NC0025453_Fact Sheet_20210115

Fact Sheet
NPDES Permit No. NCO02.5453
Permit Writer/Email Contact Nick Coco, [e-mail]:
Date: September 29, 2020
Division/Branch: NC Division of Water Resources/NPDES Complex Permitting
Fact Sheet Template: Version 09Jan2017
Permitting Action:
❑ Renewal
❑ Renewal with Expansion
❑ New Discharge
❑X Modification (Fact Sheet should be tailored to mod request)
Note: A complete application should include the following:
• For New Dischargers, EPA Form 2A or 2D requirements, Engineering Alternatives Analysis, Fee
• For Existing Dischargers (POTW), EPA Form 2A, 3 effluent pollutant scans, 4 2nd species WET
tests.
• For Existing Dischargers (Non-POTW), EPA Form 2C with correct analytical requirements based
on industry category.
Complete applicable sections below. If not applicable, enter NA.
1. Basic Facility Information
Facility Information
Applicant/Facility Name:
Town of Clayton/Little Creek Water Reclamation Facility (WRF)
Applicant Address:
PO Box 879, Clayton, NC 27528
Facility Address:
1422 N. O'Neil Street, Clayton, NC 27520
Permitted Flow:
2.5 MGD
Facility Type/Waste:
MAJOR Municipal; 95% domestic, 5% industrial
Facility Class:
Grade IV Biological Water Pollution Control System (WPCS)
Treatment Units:
Mechanical bar screens & grit removal, influent pump station,
anaerobic basin, anoxic tanks, oxidation basins, clarifiers, tertiary
filters, UV disinfection with backup chlorination/dechlorination, aerated
sludge digester, sludge holding tank, sludge thickener, non -potable
reclaimed water system
Pretreatment Program (Y/1)
Y
County:
Johnston
Region
Raleigh
Briefly describe the proposed permitting action and facility background: The Town of Clayton applied
for an NPDES permit modification for the Little Creek WRF on September 11, 2020, requesting the
addition of an expansion limitation page to 6.0 MGD, and 10.0 MGD, as well as the inclusion of
additional nitrogen credits purchased from International Paper, a facility permitted under NPDES permit
NC0003191. An Engineering Alternatives Analysis was submitted to the Division for their expansion in
their modification request package.
The Town is planning a phased approach to meet current and projected demands, beginning with
Page 1 of 19

construction of a new 6- MGD treatment facility. The proposed project includes the following major
components:
• New 6- MGD water reclamation facility ( WRF) constructed on a Town- owned site adjacent to
the Neuse River and including the Town' s existing outfall as a first phase, with anticipated
incremental expansion to 10 MGD to meet future needs
Abandonment of the Town's existing LCWRF
Construction of a pump station at the LCWRF site and associated Little Creek ( LC)
Transmission Main infrastructure to convey flow to the new WRF
The Little Creek facility serves a population of 25,234 residents and operates a pretreatment program with
two pharmaceutical Categorical Industrial Users, Novo Nordisk and Grifols. Currently, Grifols discharges
to Johnston County's WWTP. Novo Nordisk's flow to Little Creek WWTP was 0.076 MGD. Clayton has
agreements with Johnston County and Raleigh's Neuse River WWTP to divert up to 1.3 MGD and 1.0
MGD to those plants respectively. Clayton also operates a reclaimed water system and land applies up to
237,840 GPD under permit WQ0022224. I&I was reported at 438,000 GPD. The Town's permit was last
reissued December 6, 2019, and became effective January 1, 2020. The Town received a major
modification to their NPDES permit on September 15, 2020, effective October 1, 2020, to document the
purchase of nutrient offset credits in the Town's permit. No limits were modified as a result. The credits
were added to the listing of allocations and credits in Condition A.(6.) of the permit and were recorded as
being held in reserve. The offset credits will be activated and used to increase the Town's TN limit for
future expansion. That change will also be subject to public review in accordance with NPDES
regulations.
2. Receiving Waterbody Information:
Receiving Waterbody Information
Outfalls/Receiving Stream(s):
Outfall 001 — Neuse River
Stream Segment:
27-41.3
Stream Classification:
WS-IV;NSW,CA
Drainage Area (m12):
1,150
Summer 7Q10 (cfs)
186 (regulated)
Winter 7Q10 (cfs):
186 (regulated)
30Q2 (cfs):
186 (regulated)
Average Flow (cfs):
186 (regulated)
IWC (% effluent):
1.6 at 2.5 MGD
303(d) listed/parameter:
No
Subject to TMDL/parameter:
Yes- Subject to Neuse nutrient rule 15A NCAC 02B .0234,
Statewide Mercury TMDL implementation.
Basin/Sub-basin/HUC:
Neuse/03-04-02/03020201
USGS Topo Quad:
E25NW/N W Clayton
3. Effluent Data Summary
Effluent data for Outfall 001 is summarized below for the period of September 2016 through September
2019.
Table 1. Effluent Data Summary Outfall 001
Page 2 of 19

Permit
Parameter
Units
Average
Max
Min
Limit
Flow
MGD
1.6
5.82
0.591
MA 2.5
Total Monthly Flow
MG/mo
50.0
67.796
36.323
WA 7.5
BOD summer
mg/l
f Q 5
MA 5.0
WA 15.0
BOD winter
mg/l
2.5
9.6
MA 10.0
WA 3.0
NH3N summer
mg/l
0.3
4.1
MA 1.0
WA 6.0
NH3N winter
mg/l
3.88
MA 2.0
WA 45.0
TSS
mg/1
48.6
MA 30.0
6. 0 < pH <
pH
SU
8.1
9.0
(geometric)
Fecal coliform
#/100 ml
2.3
1600
1
WA 400
MA 200
DO
mg/1
7.6
9.82
5.6
DA > 6.0
Temperature
° C
21.5
30
12
TRC
ug/1
18.7
20
1
DM 28
Conductivity
umhos/cm
622
1703
7.36
Nitrite+Nitrate
mg/1
2.6
11.24
0.05
TKN
mg/1
1.3
11.5
0.2
TN
mg/1
4.0
13.08
0.95
TN Load
lb/mo
1665
3309
631
TN Load
lb/yr
19487
20934
17045
22,832
TP
mg/1
1.2
6.53
0.06
QA 2.0
Bis (2-ethylhexyl)
ug/1
< 2
< 2
< 2
phthtalate
MA -Monthly Average, WA -Weekly Average, DM -Daily Maximum, DA=Daily Average, QA=Quarterly Average
4. Instream Data Summary
Instream monitoring may be required in certain situations, for example: 1) to verify model predictions
when model results for instream DO are within 1 mg/1 of instream standard at full permitted flow; 2) to
verify model predictions for outfall diffuser; 3) to provide data for future TMDL; 4) based on other
instream concerns. Instream monitoring may be conducted by the Permittee, and there are also
Monitoring Coalitions established in several basins that conduct instream sampling for the Permittee (in
which case instream monitoring is waived in the permit as long as coalition membership is maintained).
If applicable, summarize any instream data and what instream monitoring will be proposed for this
permit action: The current permit requires instream temperature, dissolved oxygen, conductivity and
fecal coliform monitoring. As the Permittee is a member of the Lower Neuse Basin Association (LNBA),
instream monitoring if provisionally waived. Data from January 2017 through June 2020 were reviewed
Page 3 of 19

from LNBA monitoring station J4130000, located upstream of the outfall and J4170000, located
downstream of the outfall. LNBA data has been summarized in Table 2, shown below.
Table 2. Instream Monitoring Coalition Data Summary
Parameter
Units
J4130000 Upstream
J4170000 Downstream
Average
Max
Min
Average
Max
Min
DO
mg/1
7.9
11.3
5.8
7.8
11.2
5.8
Fecal
Coliform
#/100m1
(geomean)
267.3
8500
20
1
(geomean)
246.7
8300
28
Conductivity
umhos/cm
163.3
272
161
266
Temperature
° C
19.8
28.7
4.9
19.7
28.6
4.8
Students t-tests were run at a 95% confidence interval to analyze relationships between instream
samples. A statistically significant difference is determined when the t-test p-value result is < 0.05
The downstream temperature did not exceed 32 degrees Celsius [per 15A NCAC 02B .0211 (18)]. The
temperature differential was greater than 2.8 degrees Celsius on no occasion during the period reviewed.
It was concluded that no statistically significant difference between upstream and downstream
temperature exists.
Downstream DO did not drop below 5 mg/L [per 15A NCAC 02B .0211 (6)] during the period reviewed.
It was concluded that no significant difference between upstream and downstream DO exists.
It was concluded that no statistically significant difference between upstream and downstream
conductivity exists.
Downstream fecal coliform exceeded a geomean of 200/100ml [per 15A NCAC 02B .0211 (7)(4)]
Downstream fecal coliform exceeded 400/100ml in more than 20% of samples during the period
reviewed. Upstream fecal coliform exceeded a geomean of 200/100ml and also exceeded 400/100ml in
more than 20% of samples during the period reviewed. It was concluded that no statistically significant
difference between upstream and downstream fecal coliform exists. Effluent fecal coliform was
consistently lower than instream fecal coliform and does not appear to influence downstream fecal
coliform levels.
The draft permit maintains the same instream monitoring requirements as the current permit for
temperature, DO, fecal coliform and conductivity. Upstream hardness sampling has been added to the
permit at a quarterly frequency for the additional flow tiers.
Is this facility a member of a Monitoring Coalition with waived instream monitoring (YIN): Yes
Name of Monitoring Coalition: Lower Neuse Basin Association (LNBA)
5. Compliance Summary
Summarize the compliance record with permit effluent limits (past 5 years): The facility reported 2 BOD
limit violations and 3 dissolved oxygen limit violations resulting in enforcement actions in 2017. In 2019,
the facility reported 1 BOD limit violation resulting in enforcement action.
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Summarize the compliance record with aquatic toxicity test limits and any second species test results
(past 5 years): The facility passed 18 of 18 chronic toxicity tests, as well as all 4 of 4 second species
chronic toxicity tests, between March 2016 and June 2020.
Summarize the results from the most recent compliance inspection: The last facility inspection conducted
in June 2019 reported that the facility was compliant.
6. Water Quality -Based Effluent Limitations (WQBELs)
Dilution and MixingZones
ones
In accordance with 15A NCAC 213.0206, the following streamflows are used for dilution considerations
for development of WQBELs: 1Q10 streamflow (acute Aquatic Life); 7Q10 streamflow (chronic Aquatic
Life; non -carcinogen HH); 30Q2 streamflow (aesthetics); annual average flow (carcinogen, HH).
If applicable, describe any other dilution factors considered (e.g., based on CORMIX model results): NA
If applicable, describe any mixing zones established in accordance with 15A NCAC 2B. 0204(b): NA
Oxygen -Consuming Waste Limitations
Limitations for oxygen -consuming waste (e.g., BOD) are generally based on water quality modeling to
ensure protection of the instream dissolved oxygen (DO) water quality standard. Secondary TBEL limits
(e.g., BOD= 30 mg/1 for Municipals) may be appropriate if deemed more stringent based on dilution and
model results.
Ifpermit limits are more stringent than TBELs, describe how limits were developed: Speculative effluent
limits for the proposed expansions to 6.0 MGD and 10.0 MGD were provided on September 4, 2020,
based on Division review of receiving stream conditions and water quality modeling results. The Division
indicated year-round limits for BOD5 and ammonia based on the results of a 2020 QUAL2K model.
However, it was noted that, if the Town were to justify seasonal limits with additional modeling per 15A
NCAC 02B .0404(b), the Division would incorporate seasonal limits into the permit. The Division
received results from additional modeling of the Neuse River to support seasonal limits in the NPDES
permit on September 18, 2020. The additional modeling was conducted by Dewberry. The Division
reviewed and approved the modeling results on September 24, 2020. The Division received the official
request from the Town of Clayton for seasonal BOD5 and ammonia limits on September 25, 2020, citing
the additional model results. BOD has been limited at both flow tiers as follows:
Table 3. Proposed BOD5 limits for modification
6.0 MGD Flow Tier
10.0 MGD Flow Tier
Summer BOD5 Limits
Winter BOD5 Limits
Summer BOD5 Limits
Winter BOD5 Limits
Monthly
Ave ra e
Weekly
Average
Monthly
Average
Weekly
Average
Monthly
Average
Weekly
Average
Monthly
Average
Weekly
Average
5.0 mg/L
7.5 mg/L
10.0 mg/L
15.0 mg/L
5.0 mg/L
7.5 mg/L
10.0
m /L
15.0
m /L
Ammonia and Total Residual Chlorine Limitations
Page 5 of 19

Limitations for ammonia are based on protection of aquatic life utilizing an ammonia chronic criterion of
1.0 mg/l (summer) and 1.8 mg/l (winter). Acute ammonia limits are derived from chronic criteria,
utilizing a multiplication factor of 3 for Municipals and a multiplication factor of 5 for Non -Municipals.
Limitations for Total Residual Chlorine (TRC) are based on the NC water quality standard for protection
of aquatic life (17 ug/1) and capped at 28 ug/l (acute impacts). Due to analytical issues, all TRC values
reported below 50 ug/l are considered compliant with their permit limit.
Describe any proposed changes to ammonia and/or TRC limits for this permit renewal: Refer to the
Oxygen Consuming Waste section for the description of the model and rationale behind the TRC and
ammonia limits.
TRC has been limited at a daily maximum of 28 ug/L, at both the 6.0 MGD and 10.0 MGD flow tier. The
proposed expansion project does not include the existing backup chlorination system. The limits have
been added to the modified permit, but can be reassessed during the modification of the NPDES permit
upon completion of construction of the proposed plant.
Ammonia has been limited at both flow tiers as follows:
Table 4. Proposed Ammonia limits for modification
6.0 MGD Flow Tier
10.0 MGD Flow Tier
Summer NH3 Limits
Winter NH3 Limits
Summer NH3 Limits
Winter NH3 Limits
Monthly
Ave ra e
Weekly
Average
Monthly
Average
Weekly
Average
Monthly
Average
Weekly
Average
Monthly
Average
Weekly
Average
5.0 mg/L
7.5 mg/L
10.0 mg/L
15.0 mg/L
5.0
m /L
7.5 mg/L
10.0
m /L
15.0
m /L
Reasonable Potential Analysis (RPA) for Toxicants
If applicable, conduct RPA analysis and complete information below.
The need for toxicant limits is based upon a demonstration of reasonable potential to exceed water quality
standards, a statistical evaluation that is conducted during every permit renewal utilizing the most recent
effluent data for each outfall. The RPA is conducted in accordance with 40 CFR 122.44 (d) (i). The NC
RPA procedure utilizes the following: 1) 95% Confidence Level/95% Probability; 2) assumption of zero
background; 3) use of detection limit for "less than" values; and 4) streamflows used for dilution
consideration based on 15A NCAC 2B.0206. Effective April 6, 2016, NC began implementation of
dissolved metals criteria in the RPA process in accordance with guidance titled NPDES Implementation of
Instream Dissolved Metals Standards, dated June 10, 2016.
A reasonable potential analysis was conducted on effluent toxicant data collected between September
2016 and June 2020 and on Effluent Pollutant Scan data collected between August 2015 and September
2019. Pollutants of concern included toxicants with positive detections and associated water quality
standards/criteria. Based on this analysis, the following permitting actions are proposed for this permit:
Effluent Limit with Monitoring. The following parameters will receive a water quality -based
effluent limit (WQBEL) since they demonstrated a reasonable potential to exceed applicable
water quality standards/criteria: NA
Monitoring Only. The following parameters will receive a monitor -only requirement since they
did not demonstrate reasonable potential to exceed applicable water quality standards/criteria,
but the maximum predicted concentration was >50% of the allowable concentration: NA
Page 6 of 19

