The potential exists for this habitat to be present in the service area
and the project site. No known occurrences of the species have been documented in the service area or
project site. Direct impacts to the spine -crowned clubtail are not likely to occur due to the proposed project.
Indirect or cumulative impacts may occur as a result of future development in the service area.
Septima's clubtail (Gomphus septima)
igst Habitat for Septima's clubtail consists of rivers with rocky substrates. Habitat is present in the service area.
No populations of this dragonfly are known to occur in the service area or the project site. Direct impacts to
rya the species are not likely to occur from project construction. Indirect or cumulative impacts to the Septima's
clubtail may be possible due to development.
/11
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Yellow lampmussel (Lampsilis cariosa)
Appropriate habitat for the yellow lampmussel is available in the service area and project site. No
populations of the mussel have been documented in the service area or project site. Direct impacts to the
species are not expected to occur during project construction. Indirect or cumulative impacts to yellow
lampmussel may be possible due to future development in the service area.
Eastern lampmussel (Lampsilis radiate)
The preferred habitat for the eastern lampmussel is present in the service area and may be present at the
project site. No populations of the species have been documented in the service area or the project site.
Direct impacts to the mussel are not likely to occur as a result of project construction. Indirect or cumulative
impacts may be possible due to future development.
Carolina heelsplitter (Lasmigona decorate)
Habitat for the Carolina heelsplitter may be present in the service area or project site. Two populations are
known to occur within Union County, North Carolina; however, neither of these documented populations is
located in the service area or the project site. In 2002, USFWS designated the locations of these
populations as Critical Habitat for the species. Direct impacts to the species are not expected to result from
construction of the proposed project. To protect the water quality conditions and habitat that are necessary
for the Carolina heels litt mans ement rules was ado ted b the EMC and became effective in
2009. Compliance with these rules will minimize indirect or cumulative impacts that may occur as a res
potential future development in the service area.
Creeper (Strophitus undulatus)
Habitat for the creeper is present in the service area and the project site. No known populations have been
documented in the service area or the project site. Direct impacts to the species are not likely to result from
construction of the proposed project. Indirect or cumulative impacts may occur due to future development in
the service area.
Savannah Iilllput (Toxolasma pullus)
Suitable habitat for the savannah lilliput is present in the service area and the project site. No populations of
the lilliput are documented in the service area or project site. Direct impacts to the species are not likely to
result from construction of the proposed project. Indirect or cumulative impacts may occur due to future
development.
Notched rainbow (Villosa constricta)
Habitat for the notched rainbow is present in the service area and may be present at the project site. One
population of the notched rainbow has been identified and documented in East Fork Twelve Mile Creek in
the central portion of the service area, which is within an SNHA. Direct impacts to the species are not likely
Hazen and Sawyer Project No. 30831-030
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Environmental Engineers & Scientists
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Environmental Assessment for
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Predicted Environmental Effects
to occur as a result of construction of the project. Indirect or cumulative impacts to the notched rainbow
toitN
may result from future development in the service area.
Eastern creekshell (Villosa delumbis)
Little information is available relative to the habitat preferred by the eastern creekshell. Its distribution has
been documented from Altamaha River basin in Georgia to the Cape Fear River basin in North Carolina.
No known populations have been documented in the service area or project site. Direct impacts to the
species are not likely to result from construction of the proposed project. Indirect or cumulative impacts may
rt\ occur due to future development in the service area.
Carolina creekshell (Villosa vauqhaniana)
Habitat for the Carolina creekshell is present in the service area and possibly at the project site. Three
populations of the Carolina creekshell have been identified and documented in the service area, and one of
the populations is in an SNHA. These populations are located in Price Mill Creek approximately 7.3 miles
northeast of the project site, in Blythe Creek approximately 2.3 miles southeast of the project site, and in
Goose Creek more than 15 miles northeast of the project site. Direct impacts to the mussel may occur
,- during project construction, but impacts will be minimized by implementation of the ESC Plan for the project
and applicable BMPs. Indirect or cumulative impacts to the species may be possible due to future
elciN
development in the service area.
earN
5.13.1.3 Vascular Plants
rxt‘
Thick -pod white wild indigo (Baptisia alba)
Thick -pod white wild indigo inhabits sunny locations with rich soil that ranges from moist to dry. Habitat is
available in the service area and at the project site. Two populations of the plant have been identified and
ewes
documented in the service area, located in the north -central and south-central portions of the service area.
Direct impacts to thick -pod white wild indigo from construction of the proposed project may be possible and
cannot be determined until the project site field survey is performed during the flowering season, which
extends from May through July. Indirect or cumulative impacts to the species are possible from future
fIrP
development in the service area.
e Missouri rockcress (Boechera missouriensis)
Suitable habitat for the Missouri rockcress is not present in the service area. No populations of the plant are
ems documented in the service area. No direct, indirect, or cumulative impacts to Missouri rockcress are
anticipated from construction of the proposed project.
siar American bluehearts (Buchnera americana)
' ' Appropriate habitat for American bluehearts is present in the service area. There are no documented
populations of American bluehearts in the service area. Direct impacts to American bluehearts are not
rgeN
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Predicted Environmental Effects
anticipated from construction of the proposed project. Indirect or cumulative impacts to the plant may be
possible from development in the service area.
Terrestrial water-starwort (Callitriche tenestris)
Habitat for terrestrial water-starwort may be present in the service area and at the project site. There are no
known populations of the plant documented within the service area or project site. Direct impacts to the
species are not likely to occur from construction of the proposed project. Indirect or cumulative impacts to
the terrestrial water-starwort may occur due to future development.
Dissected toothwort (Cardamine dissecta)
Habitat for dissected toothwort is likely present within the service area. There are no documented
populations of the dissected toothwort in the service area. Direct impacts to the species are not anticipated
to occur from construction of the proposed project. Indirect or cumulative impacts are possible due to
future development in the service area.
Ravine sedge (Carex imAressinervia)
Ravine sedge inhabits rich alluvial forests, which are present along stream channels throughout the service
area and at the project site. No known populations of the ravine sedge are documented in the service area
or the project site. Direct impacts to the species are not anticipated to occur from construction of the
proposed project. Indirect or cumulative impacts are possible as a result of future development.
Carolina jointgrass (Coelorachis cvlindrica)
Habitat for the Carolina jointgrass consists of low elevation areas underlain by sandy soil and is present in
the service area. There are no documented populations of the plant in the service area; therefore, direct
impacts to the species due to project implementation are not anticipated to occur. Indirect or cumulative
impacts may be possible as a result of future development.
Nerved witch grass (Dichanthelium aciculare ssP. neuranthum)
Habitat for nerved witch grass may be present in the service area. There are no known populations of the
species documented in the service area. No direct impacts are anticipated to occur from project
construction. Indirect or cumulative impacts may be possible as a result of future development.
Dwarf aster (Eurvbia mirabilis)
Dwarf aster habitat is available in the service area. There is one known population of the dwarf aster within
the service area, which is located more than 12 miles east of the project site. Therefore, no direct impacts
to the plant are anticipated to occur from the proposed project. Indirect or cumulative impacts may be
possible due to future development.
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Environmental Englneers & Scientists
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Environmental Assessment for
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Predicted Environmental Effects
Indian physic (Gillenia stipulate)
Habitat for the Indian physic is present in the service area. There are no known populations of the plant
documented in the service area. No direct impacts to the species are anticipated to occur due to project
`At\ construction. Indirect or cumulative impacts to the Indian physic may occur as a result of the project.
Smooth sunflower (Helianthus laevigatus)
Habitat for smooth sunflower is available throughout the service area. There are four known populations of
this species documented in the service area. The population that is nearest the project site is located
approximately 8.5 miles east of the project site. Direct impacts to the smooth sunflower are not anticipated
to occur due to the proposed project. Indirect or cumulative impacts to smooth sunflower are possible as a
result of development.
Schweinitz's sunflower (Helianthus schweinitzii)
/INK\ Suitable habitat for Schweinitz's sunflower is present throughout the service area and at the project site.
There are sixteen known populations of Schweinitz's sunflower documented in the service area, and the
one nearest the project site is approximately 0.67 mile west-southwest of the project site. Twelve of the
sixteen known populations of the flower are located in an SNHA. Direct impacts to Schweinitz's sunflower
from construction of the proposed project may be possible and cannot be determined until a project site
field survey is performed during the flowering season, which extends from late August through October.
Indirect or cumulative impacts to Schweinitz's sunflower may be possible from future development in the
service area.
foAN Shoals spiderlily (Hvmenocallis coronaria)
Appropriate habitat for shoals spiderlily may be present in the service area. No known populations of this
species are documented in the service area. No direct impacts to shoals spiderlily are anticipated from
construction of the proposed project. Indirect or cumulative impacts to the species may be possible due to
future development in the service area.
Georgia holly (Ilex longipes)
est\ Appropriate habitat for Georgia holly is present in the service area. No known populations have been
mit\ documented in the service area; therefore, no direct impacts to the species are anticipated to occur due to
construction of the proposed project. Indirect or cumulative impacts to the Georgia holly may occur from
future development.
tireN
tiest Virginia quillwort (Isoetes virainica)
eieN
Suitable habitat for Virginia quillwort is not present in the service area. No known populations of the plant
have been identified and documented in the service area. No direct, indirect, or cumulative impacts to
Virginia quillwort are anticipated to occur from the proposed project construction.
Hazen and Sawyer Project No. 30831-030
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Environmental Assessment for
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Treatment Plant Expansion
Predicted Environmental Effects
Keeled beakrush (Isolepis carinata)
Habitat for the keeled beakrush is present within the service area and may be present within the project
site. No known populations have been documented within the service area. Direct impacts to the species
are not anticipated to occur due to project construction. Indirect or cumulative impacts may be possible as
a result of future development in the service area.
Prairie birdsfoot-trefoil (Lotus unifoliolatus var. helleri)
Suitable habitat for prairie birdsfoot-trefoil is present in the service area. Two populations of the prairie
birdsfoot-trefoil are documented in the service area. One population is located approximately 8.8 miles
northeast of the project site, and the other population is documented approximately 4.5 miles east-
southeast of the project site. The latter location is in an SNHA. No direct impacts to prairie birdsfoot-trefoil
are anticipated from construction of the proposed project. Indirect or cumulative impacts may be possible
due to future development in the service area.
Mudbank crown grass (Paspalum dissectum)
Appropriate habitat for mudbank crown grass is present in the service area. No known populations of
mudbank crown grass are documented in the service area. Construction of the proposed project is not
anticipated to have a direct impact to this species. Indirect or cumulative impacts to this species from
development in the service area may be possible.
Shooting -star (Primula meadia)
Suitable habitat for shooting -star is present in the service area. No known populations of the plant have
been documented; therefore, no direct impacts to this species are anticipated from construction of the
proposed project. Indirect or cumulative impacts to the species may be possible due to development in the
service area.
Heller's rabbit -tobacco (Pseudognaphalium helleri)
Appropriate habitat for Heller's rabbit -tobacco is present in the service area. There is one known population
of Heller's rabbit -tobacco documented in the service area. This population is located approximately
4.5 miles east-southeast of the project site and is in an SNHA. Construction of the proposed project is not
anticipated to have direct impacts to this species. Indirect or cumulative impacts may be possible due to
future development in the service area.
Michaux's sumac (Rhus michauxii)
Habitat for Michaux's sumac is present in the service area. No populations of Michaux's sumac have been
identified and documented in the service area. Direct impacts to the plant are not anticipated to occur from
the construction of the proposed project. Indirect or cumulative impacts may be possible due to future
development.
Hazen and Sawyer Project No. 30831-030
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Environmental Engineers & Scientists
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Environmental Assessment for
Twelve Mile Creek Wastewater
'lat\ Treatment Plant Expansion
Predicted Environmental Effects
Southeastern bold goldenrod (Solidago rigida var. alabrata)
Habitat for the southeastern bold goldenrod is present within the service area and may be present within
the project site. No known populations have been documented within the service area. Direct impacts to
the species are not anticipated to occur due to construction of the proposed project. Indirect or cumulative
impacts may occur as a result of future development in the service area.
Georgia aster (Svmphvotrichum aeorgianum)
eRN Suitable habitat for Georgia aster is present in the service area. Nine populations of Georgia aster are
documented in the service area. The populations are primarily located along Highway 75 in the southern
portion of the service area. The distance between the project site and the documented populations range
from approximately 2.7 miles to 8.5 miles. Two of the nine populations are located in an SNHA. Direct
impact to this species is not anticipated to occur due to construction. Indirect or cumulative impacts to
Georgia aster may be possible from future development in the service area.
erif
Narrow -leaf aster (Svmphyotrichum laeve var. concinnum)
esit
Habitat for the narrow -leaf aster is not present in the service area. No known populations of the species
folks have been documented. No direct, indirect, or cumulative impacts to the narrow -leaf aster are expected to
rst, occur due to construction of the proposed project.
5.13.1.4 Nonvascular Plants
Small wood -bark moss (Orthotrichum exiguum)
Habitat for the small wood -bark moss is present throughout the service area and the project site. No known
populations of the moss have been documented in the service area. Direct impacts to the species are not
expected to occur due to project implementation. It is possible that construction of the proposed project
may have indirect or cumulative impacts on the small wood -bark moss.
5.14 Introduction of Toxic Substances
Potential sources of toxic substances during construction of the proposed project may include exhaust
emissions, oil, fuel, and other vehicle fluids. Escape of these substances will be minimized by proper
vehicle maintenance, collection, and disposal of fluid containers. Contractors will be instructed to take
precautions to ensure that un-cured concrete is not allowed to contact surface waters.
estN
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elgres
Mitigative Measures
6. Mitigative Measures
rak, Per Section 6, the proposed project will have minimal direct impact on of topography, soils, land use, prime
or unique agricultural lands, public land, areas of archaeological or historical value, air quality, noise, water
resources, forest resources, shellfish and habitats, wildlife and vegetation, and the introduction of toxic
substances.
Local programs and ordinances will continue to minimize the indirect and cumulative impacts as a result of
evN topography, soils, land use, prime or unique agricultural lands, public land, areas of archaeological or
historical value, air quality, noise, water resources, forest resources, shellfish and habitats, wildlife and
vegetation, and the introduction of toxic substances.
_ Table 6-1 provides a summary of the local ordinances and programs with respect to resource impacts.
Table 6-1: Summary of Resource Impact Mitigative Measures
Resource(s) Section Title
Topography 8.3 Open Space Plans/Initiatives, Greenways, and Riparian Buffers
Fzi*` 8.4 Erosion and Sedimentation Control
8.5 Stormwater Programs and Impervious Surface Limitation
8.6 . Floodplain Development Regulations
Soils 8.3 Open Space Plans/Initiatives, Greenways, and Riparian Buffers
elms 8.4 Erosion and Sedimentation Control
8.5 Stormwater Programs and Impervious Surface Limitation
8.6 Floodplain Development Regulations
Land Use 8.1 Land Use Planning and Environmental Resource Protection Initiatives
8.2 Zoning
8.3 Open Space Plans/Initiatives, Greenways, and Riparian Buffers
8.4 Erosion and Sedimentation Control
___..._.____......_.._.__...-_._......_._......................_......_..._...._._..._.8:5.._..._._._...__._._.._Stormwater Programs and Impervious Surface Limitation
Wetlands 8.1 Land Use Planning and Environmental Resource Protection Initiatives
8.2 Zoning
8.3 Open Space Plans/Initiatives, Greenways, and Riparian Buffers
8.4 Erosion and Sedimentation Control
Prime or Unique 8.1 Land Use Planning and Environmental Resource Protection Initiatives
Agricultural Lands 8.2 Zoning
8.3 Open Space Plans/Initiatives, Greenways, and Riparian Buffers
8.4 Erosion and Sedimentation Control
8.5 Stormwater Programs and Impervious Surface Limitation
firtS Public Lands and 8.1 Land Use Planning and Environmental Resource Protection Initiatives
Scenic, Recreational, 8.2 Zoning
and State Natural 8.3 Open Space Plans/Initiatives, Greenways, and Riparian Buffers
Areasems 8.4 Erosion and Sedimentation Control
8.5 Stormwater Programs and Impervious Surface Limitation
`fiN HAZEN AND SAVYER
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Table 6-1: Summary of Resource Impact Mitigative Measures
Resource(s) Section Title
Archaeological and
Historic Areas
8.1 Land Use Planning and Environmental Resource Protection Initiatives
8.2 Zoning
8.3 Open Space Plans/Initiatives, Greenways, and Riparian Buffers.
Air Quality 8.1 Land Use Planning and Environmental Resource Protection Initiatives
8.2 Zoning
8.3 Open Space Plans/Initiatives, Greenways, and Riparian Buffers
Noise
Water Resources
8.1 Land Use Planning and Environmental Resource Protection Initiatives
8.2 Zoning
8.3 Open Space Plans/Initiatives, Greenways, and Riparian Buffers
8.1 Land Use Planning and Environmental Resource Protection Initiatives
8.2 Zoning
8.3 Open Space Plans/Initiatives, Greenways, and Riparian Buffers
8.4 Erosion and Sedimentation Control
8.5 Stormwater Programs and Impervious Surface Limitation
8.6 Floodplain Development Regulations
Forest Resources
8.1 Land Use Planning and Environmental Resource Protection Initiatives
8.2 Zoning
8.3 Open Space Plans/Initiatives, Greenways, and Riparian Buffers
8.4 Erosion and Sedimentation Control
8.5 Stormwater Programs and Impervious Surface Limitation
8.6 Floodplain•Development Regulations
Aquatic and Wildlife
Habitat and
Resources
8.1 Land Use Planning and Environmental Resource Protection Initiatives
8.2 Zoning
8.3 Open Space Plans/Initiatives, Greenways, and Riparian Buffers
8.4 Erosion and Sedimentation Control
8.5 Stormwater Programs and Impervious Surface Limitation
8.6 Floodplain Development Regulations
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Environmental Engineers & Scientists
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Environmental Assessment for
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Summary of Local Programs and
etirt, Ordinances
egN 7. Summary of Local Programs and Ordinances
ram,
Union County has implemented programs that will help mitigate potential long-term impacts that may occur
'w, due to the growth and development in the service area. This section identifies and discusses pertinent
regulations and programs that will mitigate the potential for direct, indirect, and cumulative impacts
associated with the expansion of the Twelve Mile WWTP. Union County has implemented programs for
open space preservation, riparian buffers, stormwater pollution prevention, and floodplain management.
In the Twelve Mile Creek WWTP service area, Union County has jurisdiction only over the unincorporated
areas. The towns and villages in the Twelve Mile Creek WWTP service area include the Town of Waxhaw,
the Town of Mineral Springs, the Village of Wesley Chapel, the Village of Marvin, the Town of Weddington,
the Town of Indian Trail, the Town of Stallings, the Town of Hemby Bridge, and the Village of Lake Park.
The ordinances associated with Union County and each of the towns and villages are summarized in the
following subsections.
7.1 Land Use Planning and Environmental Resource Protection Initiatives
`sit` 7.1.1 Union County
Union County released its first Comprehensive Plan in October 2010 to identify growth management
strategies across the County. The 2025 Comprehensive Plan was developed based on analyses of
community data, input from County staff, municipal citizens and business owners, and rigorous discussion
and debate regarding the future vision for the County and what it should achieve by 2025. The purpose of
the Plan is to serve as a guide for the County over the next planning period. The Plan includes community
goals, policies, strategies, and an implementation plan that sets the course for future actions and initiatives.
Ask' Chapter 4 of the 2025 Comprehensive Plan is the Future Land Use Plan developed over the course of
several years and includes input from the community, representatives of the municipalities, and the
committees overseeing development in the County. Union County will use the Future Land Use Plan as a
guide for decision -making regarding development approvals, rezoning decisions, and infrastructure
improvements. Development of the Future Land Use Plan was guided by several overarching themes:
• Direct growth to urban and suburban areas along the edges of the towns to limit urban
t•R'' sprawl, to make wise use of development patterns in the towns, to maximize the use of
existing transportation corridors, and to lay the framework for future transit expansion.
• Focus denser residential land uses in areas where existing water and wastewater capacity
is available or likely to be expanded in the future.
• Provide new opportunities for commercial and employment growth in areas identified as
marketable for non-residential uses to increase employment opportunities in the County
and balance the tax base.
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Summary of Local Programs and
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• Maintain the rural character of lands by encouraging land conservation, supporting
agricultural practices, and managing new development to ensure it is compatible with
adjacent rural lands.
• Provide more transitional land uses between urban and rural areas to reduce the potential
for incompatible land uses being located in proximity, and to create more of a transition
between urban and rural lands (Union County, 2010a).
7.1.2 Town of Waxhaw
A 2030 Comprehensive Plan was adopted by the Town of Waxhaw in April 2009 and amended in
September 2009. The Comprehensive Plan serves as a guide to Town decision -makers for the next
planning period. It includes community goals, policies, strategies, and an implementation plan that focuses
on the following planning themes: managing and directing growth and infrastructure, enhancing quality of
life, improving design, building a sense of community, and strengthening collaboration with regional
partners (Town of Waxhaw, 2009).
7.1.3 Town of Mineral Springs
The Town of Mineral Spring's Land Use Plan is a series of goals, recommendations, and actions that
reflect the themes outlined in the Mineral Springs Vision Plan, adopted by the Town Council in May 2006.
The major goals are to develop downtown Mineral Springs as a unique retail, service, cultural,
governmental and mixed -use residential hub to service the citizens of the Town. Additionally, the Town
aims to provide a variety of lot types and housing opportunities for the citizens of Mineral Springs while
maintaining open space and rural character in the outlying areas of town (Town of Mineral Springs, 2006).
7.1.4 Village of Wesley Chapel
The Village's Land Use Plan was adopted in December 2003 by the Village Council. The Village of Wesley
Chapel has been primarily an agricultural community for many years. However, given its proximity to
Charlotte, the Village has been steadily losing its farming atmosphere and has witnessed a significant
amount of suburban residential development. In 1998, in response to increasing residential and commercial
development in Union County, residents of the Wesley Chapel area formed the Village with their primary
goal being to preserve the low -density residential character of the area (Village of Wesley Chapel, 2003).
The Village adopted its current Zoning and Subdivision Ordinances on August 22, 2000 to help guide
growth in the community. One of the primary goals of the Land Use Plan is to maintain the strong single-
family, low -density residential character of the Village. In terms of non-residential development, the Village's
goal is to prevent strip development from occurring anywhere in Wesley Chapel by limiting new non-
residential development to designated strategic locations (Village of Wesley Chapel, 2010).
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faN Environmental Assessment for
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Summary of Local Programs and
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7.1.5 Village of Marvin
The Village of Marvin adopted its Land Use Plan in October 2004. The Marvin Land Use Plan aims to
establish a unique sense of place that differentiates the Village from other Union County communities. The
primary objectives are to maintain the small-town village atmosphere through low -density residential
development and to limit commercial development to community -oriented, smaller -scale developments that
are located in specified portions of the Village. Additional industrial development in the Village is strongly
discouraged. Furthermore, the Land Use Plan aims to provide opportunities for open space and
recreational opportunities through a series of planned greenways and parks (Village of Marvin, 2004).
7.1.6 Town of Weddington
'nt' The Town of Weddington adopted its own Land Use Plan in March 2002 as a replacement to the 1996
Weddington Land Use Plan that was written by the UNC Charlotte Urban Institute. The Plan is designed to
tailz, serve as a guide for future growth and development in the Town. The Land Use Plan's goals are:
• To ensure that all new development takes place in a manner that conserves open space
and scenic views.
• To limit development activities on environmentally sensitive lands.
ionks
• To preserve open space and scenic views while providing for low -density development.
rat, • To maintain the town's strong single-family residential character.
• To retain a mix of land uses that reinforces Weddington's unique small town character.
• To ensure that the type, location, and scale of existing and future commercial development
' in the Town provides essential goods and services for the residents of Weddington through
the development process while also preserving open space.
• Through the conditional zoning process, provide smaller lot sizes to accommodate a variety
of age and income groups, and broader residential preferences, so that the community's
population diversity may be enhanced (Town of Weddington, 2002).
`AIN 7.1.7 Town of Indian Trail
,n The Town of Indian Trail adopted its first Comprehensive Plan in 2005. The Plan provides guidance for
future development in Indian Trail and establishes.a guide for zoning, land use, economic development,
est
public facilities and utilities decision -making by Town officials. The Comprehensive Plan establishes goals
for quality of life, land use, transportation, downtown revitalization, and public utilities. The specific goals for
land use are to have a mix of different types of land uses, to avoid potential land use conflicts between
neighboring properties and surrounding municipalities and to have a more balanced tax base by promoting
the development of office parks, businesses, retail centers, and industrial parks (Indian Trail, 2005).
/011
SAWYER
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Environmental Assessment for
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Summary of Local Programs and
Ordinances
7.1.8 Town of Stallings
The Stallings Land Use Plan (updated April 12, 2006) establishes goals for residential land uses,'
commercial land uses, downtown Stallings, industrial land uses, and open space and environmental issues.
The residential land use goal is to ensure that the Town is comprised of well -planned, aesthetic, and
pedestrian -friendly residential developments that offer a wide variety of housing choices to persons of a
variety of age and income groups. The commercial land use goal is to promote commercial development in
Stallings that is aesthetically pleasing, pedestrian -friendly, and which will add long-term economic benefits
to the community and not ultimately lead to additional commercial sprawl. In terms of industrial land use,
the Town's primary objective is to continue to provide a good environment for a range of light industrial
uses that are well -planned with respect to adjoining neighborhoods and land uses, take advantage of
existing and planned transportation resources, and do not negatively affect the natural environment or
community services and infrastructure. The Town aims to create a unique downtown area that serves as a f"PI'
retail, service, cultural, governmental, mixed -use transit hub (Town of Stallings, 2006). PiaN
7.1.9 Town of Hemby Bridge
The Town of Hemby Bridge has adopted Union County's Land Use Ordinance, discussed in Section 8.2.1.
7.1.10 Village of Lake Park
rabN
The Village of Lake Park has adopted Union County's Land Use Ordinance. The Village is currently
developing its own Unified Development Ordinance, which is discussed in Section 8.2.1. elh
A'i+
7.2 Zoning
figN
7.2.1 Union County e's
Union County has developed four volumes of County Ordinances in addition to the 2025 Comprehensive
ribs
Plan. The Land Use Ordinance was prepared by the Union County Planning Department and became
effective in May 2001. The Land Use Ordinance divides zoning districts into residential districts, commercial et'''
districts, manufacturing districts, planned unit development districts, floodplain and floodway overlay iffe
districts, water supply watershed overlay districts, mining overlay districts, and airport overlay districts. To
control development, minimum lot sizes have been established for each zoning district. Table 7-1
summarizes the descriptions and requirements for each zoning district.1411
The watershed overlay district is divided into the following areas:
• T-CA (Lake Twitty Critical Area) Pib\
o Single-family residential uses may be allowed at a maximum of one dwelling unit per P',
40,000 square feet. All other residential and non-residential development is allowed to ea*,
I*"s
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Summary of Local Programs and
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a maximum of twelve percent built -upon area.
• T-BW (Lake Twitty Balance of Watershed)
o Single-family residential uses may develop at a maximum of two dwelling, units per
40,000 square feet. All other residential and non-residential development is allowed a
maximum of 24 percent built -upon area. In addition, up to ten percent of the balance of
the watershed, which is located -in Union County's planning jurisdiction, may be
developed for non-residential uses up to a maximum built -upon area of 70 percent on a
project by project basis allocated on a first -come -first -serve basis.
• L-CA (Lake Lee Critical Area)
o Single-family residential uses are allowed at a maximum of two dwelling units per
40,000 square feet. All other residential and non-residential development is allowed a
24 percent built -upon area.
• L-PA (Lake Lee Protected Area)
o Single-family residential uses may develop at a maximum of two dwelling units 'per
40,000 square feet. All other residential and non-residential development is allowed a
maximum of 24 percent built -upon area. A maximum of three dwelling units per acre or
36 percent built -upon area may be allowed for projects without a curb and gutter street
system (Union County, 2001).
Table 7-1: Density Limits in Union County Land Use Ordinance
Zoning
District
R-6
R-8
R-10
R-15
R-20
RA-20
R-40
RA-40
RC-80
B-1
B-2
B-3
B-4
B-6
HC
Description
Single family, two-family and multi -family, high densities
Single family, two-family and multi -family, high densities
Single family, medium densities
Single family, medium densities
Single family, low to medium densities
Single family residential, low to medium densities
Single family residential, low to medium densities
Agribusiness uses & low density residential development
Resource conservation district
Central business
Community business
Office
General commercial
College campus
Highway corridor mixed -use
Minimum
Lot Size
(square feet)
6,000
8,000
10,000
15,000
20,000
20,000
40,000
40,000
80,000
6,000
6,000
6,000
6,000
8,000
6,000
Minimum
Lot Width
(feet)
60
80
80
80
100
100
120
120
120
None
60
60
60
80
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Table 7-1: Density Limits in Union County Land Use Ordinance
Minimum Minimum
Zoning Lot Size Lot Width
District Description (square feet) (feet)
LI Light industrial No minimum 100
HI Heavy industrial No minimum 100
O Office district 15,000 80
7.2.2 Town of Waxhaw
Chapters 5 and 6 of the Town of Waxhaw's Unified Development Ordinance discuss the conditional zoning
and conditional use districts (adopted November 2009) and established overlay districts (adopted
September 2010), respectively. There are16 established zoning districts that designate the amount, type,
and location of development that can occur in the Town. Seven of the districts are residential, five are
commercial, and the remaining four are industrial and office/institutional. Each of these districts has a
related "conditional use" district, resulting in a total of 32 districts. Table 7-2 summarizes minimum lot sizes
for residential zoning jurisdictions (Town of Waxhaw, 2009).
Table 7-2: Density Limits in Town of Waxhaw Zoning Ordinance
Zoning District Description Minimum Lot Size (square feet)
R-1 Single-family, low density 100,000
R-2 Single-family, medium density 40,000
R-3 Single-family, moderate density 20,000
R-4 Single-family, high density 12,000
RM-1 Multi -family, low density NA
RM-2 Multi -family, high density NA
7.2.3 Town of Mineral Springs
The Town of Mineral Springs Zoning Ordinance (amended February 14, 2008) establishes ten zoning
districts, including Downtown Overlay and Airport Overlay Districts. The zoning districts were established
based on the concepts and proposals of the Town's land development plan. Table 7-3 includes the
description and minimum lot sizes for all established residential districts (Town of Mineral Springs, 2002).
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Table 7-3: Density Limits in Mineral Springs Zoning Ordinance
mats
Zoning District Description Minimum Lot Size (square feet)
Agricultural Residential Single-family and agricultural 2 acres
Rural Residential Single-family and agricultural 1.5 acres
RA-40 Single-family and agricultural 40,000
eihN RA-20 Single-family and agricultural 20,000
R-20 Single-family and agricultural 20,000
7.2.4 Village of Wesley Chapel
The Village of Wesley Chapel Zoning Ordinance (last amended in May 2011) has established twelve
zoning districts under the following general categories: residential, business, conditional use, and airport
overlay districts. Table 7-4 summarizes the residential zoning districts along with minimum lot sizes (Village
of Wesley Chapel, 2010).
Table 7-4: Density Limits in Village of Wesley Chapel Zoning Ordinance
Zoning District Description Minimum Lot Size (square feet)
R-80 Single-family and agricultural 80,000
R-60 Single-family and agricultural 60,000
R-40 Single-family and agricultural 40,000
R-20 Single-family and agricultural 20,000
R-A40 Single-family 40,000
R-A20 Single-family 20,000
Milts
'`i' 7.2.5 Village of Marvin
The Village of Marvin Zoning Ordinance (amended through October 22, 2004) establishes six zoning
districts: Marvin Residential, Marvin Residential Union County, Office, Business, Conditional Zoning, and
Education Overlay. The minimum lot area for single-family dwellings is 43,560 square feet, except for lots
that are located in subdivisions developed to large tract subdivision standards. If built to large tract
subdivision standards, the minimum lot area requirement is 30,000 square feet. Minimum lot widths are
130 feet as measured at the front yard setback (Village of Marvin, 1996).
''i` 7.2.6 Town of Weddington
rom
The Town of Weddington Code of Ordinances was adopted on March 10, 2008. Chapter 58, "Zoning", of
the Code of Ordinances establishes 12 zoning districts under the residential, business, conditional, and
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educational zoning categories. Table 7-5 summarizes minimum lot sizes and widths for residential zoning
jurisdictions. The Town explored zoning alternatives that allow for better integration of the town center and
residential development within and adjacent to this center. Nearly one-half of the Town's area remains
undeveloped and consists primarily of farms and forestland. Using land development data collected in
1995, combined with existing land use guidelines and demographic data, a community growth model was
developed by the Urban Institute at UNC Charlotte as part of Weddington's 1996 Land Use Plan. The
model helped identify the general development trends in the Town. Under this model, Weddington's land
area was categorized as Rural Residential, Developed, or Vacant (Town of Weddington, 2010).
Table 7-5: Density Limits in Town of Weddington Code of Ordinances
Zoning
District
R-80
R-60
R-40
R-40(D)
R-CD
R-E
Description
Single-family, very low density
Single-family, very low density
Single-family, low density
Single-family and duplex lots, low density
Single-family (residential conservation district)
Single-family (residential established, for lots
annexed by the town and do not conform to all
other town zoning districts)
Minimum Lot Size
(square feet)
80,000
60,000
40,000
40,000
40,000
20,000
Minimum Lot
Width (feet)
150
125
120
100
120
100
7.2.7 Town of Indian Trail
Chapter 130, Division 500, and Division 600 of the Town of Indian Trail's Unified Development Ordinance
discuss the zoning districts, base zoning districts, and special purpose districts, respectively. Zoning
classifications in the existing Town limits were originally adopted in 1996 and updated in 2004. There are
seven residential districts, six business and commercial districts, two industrial districts, one institutional
district, and eight special purpose districts. The eight special purpose districts include the following:
manufactured home park overlay zone, Goose Creek overlay district, village center overlay zone,
downtown master plan overlay district, flood plain and flood way overlay district, planned unit development
district, pre-existing development overlay district, and mining overlay district. Approximately 85 percent of
the planning area is zoned as residential single-family subdivisions. Recently, there has been a trend
toward traditional neighborhood developments, planned urban developments, and planned residential
developments. Commercial and industrial zoning is focused along US 74, near the Monroe Regional
Airport, Old Hickory Business Park, and in downtown Indian Trail. Table 7-6 summarizes minimum lot sizes
for the residential zoning jurisdictions (Town of Indian Trail, 2008).
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Table 7-6: Density Limits in Town of Indian Trail Zoning Ordinance