No Limit or Monitoring: The following parameters will not receive a limit or monitoring, since
they did not demonstrate reasonable potential to exceed applicable water quality
standards/criteria and the maximum predicted concentration was <50% of the allowable
discharge concentration: Arsenic, Cadmium, Total Chromium, Copper, Cyanide, Lead,
Molybdenum, Nickel, Selenium, Silver, Zinc, Nitrate
POTW Effluent Pollutant Scan Review: Three effluent pollutant scans were evaluated for
additional pollutants of concern.
o The following parameter(s) will receive a water quality -based effluent limit (WQBEL)
with monitoring, since as part of a limited data set, two samples exceeded the allowable
discharge concentration: NA
o The following parameter(s) will receive a monitor -only requirement, since as part of a
limited data set, one sample exceeded the allowable discharge concentration: NA
o The following parameter(s) will receive no monitoring requirement, since as part of a
limited data set, no sample exceeded the allowable discharge concentration: Beryllium,
Chlorides, Total Phenolic Compounds, Total Dissolved Solids (TDS)
An RPA was conducted at 6.0 MGD and 10.0 MGD flow tiers and results were consistent with those of
the 2.5 MGD flow tier. Nitrate nitrogen was reviewed based on nitrate/nitrite samples reported.
Chlorinated phenolic compounds were not detected in the PPA scans submitted by the Town.
Effluent hardness exceeded 100 mg/L on one occasion (9/27/2016) during the period reviewed [per 15A
NCAC 02B .0216].
If applicable, attach a spreadsheet of the RPA results as well as a copy of the Dissolved Metals
Implementation Fact Sheet for freshwater/saltwater to this Fact Sheet. Include a printout of the RPA
Dissolved to Total Metal Calculator sheet if this is a Municipality with a Pretreatment Program.
Toxici . Testing Limitations
Permit limits and monitoring requirements for Whole Effluent Toxicity (WET) have been established in
accordance with Division guidance (per WET Memo, 8/2/1999). Per WET guidance, all NPDES permits
issued to Major facilities or any facility discharging "complex" wastewater (contains anything other than
domestic waste) will contain appropriate WET limits and monitoring requirements, with several
exceptions. The State has received prior EPA approval to use an Alternative WET Test Procedure in
NPDES permits, using single concentration screening tests, with multiple dilution follow-up upon a test
failure.
Describe proposed toxicity test requirement: This is a Major POTW, and a chronic WET limit at 2%
effluent at 2.5 MGD flow will continue on a quarterly frequency. Based on Division review of receiving
stream conditions and water quality modeling results provided in the September 2020 speculative limits,
the 6.0 MGD and 10.0 MGD flow tiers will include chronic WET testing requirement at 4.8% effluent
and 7.7% effluent, respectively. Chronic WET testing shall be conducted on a quarterly frequency at both
the 6.0 MGD and 10.0 MGD flow tiers.
Mercury Statewide TMDL Evaluation
There is a statewide TMDL for mercury approved by EPA in 2012. The TMDL target was to comply
with EPA's mercury fish tissue criteria (0.3 mg/kg) for human health protection. The TMDL established a
wasteload allocation for point sources of 37 kg/year (81 lb/year), and is applicable to municipals and
Page 7 of 19

industrial facilities with known mercury discharges. Given the small contribution of mercury from point
sources (-2% of total load), the TMDL emphasizes mercury minimization plans (MMPs) for point source
control. Municipal facilities > 2 MGD and discharging quantifiable levels of mercury (>1 ng/1) will
receive an MMP requirement. Industrials are evaluated on a case -by -case basis, depending if mercury is a
pollutant of concern. Effluent limits may also be added if annual average effluent concentrations exceed
the WQBEL value (based on the NC WQS of 12 ng/1) and/or if any individual value exceeds a TBEL
value of 47 ng/1
Table 5. Mercury Effluent Data Summary
2016
2017
2018
2019
2020
4 of Samples
2
4
4
4
2
Annual Average Conc. n /L
0.5
0.5
0.5
0.5
0.5
Maximum Conc., n /L
0.5
0.5
0.5
0.5
0.5
TBEL, n /L
47
WQBEL, n /L
588.0
Describe proposed permit actions based on mercury evaluation: Since no annual average mercury
concentration exceeded the WQBEL, and no individual mercury sample exceeded the TBEL, no mercury
limit is required. Since the facility did not report quantifiable levels of mercury (> 1 ng/1) during the
period reviewed, no mercury minimization plan (MMP) is required. This applies to all flow tiers.
Other TMDL/Nutrient Management Strategy Considerations
If applicable, describe any other TNDDLs/Nutrient Management Strategies and their implementation
within this permit:
Neuse River Nitrogen TMDL and Nutrient Management Strategy
The Neuse River estuary has an extensive history of nutrient -related water quality impacts and was
classified as Nutrient Sensitive Waters in 1988. Nutrient Management Strategy rules were first adopted in
December 1997 and modified in 2000 and 2020. The wastewater discharge rule, 15A NCAC 2B .0713
(formerly .0234), established requirements for control of Total Nitrogen (TN) from point source
discharges. It requires TN limits for all dischargers with a permitted capacity of 0.5 MGD or greater and
allows the transfer of allocation among the Neuse dischargers so long as the total of estuary allocations
and loads do not exceed those allowed in the 1999 TN TMDL. The rule also sets technology -based limits
for Total Phosphorus (TP).
The wastewater rule provides a group compliance option in which interested dischargers can work
collectively to comply with an aggregate TN limit. Clayton is a co-permittee member of the Neuse River
Compliance Association, whose group NPDES permit, NCC000001, was last re -issued December 12,
2018. Co-permittee members are deemed to be in compliance with the TN limits in their individual
permits and are instead subject to the aggregate limit established in the group permit. The group's TN
limit is the sum of the members' active estuary allocations.
Nitrogen Allocations and Offset Credits
In accordance with the Neuse rule, the Town of Clayton was assigned a base Total Nitrogen (TN)
discharge allocation of 21,400 lb/yr. This was the basis for its original (2003) TN discharge limit. Based
on its location in the basin, the facility was assigned a transport factor of 50%; thus, its discharge
allocation is equivalent to 10,700 lb/yr delivered to the estuary. Transport factors and delivered loads
come into play when transferring allocation or offset credits to or from a discharger.
Page 8 of 19

The Town has experienced significant growth since the early 2000s and in 2006 was permitted to
expanded to 2.5 MGD. To meet additional needs, the Town acquired 3,668 lb/yr estuary nitrogen
allocation from South Granville WASA (NC0026824) in 2006, 1,645 lb/yr from UNIFI-Kinston
(formerly and once again, DuPont -Kinston, NC0003760) in 2007.
In 2020, The transactions were conducted in accordance with the Neuse River nutrient strategy and rule.
In September 2020, the Town acquired nitrogen offset credits from RS Flat Swamp, LLC. RS Flat Swamp
is the Bank Sponsor for the RS Flat Swamp Buffer & Nutrient Offset Mitigation Bank, a mitigation
project undertaken to generate nutrient offset credits. The transaction was conducted in accordance with
the Neuse strategy and the procedures of the Division's Nutrient Offset and Riparian Buffer Mitigation
Banking Program. These procedures included submittal of a Letter of Intent to purchase offset credits
from the Town and the Bank Sponsor, a Statement of Nutrient Offset Credit Availability by the Bank
Sponsor, and a Nutrient Offset Credit Transfer Certificate by the Sponsor upon payment and completion
of the transaction. (See the September 20, 2020, Fact Sheet for further details.)
Also in September 2020, the Town acquired 13,000 lb/yr of estuary TN allocation from International
Paper —New Bern (NC0003191). One purpose of this modification is to note the additional reserve
allocation in the Town's permit. International Paper's permit is being modified at the same time to reflect
the 13,000 lb/yr reduction in its TN allocation and limit.
The Town's TN allocation and offset credit holdings are listed in Tables 2-4 for the 2.5, 6.0, and 10.0
MGD tiers of the permit. The tables also note the resulting TN Load limits at each flow tier. At 2.5 and
6.0 MGD, the total allowance (allocation plus offset credits) exceeds the Neuse rule's technology -based
cap of 3.5 mg/L for existing facilities, and the excess allowance is held in reserve. At 10.0 MGD, the
Town's entire allowance is equivalent to 2.95 mg/L TN and so can be applied toward its TN Load limit.
(The equivalent TN concentrations in the tables indicate the level of treatment required at design flow but
will not be included as limits in the permit.).
Table 6. Allocations and Offset Credits — 2.5 MGD
ALLOCATION/ CREDITS AMOUNT
SOURCE
STATUS
Estuary
Discharge
Equiv TN
(lb/yr)
(lb/yr)
(mg/L)
Assigned by Rule
10,700
21,400
Active
Purchased from South Granville
3,668
7,336
Reserve
WASA (NC0026824)
1,645
3,290
Mixed
Purchased from UNIFI-Kinston
716
1,432
Active
(NC0003760)
929
1,858
Reserve
Purchased from
RS-Flat Swamp, LLC (Flat Swamp
15,908
31,816
Reserve
Mitigation Bank)
Purchased from International Paper,
13,000
26,000
Reserve
NC0003191
Page 9 of 19

TOTAL
44,921
89,842
Mixed
11,416
22,832
3.0
Active
33,505
67,010
Reserve
Table 7. Allocations and Offset Credits - 6.0 MGD
ALLOCATION/ CREDITS AMOUNT
SOURCE
STATUS
Estuary
Discharge
Equiv TN
(lb/yr)
(lb/yr)
(mg/L)
Assigned by Rule
10,700
21,400
Active
Purchased from South Granville
WASA (NC0026824)
3,668
7,336
Reserve
Purchased from UNIFI-Kinston
1,645
3,290
Active
(NC0003760)
Purchased from
RS-Flat Swamp, LLC (Flat Swamp
15,908
31,816
Reserve
Mitigation Bank)
13,000
26,000
Purchased from International Paper,
Mixed
NC0003191
42
84
Active
Reserve
12,958
25,916
TOTAL
44,921
89,842
Mixed
31,963
63,926
3.50
Active
12,958
25,916
Reserve
Table 8. TN Allocations and Offset Credits -10.0 MGD
ALLOCATION/ CREDITS AMOUNT
SOURCE
STATUS
Estuary
Discharge
Equiv TN
(lb/yr)
(lb/yr)
(mg/L)
Assigned by Rule
10,700
21,400
Active
Purchased from South Granville
3,668
7,336
Active
WASA (NC0026824)
Purchased from UNIFI-Kinston
1,645
3,290
Active
(NC0003760)
Purchased from
RS-Flat Swamp, LLC (Flat Swamp
15,908
31,816
Active
Mitigation Bank)
Page 10 of 19

Purchased from International Paper,
13,000
26,000
Active
NC0003191
TOTAL
44,921
89,842
2.95
Active
Other WQBEL Considerations
If applicable, describe any other parameters of concern evaluated for WQBELs: NA
If applicable, describe any special actions (HQW or ORW) this receiving stream and classification shall
comply with in order to protect the designated waterbody: NA
If applicable, describe any compliance schedules proposed for this permit renewal in accordance with
15A NCAC 2H 0107(c)(2)(B), 40CFR 122.47, and EPA May 2007 Memo: NA
If applicable, describe any water quality standards variances proposed in accordance with NCGS 143-
215.3(e) and 15A NCAC 2B. 0226 for this permit renewal: NA
7. Technology -Based Effluent Limitations (TBELs)
Municipals (if not applicable, delete and skip to Industrials)
Are concentration limits in the permit at least as stringent as secondary treatment requirements (30 mg/1
BOD5/TSS for Monthly Average, and 45 mg/l for BOD5/TSS for Weekly Average). YES
If NO, provide a justification for alternative limitations (e.g., waste stabilization pond). NA
Are 85% removal requirements for BOD5/TSS included in the permit? YES
If NO, provide a justification (e.g., waste stabilization pond). NA
If any limits are based on best professional judgement (BPJ), describe development: NA
Document any TBELs that are more stringent than WQBELs: NA
Document any TBELs that are less stringent than previous permit: NA
8. Antidegradation Review (New/Expanding Discharge):
The objective of an antidegradation review is to ensure that a new or increased pollutant loading will not
degrade water quality. Permitting actions for new or expanding discharges require an antidegradation
review in accordance with 15A NCAC 213.0201. Each applicant for a new/expanding NPDES permit
must document an effort to consider non -discharge alternatives per 15A NCAC 2H.0105( c)(2). In all
cases, existing instream water uses and the level of water quality necessary to protect the existing use is
maintained and protected.
If applicable, describe the results of the antidegradation review, including the Engineering Alternatives
Analysis (EAA) and any water quality modeling results: The proposed expansion is not subject to review
under the State of North Carolina Environmental Policy Act (SEPA). The project is funded by the State
via the State Revolving Fund (SRF) and received an approved Finding of No Significant Impact (FONSI)
on January 5, 2021, following an environmental review.
Page 11 of 19

An Engineer's Alternatives Analysis (EAA) was submitted by Jacobs, the consulting firm hired by the
Town of Clayton, on September 11, 2020. Flow needs were projected based on a 20-year planning
horizon. The projected flows considered population growth, as well as industrial growth. The Little Creek
WRF currently treats wastewater for a population of 25,234 residents and operates a pretreatment
program with two pharmaceutical Categorical Industrial Users, Novo Nordisk and Grifols. Currently,
Grifols discharges to Johnston County's WWTP. Novo Nordisk's flow to Little Creek WWTP was 0.076
MGD. Clayton has agreements with Johnston County and Raleigh's Neuse River WWTP to divert up to
1.3 MGD and 1.0 MGD to those plants respectively. Between 2010 and 2018, The Town of Clayton has
experienced a roughly 40% increase in population. Population growth was projected to 2040 using a
probabilistic modeling approach that divided the Town's service area into different zones and assessed the
current and projected for each zone. This modeling approach allowed for more localized understandings
in growth. Additionally, industries serviced by the Town have shared their individual growth plans, and
those expanded flows were able to be accounted for in the applicable zones. The modelled population
growth is consistent with the 2010 — 2019 North Carolina Office of State Budget and Management
population growth extrapolated out to 2040.
The following alternatives were evaluated for the expanded flow:
1. No Action — The Town would not increase capacity of the facility. This would not support the
projected growth of the Town and is thus infeasible.
2. A. Construction of New WRF, and Continued Use 2a of a Surface Water Discharge( at
Neuse 2 Pump Station site) - the Town would build a new 6-MGD WRF at the Neuse 2 Pump
Station site, with potential for future incremental expansion to 10 MGD. The Town -owned parcel
with the Neuse 2 and Clayton to Raleigh Pump Station and LCWRF Neuse River discharge into
the Neuse River is of sufficient size for the construction of a new 6-MGD WRF and could
maintain stream and property buffers and avoid the floodplain along the Neuse River.
B. Construction of New WRF, and Continued Use of a Surface Water Discharge (at East
Clayton Industrial Area Pretreatment Facility Site) - the Town would construct a new WRF
adjacent to the R. Steven Biggs Regional Pretreatment Facility. This site is located near the
Town's primary industrial and commercial customers; however, it is not in an area expected to
undergo significant residential growth or development. This land is currently intended for
pretreatment facility expansions that would allow the Town to serve more industrial customers in
the future.
3. Expansion of Little Creek WRF and Continued Use of Surface Water Discharge - the Town
would rehabilitate the existing LCWRF and expand its capacity to 6 MGD by 2023 from its
current permitted capacity of 2.5 MGD. In addition, the Town would upgrade its discharge force
main, pump station, gravity line to the discharge location and Neuse River discharge. (Note: The
existing plant sends its effluent through miles of pipe before discharge through the outfall.
Moving the plant closer to the outfall would mitigate potential for bacterial regrowth in route to
the receiving stream.)
4. Continued Use of Little Creek WRF, Maximizing Regional Connections to Existing
Wastewater Treatment — The Town would expand its current purchased flow agreements with
the City of Raleigh and Johnston County to divert more flow to these plants, maintaining the
existing facility as is. Johnston County will not accept industrial waste, and the City of Raleigh
intends to increase rates for accepted flow upwards of 40% after the current 1.0 MGD contract.
The Town of Clayton would need to accommodate up to 10 MGD of flow and a sizable portion of
that would be industrial. This alternative was eliminated from the evaluation due to its
constraints, and no NPV was calculated.
5. Construction of a New WRF and Use of Land Application - the Town would build a new 6-
MGD WRF, with plans for future incremental expansion to 10 MGD. The effluent discharge
location at the Neuse River would be abandoned, and the WRF treated effluent disposal would be
diverted to suitable locations for spray irrigation. Land application nutrient removal requirements
are less stringent than for surface water discharge, and the purchase of nitrogen credits in the
Page 12 of 19

Neuse River basin would be reduced or not necessary. The Town currently provides a small
amount of reuse water to the Pine Hollow Golf Course; however, demand is seasonal, and other
land application sites would be necessary. For this evaluation, the Neuse 2 Pump Station site was
used as the new WRF site. The amount of land necessary for land application was estimated using
area soil conditions.
Construction of a New Water Reclamation Facility, and Implementation of Larger -scale
Wastewater Reuse - the Town would build a new 6- MGD WRF, with the potential to
incrementally expand to 10 MGD as well as build a customer base to support wastewater reuse of
effluent. The Town currently provides a small amount of reuse water seasonally to a golf course.
The Town has surveyed nearby potential users and found some additional golf courses and
industrial users, limited potential exists for the large- scale reuse. The demand from the golf
course equated to roughly 0.15 MGD and the industrial users have sustainability programs in
place that limit any need for reuse water. The alternative was considered to be infeasible for the
amount of growth projected. As such, no NPV was calculated.
Construction of New WRF with Alternative Secondary Treatment Process - the Town would
build a new 6-MGD WRF with potential for future incremental expansion to 10 MGD and would
replace the biological phosphorous removal process for the new 6-MGD WRF with a four -stage
BNR process with metal salt addition for phosphorus removal.
Construction of New WRF with Alternative Biosolids Treatment Strategy — the Town would
build a new 6-MGD WRF with potential for future incremental expansion to 10 MGD and would
contract Lystek for management and disposal of biosolids at the new WRF. This solids treatment
process employs the same thickening and dewatering equipment as the Preferred Alternative
(Alternative 2a) and adds Lystek THP reactors to produce Class A biosolids capable of being sold
as biosolids fertilizer. The primary benefit of this alternative is the contracted management of
biosolids with Lystek, and the potential for significantly reduced disposal costs (approximately 20
percent of composting costs) believed possible with this approach. This process produces a more
concentrated product; therefore, the 30-day solids storage and aeration equipment are reduced in
size.
9. Combination of Alternatives — Multiple options considered:
a. The Town would continue operation of the LCWRF at its current capacity and construct a
smaller plant at a new site. This alternative would require the construction of a 4-MGD
WRF at a second site. While this would have a lower capital cost than a new 6-MGD
facility, rehabilitation of aging equipment at the LCWRF would still require investment
to maintain operational functionality of 2 MGD. Operational cost efficiencies would also
be lost if two facilities remained in operation. This combination does not yield significant
cost -savings for the Town and was not considered further.
b. The Town would land apply effluent during the dry season and revert to NPDES
discharge via the LCWRF outfall during the wet season. As noted in Alternative 5, a
large area would be required for land application, and the cost of that land and the
associated infrastructure is very high. In addition, because the WRF would be required to
treat to a high enough level for a surface water discharge, there would be no cost -savings
related to the reduced effluent quality associated with land application. As such, this
combination of alternatives provides no benefit over the other options and was not
considered further.
c. The Town would combine land application and large-scale reuse. Neither of these
alternatives were found to be feasible individually and are not considered feasible in
combination.
10. Decentralized System - The Town's wastewater treatment strategy is to collect wastewater at
centralized points and transmit it to LCWRF and regional partners for treatment. Given the
Town's approach for centralized collection and treatment, it would not be efficient or effective to
transition to a decentralized approach. Based on these factors, development of a decentralized
system is not considered a viable or feasible alternative for the Town's WRF expansion project.
Page 13 of 19

11. Optimum Operation of Existing Facilities — Optimum operation of a 2.5 MGD treatment
facility would not accommodate the increased flow projected by population growth.
Alternative Description
20- ear NP'
1. No Action.
N/A
2a. Construction of a New Water Reclamation Facility, and
Continued Use of Surface Water Discharge
$154,487,401
2b. Construction of New WRF, and Continued Use of a Surface Water Discharge( at
ECIA Site)
$173,317,373
3. Expansion of Little Creek WRF and Continued Use of Surface Water Discharge
$134,079,561
4. Continued Use of Little Creek WRF, Maximizing Regional Connections to Existing
Wastewater Treatment
N/A
5. Construction of a New WRF and Use of Land Application
$186,800,000
6. Construction of a New Water Reclamation Facility, and Implementation of Larger-
scale Wastewater Reuse
N/A
7. Construction of New WRF with Alternative Secondary Treatment Process
$152,238,474
8. Construction of New WRF with Alternative Biosolids Treatment Strategy
$155,869,749
9. Combination of Alternatives
N/A
10. Decentralized System
N/A
11. Optimum Operation -of Existing Facilities
N/A
The Town's chosen option was Alternative 2a, the Construction of a New Water Reclamation Facility,
and Continued Use of Surface Water Discharge.
The most economically feasible option proposed was Alternative 3. However, this estimate assumes
existing LCWRF treatment system structures will be used in the upgraded and expanded process. This
assumption about reuse of existing structures accounts for the capital cost differential between this and
the Preferred Alternative. While this option makes use of existing structures, which are not expected to
need replacement within the 20-year planning period, they would reach the end of their expected useful
life sooner after the planning period than Alternative 2a, which is the Town's preferred alternative,
structures would. This reflects a future cost liability for the Town that is not captured in the 20-year cost
estimate.
The next most economically feasible option was Alternative 7. However, chemicals used for phosphorus
removal have the potential to vary in price, leading to uncertainty of operational cost. The slightly higher
capital cost of biological phosphorous removal is offset by these considerations.
Alternative 2a is the most economically feasible after Alternatives 3 and 7.
The Division has reviewed the alternatives and concurs with this decision.
9. Antibacksliding Review:
Sections 402(o)(2) and 303(d)(4) of the CWA and federal regulations at 40 CFR 122.44(1) prohibit
backsliding of effluent limitations in NPDES permits. These provisions require effluent limitations in a
reissued permit to be as stringent as those in the previous permit, with some exceptions where limitations
may be relaxed (e.g., based on new information, increases in production may warrant less stringent TBEL
limits, or WQBELs may be less stringent based on updated RPA or dilution).
Are any effluent limitations less stringent than previous permit (YESINO): NO
If YES, confirm that antibacksliding provisions are not violated.- NA
Page 14 of 19

10. Monitoring Requirements
Monitoring frequencies for NPDES permitting are established in accordance with the following
regulations and guidance: 1) State Regulation for Surface Water Monitoring, 15A NCAC 2B.0500; 2)
NPDES Guidance, Monitoring Frequency for Toxic Substances (7/15/2010 Memo); 3) NPDES Guidance,
Reduced Monitoring Frequencies for Facilities with Superior Compliance (10/22/2012 Memo); 4) Best
Professional Judgement (BPJ). Per US EPA (Interim Guidance, 1996), monitoring requirements are not
considered effluent limitations under Section 402(o) of the Clean Water Act, and therefore anti -
backsliding prohibitions would not be triggered by reductions in monitoring frequencies.
For instream monitoring, refer to Section 4.
The Town of Clayton was granted monitoring frequency reductions for BOD5, Total Suspended Solids,
NH3-N and Fecal Coliform in their December 2019 NPDES permit renewal based on DWR Guidance
Regarding the Reduction of Monitoring Frequencies in NPDES Permits for Exceptionally Performing
Facilities. The last three years of the facility's data for these parameters have been reviewed. No changes
are proposed to the 2/week monitoring frequency requirements for BOD5, Total Suspended Solids, NH3-
N and Fecal Coliform.
11. Electronic Reporting Requirements
The US EPA NPDES Electronic Reporting Rule was finalized on December 21, 2015. Effective
December 21, 2016, NPDES regulated facilities are required to submit Discharge Monitoring Reports
(DMRs) electronically. While NPDES regulated facilities would initially be required to submit additional
NPDES reports electronically effective December 21, 2020, EPA is proposing to extend this deadline
from December 21, 2020, to December 21, 2025. This permit contains the requirements for electronic
reporting, consistent with Federal requirements. The current compliance date will be extended if the
implementation date is extended as a final regulation change in the federal register.
12.Summary of Proposed Permitting Actions:
Table 3. Current Permit Conditions and Proposed Changes 2.5 MGD
Parameter
Current Permit
Proposed Change
Basis for Condition/Change
Flo
MA 2.5 MGD
MA 2.5 MGD with
15A NCAC 2B .0505; Expansion
expansion pages for
application and EAA Review;
6.0 MGD and 10.0
Results of 2020 QUAL2K model
MGD
Total Monthly
Monitor and Report
No change at 2.5
For calculation of total nitrogen
Flow
monthly
MGD flow tier.
At both 6.0 MGD and
10.0 MGD flow tiers:
Monitor and Report
monthly
Page 15 of 19

BOD5
Summer:
No change at 2.5
WQBEL. Based 2020 QUAL2K
MA 5.0 mg/l
MGD flow tier.
model results.
WA 7.5 mg/l
Winter:
At both 6.0 MGD and
DWR Guidance Regarding the
MA 10.0 mg/l
10.0 MGD flow tiers:
Reduction of Monitoring
WA 15.0 mg/l
Summer:
Frequencies in NPDES Permits for
2/week monitoring
MA 5.0 mg/l
WA 7.5 mg/l
Exceptionally Performing Facilities
Winter:
MA 10.0 mg/l
WA 15.0 mg/l
NH3-N
Summer:
No change at 2.5
WQBEL. Based 2020 QUAL2K
MA 1 mg/l
MGD flow tier.
model results.
WA 3 mg/l
Winter:
At both 6.0 MGD and
DWR Guidance Regarding the
MA 2 mg/l
10.0 MGD flow tiers:
Reduction of Monitoring
WA 6 mg/l
Summer:
Frequencies in NPDES Permits for
2/week monitoring
MA 1 mg/l
WA 3 mg/l
Exceptionally Performing Facilities
Winter:
MA 2 mg/l
WA 6 mg/l
TSS
MA 30 mg/l
No change at 2.5
TBEL. Secondary treatment
WA 45 mg/l
MGD flow tier.
standards/40 CFR 133 / 15A NCAC
2B .0406. DWR Guidance
2/week monitoring
At both 6.0 MGD and
Regarding the Reduction of
10.0 MGD flow tiers:
Monitoring Frequencies in NPDES
MA 30 mg/l
Permits for Exceptionally
WA 45 mg/l
Performing Facilities
Fecal coliform
MA 200 /100ml
No change at 2.5
WQBEL. State WQ standard, 15A
WA 400 /100ml
MGD flow tier.
NCAC 2B .0200. DWR Guidance
Regarding the Reduction of
2/week monitoring
At both 6.0 MGD and
Monitoring Frequencies in NPDES
10.0 MGD flow tiers:
Permits for Exceptionally
MA 200 /100ml
Performing Facilities
WA 400 /100ml
DO
> 6 mg/l
No change at 2.5
WQBEL. Based on 2020 QUAL2K
MGD flow tier.
model results.
At both 6.0 MGD and
10.0 MGD flow tiers:
> 6 mg/l
Temperature
Monitor and Report
No change at 2.5
15A NCAC 2B .0508 — Surface
Daily
MGD flow tier.
Water Monitoring: Reporting
At both 6.0 MGD and
10.0 MGD flow tiers:
Monitor Daily
pH
6 — 9 SU
No change at 2.5
WQBEL. State WQ standard, 15A
MGD flow tier.
NCAC 2B .0200. 2020 Speculative
Limits.
Page 16 of 19

At both 6.0 MGD and
10.0 MGD flow tiers:
6-9SU
TRC
DM 28 ug/L
No change at 2.5
WEBEL. 2020 Speculative limits.
MGD flow tier.
At both 6.0 MGD and
10.0 MGD flow tiers:
DM 28 ug/L
Conductivity
Monitor and Report
No change at 2.5
Daily
MGD flow tier.
At both 6.0 MGD and
10.0 MGD flow tiers:
Monitor and Report
Daily
TKN
Monitor and Report
No change at 2.5
For calculation of total nitrogen
Weekly
MGD flow tier.
At both 6.0 MGD and
10.0 MGD flow tiers:
Monitor and Report
Weekly
Nitrate+Nitrite
Monitor and Report
No change at 2.5
For calculation of total nitrogen
Weekly
MGD flow tier.
At both 6.0 MGD and
10.0 MGD flow tiers:
Monitor and Report
Weekly
Total Nitrogen
Monitor and Report
No change at 2.5
Surface Water Monitoring. 15A
Weekly
MGD flow tier.
NCAC 2B .0713
At both 6.0 MGD and
10.0 MGD flow tiers:
Monitor and Report
Weekly
TN Load
63,842 lb/yr
89,842 lb/yr at all flow
WQBEL. 15A NCAC 2B .0713.
tiers
Addition of purchased credits from
International Paper
Total Phosphorus
QA 2.0 mg/L
No change at 2.5
WQBEL. 15A NCAC 2B .0713
MGD flow tier.
At both 6.0 MGD and
10.0 MGD flow tiers:
QA 2.0 mg/L
Bis (2-ethylhexyl)
Monitor and Report
No change at 2.5
Based on RPA for Limited Dataset
phthalate
Quarterly
MGD flow tier.
Results; RP for Limited Dataset
(n<8 samples) - apply Quarterly
Monitoring
Page 17 of 19