Zoning District Description Minimum Lot Size (square feet)
RSF Rural, single-family 40,000
SF-1 Single-family, low density 20,000
SF-2 Single-family, low/medium density 15,000
SF-3 Single family, medium density 12,000
SF-4 Single-family, medium/high density 10,000
SF-5 Single-family, high density 8,000
MFR Multi -family residential 3,350
O-MHP • Mobile home park overlay NA
7.2.8 Town of Stallings
The Land Usage Ordinance of the Town of Stallings Code of Ordinances was updated in July 2010. The
Ordinance contains five chapters pertaining to flood hazard regulations, subdivision regulations, zoning,
"ON, minimum housing code, and landscaping and tree preservation requirements. The Ordinance establishes
twenty zoning districts, eight of which are residential. Table 7-7 contains the residential zoning districts and
minimum lot sizes (Town of Stallings, 2010).
n�,
Table 7-7: Density Limits in Town of Stallings Land Usage Ordinance
Zoning District Description Minimum Lot Size (square feet)
R-20 Low density residential 20,000
CU-R-20 Low -density residential, conditional use 20,000
R-15 Low density residential 15,000
CU-R-15 Low -density residential, conditional use 15,000
_ R-12 Medium density residential 12,000
CU-R-12 Medium density residential, conditional use 12,000
R-10 Medium density residential 10,000
CU-R-10 Medium density, conditional use 10,000
7.2.9 Town of Hemby Bridge
The Town of Hemby Bridge has adopted Union County's Land Use Ordinance.
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7.2.10 Village of Lake Park
The Village of Lake Park has adopted Union County's Land Use Ordinance. The Village is currently
developing its own Unified Development Ordinance.
7.3 Open Space Plans/Initiatives, Greenways, and Riparian Buffers
7.3.1 Union County
7.3.1.1 Parks and Open Space
Union County adopted a Parks and Recreation Comprehensive Master Plan update in 2006. The Master
Plan outlines the long-range strategies for providing adequate parks and recreation facilities and programs
to Union County residents through 2015. The Plan identifies several large capital projects: development of
the Jesse Helms Park Site, acquisition and development of a North District Park, and joint development
with Union County schools to create a Western School Park. A strong recommendation of the plan is for
the County to cultivate partnerships with the school system and other private recreational providers to
expand parks and recreation offerings. The Master Plan also calls for increasing funding for the countywide
funding and grant program to assist municipalities in the development of community and neighborhood
parks. The County will also become a lead coordinator in development of greenways and trails throughout
the County. The Plan identifies over 120 miles of trails.
There are no overall greenway and open space requirements in the County's Zoning and Subdivision
Ordinance. However, as a condition of using the cluster provision (Section 187), a developer is required to
dedicate at least 10 percent of the total site as permanent open space, 50 percent of which must not be
located in a Special Flood Hazard Area. Sections 187(e)(1) and (2) contains the method to calculate the
open space required, which is calculated by subtracting the proposed lot size for each lot in the
development from the minimum lot size requirement in the zoning district. The sum of the results for each
lot is the amount of open space required. If the result is less than 10 percent of the total development site,
then 10 percent of the total site should be reserved as permanent open space.
There are also open space requirements as a condition of developing mobile home parks and
campgrounds. Mobile home parks require at least 10,000 square feet of open space per 25 mobile home
sites. If there are less than 25 sites planned, the requirement is 10,000 square feet. Campgrounds require
that at least 8 percent of the total site be set aside as common area.
There are no open space requirements for commercial developments or for subdivisions in which the
proposed lots meet or exceed the minimum lot size requirements. The County's Parks and Recreation
Master Plan and the Carolina Thread Trail Master Plan for Union County may be considered during any
quasi-judicial process and conditions can be placed on approved plans related to these adopted plans,
meaning that these Boards may be able to require open space based on these approved plans.
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,t 7.3.1.2 Riparian Buffers
rank,
In water supply watershed overlay districts, a minimum 30-foot vegetative buffer for development activities
is required along all perennial waters indicated on the more recent versions of USGS topographic maps as
_ determined by local government studies per Article XXI of the Land Use Ordinance. Desirable artificial
stream -bank or shoreline stabilization is permitted. New development is not allowed in the buffer except for
water dependent structures and public projects such as road crossings and greenways where no practical
alternative exists. These activities should minimize built -upon surface area, direct runoff away from the
surface water and maximize the utilization of stormwater best management practices.
7.3.2 Town of Waxhaw
According to the Town of Waxhaw 2030 Comprehensive Plan adopted on April 14, 2009, the Town of
Waxhaw values its natural environment and rural character as much as its historic background. The Town's
residents have access to a network of greenways, parks, and open space. New developments will set
aside public green space and cluster development to conserve environmentally sensitive areas. Natural
topography and existing trees will be preserved in new developments. The goal of the Town is to develop a
oast system of greenways, bikeways, and open spaces that will link neighborhoods with activity centers and
_ protect important natural resources.
The General Provisions (Section 9) of the Town's Unified Development Ordinance (adopted in September
9, 2004 and amended through July 26, 2011) contain open space requirements (Section 9-2), buffers,
screening and landscaping (Section 9-8), and tree preservation requirements (Section 9-21). The open
space requirements state that no part of a yard, court or other open space provided around any building or
structure for the purposes of complying with the provision of the Ordinance should be included as part of a
yard or other open space requirement under the Ordinance for another building or structure. Every part of a
"ow, required yard must be open and unobstructed from its lowest level to the sky, except for the ordinary
projection of sills, chimneys, flues and eaves; however, none of the aforesaid projections should project into
flak a minimum side yard more than one third of the width of such yard nor more than 24 inches, whichever is
the least.
ram,
The Town Board designated an Administrator to manage and enforce the tree preservation regulations
stipulated in Section 9.21 of the Unified Development Ordinance. The Tree Preservation Provisions require
that a tree removal permit is required before removing the following:
taxa
• Trees eight inches and larger and any understory tree (e.g. Dogwood, Redbud, Ironwood,
American Holly, etc.) with a caliper measurement of four inches or more or trees on any
parcels of land being developed for nonresidential, multi -family, single-family subdivision or
nonagricultural use.
• Trees growing on slopes over twenty-five percent.
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• Any threatened or endangered species of tree as defined by the North Carolina State
Department of Environmental Conservation, regardless of size.
7.3.3 Town of Mineral Springs
One of the goals of the Town's Land Use Plan is to maintain Mineral Spring's high quality of life by
providing for the protection of open space throughout the community and proactively protecting and
enhancing the community's natural assets and environmental features. The specific goals pertaining to
open space and environmental issues are to provide for open space throughout the community, to ensure
the protection of trees during the development process, and to protect water quality in the Town.
Associated actions with these goals include adopting a greenway plan, making provisions for parks and
other open space areas in the Town Center, adopting a tree ordinance, and adopting stormwater design
guidelines.
Additionally, Article 15 of the Town's Zoning Ordinance has provisions for tree preservation and
landscaping. The Town's Zoning Ordinance was adopted on July 1, 2002 and amended February 14, 2008.
The general provisions for tree protection include the following:
• The Administrator reviews all requests for removal, trimming or cutting of trees in public
areas and required plantings for landscaping and screening on private property. The
Administrator also administers all the provisions of the Article to guarantee that adequate
trees and vegetation have been preserved. The Administrator ensures that all development
is consistent with approved plans, including trees that are designated to be saved.
• The Administrator has the authority to contract or require an applicant or property owner to
contract services from a Town -approved arborist on a case by case basis for the purpose of.
education, review, or recommendations pertaining to preservation, protection, removal,
cutting, pruning, planting, soils, dangers, and diseased and infected trees and their
treatment or removal.
• The Administrator has the authority to approve the removal of trees upon public or private
property only if one of the following two criteria are met: (1) the trees are in an advanced
state of decline, dead, irreparably damaged, hazardous, creating damage to public or
private property or have a strong potential of creating damage to public or private property
as determined by a certified arborist, horticulturist, or landscape architect; (2) the trees are
located where an infrastructure improvement or structure (complying with all applicable
codes) is to be located and the applicant has made all reasonable efforts to relocate the
infrastructure improvement or structure in order to preserve the trees.
Sections 4.22.1 and 4.22.2 contain provisions for Permitted Uses of Open Space and Permanent
Protection of Open Space, respectively, in Article 4 of the Town's Zoning Ordinance. No use or
development is allowed on the required open space, except as follows:
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• Conservation of open land in its natural state.
,tea, • Pastureland for horses.
• Forestry, in keeping with established best management practices for selective harvesting
and sustained yield forestry.
The required open space is subject to a conservation easement that will be held by the homeowners
association, the Town of Mineral Springs, or a conservation organization approved by the Town Council.
esst, Any homeowners association that is a holder of a conservation easement as provided in Section 4.22.4(g)
ivieN is subject to and must comply with all applicable requirements for homeowners associations as set forth in
North Carolina General Statutes. In addition, the following criteria must be met:
• The applicant for subdivision approval shall provide the Town a description of the
organization of the proposed association, including its by-laws, and all documents
governing ownership, maintenance, and use restrictions for common facilities.
• The proposed homeowners association shall be established by the subdivision applicant
and shall be operating (with financial underwriting by the applicant, if necessary) before the
figb, sale of any dwelling units in the development.
• Membership in the homeowners association shall be mandatory for all purchasers of lots
within the subdivision and their successors in title.
• The homeowner' association by-laws shall confer legal authority on the association to place
a lien on the real property of any member who falls delinquent in his dues. Such dues shall
be paid with the accrued interest before the lien may be lifted.
• The homeowners association shall annually provide to the Town a listing of the names,
addresses, and telephone numbers of all their officers and board members.
• Any proposed changes to the conservation easement that substantively affect the usage,
location, or maintenance of conservation land within the conservation subdivision must first
be consented to and approved by 100 percent of the Mineral Springs Town Council and
AiLN 100 percent of all homeowners.
7.3.4 Village of Wesley Chapel
411L1 The Village of Wesley Chapel's Zoning Ordinance and Subdivision Ordinance do not contain any
— provisions for open space/parks/tree preservation.
7.3.5 Village of Marvin
CAtN
fook
e
In 2008, LandDesign Inc. prepared the Village of Marvin Parks and Greenways Master Plan as a guide for
future recreation facility planning and development in the Village of Marvin. There are seven goals of the
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Greenways Master Plan. Each goal is broken down to specific steps in the form of recommendations. The
prioritization of goals, as well as the recommendations and implementation strategies to address each goal,
is the responsibility of the appropriate parties in Marvin (Village of Marvin, 2008). The goals of the
Greenways Master Plan include:
• Provide a safe, interconnected network of parks, greenways and trails.
• Use greenways and parks to promote conservation and environmental protection
• Provide a system built upon strong private -public partnerships.
• Provide neighborhood connectivity to local destinations.
• Expand existing equestrian trails and continue to support Marvin's equestrian heritage.
• Provide for parks and open space for Marvin residents.
• Ensure that all parks, trails and greenways are safe, well maintained, and well managed.
Article V, Section 7 (Dedication of Land and/or Fees in Lieu of Park, Recreation and Open Space
Purposes) of the Village of Marvin Subdivision Ordinance (revised October 2004) provides general
provisions for the dedication of a portion of land to the Village for public park, greenway, recreation, and
open space or pay a fee in lieu thereof. Every developer who proposes a subdivision of land into five lots or
more developed under large tract subdivision standards must dedicate a portion of land to the Village for
public park, greenway, recreation, and open space sites to serve the recreational needs of the residents. At
least one thirty-fifth of an acre must be dedicated for each dwelling unit proposed in the subdivision plat or
development that contains five lots or more (Village of Marvin, 1996a).
Additionally, Section 5.2 of the Village of Marvin Zoning Ordinance provides standards for developments
located in large tract subdivisions. This section provides density standards as well as minimum required
conservation land. At least 15 percent of the gross area of the tract shall be permanently retained as
conservation land. If the required viewshed buffer combined with any additional conservation land on the
tract comprises Tess than 15 percent of the tract area (except when the fee -in -lieu -option is employed by
the Village Council) the minimum lot size must be 87,120 square feet. Certain portions of any tract being
developed as a large tract subdivision are required to be included as conservation land, as follows:
• Viewshed buffers • Tree preservation areas
• Floodplains • Wetlands
• Lakes • Ponds
• Lands proposed for greenways • Hydric soils
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tigiN 7.3.5.1 Riparian Buffers
elms
According to Article 4 Section 10 of the Village of Marvin Subdivision Ordinance (October 22, 2004), stream
buffers are required for all stream segments where the upstream drainage basin is greater than or equal to
_ 50 acres. On each side of the stream, a stream buffer will begin at the edge of the stream channel and
extend perpendicular to the stream a distance equal to the lesser of 100 feet or to a ridgeline that
changes the runoff flow to be away from the stream. A stream buffer must be divided into the following
three stream buffer management zones, each of which has different permitted land uses:
• Streamside Zone — The streamside zone is the thirty feet of stream buffer nearest the
stream channel, measured from the bank. If the stream buffer is at most thirty feet wide,
then the entire stream buffer falls within the streamside zone. With the exceptions noted
below, land uses within the streamside zone are limited to flood control and stream bank
stabilization. Otherwise, land disturbances and vegetation clearing are prohibited. No
buildings are permitted within the streamside zone.
• Managed Use Zone — The managed use zone immediately follows the streamside zone to
elk" a maximum width of 45 feet. If the stream buffer is greater than 30 feet but is at most
75 feet wide, then the stream buffer consists of the 30 feet of streamside zone followed by
the residual as the managed use zone. No buildings are permitted within the managed use
zone.
• Upland Zone — The upland zone immediately follows the managed use zone to a maximum
width of 25 feet. If the stream buffer is greater than 75 feet but is at most 100 feet wide,
takk
then the stream buffer shall consist of 30 feet of streamside zone, followed by 45 feet of
managed use zone, followed by the residual as upland zone. Only small storage buildings
less than twelve feet in every direction are permitted within the upland zone.
7.3.6 Town of Weddington
OK) Section III of the Town of Weddington's Land Use Plan (April 2011) lists the Town's goals associated with
land use. One of the Town's goals is to create a system of open space linkages throughout the planning
area. There is considerable concern over the Town's rapid rate of growth and the associated loss of open
space. Most of the Town is currently zoned R-40 (i.e., 40,000 square foot minimum lots) with only limited
requirements for the provision of open space in subdivisions. The Town's goal is to develop strategies and
regulations for protecting open spaces. There is some concern that the amount and rate of growth that has
Ant, been occurring will eliminate all of the open spaces that are an essential component of the Town's
character. Additionally, land use planning will be used to protect wetlands, floodplains, aquifers and
wellhead protection areas. Furthermore, the Town aims at establishing standards for development on steep
frth
slopes to reduce environmental impacts and hazards to residents. Developments that are built with natural
environmental features are preferred.
401
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rre,
Parks, recreation, and open space are important parts of the quality of life for any community and an
important aspect of a land use plan. Recreational facilities in Weddington are presently limited in scope and
Article II in Chapter 58 of the Town's Code of Ordinances (enacted May 2011) contains the Zoning District
Regulations. The following are the regulations for permitted uses of open space:
location. The Town's one existing facility, partially located within the corporate limits, Optimist Park, isrdifti
located on NC 84. The park contains baseball and soccer fields, a playground, and a picnic area and is
currently in the process of expanding. This facility is not owned by the Town, but rather is owned by a
private non-profit organization. A private, membership -only swim and racquet club is also located on
Weddington-Matthews Road. The Town has created a Parks and Recreation Advisory Board that meets on
a quarterly basis. This board serves as the lead agency for planning, organizing and coordinating a variety elmN
of community improvement and beautification projects. elks
faa
emN
• The required open space is subject to a conservation easement held by the homeowners
association. Any homeowners association that is a holder of a conservation easement is
subject to and must comply with all applicable requirements for homeowners associations r t\
as set forth in the state statutes.
• The applicant for subdivision approval must provide the Town a description of the �►
organization of the proposed association, including its bylaws, and all documents governing
ownership, maintenance and use restrictions for common facilities.
• The proposed homeowners association must be established by the subdivision applicant
and must be operating before the sale of any dwelling units in the development.
• Membership in the homeowners association is mandatory for all purchasers of lots in the
subdivision and their successors in title.
• The homeowners association bylaws must confer legal authority on the association to place
a lien on the real property of any member who falls delinquent in dues. Such dues must be
paid with the accrued interest before the lien may be lifted. ram*
• The homeowners association must annually provide to the town a listing of the names, f""�
addresses and telephone numbers of all officers and board members.
Any proposed changes to the conservation easement that substantially affect the usage, ra"'N
location' or maintenance of conservation land within the conservation subdivision must first
(461
be consented to and approved by 100 percent of the town council and 100 percent of all
homeowners. fa'`
7.3.7 Town of Indian Trail
The Town of Indian Trail intends to implement three systems that serve the recreation and open space
needs of the community: 1) neighborhood and community parks for active use, 2) an open space greenway
network for protection of flood plains and environmentally sensitive areas, and 3) town -wide hike and bike
rails
eaN
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rIP\
trails and a landscaped boulevard system that links the entire community. The parks, boulevards, and
greenways element of the Comprehensive Plan recommends an extensive system to provide a park and
open space network for Indian Trail. This system will require a parks department to implement, maintain
and operate the system. The Town is considering establishing a•parks department when it is warranted by
, the ongoing growth of the community.
(114
The park system is based on the recommended standards published by the National Parks and Recreation
Association. With approximately 2,000 acres of proposed greenway throughout the planning area, there is
ANN an abundant amount of land for a regional greenway/trail system that links parks and boulevards to
mob, neighborhoods and village centers. The Town dedicated nearly 1,000 acres of land dedicated for park and
recreation use as part of the Comprehensive Plan. In keeping with the vision that Indian Trail will preserve
its rural amenities, an extensive greenway network of open space and trails will be preserved throughout
the Town. The floodplains and wetlands will be protected, to avoid flooding as growth continues. This will
eitk also protect environmentally sensitive natural areas and wildlife habitats. In addition to the environmental
benefits, the greenway network will provide a location for a Town -wide hike and bike trail system, which will
interconnect with the boulevard pedestrian and bicycle network, and will provide an amenity for adjacent
neighborhoods and developments. The greenway network will be comprised of a combination of public and
privately owned lands, but the trail system will be public.
Chapter 1160 of the Town's Unified Development Ordinance (amended December 2008) requires that
every applicant who proposes a subdivision of land for residential purposes shall dedicate a portion of land
or pay a fee in lieu thereof, for public park, greenway, recreation, and open space sites to serve the
recreational needs of the residents of the subdivision. Additionally, Section 1160.060 titled "Greenways"
states that greenways may be credited toward the land dedication requirements provided the greenways
are part of the Town's Comprehensive Pedestrian Plan and dedicated to public use. An easement must be
recorded for any greenway and will provide public access for pedestrians, bicyclists, and others expected to
rank, make use of the open space.
7.3.7.1 Riparian Buffers
The Town of Indian Trail's Post -Construction Storm Water Ordinance (adopted September 2007) provides
AINdevelopment standards for the Goose Creek, Twelve Mile Creek, and Crooked Creek Watersheds. The
development standards for both low and high -density projects in the Goose Creek Watershed require that
perennial streams have a 200-foot undisturbed buffer and that intermittent streams have a 100-foot
riaN
undisturbed buffer. Buffer widths are measured horizontally on a line perpendicular to the surface water,
landward from the top of the bank on each side of the stream.
Development standards for both low and high -density projects in the Twelve Mile and Crooked Creek
districts require that all built -upon areas must be a minimum of 30 feet landward of all perennial and
efti
intermittent surface waters in the Twelve Mile Creek and Crooked Creek Watersheds. Buffers widths are
measured horizontally on a line perpendicular to the surface water, landward from the top of the bank on
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each side of the stream. Allowable stream buffer uses include road crossings, driveways crossings,
greenway/hiking trails, bike trails, fences, utility line crossings, parallel or near parallel utility lines, flood
control structures, stream and bank stabilization/restoration projects, grading and re -vegetation, stormwater
BMPs, temporary sediment and erosion control devices, animal trails, and activities permitted under
Section 404 of the Clean Water Act.
7.3.8 Town of Stallings
According to the Stallings Land Use Plan, the Town aims to maintain and enhance the quality of life by
providing meaningful and usable open space areas throughout the community and proactively protecting
and enhancing the community's natural assets and environmental features. The Town will provide for parks
and open space areas throughout the community by establishing, promoting, and implementing a Master
Open Space Plan for the Town that identifies how and where open space areas will be developed,
protected, and utilized. An Open Space Master Plan has not yet been developed. Currently, there are no
greenways in the Town of Stallings. The future Open Space Plan would outline what the Town's overall
open space needs are, how they can be met, and how they could be financed.
Section 151.081 of the Town's Land Usage Ordinances (updated July 2010) states that residential
subdivisions must dedicate a portion of land to open space or pay a fee in lieu thereof. At least one thirty-
fifth of an acre shall be dedicated for each dwelling unit planned or proposed in the subdivision plat or
development. Section 152.102 titled "Open Space Requirements" states that no part of a yard, court, or
other open space provided around any building or structure for the purpose of complying with the
provisions of the Ordinance can be included as part of a yard or other required open space for another
building or structure.
7.3.8.1 Riparian Buffers
The Town of Stallings' Post -Construction Storm Water Ordinance (adopted September 2007) is identical to
that of the Town of Indian Trail. Stream buffer requirements are provided for development standards for
both low and high -density projects in the Twelve Mile Creek, Crooked Creek, and Goose Creek districts.
Refer to Section 7.3.7.1 for details on stream buffer requirements.
7.3.9 Town of Hemby Bridge
The Town of Hemby Bridge has adopted the County's Land Use Ordinance.
7.3.10 Village of Lake Park
The Village of Lake Park has adopted the County's Land Use Ordinance.
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7.4 Erosion and Sedimentation Control
7.4.1 Union County
The DENR Division of Land Resources (DLR) implements and enforces the Union County ESC Plan.
DENR regulates land -disturbing activities to control accelerated erosion and sedimentation in order to
prevent the pollution of water and damages to lakes, watercourses, and other public and private property.
According to Article XVI Section 264 of the County's Land Use Ordinance (codified August 31, 2008), no
✓ zoning, special use, conditional use, or major development permit may be issued for any development that
causes land -disturbing activity prior to submission of an erosion and sedimentation control plan. An erosion
and sedimentation control plan must be submitted to the N.C. Sedimentation Control Commission under
G.S. 113A-57(4). Prior to any permit being issued or any work commencing, the developer must file with
the County's Land Use Administrator a copy of the approved sedimentation and erosion control plan and a
letter of approval from DENR.
7.4.2 Town of Waxhaw
'at` The Town of Waxhaw's erosion and sedimentation control program is implemented and enforced by DLR.
7.4.3 Town of Mineral Springs
taN
The Town of Mineral Spring's erosion and sedimentation control program is implemented and enforced by
DLR.
7.4.4 Village of Wesley Chapel
"k` The Village of Wesley Chapel adopted the Drainage, Stormwater Management and Wetland Protection
pm, Ordinance (Article 14 of the Village Zoning Ordinance) on September 14, 2009. The requirements set forth
by the Drainage, Stormwater Management and Wetland Protection Ordinance are organized in the
following categories:
• Natural drainage system utilized to extent feasible.
• Proper drainage within developments.
rat‘
• General standards for stormwater management.
tab,
• Requirements for stormwater management plan approval.
r • • Maintenance of stormwater facilities.
The provisions of the Drainage, Stormwater Management & Wetland Protection Ordinance are enforced by
the Zoning Administrator, his or her designee, or any authorized agent of the Village of Wesley Chapel
(Village of Wesley Chapel, 2009).
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7.4.5 Village of Marvin
The Village of Marvin's erosion and sedimentation control program is implemented and enforced by DLR.
7.4.6 Town of Weddington
The Town of Weddington's erosion and sedimentation control program is found in Chapter 8- Article III of
the Town's Code of Ordinances (adopted March 10, 2008). The Town's Erosion and Sediment Control
Ordinance is modeled after the State program and is enforced by DLR.
7.4.7 Town of Indian Trail
The Town of Indian Trail's erosion and sedimentation control program is implemented by DLR. The Town's
Unified Development Ordinance (Chapter 1390) discusses erosion and sedimentation control and states
that in order to prevent soil erosion and sedimentation pollution of waterways, the applicant must comply
with all requirements of the North Carolina Pollution Control Act. A plan must be submitted and approved
by the Sedimentation Control Commission and a copy of the plan and permit must be provided to the Town
prior to Zoning Certificate permit issuance.
7.4.8 Town of Stallings
The Town of Stallings adopted the Post -Construction Storm Water Ordinance in September 2007 as part of
the Town's Code of Ordinances, which provides provisions for sedimentation and soil erosion prevention.
The Town of Stallings designates a storm water administrator to administer and enforce the Post -
Construction Storm Water Ordinance. The Post -Construction Storm Water Ordinance contains different
development standards for the portions of the Town within the Twelve Mile, Crooked Creek, and Goose
Creek Watersheds (Town of Stallings, 2007).
7.4.9 Town of Hemby Bridge
The Town of Hemby Bridge's erosion and sedimentation control program is implemented and enforced by
DLR.
7.4.10 Village of Lake Park
The Village of Lake Park's erosion and sedimentation control program is implemented and enforced by
DLR.
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7.5 Stormwater Programs and Impervious Surface Limitation
r=,
The Goose Creek Watershed located in the northern tip of Union County is home to the Carolina
heelsplitter mussel, a federally endangered species since 1993. To protect the water quality conditions and
habitat that are necessary for the Carolina heelsplitter mussel, a set of management rules known as the
Goose Creek Watershed Site Specific Water Quality Management Plan was adopted by the Environmental
Management Commission (EMC). The Goose Creek Watershed Site Specific Water Quality Management
Plan became effective February 1, 2009. Parts of the Town of Stallings, the Town of Indian Trail, and the
esik Town of Hemby Bridge are located in the Goose Creek Watershed are therefore affected by the Water
Quality Management Plan. The Goose Creek Watershed Site Specific Water Quality Management Plan
contains the following requirements:
• Control of stormwater for projects disturbing one acre or more of land and an increase in
r-
impervious surface (there is no density threshold associated with this requirement).
• No new NPDES wastewater discharges or expansions to existing discharges will be
permitted.
• No activity that results in direct or indirect discharge is allowed if it causes toxicity to the
Carolina heelsplitter. Ammonia toxicity is to be reduced.
• Maintain undisturbed riparian buffers (200 feet either side of a stream in a floodplain,
100 feet on either side of a stream outside a floodplain) when a change in land use occurs
regardless of the amount of area disturbed. The riparian buffer rules become effective
immediately as soon as any change in land use takes place.
In the Six Mile and Waxhaw Creek watersheds, DWQ implements the first and fourth requirements listed
above. However, one acre or more of land must be disturbed before the riparian buffer rule is effective. The
►a*, only municipality in the Twelve Mile Creek service area located in either the Six Mile or Waxhaw Creek
watershed is the Town of Waxhaw, which is consequently effected by the Water Quality Management Plan.
All the municipalities in Union County are identified under EPA's NPDES Stormwater Phase II Rule
(Phase II) as tipped Phase II communities. DWQ implements post -construction requirements, the Goose
4=N Creek Site Specific Water Quality Management Plan (in affected municipalities), and Stormwater
Management Permits for all of Union County except for the Town of Stallings, Town of Indian Trail, and
fAIN
Village of Lake Park unless development is in a Water Supply Watershed, then Water Supply Watershed
`� rules apply.
(1124,
7.5.1 Union County
Union County is a Phase II tipped county, indicating that all new development that will disturb one acre or
'xt, more of land in the County must apply for a stormwater management permit (for post -construction) from
DWQ. Furthermore, Union County does have general stormwater requirements in Sections 261 to 263 of
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Article XVI in the Land Use Ordinance (codified August 31, 2008). The County's stormwater requirements
are as follows:
• To the extent practicable, all development shall conform to the natural contours of the land
and natural and pre-existing man-made drainage ways must remain undisturbed.
• To the extent practicable, lot boundaries must be made to coincide with natural and pre-
existing man-made drainage ways in subdivisions to avoid the creation of lots that can be
built upon only by altering such drainage ways.
• All developments must be provided with a drainage system that is adequate to prevent the
undue retention of surface water on the development site. Surface water must not be �°►
regarded as unduly retained if:
o The retention results from a technique, practice or device deliberately installed as part
of an approved sedimentation or storm water runoff control plan; or
o The retention is not substantially different in location or degree than that experienced
by the development site in its pre -development stage, unless such retention presents a
danger to health or safety.
• No surface water may be channeled or directed into a sanitary sewer.
• Whenever practicable, the drainage system of a development must coordinate with and
connect to the drainage systems or drainage ways on surrounding properties or street.
• Drainage swales may be used in residential districts where all lots equal or exceed
20,000 square feet.egibl
• Private roads and access ways in un-subdivided developments must utiliz6 curb -and -gutter
systems and storm drains to provide adequate drainage if the grade of such roads or
access ways is too steep to provide drainage in another manner or if other sufficient ea°►
reasons exist to require such construction.
• All developments must be constructed and maintained so that adjacent properties are not
unreasonably burdened with surface waters as a result of such developments. More
specifically:
o No development may be constructed or maintained so that such development impedes
the natural flow of water from higher adjacent properties across such development,
thereby causing damage to such higher adjacent properties; and egiN
o No development may be constructed or maintained so that surface waters from such rob‘
development are collected and channeled onto lower adjacent properties at such p+t,
locations or at such volumes as to cause damage to such lower adjacent properties. r
efts
In Section 187 of Article XII of the Land Use Ordinance, stormwater management is a requirement to use
the Cluster Provision. Post development discharge rate at the property boundary must be equal to the pre- tarb'
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development rate for the two and twenty-five year storm events. This rule is not applicable if stormwater is
directly discharging into a FEMA regulated floodplain.
rk-‘
7.5.2 Town of Waxhaw
The Town of Waxhaw is a Phase 11 tipped community. DWQ implements post -construction requirements
and issues stormwater management permits. Furthermore, a small southern portion of the Town of
Waxhaw is located in the Waxhaw Creek Watershed, which contains the provisions described in the Goose
Creek Site Specific Water Quality Management Plan.
The Town of Waxhaw has a Stormwater Design Manual, written in March 2000, which serves as a guide
eait
for engineers for the planning and design of stormwater control structures and systems in the Town. No
development or use of land that creates more than 20,000 square feet of impervious ground cover will be
permitted without the submission and approval of a drainage plan by the Town Engineer, with the exception
;,®, of land development used for agricultural purposes: The drainage plan must include a site plan showing
existing and proposed buildings, storm water drainage facilities and impervious ground cover, site
construction plans, grading plans and drainage system, drainage facility design data, a drainage area map,
engineering calculations, area of impervious cover, total land area, and any other appropriate information
requested by the Town Engineer (Town of Waxhaw; 2000).
7.5.3 Town of Mineral Springs
The Town of Mineral Springs is a Phase II tipped community. DWQ implements post -construction
requirements and issues stormwater management permits. Article 14 of the Town of Mineral Springs
Zoning Ordinance, adopted in February 2007, provides regulations regarding floodplains, drainage,
stormwater management, and wetland protection. Specifically, Section 14.18 specifies the required
o°` drainage easement for all lots containing storm drainage pipes or channels. The minimum drainage
fita easement guide for all open channels and streams are as follows:
• Less than 25 acres — a drainage easement of 20 feet.
• Less than 50acres — a drainage easement of 30 feet.
r • Less than 75 acres — a drainage easement of 40 feet.
• More than 75 acres — a drainage easement of 50 feet.
• All drainage pipes shall have a minimum drainage easement width of twenty feet.
ram- ,
7.5.4 Village of Wesley Chapel
The Village of Wesley Chapel is a Phase II tipped community. DWQ implements post -construction
requirements and issues stormwater management permits. The Village was exempt from an MS4 permit.
According to the Drainage, Stormwater Management and Wetland Protection Ordinance (Article 14 of the
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Village's Zoning Ordinance), all development must conform to the natural contours of the land and natural
and pre-existing manmade drainage ways must remain undisturbed. Lot boundaries must be made to
coincide with natural and pre-existing manmade drainage ways in subdivisions to eliminate the creation of
lots that could only be built upon by altering such drainage ways. The Ordinance was last revised in
October 2008.
The Drainage, Storm Water Management and Wetland Protection Ordinance requires that all
developments be provided with a drainage system that is adequate to prevent the undue retention of
surface water on the development site. No development may be constructed or maintained so that the
development unreasonably impedes the natural flow of water from high adjacent properties across such
development, thereby unreasonably causing substantial damage to such higher adjacent properties. No
surface water may be channeled or directed into a sanitary sewer. Whenever practicable, the drainage
system of a development must coordinate with and connect to the drainage systems or drainage ways on
surrounding properties or adjacent streets.
Determination of practicability will be made by the Village engineer during Stormwater Management
Concept Plan review. The Stormwater Management Concept Plan is a document detailing the concept of
how runoff, resulting from development, will be controlled or managed. No conditional use, vested rights,
rezoning, or zoning application for non-residential uses or preliminary subdivision plat for residential or non-
residential uses will be considered complete unless it includes a Stormwater Management Concept Plan.
Private roads and access ways in non -subdivided developments must utilize curb -and -gutter systems and
storm drains to provide adequate drainage if the grade of such roads or access ways is too steep to provide
drainage in another manner, or if other sufficient reasons exist to require such construction. Construction
specifications for drainage swales, curbs and gutters, and storm drains must be reviewed and approved by
the zoning administrator with the assistance of the Village's engineering consultant, as necessary. All
systems must be designed in accordance with the Village of Wesley Chapel Drainage, Storm Water
Management and Wetland Protection Ordinance. The general standards for stormwater management are
as follows:
• All non-residential development and major residential subdivisions must provide stormwater
management facilities to control the peak stormwater runoff. Facilities must be designed to
control the peak runoff from the 1-, 2-, 10-, and 25-year, 24-hour storm events to pre -