At both 6.0 MGD and
10.0 MGD flow tiers:
Monitor and Report
Quarterly
Total Hardness
Quarterly monitoring
No change at 2.5
In accordance with NPDES guidance
Upstream and in
MGD flow tier.
on Implementing Instream Dissolve
Effluent
Metals Standards for Freshwater —
At both 6.0 MGD and
Pretreatment POTW sampling for
10.0 MGD flow tiers:
hardness -dependent metals in LTMP
Quarterly monitoring
Upstream and in
Effluent
Toxicity Test
Chronic limit, 2%
No change at 2.5
WQBEL. No toxics in toxic
effluent
MGD flow tier.
amounts. 15A NCAC 213.0200 and
15A NCAC 213.0500
6.0 MGD flow tier -
Chronic limit, 4.8%
effluent
10.0 MGD flow tier -
Chronic limit, 7.7%
effluent
Effluent Pollutant
Three times per permit
No change
40 CFR 122
Scan
cycle
Electronic
Electronic Reporting
No change
In accordance with EPA Electronic
Reporting
I Special Condition
I Reporting Rule 2015.
MGD — Million gallons per day, MA - Monthly Average, WA — Weekly Average, DM — Daily Max
13. Public Notice Schedule:
Permit to Public Notice: 11/10/2020
Per 15A NCAC 2H .0109 & .0111, The Division will receive comments for a period of 30 days following
the publication date of the public notice. Any request for a public hearing shall be submitted to the
Director within the 30 days comment period indicating the interest of the party filing such request and the
reasons why a hearing is warranted.
14. Fact Sheet Addendum (if applicable):
The draft was submitted to the Town of Clayton, EPA Region IV, and the Division's Raleigh Regional
Office, Aquatic Toxicology Branch, Ecosystems Branch and Operator Certification Program for review.
The draft was also submitted to the Raleigh Regional Public Water Supply Officer for concurrence. The
Aquatic Toxicology Branch submitted a comment to correct inconsistencies within the footnotes of the
permit. The Raleigh Regional Office submitted a comment to fix a typographical error and to add a
footnote regarding TRC. No comments were received from any of the other parties.
Were there any changes made since the Draft Permit was public noticed (Yes/No): YES
Page 18 of 19

If Yes, list changes and their basis below:
Footnote numbering was corrected in Sections A.(2.) and A.(3.).
For consistency, footnote language referencing Authorizations to Operate have been revised to
instead reference acceptance of an Engineer's Certificate [See A.(2.) and A.(3.)].
Total residual chlorine footnote language was revised [See A.(1.), A.(2.) and A.(3.)].
15. Fact Sheet Attachments (if applicable):
• RPA Spreadsheet Summary
• Dissolved Metals Implementation/Freshwater
• Mercury TMDL Evaluation
• NPDES Speculative Limits Letter
• 2018-19 QUAL2K Summary
• Monitoring Frequency Reduction Evaluation
• Instream Monitoring Summary
• Aquatic Toxicity Summary
• Inspection Summary
• Mercury Minimization Plan
Page 19 of 19

Powered by McClatchy
The News & Observer
N N 0 421 FayettuvNe Street, Suite 104
MEDIA COMPANY Raieigh, Nc 27601
consult. strategize. deliver.
AFFIDAVIT OF PUBLICATION
Account ik Ad Number
I Identification PO
Cots
Lines
104811 0004808098
1 NCO020389 Benson WNIrP and Little Creek
1
55
Attention:
DEPARTMENT OF WATER RESOURCES
1617 MAIL SERVICE CENTER
RALEIGH, NC 276991617
Public Notice
North Carolina Environmental
Management C'manission/N POE S Unit
1617 Moil Service Center
Roleigl NC 27699d617
Notice of Intent to Issue a NPDE5
Woslewoter Permit NC0020389 Benson
WwTPond NCO25453 Little Creek WRF
The North Carolina Environmen tot
Management Commission pYapases to
issue a NPDES woslewaler discharge
permit to the perso
n(s) Iisled below.
Written comments regarding the Pro-
posed permit will be oCcep led until 30
dogs after the publish dale of this notice.
The Director of the NC Division of Water
Resources (DWR) may hold a public
hearing should there be a significant de.
gree of public intere5l- Please rtwi I com-
ments and/or information requests to
DWR of the ohnve address. interested
Persons may visit the DWR at 512 N, Sol-
isbury Street, Raleigh, NC 27604 to re-
view information an file, Aduiti0hol in-
formation an NPDE5 permits and this
notice may be found on our wehsite:
hitp:/Ideq.nc.gov/aboutidivisionsfwater-
wnle ater er-resources peri'nit3/-
wasldw6ter-branch7hpdes wasfeWater7
Ruh io-notices. or -by calling (919) 707.
3601. The Town of Benson SP,O. Box 69,
Benson, NC 275041 has requested renew-
al of permit NCO020389 for the Benson
Wastewater Treatment Plant in John
stun County. This permitted facility dis.
Charges treated municipal and indusiri.
al wastewater to Hannah Creek, a Class
C-NSW water in the Neuse River Basin.
Currently, GOD, ammonia n1ir191 dis-
solved oxygen, total residual chlorine.
fecal
coliform, toiel nitrogen, and total
Phosphor"
are water quality limited.
This discharge mov affect future alloca.
tions in the receiving stream. The Town
of Clayton has requested modification of
Permit NCOO25453 for its Little Creek
Water Re'lamation Facility in Johnston
County; ihls permitted discharge is
treated municipal and induslriat waste-
water to the Neuse River, In the Neuse
River Basin, The modification will add
oddliiunal flow tiers and record the our.
chase of nutrient credits far future ex,
pansens-
N&O. November 13, 202O
STATE OF NORTH CAROLINA
COUNTY OF WAKE
Before the undersigned, a Notary Public of
Johnston County, North Carolina, duly
commissioned and authorized to administer
oaths, affirmations, etc., personally appeared
BETSY WOMBLE, who being duly sworn or
affirmed, according to law, cloth depose and
say that he or she is Accounts Receivable
Specialist of the News & Observer Publishing
Company, a corporation organized and doing
business under the Laws of the State of
North Carolina, and publishing a newspaper
known as The News & Observer, Wake
County and State aforesaid, the said
newspaper in which such notice, paper,
document, or legal advertisement was
published was, at the time of each and every
such publication, a newspaper meeting all of
the requirements and qualifications of Section
1-597 of the General Statutes of North
Carolina and was a qualified newspaper
within the meaning of Section 1-597 of the
General Statutes of North Carolina, and that
as such he or she makes this affidavit; and is
familiar with the books, files and business of
said corporation and by reference to the files
of said publication the attached advertisement
I Insertion(s)
Published On:
November 13, 2020
BETSY WOMBLE, Accounts Receivable
Specialist
Electronic Notary Pu61ic
State of North Carolina
Sworn to and subscribed before me this
13th day of November, 2020
My Commission Expires: 7110/2023
WENDY DAWSON
!Votary Public
North Carolina
Is Johnston County

r �
Water Resources
Environmental Quality
November 13, 2020
MEMORANDUM
To: Shawn Guyer
NC DEQ / DWR / Public Water Supply Regional Engineer
Raleigh Regional Office
From: Nick Coco
919-707-3609
NPDES Unit
Subject: Review of Draft NPDES Permit Modification NCO025453
Little Creek WRF
Johnston County
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
Director
Please indicate below your agency's position or viewpoint on the draft permit and return this form by December 14,
2020. If you have any questions on the draft permit, please feel free to contact me at the telephone number shown
above.
RESPONSE: (Check one)
Concur with the issuance of this permit provided the facility is operated and maintained properly, the stated
Fx-1 effluent limits are met prior to discharge, and the discharge does not contravene the designated water quality
standards.
F-1 Concurs with issuance of the above permit, provided the following conditions are met:
F-1 Opposes the issuance of the above permit, based on reasons stated below, or attached:
:):�-
4
Signed Date:12/10/2020
'Nothing Compares�ti
State of North Carolina I Environmental Quality
1611 Mail Service Center I Raleigh, North Carolina 27699-1611
919-707-9000

Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
Table 1. Project Information
❑ CHECK IF HQW OR ORW WQS
Facility Name
WWTP/WTP Class
NPDES Permit
Outfall
Flow, Qw (MGD)
Receiving Stream
HUC Number
Stream Class
Little Creek WRF
IV
NCO025453
001
2.500
Neuse River
03020201
WS-IV;NSW;CA
❑✓ Apply WS Hardness WQC
7Q10s (cfs)
7Q10w (cfs)
30Q2 (cfs)
QA (cfs)
1 Q10s (cfs)
Effluent Hardness
Upstream Hardness
Combined Hardness Chronic
Combined Hardness Acute
Data Source(s)
186.000
186.00
186.00
186.00
151.17
I 70.39 mg/L (Avg)
I 45.27 mg/L (Avg)
I 45.79 mg/L
I 45.9 mg/L
Note: Data for Nitrite+Nitrate used in assessing
Nitrate.
❑ CHECK TO APPLY MODEL
REQUIRED DATA ENTRY
Par01
Par02
Par03
Par04
Par05
Par0611111111
Par07
Par08
Par09
Par10
Par11
Par12
Par13
Par14
Par15
Par16
Par17
Par18
Par19
Par20
Par21
Par22
Par23
Par24
Table 2. Parameters of Concern
Name WQs Type Chronic Modifier Acute PQL Units
Arsenic
Aquactic Life
C
150
FW
340
ug/L
Arsenic
Human Health
Water Supply
C
10
HH/WS
N/A
ug/L
Beryllium
Aquatic Life
NC
6.5
FW
65
ug/L
Cadmium
Aquatic Life
NC
0.9320
FW
5.5056
ug/L
Chlorides
Water Supply
NC
250
WS
ng/L
Chlorinated Phenolic Compounds
Water Supply
NC
1
A
ug/L
Total Phenolic Compounds
Aquatic Life
NC
300
A
ug/L
Chromium III
Aquatic Life
NC
193.2499
FW
1488.6896
ug/L
Chromium VI
Aquatic Life
NC
11
FW
16
pg/L
Chromium, Total
Aquatic Life
NC
N/A
FW
N/A
pg/L
Copper
Aquatic Life
NC
13.2164
FW
18.5633
ug/L
Cyanide
Aquatic Life
NC
5
FW
22
10
ug/L
Fluoride
Aquatic Life
NC
1,800
FW
ug/L
Lead
Aquatic Life
NC
5.7907
FW
149.0158
ug/L
Mercury
Aquatic Life
NC
12
FW
0.5
ng/L
Molybdenum
Water Supply
NC
160
WS
ug/L
Nickel
Aquatic Life
NC
62.1193
FW
560.4751
pg/L
Nickel
Water Supply
NC
25.0000
WS
N/A
pg/L
Selenium
Aquatic Life
NC
5
FW
56
ug/L
Silver
Aquatic Life
NC
0.06
FW
0.8428
ug/L
Zinc
Aquatic Life
NC
211.6172
FW
210.3475
ug/L
Nitrate
Water Supply
NC
10
WS
mg/L
TDS
Water Supply
NC
500
WS
mg/L
Bis (2-ethylhexyl) phthalate
Water Supply
I C
0.32
WS
pg/L
25453 RPA, input
10/16/2020

Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
Table 1. Project Information
❑ CHECK IF HQW OR ORW WQS
Facility Name
WWTP/WTP Class
NPDES Permit
Outfall
Flow, Qw (MGD)
Receiving Stream
HUC Number
Stream Class
Little Creek WRF
IV
NCO025453
001
6.000
Neuse River
03020201
WS-IV;NSW;CA
❑✓ Apply WS Hardness WQC
7Q10s (cfs)
7Q10w (cfs)
30Q2 (cfs)
QA (cfs)
1 Q10s (cfs)
Effluent Hardness
Upstream Hardness
Combined Hardness Chronic
Combined Hardness Acute
Data Source(s)
186.000
186.00
186.00
186.00
151.17
I 70.39 mg/L (Avg)
I 45.27 mg/L (Avg)
I 46.47 mg/L
I 46.73 mg/L
Note: Data for Nitrite+Nitrate used in assessing
Nitrate.
❑ CHECK TO APPLY MODEL
REQUIRED DATA ENTRY
Par01
Par02
Par03
Par04
Par05
Par0611111111
Par07
Par08
Par09
Par10
Par11
Par12
Par13
Par14
Par15
Par16
Par17
Par18
Par19
Par20
Par21
Par22
Par23
Par24
Table 2. Parameters of Concern
Name WQs Type Chronic Modifier Acute PQL Units
Arsenic
Aquactic Life
C
150
FW
340
ug/L
Arsenic
Human Health
Water Supply
C
10
HH/WS
N/A
ug/L
Beryllium
Aquatic Life
NC
6.5
FW
65
ug/L
Cadmium
Aquatic Life
NC
0.9425
FW
5.5922
ug/L
Chlorides
Water Supply
NC
250
WS
ng/L
Chlorinated Phenolic Compounds
Water Supply
NC
1
A
ug/L
Total Phenolic Compounds
Aquatic Life
NC
300
A
ug/L
Chromium III
Aquatic Life
NC
195.6098
FW
1510.6497
ug/L
Chromium VI
Aquatic Life
NC
11
FW
16
pg/L
Chromium, Total
Aquatic Life
NC
N/A
FW
N/A
pg/L
Copper
Aquatic Life
NC
13.3848
FW
18.8787
ug/L
Cyanide
Aquatic Life
NC
5
FW
22
10
ug/L
Fluoride
Aquatic Life
NC
1,800
FW
ug/L
Lead
Aquatic Life
NC
5.8869
FW
152.0074
ug/L
Mercury
Aquatic Life
NC
12
FW
0.5
ng/L
Molybdenum
Water Supply
NC
160
WS
ug/L
Nickel
Aquatic Life
NC
62.9030
FW
569.0174
pg/L
Nickel
Water Supply
NC
25.0000
WS
N/A
pg/L
Selenium
Aquatic Life
NC
5
FW
56
ug/L
Silver
Aquatic Life
NC
0.06
FW
0.8692
ug/L
Zinc
Aquatic Life
NC
214.2912
FW
213.5584
ug/L
Nitrate
Water Supply
NC
10
WS
mg/L
TDS
Water Supply
NC
500
WS
mg/L
Bis (2-ethylhexyl) phthalate
Water Supply
I C
0.32
WS
pg/L
25453 RPA, input
10/16/2020

Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
Table 1. Project Information
❑ CHECK IF HQW OR ORW WQS
Facility Name
WWTP/WTP Class
NPDES Permit
Outfall
Flow, Qw (MGD)
Receiving Stream
HUC Number
Stream Class
Little Creek WRF
IV
NCO025453
001
10.000
Neuse River
03020201
WS-IV;NSW;CA
❑✓ Apply WS Hardness WQC
7Q10s (cfs)
7Q10w (cfs)
30Q2 (cfs)
QA (cfs)
1 Q10s (cfs)
Effluent Hardness
Upstream Hardness
Combined Hardness Chronic
Combined Hardness Acute
Data Source(s)
186.000
186.00
186.00
186.00
151.17
I 70.39 mg/L (Avg)
I 45.27 mg/L (Avg)
I 47.21 mg/L
I 47.61 mg/L
Note: Data for Nitrite+Nitrate used in assessing
Nitrate.
❑ CHECK TO APPLY MODEL
REQUIRED DATA ENTRY
Par01
Par02
Par03
Par04
Par05
Par0611111111
Par07
Par08
Par09
Par10
Par11
Par12
Par13
Par14
Par15
Par16
Par17
Par18
Par19
Par20
Par21
Par22
Par23
Par24
Table 2. Parameters of Concern
Name WQs Type Chronic Modifier Acute PQL Units
Arsenic
Aquactic Life
C
150
FW
340
ug/L
Arsenic
Human Health
Water Supply
C
10
HH/WS
N/A
ug/L
Beryllium
Aquatic Life
NC
6.5
FW
65
ug/L
Cadmium
Aquatic Life
NC
0.9538
FW
5.6840
ug/L
Chlorides
Water Supply
NC
250
WS
ng/L
Chlorinated Phenolic Compounds
Water Supply
NC
1
A
ug/L
Total Phenolic Compounds
Aquatic Life
NC
300
A
ug/L
Chromium III
Aquatic Life
NC
198.1442
FW
1533.9193
ug/L
Chromium VI
Aquatic Life
NC
11
FW
16
pg/L
Chromium, Total
Aquatic Life
NC
N/A
FW
N/A
pg/L
Copper
Aquatic Life
NC
13.5658
FW
19.2136
ug/L
Cyanide
Aquatic Life
NC
5
FW
22
10
ug/L
Fluoride
Aquatic Life
NC
1,800
FW
ug/L
Lead
Aquatic Life
NC
5.9907
FW
155.1929
ug/L
Mercury
Aquatic Life
NC
12
FW
0.5
ng/L
Molybdenum
Water Supply
NC
160
WS
ug/L
Nickel
Aquatic Life
NC
63.7451
FW
578.0737
pg/L
Nickel
Water Supply
NC
25.0000
WS
N/A
pg/L
Selenium
Aquatic Life
NC
5
FW
56
ug/L
Silver
Aquatic Life
NC
0.06
FW
0.8975
ug/L
Zinc
Aquatic Life
NC
217.1642
FW
216.9626
ug/L
Nitrate
Water Supply
NC
10
WS
mg/L
TDS
Water Supply
NC
500
WS
mg/L
Bis (2-ethylhexyl) phthalate
Water Supply
I C
0.32
WS
pg/L
25453 RPA, input
10/16/2020

REASONABLE POTENTIAL ANALYSIS
H1
Use"PASTE
HZ
Use "PASTE SPECIAL
Effluent Hardness
SPECIAL -Values"
then "COPY".
Upstream Hardness
Values' then "COPY" .
Maximum data
Maximum data points
points = 58
= Sg
Date
Data
BDL=1/2DL
Results
Date
Data
BDL=1/2DL
Results
1
9/27/16
101
101
Std Dev.
14.9314
1 01/05/18
52
52
Std Dev.
15.2649
2
11/10/16
56
56
Mean
70.3947
2 01/18/18
40
40
Mean
45.2727
3
12/13/16
84
84
C.V.
0.2121
3 02/18
44
44
C.V.
0.3372
4
1/13/17
86
86
n
38
4 03/18
56
56
n
11
5
2/9/17
88
88
10th Per value
51.00 mg/L
5 04/18
41
41
10th Per value
32.00 mg/L
6
3/7/17
88
88
Average Value
70.39 mg/L
6 05/18
36
36
Average Value
45.27 mg/L
7
4/28/17
36
36
Max. Value
101.00 mg/L
7 06/18
40
40
Max. Value
81.00 mg/L
8
5/11/17
84
84
8 07/18
32
32
9
6/13/17
40
40
9 09/18
81
81
10
6/16/17
76
76
10 11/18
53
53
11
7/20/17
80
80
11 12/18
23
23
12
8/9/17
84
84
12
13
9/26/17
77
77
13
14
11/20/17
84
84
14
15
12/5/17
88
88
15
16
2/8/18
72
72
16
17
3/6/18
76
76
17
18
4/26/18
86
86
18
19
5/8/18
79
79
19
20
6/5/18
68
68
20
21
7/31/18
72
72
21
22
8/26/18
65
65
22
23
9/21/18
53
53
23
24
11/27/18
73
73
24
25
12/11/18
51
51
25
26
1/9/19
51
51
26
27
2/28/19
59
59
27
28
3/12/19
49
49
28
29
4/2/19
63
63
29
30
6/4/19
79
79
30
31
7/2/19
78
78
31
32
8/9/19
63
63
32
33
9/10/19
62
62
33
34
10/1/19
74
74
34
35
11/7/19
76
76
35
36
1/28/20
57
57
36
37
2/25/20
53
53
37
38
6/2/20
64
64
38
39
39
40
40
41
41
42
42
43
43
44
44
45
45
46
46
47
47
48
48
49
49
50
50
51
51
52
52
53
53
54
54
55
55
56
56
57
57
58
58
25453 RPA.xlsm, data
1 - 11 /9/20

REASONABLE POTENTIAL ANALYSIS
Par01 & Par02
Use "PASTE SPECIAL -
Arsenic
Values -then "COPY".
Maximum data points=
58
Date
Data
BDL=1/2DL
Results
1
9/27/16
<
5
2.5
Std Dev.
0.5925
2
12/15/16
<
5
2.5
Mean
2.0882
3
3/8/17
<
5
2.5
C.V.
0.2838
4
6/13/17
<
5
2.5
n
17
5
6/16/17
<
5
2.5
6
9/26/17
<
3
1.5
Mult Factor =
1.20
7
12/5/17
<
5
2.5
Max. Value
2.5 ug/L
8
3/6/18
<
5
2.5
Max. Fred Cw
3.0 ug/L
9
6/5/1 8
<
5
2.5
10
9/11/18
<
5
2.5
11
12/4/18
<
5
2.5
12
3/5/19
<
5
2.5
13
6/4/19
<
3
1.5
14
9/10/19
<
3
1.5
15
12/3/19
<
3
1.5
16
3/3/20
<
2
1
17
6/2/20
<
2
1
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
25453 RPA.xlsm, data
-2- 11 /9/20

REASONABLE POTENTIAL ANALYSIS
Par03
Use"PASTE
Par04
Use -PASTE
Beryllium
SPECIAL-
Values'then
"COPY".
Cadmium
SPECIAL -Values"
then "COPY" .
Maximum data
Maximum data
Date Data
BDL=1/2DL
Results
points =58
Date
Data
BDL=1/2DL
Results
points =58
1
3/3/15 <
1
0.5
Std Dev.
0.0
1
9/27/16
<
1
0.5
Std Dev.
0.1231
2
6/7/16 <
1
0.5
Mean
0.5
2
12/15/16
<
1
0.5
Mean
0.4118
3
6/16/17 <
1
0.5
C.V. (default)
0.6
3
3/8/17
<
1
0.5
C.V.
0.2991
4
9/10/19 <
1
0.5
n
4
4
6/13/17
<
1
0.5
n
17
5
5
6/16/17
<
1
0.5
6
Mult Factor=
2.59
6
9/26/17
<
0.5
0.25
Mu It Factor =
1.21
7
Max. Value
0.50 ug/L
7
12/5/17
<
1
0.5
Max. Value
0.500 ug/L
8
Max. Fred Cw
1.30 ug/L
8
3/6/18
<
1
0.5
Max. Fred Cw
0.605 ug/L
9
9
6/5/18
<
1
0.5
10
10
9/11/18
<
1
0.5
11
11
12/4/18
<
1
0.5
12
12
3/5/19
<
1
0.5
13
13
6/4/19
<
0.5
0.25
14
14
9/10/19
<
0.5
0.25
15
15
12/3/19
<
0.5
0.25
16
16
3/3/20
<
0.5
0.25
17
17
6/2/20
<
0.5
0.25
18
18
19
19
20
20
21
21
22
22
23
23
24
24
25
25
26
26
27
27
28
28
29
29
30
30
31
31
32
32
33
33
34
34
35
35
36
36
37
37
38
38
39
39
40
40
41
41
42
42
43
43
44
44
45
45
46
46
47
47
48
48
49
49
50
50
51
51
52
52
53
53
54
54
55
55
56
56
57
57
58
58
25453 RPA.xlsm, data
-3- 11 /9/20

REASONABLE POTENTIAL ANALYSIS
Par05
Par07
Use"PASTE
Use"PASTE SPECIAL-
SPECIAL -Values
Chlorides
Values•then"COPY•.
Total
Phenolic Compounds
then "COPY".
Maximum data points= 58
Maximum data
Date Data
BDL=1/2DL
Results
Date Data
BDL=1/2DL
Results
points = 58
1
3/3/15
56 56
Std Dev.
27.7849
1
3/3/15
5 2.5
Std Dev.
0.0000
2
7/1/15
52 52
Mean
70.0
2
6/7/16
5 2.5
Mean
2.5000
3
9/15/15
102 102
C.V. (default)
0.6000
3
6/16/17
5 2.5
C.V. (default)
0.6000
4
n
3
4
9/10/19
5 2.5
n
4
5
5
6
Mu It Factor =
3.0
6
Mu It Factor =
2.59
7
Max. Value
102.0 mg/L
7
Max. Value
2.5 ug/L
8
Max. Fred Cw
306.0 mg/L
8
Max. Fred Cw
6.5 ug/L
9
9
10
10
11
11
12
12
13
13
14
14
15
15
16
16
17
17
18
18
19
19
20
20
21
21
22
22
23
23
24
24
25
25
26
26
27
27
28
28
29
29
30
30
31
31
32
32
33
33
34
34
35
35
36
36
37
37
38
38
39
39
40
40
41
41
42
42
43
43
44
44
45
45
46
46
47
47
48
48
49
49
50
50
51
51
52
52
53
53
54
54
55
55
56
56
57
57
58
58
25453 RPA.xlsm, data
-4- 11 /9/20

REASONABLE POTENTIAL ANALYSIS
Par10
Use"PASTE
Pall
Use -PASTE
SPECIAL -Values-
SPEC IAL-Values'
Chromium,
Total
then ..COPY".
Copper
then "COPY".
Maximum data
Maximum data
Date
Data
BDL=1/2DL
Results
points= 58
Date
Data
BDL=1/2DL
Results
points= 58
1
9/27/16
<
5
2.5
Std Dev.
0.7389
1
9/27/16
3
3
Std Dev.
6.5670
2
12/15/16
<
5
2.5
Mean
1.9706
2
12/15/16
4
4
Mean
5.0000
3
3/8/17
<
5
2.5
C.V.
0.3750
3
3/8/17
3
3
C.V.
1.3134
4
6/13/17
<
5
2.5
n
17
4
6/13/17
< 2
1
n
17
5
6/16/17
<
5
2.5
5
6/16/17
< 10
5
6
9/26/17
<
2
1
Mult Factor =
1.27
6
9/26/17
3
3
Mult Factor=
1.93
7
12/5/17
<
5
2.5
Max. Value
2.5 Ng/L
7
12/5/17
3
3
Max. Value
30.00 ug/L
8
3/6/18
<
5
2.5
Max. Pred Cw
3.2 Ng/L
8
3/6/18
4
4
Max. Pred Cw
57.90 ug/L
9
6/5/18
<
5
2.5
9
6/5/18
2
2
10
9/11/18
<
5
2.5
10
9/11/18
4
4
11
12/4/18
<
5
2.5
11
12/4/18
3
3
12
3/5/19
<
5
2.5
12
3/5/19
3
3
13
6/4/19
<
2
1
13
6/4/19
4
4
14
9/10/19
<
2
1
14
9/10/19
3
3
15
12/3/19
<
2
1
15
12/3/19
30
30
16
3/3/20
<
2
1
16
3/3/20
7
7
17
6/2/20
<
2
1
17
6/2/20
3
3
18
18
19
19
20
20
21
21
22
22
23
23
24
24
25
25
26
26
27
27
28
28
29
29
30
30
31
31
32
32
33
33
34
34
35
35
36
36
37
37
38
38
39
39
40
40
41
41
42
42
43
43
44
44
45
45
46
46
47
47
48
48
49
49
50
50
51
51
52
52
53
53
54
54
55
55
56
56
57
57
58
58
25453 RPA.xlsm, data
-5- 11 /9/20

REASONABLE POTENTIAL ANALYSIS
Par12
Cyanide
Date
Data
BDL=1/2DL
Results
1
9/27/16
<
5 5
Std Dev.
2
12/16/16
<
5 5
Mean
3
3/8/1 7
<
5 5
C.V.
4
6/13/17
<
5 5
n
5
6/16/17
<
5 5
6
9/26/17
<
5 5
Mu It Factor=
7
12/5/17
<
5 5
Max. Value
8
3/6/18
<
5 5
Max. Fred Cw
9
6/5/18
<
5 5
10
9/11/18
<
5 5
11
12/4/18
<
5 5
12
3/5/19
<
5 5
13
6/4/19
<
5 5
14
9/10/19
<
5 5
15
12/3/19
<
5 5
16
3/3/20
<
5 5
17
6/2/20
<
5 5
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
use -PASTE Par14
SPECIAL.Values"
then "COPY" .
Maximum data
points= 58
5.00
0.0000
17
1.00
5.0 ug/L
5.0 ug/L
Lead
Date
BDL=1/2DL
Results
1 9/27/16
<
5
2.5
Std Dev.
2 12/15/16
<
5
2.5
Mean
3 3/8/1 7
<
5
2.5
C.V.
4 6/13/17
<
5
2.5
n
5 6/16/17
<
5
2.5
6 9/26/17
<
2
1
Mu It Factor =
7 12/5/17
<
5
2.5
Max. Value
8 3/6/18
<
5
2.5
Max. Fred Cw
9 6/5/18
<
5
2.5
10 9/11/18
<
5
2.5
11 12/4/18
<
5
2.5
12 3/5/19
<
5
2.5
13 6/4/19
<
2
1
14 9/10/19
<
2
1
15 12/3/19
<
2
1
16 3/3/20
<
2
1
17 6/2/20
<
2
1
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Use "PASTE SPECIAL
Values- then "COPY"
. Maximum data
points= 58
1.9706
0.3750
17
1.27
2.500 ug/L
3.175 ug/L
-6-
25453 RPA.xlsm, data
11 /9/20