development levels, and must safely pass the 50- and 100-year, 24-hour storm with
minimum 0.5 feet of freeboard. Stormwater management facilities must not be located
within 10 feet of any property lines.
• Minor residential subdivisions and individual single-family residences are exempt from
requirements of this section. A minor subdivision is any subdivision that does not result in
the creation of more than three lots out of a single tract. A minor subdivision also does not
involve an area larger than six acres as well as any subdivision that does not include any
floodplains or wetlands, nor require the construction of new streets, roads, public water or
sewer facilities, sidewalks, or similar facilities.
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Village's Zoning Ordinance), all development must conform to the natural contours of the land and natural
and pre-existing manmade drainage ways must remain undisturbed. Lot boundaries must be made to
coincide with natural and pre-existing manmade drainage ways in subdivisions to eliminate the creation of
Tots that could only be built upon by altering such drainage ways. The Ordinance was last revised in
October 2008.
The Drainage, Storm Water Management and Wetland Protection Ordinance requires that all
developments be provided with a drainage system that is adequate to prevent the undue retention of
surface water on the development site. No development may be constructed or maintained so that the
development unreasonably impedes the natural flow of water from high adjacent properties across such
development, thereby unreasonably causing substantial damage to such higher adjacent properties. No
surface water may be channeled or directed into a sanitary sewer. Whenever practicable, the drainage
system of a development must coordinate with and connect to the drainage systems or drainage ways on
surrounding properties or adjacent streets.
Determination of practicability will be made by the Village engineer during Stormwater Management
Concept Plan review. The Stormwater Management Concept Plan is a document detailing the concept of
how runoff, resulting from development, will be controlled or managed. No conditional use, vested rights,
rezoning, or zoning application for non-residential uses or preliminary subdivision plat for residential or non-
residential uses will be considered complete unless it includes a Stormwater Management Concept Plan.
Private roads and access ways in non -subdivided developments must utilize curb -and -gutter systems and
storm drains to provide adequate drainage if the grade of such roads or access ways is too steep to provide
drainage in another manner, or if other sufficient reasons exist to require such construction. Construction
specifications for drainage swales, curbs and gutters, and storm drains must be reviewed and approved by
the zoning administrator with the assistance of the Village's engineering consultant, as necessary. All
systems must be designed in accordance with the Village of Wesley Chapel Drainage, Storm Water
Management and Wetland Protection Ordinance. The general standards for stormwater management are
as follows:
• All non-residential development and major residential subdivisions must provide stormwater
management facilities to control the peak stormwater runoff. Facilities must be designed to
control the peak runoff from the 1-, 2-, 10-, and 25-year, 24-hour storm events to pre -
development levels, and must safely pass the 50- and 100-year, 24-hour storm with
minimum 0.5 feet of freeboard. Stormwater management facilities must not be located
within 10 feet of any property lines.
• Minor residential subdivisions and individual single-family residences are exempt from
requirements of this section. A minor subdivision is any subdivision that does not result in
the creation of more than three lots out of a single tract. A minor subdivision also does not
involve an area larger than six acres as well as any subdivision that does not include any
floodplains or wetlands, nor require the construction of new streets, roads, public water or
sewer facilities, sidewalks, or similar facilities.
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r • Additions to existing non-residential structures that are over 50 percent of the existing floor
area square footage will be subject to the requirements of this section.
• All developments with existing impervious area that add impervious area (structural or non-
structural), including demolition of existing structures for purposes of redevelopment, must
provide detention only for the newly added impervious area.
ems
• Where stormwater management facilities are proposed to be constructed, the owners must
rsch, agree to perpetual maintenance of the facility. At a minimum, the facility will be inspected
exts by a registered North Carolina professional engineer on a yearly basis. The annual •
inspection report must be submitted by the owner to the Zoning Administrator for purposes
✓ of compliance.
• No certificate of occupancy or release of sureties will be issued forany development until:
eAtN
eseN o A professional land surveyor has surveyed the as -built storm drainage and stormwater
management facilities.
✓ o Any required revised calculations based upon as -built conditions have been submitted
and approved by the Village.
o The facility has been stabilized consistent with the DENR standards and specifications.
,L o The as -built survey, final calculations, and facility have been reviewed and inspected,
and final approval has been given by the Village.
• When a stormwater management facility serves more than one property, a permanent
drainage easement that encompasses the facility must be shown on a recorded plat along
with an access easement from the facility to a public right of way.
eaN
• There will be a note placed on the recorded plat that clearly describes who is responsible
for maintenance of the stormwater management facilities, pipes and/or channels located in
the permanent facility.
efflos
7.5.5 Village of Marvin
The Village of Marvin is a Phase II tipped community. The Village of Marvin has adopted and incorporated
the provisions contained in the Charlotte -Mecklenburg Stormwater Manual, as amended with the following
exceptions:
• Deviations from the Stormwater Manual may be necessary to accommodate soil types
found in Union County, and Village of Marvin Subdivision and Zoning Regulations. When
discrepancies are found between the Charlotte -Mecklenburg Stormwater Manual and the
Village of Marvin Zoning Ordinance or Subdivision Ordinance, the stricter regulation will
apply.
(041
Agra
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• In order to prevent flooding and damage to properties, all developments must provide
stormwater detention to control the peak runoff from the 2-, 10-, 25-, 50- and 100-year, 24-
hour storm events to pre development levels.
• A design professional must certify documents demonstrating that construction of the project
or subdivision will not increase the rate of runoff from the site nor cause any adverse
impacts on downstream facilities or property.
• Where ponds are proposed to be constructed, the owners, heirs, assignees, or successors
of the land must agree to perpetual maintenance of the pond. At a minimum, ponds must
be inspected on a yearly basis.
• No certificate of occupancy or release of performance bond funds (as addressed in Article
V, Section 2 of the Marvin Subdivision Ordinance) will be issued for any development until
a registered land surveyor has surveyed the as -built detention facilities and the revised
calculations have been submitted and approved by the Village. The Village will not grant
final plat approval unless the Village has approved the as -built detention plans and/or a
performance bond has been secured.
• When a detention facility serves more than one property, a "permanent detention
easement" which encompasses the detention facility must be shown.on a recorded plat.
This easement must be described by a metes and bounds description.
• There shall be a note placed on the recorded plat that clearly describes who is responsible
for maintenance of the detention facilities, pipes and/or channels located within the
permanent detention facility.
• The Village Engineer, on a case -by -case basis, may approve other deviations from the
Stormwater Manual.
7.5.6 Town of Weddington
The Town of Weddington is a Phase II tipped community. Post -construction provisions are administered by
DWQ. The Town of Weddington's Drainage, Stormwater Management and Wetland Protection Ordinance
(Article XIII of the Town's Code of Ordinances adopted on October 13, 2008) requires the same provisions
as Union County's stormwater requirements in Sections 261 to 263 of Article XVI in the County's Land Use
Ordinance.
7.5.7 Town of Indian Trail
The Town of Indian Trail has been a NPDES Phase II community since 2005. The Phase II program
extends permit coverage to communities with populations less than 100,000 and public entities that own or
operate a municipal separate storm sewer system. The components of the Phase II program are public
outreach and education, public involvement and participation, illicit discharge detection and elimination,
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construction site runoff controls, post -construction site runoff controls, and pollution prevention and good
housekeeping for municipal operations.
The Town's Post -Construction Storm Water Ordinance was adopted on September 2007 and amended on
June 2010 and can be found in Appendix III (Division 1700) in the Town's Unified Development Ordinance.
According to the Post -Construction Storm Water Ordinance, all development creating 20,000 square feet or
more of impervious area must provide stormwater detention to control the peak stormwater runoff. This
tgat
includes all new major subdivisions where the cumulative impervious area exceeds the 20,000 square foot
F"N threshold. Stormwater detention must be designed to control the peak runoff from the 2-, 10 25-, 50- and
/fi 100-year, 24-hour storm events to pre -development levels. Stormwater detention must not be located
within a FEMA floodplain or in a drainage area where the 100-year flood is within 10 feet of any property
lines. Design of the stormwater measures must be consistent with the Town of Indian Trail Stormwater
Design Manual adopted in 2005. Additionally, all non -conforming developments (existing impervious area
eath greater than 20,000 square feet) adding impervious area must provide detention for the newly added
eiihN impervious area only in compliance with the UDO. The Town Engineer administers provisions found in the
Post -Construction Storm Water Ordinance and the Stormwater Design Manual (Town of Indian Trail, 2007).
OwN
7.5.8 Town of Stallings
The Town of Stallings adopted the Post -Construction Storm Water Ordinance in September 2007 as part of
the Town's Code of Ordinances. The Town of Stallings designates a storm water administrator to
roaN
administer and enforce the ordinance. The Post -Construction Storm Water Ordinance contains different
est*' development standards for the portions of the Town in the Twelve Mile, Crooked Creek, and Goose oft, Watersheds.
The Town also has a Stormwater Advisory Committee and a Stormwater Illicit Discharge Ordinance, which
regulates the contribution of pollutants to the municipal system, prohibits illicit connections and illicit
discharges to the system, and establishes legal authority to carry out all inspection, surveillance,
monitoring, enforcement, and penalty procedures necessary to ensure compliance with the Ordinance.
7.5.9 Town of Hemby Bridge
The Town of Hemby Bridge is a tipped Phase II community. DWQ implements the post -construction
stormwater requirements and issues stormwater management permits for the Town.
7.5.10 Village of Lake Park
The Village of Lake Park jurisdiction has a Phase II permit program, which has been approved by DWQ.
Additionally, the Village adopted a Post Construction Stormwater Controls Ordinance on June 10, 2008,
which is enforced by the stormwater administrator appointed by the Village. Sections 814, 815, and 816 of
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the Post Construction Stormwater Controls Ordinance contains development standards for low -density
projects, high -density projects, and stormwater control measures.
7.6 Floodplain Development Regulations
In Part 6 of Article 21 of Chapter 143; Parts 3, 5, and 8 of Article 19 of Chapter 106A; and Article 8 of
Chapter 160A of the NCGS, the State of North Carolina has delegated the responsibility of local
government units to adopt regulation designed to promote the public health, safety and general welfare of
its citizenry. Flood hazard areas are subject to periodic inundation that may result in the loss of life,
property, health and safety hazards, disruption of commerce and governmental services, extraordinary
public expenditures of flood protection and relief, and impairment of the tax base, all of which adversely
affect public health, safety, and general welfare. These flood losses are caused by the cumulative effect of
obstruction in floodplains, causing increases in flood heights and velocities, and by the occupancy in flood
hazard areas by uses vulnerable to floods or hazardous to other lands that are inadequately elevated, flood
proofed, or otherwise protected from flood damages.
7.6.1 Union County
Article XXIV of the Union County Land Use Ordinance (Sections 400, 401, and 402) applies to all Special
Flood Hazard Areas in the jurisdiction of the County and in the jurisdictions of the Town of Hemby Bridge
and the Village of Lake Park. Union County's Land Use Ordinance contain provisions that more strict than
FEMA requirements. The latest adoption date of the Flood Damage Prevention Ordinance is October 8,
2010. A floodplain development permit is required prior to the commencement of any development
activities in determined Special Flood Hazard Areas. An application for a floodplain development permit is
made to the County's Floodplain Administrator prior to any development activities located in Special Flood
Hazard Areas. The following provisions are required in all Special Flood Hazard Areas:
• New construction and substantial improvements must be designed and adequately
anchored to prevent flotation, collapse, and lateral movement of the structure.
• New construction and substantial improvements must be constructed with materials and
utility equipment resistant to flood damage and that minimizes flood damages.
• Electrical, heating, ventilation, plumbing, air conditioning equipment, and other service
facilities must be designed and/or located to prevent water from entering or accumulating
in the components during conditions of flooding to the Regulatory Flood Protection
Elevation.
• All new and replacement water supply systems must be designed to minimize or eliminate
infiltration of floodwaters into the system.
• New and replacement sanitary sewage systems must be designed to minimize or
eliminate infiltration of floodwaters into the systems and discharges from the systems into
floodwaters.
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sizes • On -site waste disposal systems must be located and constructed to avoid impairment to
them or contamination from them during flooding.
• Any alteration, repair, reconstruction, or improvements to a structure in compliance with
the provisions of the Ordinance must meet the requirements of "new construction."
• Nothing in the Ordinance will prevent the repair, reconstruction, or replacement of a
building or structure existing on the effective date of the ordinance and located completely
or partially in the floodway, non -encroachment area, or stream setback, provided there is
no additional encroachment below the Regulatory Flood Protection Elevation in the
/lob, floodway, non -encroachment area, or stream setback, and provided that the repair,
reconstruction, or replacement meets all of the other requirements of the Ordinance.
ILN
• New solids waste disposal facilities and sites, hazardous waste management facilities,
salvage yards, and chemical storage facilities will not be permitted.
esk
• All subdivision proposals and other development proposals must be consistent with the
need to minimize flood damage.
cAN
• All subdivision proposals and other development proposals must have public utilities and
facilities such as sewer, gas, electrical, and water systems located and constructed to
minimize flood damage.
Am, • All subdivision proposals and other development proposals must have adequate drainage
fott+ provided to reduce exposure to flood hazards.
• All subdivision proposals and other development proposals must have received all
,�, necessary permits from those governmental agencies for which approval is required by
Federal or State law, including Section 404 of the Federal Water Pollution Control Act
fiszN
Amendments of 1972, 33 U.S.C. 1334.
• When a structure is partially located in a Special Flood Hazard Area, the entire structure
ext
must meet the requirements for new construction and substantial improvements.
• When a structure is located in multiple flood hazard zones or in a flood hazard risk zone
with multiple BFEs, the provisions for the more restrictive flood hazard risk zone and the
highest BFE will apply.
rot,
Furthermore, specific standards for residential construction, non-residential construction, manufactured
r
homes, elevated buildings, additions/improvements, recreational vehicles, and accessory structures are
provided in Article XXIV of the Union County Land Use Ordinance. The specific standards for residential
and non-residential construction are as follows:
• New construction and substantial improvement of any residential structure (including
manufactured homes) must have the reference level, including basement, elevated no
lower than the Regulatory Flood Protection Elevation.
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• New construction and substantial improvement of any commercial, industrial, or other non-
residential structure must have the reference level, including basement, elevated no lower
than the Regulatory Flood Protection Elevation. Structures located in A, AE, and A1-30
Zones may be flood -proofed to the Regulatory Flood Protection Elevation in lieu of
elevation provided that all areas of the'structure, together with attendant utility and sanitary
facilities, below the Regulatory Flood Protection Elevation are watertight with walls
substantially impermeable to the passage of water, using structural components having the
capability of resisting hydrostatic and hydrodynamic Toads and the effect of buoyancy. A
registered professional engineer or architect must certify that the flood proofing standards
of this subsection are satisfied. Such certification shall be provided to the Floodplain
Administrator as set forth in Section 394 of the Ordinance, along with the operational plan
and the inspection and maintenance plan.
7.6.2 Town of Waxhaw
Floodplain areas in Waxhaw lie along Twelve Mile Creek that runs south of Kensington Drive and
Cuthbertson Road. The town's Unified Development Ordinance (UDO) includes a Floodplain Overlay
District that restricts development in these areas. Development in Waxhaw's floodplains is not prohibited,
but it is regulated per the Town's UDO. The UDO meets FEMA requirements. The Flood Hazard Overlay
District exists to protect human life and health, to minimize expenditure of public money for costly floodplain
control projects, rescue and relief efforts, and damage to public facilities and utilities, and to ensure
potential homebuyers are notified that property is in a flood area.
When development in a floodplain would cause the water elevation to rise one or more feet during a
100-year storm, developers must submit plans and flood studies for any proposed construction activity to
the Federal Emergency Management Agency (FEMA) for approval, prior to submitting development
applications to the Town of Waxhaw. The lowest floor of all structures built in floodplain areas (including the
basement) must be elevated at least two feet above the base flood elevation. Flood proofing must be
certified by a registered professional engineer or architect. Utilities and structures in subdivisions must be
constructed and located in ways that minimize flood damage and provide adequate drainage.
7.6.3 Town of Mineral Springs
The Town of Mineral Springs enforces its own Floodplain, Drainage, Stormwater Management and
Wetland Protection Ordinance in Article 14 in the Town's Zoning Ordinance adopted in February 2007.
These regulations contain the same requirements as the Village of Marvin.
7.6.4 Village of Wesley Chapel
The Village enforces its own Flood Damage Prevention Ordinance 2008-13, which promotes public health,
safety, and general welfare to minimize public and private losses due to flood conditions within flood prone
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areas. The Ordinance was adopted on January 12, 2009 and revised on September 14, 2009. The
requirements stipulated in the Ordinance are the same as those in Union County's Ordinance.
egEN
7.6.5 Village of Marvin
All development that takes place in a floodplain in the Village of Marvin must meet the provisions of the
Village's Floodplains, Drainage, Stormwater Management and Wetland Protection Ordinance (Article 14 of
the Zoning Ordinance) as enforced by the Village. Sections of the Ordinance were last amended on
r"' March 10, 2009. The objectives of the Ordinance are: •
• To protect human life and health.
• To minimize expenditure of public money for costly control projects.
• To minimize the need for rescue and relief efforts associated with flooding and generally
ise' undertaken at the expense of the general public.
• To minimize prolonged business interruptions.
• To minimize damage to public facilities and utilities such as water and gas mains, electric,
telephone and sewer lines, and streets and bridges located in floodplains.
• To help maintain a stable tax base by providing for the sound use and development of
flood -prone areas in such a manner as to minimize future flood blight areas.
row'• To ensure that potential buyers are aware that property is in a Special Flood Hazard Area.
A floodplain development permit is required in conformance with the provisions of these regulations prior to
the commencement of any development activities. No structure or land must be located, extended,
converted or structurally altered without full compliance with the terms of the Village's regulations.
Furthermore, provisions for flood hazard reduction provided by the Ordinance include:
• No encroachments, including fill, new construction, stormwater detention, substantial
tit>, improvements and other developments will be permitted in any portion of a floodplain
and/or future floodplain, unless a variance is granted, with the following exceptions:
exz.` o The development is for greenway trails, boardwalks, pedestrian crossings, agricultural
,m-N uses, forestry, parks, playground or other park related equipment, fences, provided at
least 80 percent of the fence is open area, and is elevated at a minimum, one foot
above the ground.
o Public utilities and facilities such as wastewater utility lines, storm drainage construction
and repair with approval by the Village Consulting Engineer, gas, electrical, water
systems and similar uses that are located and constructed to minimize flood damage.
exks
• With respect to manufactured home parks that are nonconforming because they are
located in a floodplain, mobile homes may be relocated only if the lowest floor of relocated
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or replacement manufactured homes are elevated at least two feet above the FEMA BFE
or one foot above the Future BFE (if applicable).
• No new residential or non-residential building may be constructed and no substantial
improvement of a residential building may take place in any Floodplain unless a variance is
granted.
• Lots within Floodplains will not be approved for recordation unless the following provisions
are met:
o Lots wholly subject to flooding: No proposed building lot that lies in the floodplain
and/or future Floodplain will be approved.
o Lots partially subject to flooding: No proposed building lot that lies partially in the
floodplain and/or future floodplain will be approved unless there is a contour line
representing the FEMA BFE or the Future BFE established on the plot plan.
o Where only a portion of a proposed lot is subject to flooding, the lot may be approved
only if there will be available space for building a usable lot area of not less than
5,000 square feet. The usable lot area will be determined by deducting from the total lot
area, the area of all yard setbacks required by the applicable zoning regulations and
any remaining area of the lot lying within the area of the FEMA base flood or the future
base flood of the Ordinance.
o Usable and functional parts of the structure are defined as being inclusive of living
areas, basements, sunken dens, basement utility rooms, crawlspaces, attached
carports, garages, and mechanical appurtenances such as furnaces, air conditioners,
water pumps, electrical conduits and wiring. These parts shall not include water lines or
sanitary sewer traps, piping and clean -outs; provided openings serving the structure
are above the FEMA base flood or future base flood level.
• The future base flood elevation and the location of the future flood fringe line is established
for all large tract subdivisions and all non-residential development prior to the approval of
any development in, or within one hundred feet, of a floodplain as deemed necessary by
the Village Engineer.
• Construction of buildings within 100 feet of the limits of the FEMA Flood Fringe Line or the
Future Flood Fringe Line (measured perpendicular to the stream centerline) will have the
lowest floor, including basement, elevated no lower than: two feet above the FEMA Base
Flood Elevation or, one foot above the Future Base Flood Elevation of the Ordinance, or
three feet above the highest adjacent grade (if adjacent to an approximate Zone A area).
These elevation requirements shall be documented by a professional land surveyor on an
as -built survey of the building.
• All new non-residential development, private or public roads and all areas for the parking of
vehicles such as automobiles, trucks, and trailers, shall not be located in the future
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floodplain. Notwithstanding, parking areas for access to public parks and greenways may
be permitted if constructed with pervious materials and shall be approved by the Zoning
Administrator.
7.6.6 Town of Weddington
The Town of Weddington enforces its own Flood Damage Prevention, Stormwater Management and
Wetland Protection Ordinance as Article XIII of Chapter 58 (Zoning) in the Town's Code of Ordinances,
which was adopted on March 10, 2008. These regulations contain the same requirements as those
described for Union County.
7.6.7 Town of Indian Trail
The Town of Indian Trail enforces its own Flood Damage Reduction Ordinance in Chapter 1360 under
Division 1300 of the Town's Unified Development Ordinance, adopted on December 30, 2008. The
Ordinance provides general and specific provisions for flood hazard reduction. These provisions are
identical to those for Union County.
The Town's Flood Damage Reduction Ordinance is more restrictive than FEMA's minimum requirements in
that the Town only allows fill in the flood plain for public projects and not in the floodway. Development in
the Special Flood Hazard Area requires a variance and no fill is allowed in the floodways for private
development.
7.6.8 Town of Stallings
Chapter 150 of the Town's Land Usage Ordinance is the Flood Damage Prevention Ordinance, which has
been updated through July 12, 2010. A flood development permit will be required in conformance with the
provisions of the Flood Damage Prevention Ordinance prior to the commencement of any development
activities in Special Flood Hazard Areas determined in accordance with the requirements of the Ordinance.
The provisions for flood hazard reduction in the Town of Stallings are identical to those in Union County.
7.6.9 Town of Hemby Bridge
The Town of Hemby Bridge has adopted the County's Flood Damage Prevention Ordinance.
7.6.10 Village of Lake Park
The Village of Lake Park has adopted the County's Flood Damage Prevention Ordinance.
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7.7 Water Conservation
7.7.1 Union County
The Union County Water Conservation Ordinance became effective on July 13, 1992. It was subsequently
amended and re -stated effective on the following dates: August 5, 2002; June 4, 2007; October 15, 2007;
November 5, 2007; April 7, 2008; and May 5, 2008. Additionally, the Ordinance was amended without re-
statement on January 20, 2009. The purpose of the Ordinance is to enforce water conservation when water
demand by customers connected to the Union County water system reaches the point where continuous or
increased demand will equal or exceed the treatment and/or transmission capacity of the system. All of the
County's served communities are required to abide by the County's Water Conservation Ordinance.
Table 7-8 summarizes the water supply triggers points for the County's water conservation stages. The
County follows the same trigger points as the Low Inflow Protocol for the Catawba-Wateree Project.
Table 7-8: Summary of Union County Water Supply Triggers for Conservation
Stage
04
1
2
3
4
Storage Index 1
90%<SI<100%TSI
75% TSI < SI <_90% TSI
57%TSI <SI 75% TSI
42% TSI < SI G57% TSI
SI 5_42% TSI
and
and
and
and
Drought
Monitor 2
DM>_0
DM >_1 or
DM ?2 or
DM >_3 or
DM>_4 or
Monitored USGS Stream
Flow Gages 3
Avg S85% LT 6 mo Ave
Avg 5_78% LT 6 mo Ave
Avg <_65% LT 6 mo Ave
Avg _<55% LT 6 mo Ave
Avg 5.40% LT 6 mo Ave
The ratio of remaining useable storage to total usable storage at a given point in time.
2 The three-month numeric average of the published U.S. Drought Monitor.
3 The sum of the rolling sixth -month average for the Monitored USGS Streamflow Gages as a percentage of the period
of record rolling average for the same six-month period for the Monitored USGS Streamflow Gages.
4 Stage 0 is triggered when any two of the three trigger points are reached.
In the event that a Stage 1 water shortage condition is declared, the following guidelines apply:
• An extensive publicity campaign will be initiated using public media to inform the public of
an impending or existing water shortage.
• Conservation measures will be encouraged and recommended.
• Transport of water outside of Union County will be limited.
Furthermore, the public is encouraged to adhere to the following voluntary conservation measures:
• Limit car washing to a minimum.
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• Water shrubbery to the minimum required, reusing household water when possible.
• Limit use of clothes washers and dishwashers and when used, operate fully loaded.
• Use of showers for bathing, rather than bathtub, and limit showers to four minutes.
• Limit flushing of toilets by multiple usage.
• Limit lawn and garden watering to that which is necessary for plants to survive.
• Do not wash down outside areas such as sidewalks, patios, parking Tots, service bays or
aprons, etc.
• Do not leave faucets running while shaving or rinsing dishes.
• The use of disposable and biodegradable dishes is encouraged.
• The use of flow -restrictive and water -saving devices is encouraged.
• Limit hours of operation of water-cooled air conditioners.
• All residents, businesses, and institutions are requested to temporarily delay new
landscape work until the water shortage has ended.
• Use only hoses with spring -activated nozzles when watering lawns and gardens.
The declaration of a Stage II mandatory water shortage condition may prohibit any one or more of the types
of water uses regulated under a Stage I, Stage III, or Stage IV water shortage condition, provided that the
County Manager, in his discretion and acting in the best interests of the health, safety, and welfare of the
citizens, may further regulate usage on the following bases: time of day, day of week, customer type,
including without limitation, residential, commercial industrial and institutional, and physical attribute, such
as address. After consultation with the Board of County Commissioners, the County Manager may also
take such other measures as deemed necessary to give effect to the intent of this Ordinance.
rAN
In the event the County Manager issues a declaration of a Stage III mandatory water shortage
condition, in addition to any voluntary and mandatory guidelines already in effect, it is unlawful to
use water supplied by the Union County water system in the following manner:
• To water lawns, provided that shrubbery, trees, flowers, and vegetables gardens may be
watered by hand or by drip irrigation.
r"1
• To conduct residential vehicle washing.
• To wash public buildings, sidewalks, and streets, except as required for safety and/or to
maintain regulatory compliance.
• To use water for dust control during construction.
• To conduct flushing or hydrant testing programs, except to maintain water quality or other
special circumstances approved by the Director in advance.
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• To fill new swimming pools.
• To serve drinking water in restaurants, cafeterias, or other food establishments, except
upon request.
In the event a Stage IV mandatory water shortage condition may be declared, in addition to the restrictions r''•`
for Stage I, Stage II, and Stage III water shortage conditions, the following restrictions also apply: PERK
• Fire protection will be maintained by drafting of ponds, rivers, etc.
• The use of throwaway utensils and plates is encouraged and recommended at all eating r'°N
establishments.
• It is unlawful to use water supplied by the Union County water system in the following r"RN
manner:
o To induce water into any pool; ("q
o To use water outside a structure for any use other than an emergency involving a fire; (ERN
o To operate an evaporative air conditioner which recycles water except during operating (ERN
hours of business; and re•iN
o To use water for road construction practices, i.e. compaction and washing.
The County implements enforcement actions for the restrictions associated with each water shortage
condition. The enforcement actions implement an increasing block scale for excessive water consumption
over 10,001 gallons as the drought scale worsens. Civil penalties include a warning, a $100 fine, a $500 et's
fine, and $1,000 fine for first, second, third, and fourth or more violations, respectively. Violations are elwbN
accumulated on a calendar year basis and civil penalties are applied to the customer's water bill (Union r'E\
County, 2009).
By January 1, 2008, all irrigation systems equipped with a timer were equipped with rain sensors as
approved by the County Public Works Department. Rain sensors prevent the irrigations systems from eRN
operating after one fourth inch of rain has fallen. Additionally, the Union County website provides water
conservation resources such as links -to water conservation tips, the American Water Works Association
WaterWiser) program, and DENR's water conservation webpage.
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State and Federal Permits Required
8. State and Federal Permits Required
• State Environmental Policy Act (SEPA) Environmental Assessment (EA) review and issuance of a
Finding of No Significant Impact (FONSI).
• National Pollutant Discharge Elimination System (NPDES) permit from DWQ.
• 404/401 Nationwide Permit from the U.S. Army Corps of Engineers and Division of Water Quality.
egt\ • Erosion and Sedimentation Control from the Division of Land Resources.
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References
ram,
9. References
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Utah State University, Logan, Utah.
http:llherbarium.usu.edu/treatments/Paspalum.htm#Paspalum dissectum. Accessed April 2011.
eieN Anderberg. 2006. Pseudognaphalium helleri. In: Flora of North America Editorial Committee, eds. 1993+.
Flora of North America North of Mexico. 16+ vols. New York and Oxford. Vols. 19, 20, 21; pages
r;aN 415, 416, 421.
Black & Veatch. December 2011. Final Comprehensive Water & Wastewater Master Plan; Population,
Water Demand, & Wastewater Flow Projections for Union County, NC.
Bright, Ethan. 2003. Aquatic Insects of Michigan. Museum of Zoology, Insect Division and School of Natural
Resources and Environment, University of Michigan.
http://insects.ummz.Isa.umich.edul_ethanbr/aim/Keys/Ephemeroptera/id_eom_leptophlebiidae.html
(fik- Britton, Nathaniel Lord and Addison Brown. 1913. An Illustrated Flora of the Northern U.S., Canada, and
r2ft the British Possessions, Volume 1. Charles Scribner's Sons, New York, New York.
http://chestofbooks.com/flora-plants/flowers/l Ilustrated-Flora-1 /index.html
Charlotte -Mecklenburg Utilities. 2010. Letter attached to December 2009 Invoice Regarding Treatment and
Facility Improvement Costs at McAlpine Wastewater Management Facility. •
Clanton, C.J. and Slack, D.C. 1987. Hydraulic Properties of Soils as Affected by Surface Application of
r1R,, Wastewater. Transactions of the ASAE — American Society of Agricultural Engineers. V. 30(3) p.
683-687. May/June 1987.
Cobb, B. 1963. A Field Guide to the Ferns. Houghton Mifflin Company, Boston, eft,
✓ Environmental Laboratory. 1987. Corps of Engineers Wetlands Delineation Manual, Technical Report Y-87-
rxt.) 1. U.S. Army Engineer Waterways Experiment Station, Vicksburg, MS.
Flora of New Jersey Project (FNJP). 2011. Plants of New Jersey.
✓ http:llwww.njflora.org/2011/02/dichanthelium-aciculare-desv-ex-poir-gould-c-a-clack-bristling-
^ rosette -panic -grass/ Accessed April 2011.
r
Flora of North America (FNA). 2006. Helianfhus laevigafus. In: Flora of North America Editorial Committee,
emiN
eds. 1933+. Flora of North America North of Mexico. 16+ vols. New York and Oxford. Vol. 21, page
145, 158-159.
r
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Environmental Assessment for
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Flora of North America (FNA). 2003. Carex impressinervia. In: Flora of North America, Editorial Committee,
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Hall, Dolores. 2011. Office of State Archaeology, North Carolina Department of Cultural Resources.
Personal communication with Keven Arrance, Hazen and Sawyer. November 17, 2011.
HDR Engineering, Inc. of the Carolinas. August 2005. Twelve Mile Creek Reuse System Preliminary
Engineering Report. Union County, NC.
Indian Trail, Town of. September 11 2007. Post -Construction Storm Water Ordinance. World Wide Web:
http://www.indiantrail.org/uploads/file/Engineering/PC%20Ordinance.pdf. Accessed June 2011.
Indian Trail, Town of. 2005. The Comprehensive Plan. World Wide Web:
http://www.indiantrail.org/uploads/FINAL%20IT%2000MP%20PLAN(1).pdf. Accessed June 2011.
Indian Trail, Town of. December 30 2008. Unified Development Ordinance. World Wide Web:
http://www.indiantrail.org/uploads/file/UDO/final_1_09_09_V1 AmendmentsAPRIL2010.pdf.
Accessed June 2011.
Landau, M. 1992. Introduction to Aquaculture. New York: John Wiley & Sons Inc.
LeConte-Woodmanston Foundation (LWF). 2011. The LeConte's Legacy. LeConte-Woodmanston
Plantation and Botanical Gardens, Riceboro, Georgia. http://leconte-
woodmanston.org/discovery.html. Accessed April 2011.
Marvin, Village of. February 2008. The Village of Marvin North Carolina Parks and Greenways Master Plan.
LandDesign. World Wide Web: http://www.marvinnc.org/greenways_and_recreation.htm.
Accessed November 2011.
Marvin, Village of. October 2004. Marvin Land Use Plan. World Wide Web:
http://www.marvinnc.org/PDF%20Files/Ordinances/Land%20Use%20PIan/04-10-
11 %2OLUP%20adopted.pdf. Accessed June 2011.
Marvin, Village of. January 1996a. Subdivision Ordinance (#OR-96-02-02). World Wide Web:
http://www.marvinnc.org/subdivision%20ordinance.pdf. Accessed November 2011.
Marvin, Village of. January 1996b. Zoning Ordinance. World Wide Web:
http://www.marvinnc.org/PDF%20Files/Ordinances/zoning/Entire%20Zoning%20Ord.pdf.
Accessed June 2011.
Mineral Springs, Town of. July 1 2002. Zoning Ordinance. Town of Mineral Springs Planning Staff.
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References
Mineral Springs, Town of. Land Use Plan. World Wide Web:
http://www.mineralspringsnc.com/land_use/LUP101206.pdf. Accessed June 2011.
raz)
Natural Heritage Program (NHP). 2012. Element Occurrence List for Union County, North Carolina. North
Carolina Division of Parks and Recreation, Raleigh, North Carolina. World Wide Web
http://www.ncnhp.org/Pages/heritagedata.html. Accessed February 2012.
Mintz, John. 2011. Office of State Archaeology, North Carolina Department of Cultural Resources.
Personal communication with Keven Arrance, Hazen and Sawyer. November 18, 2011.
earN
Natural Heritage Program (NHP). 2009. North Carolina Natural Heritage Program Biennial Protection Plan:
r1 List of Significant Natural Heritage Areas.
r Nesom, G. L. 2006. Eurybia mirabilis. In: Flora of North America Editorial Committee, eds. 1993+. Flora of
North America North of Mexico. 16+ vols. New York and Oxford. Vol. 20, page 366, 373.
rgerN New York State Department of Environmental Conservation (NYSDEC). 2011. Green Rock -cress. New
York Natural Heritage Program. World Wide Web: http://acris.nynhp.org/guide.php?id=8886.
Accessed April 2011.
✓ North Carolina Department of Environment and Natural Resources (DENR). 2012. North Carolina 303(d)
List — Draft. Division of Water Quality.
North Carolina Department of Environment and Natural Resources (DENR). 2011.Fish Community Data by
✓ River Basin: Catawba Basin. World Wide Web: http://portal.ncdenr.ora/web/woless/baulncibi-data.
Accessed April 2011. Division of Water Quality.
eaRN
North Carolina Department of Environment and Natural Resources (DENR). 2010a. Ambient Air Quality
Report. Division of Air Quality.
r
tit\ North Carolina Department of Environment and Natural Resources (DENR). 2010b. Catawba River
Basinwide Water Quality Plan. Division of Water Quality.
North Carolina Department of Environment and Natural Resources (DENR). 2010c. North Carolina 303(d)
✓ List — Final. Division of Water Quality.
rgeN
North Carolina Department of Environment and Natural Resources (DENR). September 2010. NPDES
fieN
IscN
ext
rot1
torN
ror1
r
Speculative Limits for Twelve Mile Creek WWTP. Division of Water Quality.
North Carolina Department of Environment and Natural Resources (DENR). 2008a. Basinwide Assessment
Report: Catawba River Basin. Division of Water Quality.
Hazen and Sawyer Project No. 30831-030
HAz AND SER
Environmental Engineers & Scientists
9-3

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
References
North Carolina Department of Environment and Natural Resources (DENR). 2008b. Yadkin -Pee Dee River
Basinwide Water Quality Plan. Division of Water Quality.
North Carolina Department of Environment and Natural Resources (DENR). November 2006. NPDES
Discharge Permit for Twelve Mile Creek Wastewater Treatment Plant. Division of Water Quality.
North Carolina Department of Environment and Natural Resources (DENR). October 19, 2000. Letter
Correspondence to Mr. Fransen, Division of Water Resources, on Grandfathered Interbasin
Transfer Amount.
North Carolina Wildlife Resources Commission (NCWRC). 2011. Species Information and Status: Eastern
creekshell Villosa delumbis (Conrad, 1834).
http://www.ncwildlife.org/Wildlife_Species_Con/WSC Mussel 34.htm Raleigh, North Carolina.
North Creek Nurseries. 2011.Baptisia alba var. alba.
http:llwww.northcreeknurseries.com/index.cfm/fuseaction/plants.plantDetaiwplant id/147/index.htm
Landenburg, PA.
Page, L. and B. Burr. 1991. Peterson Field Guide to Freshwater Fishes. Boston: Houghton Mifflin
Company.
Pippen, Jeffrey S. 2009. North Carolina Wildflowers. Duke University, Durham, NC.
http://www.duke.edu/—jspippen/plants/aster.htm. Accessed April 2011.
Radford, A. E., H.E. Ahles, and C.R. Bell. 1968. Manual of the Vascular Flora of the Carolinas. The
University of North Carolina Press, Chapel Hill, NC.
South Carolina Department of Health and Environmental Control. January 2008. Speculative Limits Letter
to Union County for Twelve Mile Creek WWTP Wasteload Allocation to the Catawba River.
South Carolina Department of Health and Environmental Control. May 24 2002. Standards for Wastewater
Facility Construction R.61-67. Bureau of Water, South Carolina.
Stallings, Town of. April 2006. Future Land Use Plan — Goals, Objectives, Policies. World Wide Web:
http://www.stallingsnc.org/vertical/Sites/%7 B052C66EC-317E-4C0C-8034-
D2D91 E376211 %7D/uploads/%7B6A04D559-C8AC-4E6D-ADB7-3836005D4670%7D.PDF.
Accessed June 2011.
.Stallings, Town of. July 2010. Land Usage Ordinance. World Wide Web:
http://www.stallingsnc.org/index.asp?Type=B_BASIC&SEC={EAFB9747-6826-4F31-A906-
A92106F4A745}&DE={4E743133-CEA0-43C9-837C-4C36E1415125}. Accessed June 2010.
Hazen and Sawyer Project No. 30831-030
H.ZEN Alsa) SoYER
Environmental Engineers & Scientists
9-4