REASONABLE POTENTIAL ANALYSIS
Par16
Molybdenum
Date
Data
BDL=1/2DL
Results
1
9/27/16
<
10
5
Std Dev.
2
12/15/16
<
10
5
Mean
3
3/8/17
<
10
5
C.V.
4
6/13/17
<
5
2.5
n
5
6/16/17
<
5
2.5
6
9/26/17
<
5
2.5
Mu It Factor=
7
12/5/17
<
5
2.5
Max. Value
8
3/6/18
<
5
2.5
Max. Fred Cw
9
6/5/1 8
<
5
2.5
10
9/11/18
<
5
2.5
11
12/4/18
<
10
5
12
3/5/19
<
10
5
13
6/4/19
<
5
2.5
14
9/10/19
<
5
2.5
15
12/3/19
<
5
2.5
16
3/3/20
<
5
2.5
17
6/2/20
<
5
2.5
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Use -PASTE
Par17
& Par18
SPEC IAL-Values"
Nickel
then"COPr' .
M mum data
1
Date
9/27/16
Data
< 10
BDL=1/2DL
5
Results
Std Dev.
ts= 58
1.1742
3.2353
2
12/15/16
<
10
5
Mean
0.3629
3
3/8/17
<
10
5
C.V.
17
4
6/13/17
<
10
5
n
5
6/16/17
<
10
5
1.26
6
9/26/17
<
5
2.5
Mult Factor=
5.0 ug/L
7
12/5/17
<
10
5
Max. Value
6.3 ug/L
8
3/6/18
<
10
5
Max. Fred Cw
9
6/5/18
<
10
5
10
9/11/18
12
12
11
12/4/18
<
10
5
12
3/5/19
<
10
5
13
6/4/19
<
5
2.5
14
9/10/19
<
5
2.5
15
3/3/20
3
3
16
6/2/20
3
3
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Use -PASTE
SPECIAL -Values"
then "COPY".
Maximum data
&oints = 58
4.7188
0.4722
16
1.37
12.0 Ng/L
16.4 Ng/L
25453 RPA.xlsm, data
-7- 11 /9/20

REASONABLE POTENTIAL ANALYSIS
Par19
Selenium
Date
Data
BDL=1/2DL
Results
1
9/27/16
<
10
5
Std Dev.
2
12/15/16
<
10
5
Mean
3
3/8/17
<
10
5
C.V.
4
6/13/17
<
10
5
n
5
6/16/17
<
10
5
6
9/26/17
<
3
1.5
Mult Factor =
7
12/5/17
<
10
5
Max. Value
8
3/6/18
<
10
5
Max. Fred Cw
9
6/5/18
<
10
5
10
9/11/18
<
10
5
11
12/4/18
<
10
5
12
3/5/19
<
10
5
13
6/4/19
<
3
1.5
14
9/10/19
<
10
5
15
12/3/19
<
3
1.5
16
3/3/20
<
3
1.5
17
6/2/20
<
3
1.5
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Use -PASTE Par20
PEC IA L-Values'
then "COPY".
Maximum data
points= 58
3.9706
0.4140
17
1.30
5.0 ug/L
6.5 ug/L
Silver
Date
Data
BDL=1/2DL
Results
1 9/27/16
<
5 2.5
Std Dev.
2 12/15/16
<
5 2.5
Mean
3 3/8/1 7
<
5 2.5
C.V.
4 6/13/17
<
1 0.5
n
5 6/16/17
<
1 0.5
6 9/26/17
<
1 0.5
Mult Factor =
7 12/5/17
<
1 0.5
Max. Value
8 3/6/18
<
1 0.5
Max. Fred Cw
9 6/5/1 8
<
1 0.5
10 9/11/18
<
1 0.5
11 12/4/18
<
5 2.5
12 3/5/19
<
5 2.5
13 6/4/19
<
1 0.5
14 9/10/19
<
1 0.5
15 12/3/19
<
1 0.5
16 3/3/20
<
1 0.5
17 6/2/20
<
1 0.5
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Use -PASTE SPECIAL -
Values" then "COPY" .
Maximum data points=
1.0882
0.8632
17
1.63
2.500 ug/L
4.075 ug/L
25453 RPA.xlsm, data
-8- 11 /9/20

REASONABLE POTENTIAL ANALYSIS
Par21
Date
1 9/27/16
2 12/15/16
3 3/8/17
4 6/13/17
5 6/16/17
6 9/26/17
7 12/5/17
8 3/6/18
9 6/5/18
10 9/11/18
11 12/4/18
12 3/5/19
13 6/4/19
14 9/10/19
15 12/3/19
16 3/3/20
17 6/2/20
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Zinc
Data
BDL=1/2DL
Results
33
33
Std Dev.
100
100
Mean
90
90
C.V.
110
110
n
94
94
117
117
Mu It Factor =
123
123
Max. Value
146
146
Max. Fred Cw
112
112
93
93
95
95
64
64
98
98
90
90
63
63
123
123
61
61
use "PASTE I Par22
SPECIAL.Values"
then "COPY" .
Maximum data points
= 58
94.8235
0.2917
17
1.21
146.0 ug/L
176.7 ug/L
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Use-PASTE
SPEC IAL-Values"
N itrate
then "COPY" .
Maximum data
Date Data
BDL=1/2DL
Results
points= 58
9/1/16
11.24
11.24
Std Dev.
1.6057
9/7/16
6.66
6.66
Mean
5.2974
9/15/16
9.12
9.12
C.V.
0.3031
9/20/16
6.25
6.25
n
54
9/27/16
5.31
5.31
10/6/16
6.01
6.01
Mu It Factor =
1.01
10/25/16
4.21
4.21
Max. Value
11.2400 mg/L
11/1/16
5.06
5.06
Max. Fred Cw
11.3524 mg/L
11/10/16
4.86
4.86
11/15/16
3.84
3.84
11/23/16
4.06
4.06
12/1/16
3.86
3.86
12/6/16
4.99
4.99
12/13/16
3.86
3.86
12/28/16
4.01
4.01
1/6/17
4.22
4.22
1/12/17
4.21
4.21
1/19/17
6.58
6.58
1/25/17
6.28
6.28
2/3/17
10.04
10.04
2/9/17
6.65
6.65
2/23/17
5.08
5.08
3/7/17
4.62
4.62
4/4/17
4.28
4.28
7/25/17
4.24
4.24
9/1/17
4.65
4.65
11/2/17
4.72
4.72
11/7/17
3.84
3.84
11/14/17
4.41
4.41
11/20/17
4.24
4.24
12/21/17
5.77
5.77
12/28/17
6.27
6.27
1/2/18
7.86
7.86
1/11/18
4.82
4.82
2/1/18
5.45
5.45
2/8/18
3.82
3.82
2/15/18
4.47
4.47
10/9/18
5.78
5.78
10/16/18
5.36
5.36
10/23/18
4.07
4.07
11/6/18
6.44
6.44
11/14/18
4.05
4.05
11/19/18
5.65
5.65
11/27/18
7.05
7.05
12/11/18
4.23
4.23
2/12/19
4.65
4.65
4/2/19
3.81
3.81
6/13/19
3.84
3.84
12/10/19
4.32
4.32
12/23/19
4.78
4.78
3/31/20
3.93
3.93
4/27/20
8.12
8.12
5/4/20
4.93
4.93
5/11/20
5.19
5.19
-9-
25453 RPA.xlsm, data
11 /9/20

REASONABLE POTENTIAL ANALYSIS
Par23
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
TDS
Date
Data BDL=1/2DL
Results
6/16/17
296 296
Std Dev.
12/4/18
257 257
Mean
9/10/19
417 417
C.V. (default)
n
Mult Factor =
Max. Value
Max. Fred Cw
323.333
0.6000
3
3.00
417 mg/L
1251 mg/L
Use"PASTE Par24 Use"PASTE
SPECIAL -Values" SPECIAL -Values"
then "COPY". Bis (2-ethylhexyl) phthalate then "COPY".
Maximum data Maximum data poin
points = 58 = 58
Date Data
1 3/3/15 <
2 6/6/16 <
3 6/16/17
4 3/3/20 <
5 6/2/20 <
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
BDL=1/2DL
Results
20
10
Std Dev.
25.3130
20
10
Mean
16.6400
61.2
61.2
C.V. (default)
0.6000
2
1
n
5
2
1
Mult Factor =
2.32
Max. Value
61.200 Ng/L
Max. Fred Cw
141.984 Ng/L
-10-
25453 RPA.xlsm, data
11 /9/20

Little Creek WRF
NCO025453 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
Qw (MGD) =
2.5000
WWTP/WTP Class:
IV
1Ql0S (cfs) =
151.17
IWC% @ 1Ql0S =
2.499274404
7Q10S (cfs) =
186.00
IWC% @ 7Q10S =
2.040816327
7QIOW (cfs) =
186.00
IWC% @ 7Q10W =
2.040816327
30Q2 (cfs) =
186.00
1WC% @ 30Q2 =
2.040816327
Avg. Stream Flow, QA (cfs) =
186.00
IW%C @ QA =
2.040816327
Receiving Stream:
Neuse River HUC 03020201
Stream Class:
WS-IV;NSW;CA
Outfall 001
Qw = 2.5 MGD
COMBINED HARDNESS (m2/L)
Acute = 45.9 mg/L
Chronic = 45.79 mg/L
YOU HAVE DESIGNATED THIS RECEIVING
STREAM AS WATER SUPPLY
Effluent Hard: 1 value > 100 mg/L
Effluent Hard Avg = 70.39 mg/L
PARAMETER
NC STANDARDS OR EPA CRITERIA
co
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
TYPE
J
Chronic Standard Acute
n # Det. Max Pred Cw Allowable Cw
Acute (FW): 13,603.9
Arsenic
C
150 FW(7Q10s) 340
ug/L
-----------------------------------------------
17 0
3.0
Chronic (FW): 7,350.0
M_ax_MDL =5
Arsenic
C
10 HH/WS(Qavg)
ug/L
NO DETECTS
Chronic (HH) 490.0
No RP, Predicted Max < 50% of Allowable Cw - No
Max MDL = 5
Monitoring required
Acute: 2,600.75
Beryllium
NC
6.5 FW(7Q1 Os) 65
ug/L
4 0
1.30
_ _
Note: n < 9
C.V. (default)
Chronic: 318.50
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
NO DETECTS
Max MDL = 1
Monitoring required
Acute: 220.289
Cadmium
NC
0.9320 FW(7Q1 Os) 5.5056
ug/L
17 0
0.605
Chronic: 45.668
No RP, Predicted Max < 50% of Allowable Cw - No
NO DETECTS
Max MDL = 1
Monitoring required
Acute: NO WQS
Chlorides
NC
250 WS(7Q1 Os)
mg/L
3 3
306.0
Note: n < 9
C.V. (default)
_ _ _ _ _ _ _ _ _ _ _ _
Chronic: 12,250.0
_ _ _ _ _ _ _ _ _ _ _ _ _
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
No value > Allowable Cw
Monitoring required
Acute: NO WQS
Total Phenolic Compounds
NC
300 A(30Q2)
ug/L
4 0
6.5
_ _ _ _ _ _ _ _ _ _ _ _
_ _ _ _ _ _ _ _ _ _ _ _ _
Note: n < 9
C.V. (default)
Chronic: 14,700.0
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
NO DETECTS
Max MDL = 5
Monitoring required
Acute: 59,564.9
Chromium III
NC
193.2499 FW(7QlOs) 1488.6896
µg/L
0 0
N/A
--Chronic:----9,469.2 --
---------------------------
Acute: 640.2
Chromium VI
NC
11 FW(7QlOs) 16
µg/L
0 0
N/A
--Chronic:-----539.0---
---------------------------
Chromium, Total
NC
µg/L
17 0
3.2
Max reported value = 2.5
a: No monitoring required if all Total Chromium
samples are < 5 pg/L or Pred. max for Total Cr is <
allowable Cw for Cr VI.
NO DETECTS
Max MDL = 5
Acute: 742.75
Copper
NC
13.2164 FW(7Q1 Os) 18.5633
ug/L
17 15
57.90
Chronic: 647.60
No RP, Predicted Max < 50% of Allowable Cw - No
No value > Allowable Cw
Monitoring required
Page 1 of 2
25453 RPA, rpa
10/16/2020

Little Creek WRF
NCOO25453
Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
Outfall 001
Qw = 2.5 MGD
Acute: 880.3
Cyanide
NC
5 FW(7QlOs) 22
10
ug/L
17 0
5.0
Chronic: 245.0
No RP, Predicted Max < 50% of Allowable Cw - No
NO DETECTS
Max MDL = 10
Monitoring required
Acute: 5,962.364
Lead
NC
5.7907 FW(7Q1 Os) 149.0158
ug/L
17 0
3.175
Chronic: 283.746
No RP, Predicted Max < 50% of Allowable Cw - No
NO DETECTS
Max MDL = 5
Monitoring required
Acute: NO WQS
Molybdenum
NC
160 WS(7Q1 Os)
ug/L
17 0
6.3
Chronic: 7,840.0
No RP, Predicted Max < 50% of Allowable Cw - No
NO DETECTS
Max MDL = 10
Monitoring required
Acute (FW): 22,425.5
Nickel
NC
62.1193 FW(7QlOs) 560.4751
µg/L
16 3
16.4
_ _ _ ___ _ _ __
Chronic (FW) 3,043.8
___________________________
No value > Allowable Cw _
_____ _
_ _ _ _ _ _ _ _ _ _ _ _ _
Nickel
NC
25.0000 WS(7Q10s)
µg/L
Chronic (WS) 1,225.0
No RP, Predicted Max < 50% of Allowable Cw - No
No value > Allowable Cw
Monitoring required
Acute: 2,240.7
Selenium
NC
5 FW(7QlOs) 56
ug/L
17 0
6.5
--Chronic:-----245.0---
---------------------------
No RP, Predicted Max < 50% of Allowable Cw - No
NO DETECTS
Max MDL = 10
Monitoring required
Acute: 33.723
Silver
NC
0.06 FW(7QlOs) 0.8428
ug/L
17 0
4.075
Chronic: 2.940
All values reported non -detect < 5 ug/L and < 1 ug/L;
No Monitoring Required. Permittee shall continue
NO DETECTS
Max MDL = 5
reporting to PQL of 1 ug/L.
Acute: 8,416.3
No RP, Predicted Max < 50% of Allowable Cw - No
Zinc
NC
211.6172 FW(7QlOs) 210.3475
ug/L
17 17
176.7
Monitoring required
--Chronic:----10,369.2--
---------------------------
No value > Allowable Cw
Acute: NO WQS
Nitrate
NC
10 WS(7Q1 Os)
mg/L
54 54
11.35240
Chronic: 490.000
No RP, Predicted Max < 50% of Allowable Cw - No
No value > Allowable Cw
Monitoring required
Acute: NO WQS
TDS
NC
500 WS(7Q1 Os)
mg/L
3 3
1,251.00000
Note: n < 9
C.V. (default)
Chronic: 24500_ 00000
No RP, Limited Dataset (n<8 samples) - No
Limited data set
No value > Allowable Cw
Monitoring required
Acute: NO WQS
Bis (2-ethylhexyl) phthalate C 0.32 WS(Qavg) µg/L 5 1 141.98400 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Note: n < 9 C.V. (default) Chronic: 15.68000 RP for Limited Dataset (n<8 samples) - apply
Limited data seLi I 1 value(s) > Allowable Cw Quarterly Monitoring
25453 RPA, rpa
Page 2 of 2 10/16/2020

Little Creek WRF
NCO025453 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
Qw (MGD) =
6.0000
WWTP/WTP Class:
IV
1Ql0S (cfs) =
151.17
IWC% @ 1Ql0S =
5.79547579
7Q10S (cfs) =
186.00
IWC% @ 7Q10S =
4.761904762
7QIOW (cfs) =
186.00
IWC% @ 7Q10W =
4.761904762
30Q2 (cfs) =
186.00
1WC% @ 30Q2 =
4.761904762
Avg. Stream Flow, QA (cfs) =
186.00
IW%C @ QA =
4.761904762
Receiving Stream:
Neuse River HUC 03020201
Stream Class:
WS-IV;NSW;CA
Outfall 001
Qw = 6 MGD
COMBINED HARDNESS (m2/L)
Acute = 46.73 mg/L
Chronic = 46.47 mg/L
YOU HAVE DESIGNATED THIS RECEIVING
STREAM AS WATER SUPPLY
Effluent Hard: 1 value > 100 mg/L
Effluent Hard Avg = 70.39 mg/L
PARAMETER
NC STANDARDS OR EPA CRITERIA
co
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
TYPE
J
Chronic Standard Acute
n # Det. Max Pred Cw Allowable Cw
Acute (FW): 5,866.6
Arsenic
C
150 FW(7Q10s) 340
ug/L
-----------------------------------------------
17 0
3.0
Chronic (FW): 3,150.0
M_ax_MDL =5
Arsenic
C
10 HH/WS(Qavg)
ug/L
NO DETECTS
Chronic (HH) 210.0
No RP, Predicted Max < 50% of Allowable Cw - No
Max MDL = 5
Monitoring required
Acute: 1,121.56
Beryllium
NC
6.5 FW(7Q1 Os) 65
ug/L
4 0
1.30
_ _
Note: n < 9
C.V. (default)
Chronic: 136.50
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
NO DETECTS
Max MDL = 1
Monitoring required
Acute: 96.492
Cadmium
NC
0.9425 FW(7Q1 Os) 5.5922
ug/L
17 0
0.605
Chronic: 19.792
No RP, Predicted Max < 50% of Allowable Cw - No
NO DETECTS
Max MDL = 1
Monitoring required
Acute: NO WQS
Chlorides
NC
250 WS(7Q1 Os)
mg/L
3 3
306.0
Note: n < 9
C.V. (default)
_ _ _ _ _ _ _ _ _ _ _ _
Chronic: 5,250.0
_ _ _ _ _ _ _ _ _ _ _ _ _
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
No value > Allowable Cw
Monitoring required
Acute: NO WQS
Total Phenolic Compounds
NC
300 A(30Q2)
ug/L
4 0
6.5
_ _ _ _ _ _ _ _ _ _ _ _
_ _ _ _ _ _ _ _ _ _ _ _ _
Note: n < 9
C.V. (default)
Chronic: 6,300.0
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
NO DETECTS
Max MDL = 5
Monitoring required
Acute: 26,066.0
Chromium III
NC
195.6098 FW(7QlOs) 1510.6497
µg/L
0 0
N/A
--Chronic:----4,107.8 --
---------------------------
Acute: 276.1
Chromium VI
NC
11 FW(7QlOs) 16
µg/L
0 0
N/A
--Chronic:-----231.0---
---------------------------
Chromium, Total
NC
µg/L
17 0
3.2
Max reported value = 2.5
a: No monitoring required if all Total Chromium
samples are < 5 pg/L or Pred. max for Total Cr is <
allowable Cw for Cr VI.
NO DETECTS
Max MDL = 5
Acute: 325.75
Copper
NC
13.3848 FW(7Q1 Os) 18.8787
ug/L
17 15
57.90
Chronic: 281.08
No RP, Predicted Max < 50% of Allowable Cw - No
No value > Allowable Cw
Monitoring required
Page 1 of 2
25453 RPA, rpa
10/16/2020

Little Creek WRF
NCOO25453
Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
Outfall 001
Qw = 6 MGD
Acute: 379.6
Cyanide
NC
5 FW(7QlOs) 22
10
ug/L
17 0
5.0
Chronic: 105.0
No RP, Predicted Max < 50% of Allowable Cw - No
NO DETECTS
Max MDL = 10
Monitoring required
Acute: 2,622.862
Lead
NC
5.8869 FW(7Q1 Os) 152.0074
ug/L
17 0
3.175
Chronic: 123.626
No RP, Predicted Max < 50% of Allowable Cw - No
NO DETECTS
Max MDL = 5
Monitoring required
Acute: NO WQS
Molybdenum
NC
160 WS(7Q1 Os)
ug/L
17 0
6.3
Chronic: 3,360.0
No RP, Predicted Max < 50% of Allowable Cw - No
NO DETECTS
Max MDL = 10
Monitoring required
Acute (FW): 9,818.3
Nickel
NC
62.9030 FW(7QlOs) 569.0174
µg/L
16 3
16.4
_ _ _ ___ _ _ __
Chronic (FW) 1,321.0
___________________________
No value > Cw_
_ _Allowable_ __ _ _ _
_ _ _ _ _ _ _ _ _ _ _ _ _
Nickel
NC
25.0000 WS(7Q10s)
µg/L
Chronic (WS) 525.0
No RP, Predicted Max < 50% of Allowable Cw - No
No value > Allowable Cw
Monitoring required
Acute: 966.3
Selenium
NC
5 FW(7QlOs) 56
ug/L
17 0
6.5
--Chronic:-----105.0---
---------------------------
No RP, Predicted Max < 50% of Allowable Cw - No
NO DETECTS
Max MDL = 10
Monitoring required
Acute: 14.997
Silver
NC
0.06 FW(7QlOs) 0.8692
ug/L
17 0
4.075
Chronic: 1.260
All values reported non -detect < 5 ug/L and < 1 ug/L;
No Monitoring Required. Permittee shall continue
NO DETECTS
Max MDL = 5
reporting to PQL of 1 ug/L.
Acute: 3,684.9
No RP, Predicted Max < 50% of Allowable Cw - No
Zinc
NC
214.2912 FW(7QlOs) 213.5584
ug/L
17 17
176.7
Monitoring required
--Chronic:----4,500.1 --
---------------------------
No value > Allowable Cw
Acute: NO WQS
Nitrate
NC
10 WS(7Q1 Os)
mg/L
54 54
11.35240
Chronic: 210.000
No RP, Predicted Max < 50% of Allowable Cw - No
No value > Allowable Cw
Monitoring required
Acute: NO WQS
TDS
NC
500 WS(7Q1 Os)
mg/L
3 3
1,251.00000
Note: n < 9
C.V. (default)
Chronic: 10500_ 00000
No RP, Limited Dataset (n<8 samples) - No
Limited data set
No value > Allowable Cw
Monitoring required
Acute: NO WQS
Bis (2-ethylhexyl) phthalate C 0.32 WS(Qavg) µg/L 5 1 141.98400 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Note: n < 9 C.V. (default) Chronic: 6.72000 RP for Limited Dataset (n<8 samples) - apply
Limited data seLi 13 value(s) > Allowable Cw Quarterly Monitoring
25453 RPA, rpa
Page 2 of 2 10/16/2020

Little Creek WRF
NCO025453 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
Qw (MGD) =
10.0000
WWTP/WTP Class:
IV
1Ql0S (cfs) =
151.17
IWC% @ 1Ql0S =
9.299814004
7Q10S (cfs) =
186.00
IWC% @ 7Q10S =
7.692307692
7QIOW (cfs) =
186.00
IWC% @ 7Q10W =
7.692307692
30Q2 (cfs) =
186.00
1WC% @ 30Q2 =
7.692307692
Avg. Stream Flow, QA (cfs) =
186.00
IW%C @ QA =
7.692307692
Receiving Stream:
Neuse River HUC 03020201
Stream Class:
WS-IV;NSW;CA
Outfall 001
Qw = 10 MGD
COMBINED HARDNESS (m2/L)
Acute = 47.61 mg/L
Chronic = 47.21 mg/L
YOU HAVE DESIGNATED THIS RECEIVING
STREAM AS WATER SUPPLY
Effluent Hard: 1 value > 100 mg/L
Effluent Hard Avg = 70.39 mg/L
PARAMETER
NC STANDARDS OR EPA CRITERIA
co
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
TYPE
J
Chronic Standard Acute
n # Det. Max Pred Cw Allowable Cw
Acute (FW): 3,656.0
Arsenic
C
150 FW(7Q10s) 340
ug/L
-----------------------------------------------
17 0
3.0
Chronic (FW): 1,950.0
M_ax_MDL =5
Arsenic
C
10 HH/WS(Qavg)
ug/L
NO DETECTS
Chronic (HH) 130.0
No RP, Predicted Max < 50% of Allowable Cw - No
Max MDL = 5
Monitoring required
Acute: 698.94
Beryllium
NC
6.5 FW(7Q1 Os) 65
ug/L
4 0
1.30
_ _
Note: n < 9
C.V. (default)
Chronic: 84.50
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
NO DETECTS
Max MDL = 1
Monitoring required
Acute: 61.119
Cadmium
NC
0.9538 FW(7Q1 Os) 5.6840
ug/L
17 0
0.605
Chronic: 12.399
No RP, Predicted Max < 50% of Allowable Cw - No
NO DETECTS
Max MDL = 1
Monitoring required
Acute: NO WQS
Chlorides
NC
250 WS(7Q1 Os)
mg/L
3 3
306.0
Note: n < 9
C.V. (default)
_ _ _ _ _ _ _ _ _ _ _ _
Chronic: 3,250.0
_ _ _ _ _ _ _ _ _ _ _ _ _
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
No value > Allowable Cw
Monitoring required
Acute: NO WQS
Total Phenolic Compounds
NC
300 A(30Q2)
ug/L
4 0
6.5
_ _ _ _ _ _ _ _ _ _ _ _
_ _ _ _ _ _ _ _ _ _ _ _ _
Note: n < 9
C.V. (default)
Chronic: 3,900.0
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
NO DETECTS
Max MDL = 5
Monitoring required
Acute: 16,494.1
Chromium III
NC
198.1442 FW(7QlOs) 1533.9193
µg/L
0 0
N/A
--Chronic:----2,575.9 --
---------------------------
Acute: 172.0
Chromium VI
NC
11 FW(7QlOs) 16
µg/L
0 0
N/A
--Chronic:-----143.0---
---------------------------
Chromium, Total
NC
µg/L
17 0
3.2
Max reported value = 2.5
a: No monitoring required if all Total Chromium
samples are < 5 pg/L or Pred. max for Total Cr is <
allowable Cw for Cr VI.
NO DETECTS
Max MDL = 5
Acute: 206.60
Copper
NC
13.5658 FW(7Q1 Os) 19.2136
ug/L
17 15
57.90
Chronic: 176.36
No RP, Predicted Max < 50% of Allowable Cw - No
No value > Allowable Cw
Monitoring required
Page 1 of 2
25453 RPA, rpa
10/16/2020

Little Creek WRF
NCOO25453
Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
Outfall 001
Qw = 10 MGD
Acute: 236.6
Cyanide
NC
5 FW(7QlOs) 22
10
ug/L
17 0
5.0
______ ____
_ _ _ _ _ _ _ _ _ _ _ _ _
Chronic: 65.0
No RP, Predicted Max < 50% of Allowable Cw - No
NO DETECTS
Max MDL = 10
Monitoring required
Acute: 1,668.774
Lead
NC
5.9907 FW(7Q1 Os) 155.1929
ug/L
17 0
3.175
Chronic: 77.879
No RP, Predicted Max < 50% of Allowable Cw - No
NO DETECTS
Max MDL = 5
Monitoring required
Acute: NO WQS
Molybdenum
NC
160 WS(7Q1 Os)
ug/L
17 0
6.3
Chronic: 2,080.0
No RP, Predicted Max < 50% of Allowable Cw - No
NO DETECTS
Max MDL = 10
Monitoring required
Acute (FW): 6,216.0
Nickel
NC
63.7451 FW(7QlOs) 578.0737
µg/L
16 3
16.4
_ _ _ _ _
Chronic (FW)--------
---------------------------
_No value > Allowable_ __ _ _ _ Cw_
_ _ _ _ _ _ _ _ _ _ _ _ _
Nickel
NC
25.0000 WS(7Q10s)
µg/L
Chronic (WS) 325.0
No RP, Predicted Max < 50% of Allowable Cw - No
No value > Allowable Cw
Monitoring required
Acute: 602.2
Selenium
NC
5 FW(7QlOs) 56
ug/L
17 0
6.5
--Chronic: ----- 65.0 ---
---------------------------
No RP, Predicted Max < 50% of Allowable Cw - No
NO DETECTS
Max MDL = 10
Monitoring required
Acute: 9.651
Silver
NC
0.06 FW(7QlOs) 0.8975
ug/L
17 0
4.075
Chronic: 0.780
All values reported non -detect < 5 ug/L and < 1 ug/L;
No Monitoring Required. Permittee shall continue
NO DETECTS
Max MDL = 5
reporting to PQL of 1 ug/L.
Acute: 2,333.0
No RP, Predicted Max < 50% of Allowable Cw - No
Zinc
NC
217.1642 FW(7QlOs) 216.9626
ug/L
17 17
176.7
Monitoring required
--Chronic:----2,823.1 --
---------------------------
No value > Allowable Cw
Acute: NO WQS
Nitrate
NC
10 WS(7Q1 Os)
mg/L
54 54
11.35240
Chronic: 130.000
No RP, Predicted Max < 50% of Allowable Cw - No
No value > Allowable Cw
Monitoring required
Acute: NO WQS
TDS
NC
500 WS(7Q1 Os)
mg/L
3 3
1,251.00000
Note: n < 9
C.V. (default)
Chronic: 6500.00000
No RP, Limited Dataset (n<8 samples) - No
Limited data set
No value > Allowable Cw
Monitoring required
Acute: NO WQS
Bis (2-ethylhexyl) phthalate C 0.32 WS(Qavg) µg/L 5 1 141.98400 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Note: n < 9 C.V. (default) Chronic: 4.16000 RP for Limited Dataset (n<8 samples) - apply
Limited data seLi 13 value(s) > Allowable Cw Quarterly Monitoring
25453 RPA, rpa
Page 2 of 2 10/16/2020