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
References
Stallings, Town of. September 18 2007. Post -Construction Storm Water Ordinance. World Wide Web:
http://www.stallingsnc.org/vertical/Sites!%7B052C66EC-317E-4C0C-8034-
D2D91 E376211 %7D/uploads/%7B0621 F4C4-6E71-432C-BF9D-B2902017A04C%7D.PDF.
Accessed June 2011.
Sullivant. 2004. Orthotrichum exiguum. In: Bryophyte Flora of North America.
http://www.efloras.org/florataxon.aspx?flora_id=50&taxon id=200001648. Accessed April 2011.
Tetra Tech. April 2010. Scoping Level Assessment of Assimilative Capacity in Twelve Mile Creek Below
the Union County WWTP. Prepared for Union County Public Works Department and Hazen and
Sawyer.
Tetra Tech. November 2011. QUAL2 Model Update for Twelve Mile Creek Below the Union County
WWTP. Prepared for Union County Public Works Department and Hazen and Sawyer.
Union County, North Carolina. April 2009. Water Conservation Ordinance. Union County Board of
Commissioners.
Union County, North Carolina. October 2010a. 2025 Comprehensive Plan. Union County Planning
Department.
Union County, North Carolina. August 2010b. Wastewater System Performance Summary (Fiscal Year
2009-2010). Department of Public Works:
Union County, North Carolina, 2001. Land Use Ordinance. Union County Planning Department, Monroe,
North Carolina.
Union County and Anson County, North Carolina. April 1992. Water Agreement.
United States Department of Agriculture (USDA). 2011. Soil Survey Staff, Natural Resources Conservation
Service, Web Soil Survey. Available at http://websoilsurvey.nrcs.usda.gov/. Accessed April 2011.
United States Department of Agriculture (USDA). 1998. Hydrologic Units - North Carolina. Natural
Resources Conservation Service. Raleigh, NC.
United States Department of Agriculture (USDA). 1996. Soil Survey of Union County, North Carolina.
United States Department of Natural Resources and Community Development (DNRCD). 1985. Geologic
Map of North Carolina.
Hazen and Sawyer Project No. 30831-030
HAZEN AND S&\WER
Environmental Engineers 11 Scientists
9-5

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
References
United States Environmental Protection Agency (EPA). September 2006. Process Design Manual — Land
Treatment of Municipal Wastewater Effluents. EPA/625/R-06/016.Office of Research and
Development, Cincinnati, Ohio.
United States Environmental Protection Agency (EPA). 1990. National Ambient Air Quality Standards.
United States Fish and Wildlife Service (USFWS). 2010. Endangered Species, Threatened Species,
Federal Species of Concern, and Candidate Species, Union County, NC. World Wide Web:
http://www.fws.gov/nc-es/es/countyfr.html. Accessed April 2011.
United States Geological Survey (USGS). 1985. National Water Summary 1984 — Hydrologic events,
selected water -quality trends, and ground -water resources: USGS Water -Supply Paper 2275.
United States Geological Survey (USGS). May 2010. USGS DS 240: Enhanced Historical Land -Use and
Land -Cover Data Sets of the U.S. Geological Survey. Water Resources NSDI Node. World Wide
Web: http://water.usgs.gov/GIS/dsdl/ds240/index.html#poly. Accessed November 2011.
Waxhaw, Town of. March 2000. Stormwater Design Manual. Town of Waxhaw Planning Department.
Waxhaw, Town of. September 8 2009. 2030 Comprehensive Plan. World Wide Web:
http://www.waxhaw.com/index.asp?Type=B_BASIC&SEC={F4F754E5-D827-4AF6-8FD2-
F5DB833CEF4D}. Accessed June 2011.
Waxhaw, Town of. November 2009. Unified Development Ordinance. World Wide Web:
http://www.waxhaw.com/index.asp?Type=B_BASIC&SEC={E5D3EDFE-E6F6-47FC-A9DA-
19204ECF33B4}. Accessed June 2011.
Weakley, A.S. 1993. Natural Heritage Program list of the rare plant species of North Carolina. N.C. Natural
Heritage Program, Division of Parks and Recreation, Raleigh, N.C.
Weddington, Town of. September 2010. Code of Ordinances. World Wide Web:
http://libraryl.municode.com/default-test/home.htm?infobase=14164&doc action=whatsnew.
Accessed June 2011.
Weddington, Town of. March 2002. Land Use Plan. Town of Weddington Planning Department.
Wesley Chapel, Village of. December 2010. Village of Wesley Chapel Zoning Ordinance. World Wide Web:
http://ci.wesley-chapel.nc.us/vertical/Sites/%7B1 AD59A02-OFFA-4E56-AC61-
69E7464BE4D0%7D/uploads/%7BA386070A-F475-4D36-842F-44E87DCE4694%7D.PDF.
Accessed June 2011.
Hazen and Sawyer Project No. 30831-030
IIAZEN AND SAWYER
Environmental Engineers & Scientists
9-6

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
References
Wesley Chapel, Village of. September 2009. Flood Damage Prevention Ordinance. World Wide Web:
http:llci.wesley-chapel.nc. us/index.asp?Type=B_BASIC&SEC={A99EABD4-5184-48A3-95B3-
1332CE507B87}. Accessed June 2011.
Wesley Chapel, Village of. December 8 2003. Land Use Plan. Centralina Council of Governments.
Hazen and Sawyer Project No. 30831-030
HAZEN AND SOUR
Environmental Engineers & Scientists
9-7

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
References
This page intentionally !eft blank.
Hazen and Sawyer Project No. 30831-030
Environmental Engineers & Scientists
9-8

florN
Environmental Assessment for
Twelve Mile Creek Wastewater
ex.\ Treatment Plant Expansion
Qualifications of Preparers
(-AN
eok-
10. Qualifications of Preparers
Mary Sadler, PE, MS Env., of Hazen and Sawyer specializes in municipal wastewater treatment
processes and modeling, planning and design of wastewater treatment facilities, and environmental
permitting. She has been an active participant in over twenty environmental permitting projects in North
Carolina. Her environmental documents cover a range of projects and issues: new water and wastewater
✓ treatment plants, water and wastewater capacity expansions, water supply, new NPDES discharges, and
r impacts to state and federally listed species. Significant environmental permitting achievements include the
Dempsey E. Benton Environmental Assessment and associated Biological Opinion for direct impacts to the
federally endangered dwarf wedgemussel and an Interbasin Transfer for the Greenville Utilities
Commission.
Linda Diebolt, M.Bio., of Hazen and Sawyer is a senior biologist responsible for assisting in the
generation of the natural resources sections of the Environmental Assessment. She has over 20 years of
experience and has performed and managed biological assessments, wetland delineations (tidal and non-
e -AN tidal), permit applications, mitigation site searches, mitigation design and specifications, and preparation of
— environmental documents. Ms. Diebolt has prepared or assisted in the preparation of more than twenty-five
Environmental Assessments throughout the United States.
rya, Scott M. Alpert, PhD, PE, of Hazen and Sawyer has over 16 years of experience in the planning, design,
permitting, and construction administration of a wide variety of municipal water and wastewater projects.
For this environmental document, Dr. Alpert contributed to the sections related to the Project Alternatives
Analysis and Discharge Altematives Analysis. He has completed similar alternatives analyses for several
utilities in North Carolina and Tennessee.
eARN
rsk- Keven Arrance, B.Bio., of Hazen and Sawyer is a biologist responsible for assisting in the generation of
the natural resources sections of the Environmental Assessment. She has over nine years of experience
and has performed and managed biological assessments, wetland delineations, permit applications,
EstN
mitigation design and specifications, and preparation of environmental documents. Ms. Arrance has
prepared or assisted in the preparation of more than ten Environmental Assessments and Environmental
✓ Impact Statements throughout the United States.
Lamya Badr, El, MS Env., of Hazen and Sawyer is a staff engineer specializing in wastewater treatment.
She assisted Ms. Sadler with the wastewater flow projection and alternatives analysis portions of the
environmental document.
rot'N
r
SAWYER
Hazen and Sawyer Project No. 30831-030 HAZEN AND 10-1
eir, Environmental Engineers 3 Scientists

Environmental Assessment for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Qualifications of Preparers
This page intentionally left blank.
Hazen and Sawyer Project No. 30831-030
ZEII AND StW1ER
Environmental Engineers 1 Scientists
10-2

Environmental Assessment. for
Twelve Mile Creek Wastewater
Treatment Plant Expansion
Figures
11. Figures
Hazen and Sawyer Project No. 30831-030
IAZEN AND SAVtYER
Environmental Engineers & Scientists

Pineville
McAlpine Creek'WWTP
MECKLENBURG,COUNTY U
Matthews.
521 eCATAWBA RIRBASIN
Vifi_
Sixmile i '
Six Mile Creek PS''.
Indian Trail
0 C«
Mint HI
0lde•Sycamore Golf Course WRF
Fairview
Stallings., s�•l-lemy Bridge pliriiRoad PS
PS
Lake:Park‘
v-
•rgek Ni. t,:. ,;
Crooked Creek WWTP
YADKINIRIVERfBASIN
v'e''"ok Grassy Branch WWTP
s`l G
co
Monroe,
Molry Gamma
elvemiie Little Twe% Underwo
� WTP Eas���o�YS�M3 �,0e� I '�� 3
Twelve -Mile Creek:W
Indian Land WWTP It, -F m Batese
;K 7�
�� Mineral Springs
Waxhaw
LANCASTER
COUNTY, SC
Legend
Twelve Mile Creek Service Area
■ Existing Wastewater Treatment Facilities
I PSI Pump Station
-�r-�- Streams and Lakes
SCALE
1.25 2.5 5
Miles
1 inch equals 2.5 miles
,04
NV
geave cram Creek
UNION COUNTY',
m� ti
0
Proposed Monroe Connector
(preliminary -subject to change)
River Basin Boundary
County Boundary
EN AND SAWYER
Environmental Engineers & Scientists
aN ,°o,4_
=tea �n
Cit •of M_ onroeiWWTP
Wingate,
m
Reedy
CHESTERFIELD
COUNTY, SC
Figure 1-1: Twelve Mile Creek
Service Area
Union County Twelve Mile Creek WWTP

Su, gar Creek WWTP
Charlotte
to
eG%
0 c
Pineville
A
0
27
74
e Greex
MECKLENBUURG COUNTY
ine;Creek WWTP
{521
521
Six Miletereek F;S:
\/\Marvj
s \- Twelve
Indian Land WWTP
Indian
?sr
Sixmile Cr
a<eke
o. �1
Weddington
rt
I
I
I
I
i
i
W /ProposedWWTP
Legend
•I
IPsl
,
tole
Creek
Mile C+ee W 111?
me (Rhone) Br`anch
Existing Wastewater
Treatment Facility
00
By
elvem
n'tacir,.,
4n
Gi
n
Matthews
Indian
ti
Ir
o�
ork"c'aoked ere'.
Trai
Wesley Chapels •
CATAWBA : RI VER , BA S I N
eta‘
MoII'J
Little Twdr, Underw°
Mineral Springs
(2- agar Bra
LANCASTER
COUNTY, SC
or
0
Twelve Mile Creek Service Area
Project Alternatives
Proposed Wastewater
Treatment Facility / \%
Existing Water
Treatment Facility
Pump Station
Divert to Indian Land WWTP
Construct New WWTP
Divert to McAlpine Creek WWTP
roe
01
Mint Hill
■
Tallwood Estates WWT
'reek 0
-----.„.....000
Olde•Sycamore Golf Course WidF
Fairview
Pa dpi
1n
Stallings Popliri,Roa PSd
Lake Park
Crooked Creek WWTP
YADKIN7RIVER_BASIN
W1 � C;' ca
aeelS
CamP Bt
e eave soda» Creek
0
R�
Gt
Monroe
UNION COUNTY
Otter Greo
0
tat
C3
n
ro
00
Qi
e
0
Roe,
`Grassy Branch WWTP
assy �t
G1
a
CHESTERFIELD
COUNTY, SC
Proposed Monroe Connector
(preliminary - subject to change)
Streams and Lakes
River Basin Boundary
County Boundary
W
iu
3
Cree
of MonroeWWRP •
'.se:ssea$ 4:saetsv ....
Wingate-
�tsepe
Reedy Bran
Co4pens Bra
Garry Log ,
s
ct'
Gibbs Branch i0
601
PAGELAND
7401"t0"
SCALE
1.25 2.5 5
Miles
1 inch equals 2.5 miles
D SAWYER
Environmental Engineers & Scientists
Figure 3-1: Wastewater Capacity
Alternatives for Twelve Mile Creek
WWTP Expansion
Union County Twelve Mile Creek WWTP

DIVERSION PS
(2012)
INFLUENT
JUNCTION BO
INFLUENT SCREENING
STRUCTURE
\ ' ' • . INFLUENT PUMP
• . STATION
PROPERTY UNE\ \ \
12 MILE CREEK
PROPOSED
PARALLEL INFLUENT
PUMP STATION
PROPOSED
GBT FACIUTY
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DIGESTER
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CASCADE
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No. No.1
HAZEN AND SAWYER
Environmental Engineers & Scientists
KENSINGTON DR
1
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i
FIGURE 3-2
PROPOSED UPGRADE & EXPANSION
IMPROVEMENTS TO TWELVE MILE CREEK WWTP

Sugar Creek WWTP
Charlotte
Catawba River WTP
I
' eddington
Twelve:Mile Creek WWII?
1 `
Creek
Legend
Existing Wastewater
• Treatment Facility
Existing Water
Treatment Facility
f�l
Mint Hill
Matthews
Indian Trail
'
Wesley Chapel•
CATAWBA«RIVERsBASIN
LANCASTER
COUNTY, SC
Twelve Mile Creek Service Area
Effluent Disposal Alternatives
��� Proposed Force Main
S� to Potential Reuse Sites
Potential Reuse Sites r ss. Catawba River Discharge
•\ Raw Water Intake
Pump Station
Tall ood Estates WWTP
Olde•Sycamore Golf Course WRF
YADK/N93lef BASINi
6eaverda
Creek
IMon"ree`
UNION COUNTY
Fairview
Grassy Branch WWTP
551
m
v
Cree
oc
i
t jCkCity of Monroe(WWTP --�
'481a===ismCij 'x
CHESTERFIELD
COUNTY, SC
Proposed Monroe Connector
a° (preliminary - subject to change)
C3
Streams and Lakes
River Basin Boundary
County Boundary
4-Pens Bra
GurnLog B
Wingate
fl
Reedyg
SCALE
0 1.25 2.5 5
MIIP_s
FIAZENAND SAWYER
Figure 3-3: Effluent Disposal
Alternatives for Twelve Mile Creek
IAANTD Dvn�n�inn

i
PCATAWBA RIVER BASIN
Cr•ek +"
Weddington
TwelveMile Creek:WWTP
VJ_
"°Waxhaw,
Legend
MI Twelve Mile Creek WWTP
- Streams and Lakes
Twelve Mile Creek Service Area
River Basin Boundary
County Boundary
FEMA Floodplain Data
Floodway
100-year Flood Zone
is
SCALE
1.25 2.5
Mineral Springs
LANCASTER
COUNTY, SC
HAZENAND SAWYER
Unionville
Monroe
Ol
drsnn -
C
Wingat 5
Re
GUrnLog e
C,
k.‘t CHESTERFIELD
COUNTY, SC
Figure 4-1: Floodplains
in the Service Area

Legend
• Twelve Mile Creek VVVVfP
-ems- Streams and Lakes
Twelve Mile Creek Service Area
River Basin Boundary
c3
County Boundary
NWI Wetland System Classification
Lacustrine
Palustrine, Aquatic Bed
Palustrine, Emergent
Palustrine, Forested
Palustrine, Scrub -Shrub
Palustrine, Unconsolidated Bottom
Palustrine, Unconsolidated Shoreline
Riverine
SCALE
0 1.25 2.5
5
Matthews
_` esley-Cha e'
UNION COUNTY
C l
r �0
LANCASTER
COUNTY, SC
HAZEN AND SAWYER al
•
4
t
Wingate--'
y.
Jr'
:zsorSef
•
• ,Recv
CHESTERFIELD
r COUNTY, SC
r;
1
a
I Figure 4-2: National Wetlands Inventory
Wp+lanrlc in the Ramiro Aran

Archaeological Site #218
•
'Twelve Mile Creek WWTP
•
Legend
® Twelve Mile Creek WWTP
Service Area
SCALE
0 1 2
4
Miles
•
HAZENAN
D SAWYER
Figure 4-3: U.S. Geological Service
I
Map of the Service Area

24
7
HUC 03050103020
DWQ1Subbasin 03438-34
MECKLENBURG COUNTY
Charlotte HUC>i"0305t0103a20
DWQ Subbasin 03-08-34
v
1:iUCC03050103030
C V91Q Subbasin 03-08-38
LANCASTER
COUNTY, SC
Legend
■
Sixmile Cre
HUC 03040`05010
DW,Q-Subbasin0,3a111
rHUC 03o40105030
DWQ Subbasin 03-07;12'
K Cuo305o103020
DWQ.Subbasin 03-08434
Mint Hill
+HUC 03040105030'
DWQ Subbasin 103-O7=1®;
r
r`
Stallings
,.e. Fnrk F,rroAA;y,. ,,:r �. i
Hemby, Bridge;
' hw co3040105040 '
D WQSubbasin 03-07-12
Lake Park
Wesley -Chapel
CATAWBA'RIVER-BASIN
;HUC 0305010:3030
DWQ Subbasin, 03-08-38
Twelve, Mile Creek,WWTP
Waxh'aw,
;Rona phone) Branch
,4 Creek
Twelve Mile Creek WWTP
Streams and Lakes
Service Area
Critical Area
Water Supply Watershed
River Basin Boundary
Subbasin
County Boundary
SCALE
1.25 2.5
Mineral Springs
UNION COUNTY
HUC•03_050103040
e\k DWQ Subbasin 03-08-38
LANCASTER
COUNTY, SC
HAZEN AND SAWYER
HUC 0304r://
0105010
DWQ Subbasin103-07-12
HUC 030401 05050
DWQ ;Subbasin 03-07-12
Root+,F
0r
Fain Ow-
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Unionvil
Moiroe
rP
- HUC3u 04101(f5o70,
DWQ Subb'asln}�03 "47-141
Besve„ e's
HiUC:030-401050701.
DWQ:Subbasin :0.3!0.7,-.14...
HUC 03040105040
DWQ Subbasin '03 07-12
YADKIN RIVER BASIN
GuniLog
Gibbs Branch
I
Figure 4-4: Watersheds
in the Service Area
Wingate—

Charlotte
C9210000.
• a •.g
Sixniile Cr
C9370000
x,.
C•98119500
Twelve Mile Creek;wwTP,y
Creek.
Legend
Existing Wastewater Treatment Facilities
Ambient Water Quality Monitoring Station
Impaired per Final 2010 303(d) List
Streams and Lakes
Service Area
River Basin Boundary
County Boundary
" �W
�axhaw;
SCALE
1.25 2.5
5
11
Matthews,
2 co
CO
dco ,
� �r�
�08359500'
Q8360000 ►`°'
498360000
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r r; 98386000 rr•ri
8355000
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mom, -
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11 C 83420
• G ��'ce kPc�eek Gc C Roc,
Olde•Sycarnore Golf Course WR
`Fairview
s
i IL
Stallings Hernby' Bridge,,r "'o Q* •
Lake Park
indian':Trail
CKe 1K"'
ch'F9":.0 2� jp,b�4�
CrookedrCreek WWTP 0 x
LANCASTER
COUNTY, SC
HAZENAND SAWYER
e�
a
rA�r�\ 7r
'•Tallwood EstatessWWTP
ji—
..."Lt.'4, .� N.
414,41.
Grassy. Branch WWTP
Unionville
'P2e
r
icu
Q 85000
r City of Monroe iWWTP
m m
4 h
"Q88; 0,000)v.:,` ..,v, . c,
Wingate
CHESTERFIELD
COUNTY, SC
I Figure 4-5: Surface Waters
in the Sprvir_p Arpa