Permit No. NC0025453
NPDES Implementation of Instream Dissolved Metals Standards - Freshwater Standards
The NC 2007-2015 Water Quality Standard (WQS) Triennial Review was approved by the NC
Environmental Management Commission (EMC) on November 13, 2014. The US EPA subsequently
approved the WQS revisions on April 6, 2016, with some exceptions. Therefore, metal limits in draft
permits out to public notice after April 6, 2016 must be calculated to protect the new standards - as
approved.
Table 1. NC Dissolved Metals Water Q ality Standards/A uatic Life Protection
Parameter
Acute FW, µg/l
(Dissolved)
Chronic FW, µg/1
(Dissolved)
Acute SW, µg/1
(Dissolved)
Chronic SW, µg/l
(Dissolved)
Arsenic
340
150
69
36
Beryllium
65
6.5
---
---
Cadmium
Calculation
Calculation
40
8.8
Chromium III
Calculation
Calculation
---
---
Chromium VI
16
11
1100
50
Copper
Calculation
Calculation
4.8
3.1
Lead
Calculation
Calculation
210
8.1
Nickel
Calculation
Calculation
74
8.2
Silver
Calculation
0.06
1.9
0.1
Zinc
Calculation
Calculation
90
81
Table 1 Notes:
FW= Freshwater, SW= Saltwater
Calculation = Hardness dependent standard
Only the aquatic life standards listed above are expressed in dissolved form. Aquatic life
standards for Mercury and selenium are still expressed as Total Recoverable Metals due to
bioaccumulative concerns (as are all human health standards for all metals). It is still necessary
to evaluate total recoverable aquatic life and human health standards listed in 15A NCAC
213.0200 (e.g., arsenic at 10 µg/l for human health protection; cyanide at 5 µg/L and fluoride at
1.8 mg/L for aquatic life protection).
Table 2. Dissolved Freshwater Standards for Hardness -Dependent Metals
The Water Effects Ratio (WER) is equal to one unless determined otherwise under 15A
NCAC 02B .0211 Subparagraph (11)(d)
Metal
NC Dissolved Standard, µg/I
Cadmium, Acute
WER* 11.136672-[ln hardness](0.041838)} eA10.9151 [In hardness]-3.1485}
Cadmium, Acute Trout waters
WER* {1.136672-[ln hardness](0.041838)} of 0.9151[In hardness]-3.6236}
Cadmium, Chronic
WER* {1.101672-[ln hardness](0.041838)} e^{0.7998[ln hardness]-4.4451}
Chromium III, Acute
WER*0.316 e^{0.8190[ln hardness]+3.7256}
Chromium III, Chronic
WER*0.860 e^{0.8190[ln hardness]+0.6848}
Copper, Acute
WER*0.960 e^{0.9422[ln hardness]-1.7001
Copper, Chronic
WER*0.960 e^{0.8545[In hardness]-1.7021
Lead, Acute
WER*{1.46203-[ln hardness](0.145712)1 • of 1.273[ln hardness]-1.4601
Lead, Chronic
WER* {1.46203-[ln hardness](0.145712)1 • of 1.273[ln hardness]-4.705}
Nickel, Acute
WER*0.998 e^{0.8460[ln hardness]+2.255}
Nickel, Chronic
WER*0.997 e-10.8460[ln hardness]+0.0584}
Page 1 of 4

Permit No. NCO025453
Silver, Acute
WER*0.85 • e^{1.72[ln hardness]-6.59}
Silver, Chronic
Not applicable
Zinc, Acute
WER*0.978 e^{0.8473[ln hardness]+0.8841
Zinc, Chronic
WER*0.986 e-10.8473[ln hardness]+0.8841
General Information on the Reasonable Potential Analysis (RPA)
The RPA process itself did not change as the result of the new metals standards. However, application of
the dissolved and hardness -dependent standards requires additional consideration in order to establish the
numeric standard for each metal of concern of each individual discharge.
The hardness -based standards require some knowledge of the effluent and instream (upstream) hardness
and so must be calculated case -by -case for each discharge.
Metals limits must be expressed as `total recoverable' metals in accordance with 40 CFR 122.45(c). The
discharge -specific standards must be converted to the equivalent total values for use in the RPA
calculations. We will generally rely on default translator values developed for each metal (more on that
below), but it is also possible to consider case -specific translators developed in accordance with
established methodology.
RPA Permitting Guidance/WOBELs for Hardness -Dependent Metals - Freshwater
The RPA is designed to predict the maximum likely effluent concentrations for each metal of concern,
based on recent effluent data, and calculate the allowable effluent concentrations, based on applicable
standards and the critical low -flow values for the receiving stream.
If the maximum predicted value is greater than the maximum allowed value (chronic or acute), the
discharge has reasonable potential to exceed the standard, which warrants a permit limit in most cases. If
monitoring for a particular pollutant indicates that the pollutant is not present (i.e. consistently below
detection level), then the Division may remove the monitoring requirement in the reissued permit.
1. To perform a RPA on the Freshwater hardness -dependent metals the Permit Writer compiles the
following information:
• Critical low flow of the receiving stream, 7Q10 (the spreadsheet automatically calculates
the 1 Q 10 using the formula 1 Q 10 = 0.843 (s7Q 10, cfs) 0.993
• Effluent hardness and upstream hardness, site -specific data is preferred
• Permitted flow
• Receiving stream classification
In order to establish the numeric standard for each hardness -dependent metal of concern and for
each individual discharge, the Permit Writer must first determine what effluent and instream
(upstream) hardness values to use in the equations.
The permit writer reviews DMR's, Effluent Pollutant Scans, and Toxicity Test results for any
hardness data and contacts the Permittee to see if any additional data is available for instream
hardness values, upstream of the discharge.
If no hardness data is available, the permit writer may choose to do an initial evaluation using a
default hardness of 25 mg/L (CaCO3 or (Ca + Mg)). Minimum and maximum limits on the
hardness value used for water quality calculations are 25 mg/L and 400 mg/L, respectively.
If the use of a default hardness value results in a hardness -dependent metal showing reasonable
potential, the permit writer contacts the Permittee and requests 5 site -specific effluent and
upstream hardness samples over a period of one week. The RPA is rerun using the new data.
Page 2 of 4

Permit No. NCO025453
The overall hardness value used in the water quality calculations is calculated as follows:
Combined Hardness (chronic)
_ (Permitted Flow, cfs *Avg. Effluent Hardness, mg/L) + (s7Q10, cfs *Avg. Upstream Hardness, mg/L)
(Permitted Flow, cfs + s7Q10, cfs)
The Combined Hardness for acute is the same but the calculation uses the 1Q10 flow.
3. The permit writer converts the numeric standard for each metal of concern to a total recoverable
metal, using the EPA Default Partition Coefficients (DPCs) or site -specific translators, if any
have been developed using federally approved methodology.
EPA default partition coefficients or the "Fraction Dissolved" converts the value for
dissolved metal at laboratory conditions to total recoverable metal at in -stream
ambient conditions. This factor is calculated using the linear partition coefficients
found in The Metals Translator: Guidance for Calculating a Total Recoverable
Permit Limit from a Dissolved Criterion (EPA 823-B-96-007, June 1996) and the
equation:
_Cdiss - I
Ctotal I + f [Kpo] [ss(i+a)] [10 6]
Where:
ss = in -stream suspended solids concentration [mg/1], minimum of 10 mg/L used,
and
Kpo and a = constants that express the equilibrium relationship between dissolved
and adsorbed forms of metals. A list of constants used for each hardness -dependent
metal can also be found in the RPA program under a sheet labeled DPCs.
4. The numeric standard for each metal of concern is divided by the default partition coefficient (or
site -specific translator) to obtain a Total Recoverable Metal at ambient conditions.
In some cases, where an EPA default partition coefficient translator does not exist (le. silver), the
dissolved numeric standard for each metal of concern is divided by the EPA conversion factor to
obtain a Total Recoverable Metal at ambient conditions. This method presumes that the metal is
dissolved to the same extent as it was during EPA's criteria development for metals. For more
information on conversion factors see the June, 1996 EPA Translator Guidance Document.
5. The RPA spreadsheet uses a mass balance equation to determine the total allowable concentration
(permit limits) for each pollutant using the following equation:
Ca = (s7Q10 + Qw) (Cwgs) - (s7Q10) (Cb)
Qw
Where: Ca = allowable effluent concentration (µg/L or mg/L)
Cwqs = NC Water Quality Standard or federal criteria (µg/L or mg/L)
Cb = background concentration: assume zero for all toxicants except NH3* (µg/L or mg/L)
Qw = permitted effluent flow (cfs, match s7Q10)
s7Q10 = summer low flow used to protect aquatic life from chronic toxicity and human
health through the consumption of water, fish, and shellfish from noncarcinogens (cfs)
* Discussions are on -going with EPA on how best to address background concentrations
Flows other than s7Q10 may be incorporated as applicable:
IQ10 = used in the equation to protect aquatic life from acute toxicity
Page 3 of 4

Permit No. NC0025453
QA = used in the equation to protect human health through the consumption of water,
fish, and shellfish from carcinogens
30Q2 = used in the equation to protect aesthetic quality
The permit writer enters the most recent 2-3 years of effluent data for each pollutant of concern.
Data entered must have been taken within four and one-half years prior to the date of the permit
application (40 CFR 122.21). The RPA spreadsheet estimates the 95th percentile upper
concentration of each pollutant. The Predicted Max concentrations are compared to the Total
allowable concentrations to determine if a permit limit is necessary. If the predicted max exceeds
the acute or chronic Total allowable concentrations, the discharge is considered to show
reasonable potential to violate the water quality standard, and a permit limit (Total allowable
concentration) is included in the permit in accordance with the U.S. EPA Technical Support
Document for Water Quality -Based Toxics Control published in 1991.
7. When appropriate, permit writers develop facility specific compliance schedules in accordance
with the EPA Headquarters Memo dated May 10, 2007 from James Hanlon to Alexis Strauss on
40 CFR 122.47 Compliance Schedule Requirements.
The Total Chromium NC WQS was removed and replaced with trivalent chromium and
hexavalent chromium Water Quality Standards. As a cost savings measure, total chromium data
results may be used as a conservative surrogate in cases where there are no analytical results
based on chromium III or VI. In these cases, the projected maximum concentration (95th %) for
total chromium will be compared against water quality standards for chromium III and
chromium VI.
9. Effluent hardness sampling and instream hardness sampling, upstream of the discharge, are
inserted into all permits with facilities monitoring for hardness -dependent metals to ensure the
accuracy of the permit limits and to build a more robust hardness dataset.
10. Hardness and flow values used in the Reasonable Potential Analysis for this permit included:
Parameter
Value
Comments (Data Source)
Average Effluent Hardness (mg/L)
[Total as, CaCO3 or (Ca+Mg)]
70.39
Data provided in DMRs
Average Upstream Hardness (mg/L)
[Total as, CaCO3 or (Ca+Mg)]
45.27
Data provided in 2018-2019
renewal application
7Q 10 summer (cfs)
186
NPDES Files
1Q10 (cfs)
151.17
Calculated in RPA
Permitted Flow (MGD)
2.5
NPDES Files
Date: 10/15/2020
Permit Writer: Nick Coco
Page 4 of 4

Instream Temperature Summary NCO025453 Little Creek WRF
Date
Upstream
[degC]
Downstream
[degC]
Date
Upstream
[degC]
Downstream
[degC]
1 /11 /2017
5.6
5.7
10/8/2018
25.4
25.5
2/7/2017
10.3
10.4
11 /12/2018
14.5
14.5
3/16/2017
8.1
8
12/10/2018
4.9
4.8
4/11 /2017
18.5
18.4
1 /7/2019
9.9
9.9
5/3/2017
24.2
24
2/6/2019
10.5
10.2
5/24/2017
22.4
22.1
3/20/2019
11.1
11.4
6/7/2017
25.1
25
4/15/2019
18.8
19
6/22/2017
27.1
27
5/15/2019
19
19.2
7/13/2017
28.7
28.6
5/29/2019
26
26
7/24/2017
28.6
28.5
6/10/2019
24.2
24.1
8/21 /2017
27.9
27.9
6/25/2019
26.8
26.7
8/31 /2017
25.2
25.1
7/15/2019
28.7
28.5
9/14/2017
23.1
23
7/30/2019
26.4
26.5
9/25/2017
23.3
23.1
8/12/2019
26.9
26.9
10/26/2017
17.4
17.2
8/22/2019
28
27.5
11 /9/2017
15.6
15.4
9/5/2019
26.5
26.5
12/14/2017
6.3
6.1
9/27/2019
25.7
25.6
1 /30/2018
10.4
10.3
10/17/2019
18.3
17.7
2/28/2018
14.3
14.2
11 /14/2019
8.8
8.4
3/26/2018
10.6
10.5
12/26/2019
9.3
8.9
4/25/2018
18.2
18.1
1 /23/2020
6.7
6.6
5/10/2018
20.2
20.1
2/24/2020
10
9.9
5/22/2018
24.5
24.4
3/18/2020
14.1
14.1
6/7/2018
25.3
25.1
4/7/2020
17
16.8
6/21 /2018
27.3
27.2
5/4/2020
19.5
19.9
7/5/2018
28.3
28.2
5/19/2020
20.5
20.7
7/19/2018
26.1
26
6/17/2020
21.2
21.2
8/8/2018
28
27.8
Average
19.8
19.7
8/24/2018
25.8
25.7
Max
28.71
28.6
9/6/2018
27.2
27.1
Min
4.91
4.8
9/18/2018
25.1
25
p-value
> .05

Instream Conductivity Summary NCO025453 Little Creek WRF
Date
Upstream
[umhos/cm]
Downstream
[umhos/cm]
Date
Upstream
[umhos/cm]
Downstream
[umhos/cm]
1 /11 /2017
159
161
10/8/2018
94
97
2/7/2017
194
212
11 /12/2018
57
109
3/16/2017
171
168
12/10/2018
114
89
4/11 /2017
153
148
1 /7/2019
99
94
5/3/2017
174
164
2/6/2019
142
138
5/24/2017
142
133
3/20/2019
96
98
6/7/2017
170
163
4/15/2019
79
81
6/22/2017
162
153
5/15/2019
158
158
7/13/2017
165
171
5/29/2019
258
252
7/24/2017
163
158
6/10/2019
90
97
8/21 /2017
248
232
6/25/2019
110
111
8/31 /2017
194
204
7/15/2019
257
244
9/14/2017
177
169
7/30/2019
231
216
9/25/2017
169
160
8/12/2019
208
208
10/26/2017
168
161
8/22/2019
234
225
11 /9/2017
174
169
9/5/2019
222
225
12/14/2017
153
145
9/27/2019
272
266
1 /30/2018
161
156
10/17/2019
220
222
2/28/2018
160
158
11 /14/2019
170
160
3/26/2018
158
149
12/26/2019
204
195
4/25/2018
169
161
1 /23/2020
181
185
5/10/2018
165
159
2/24/2020
90
89
5/22/2018
167
160
3/18/2020
188
192
6/7/2018
158
167
4/7/2020
137
137
6/21 /2018
157
165
5/4/2020
103
101
7/5/2018
158
164
5/19/2020
230
225
7/19/2018
167
164
6/17/2020
100
90
8/8/2018
212
203
Average
163.3
161.0
8/24/2018
137
140
Max
2721
266
9/6/2018
140
137
Min
571
78
9/18/2018
82
78
p-value
> .05

Instream Fecal Coliform Summary NCO025453 Little Creek WRF
Date
Upstream
[#/100mL]
Downstream
[#/100mL]
Date
Upstream
[#/100mL]
Downstream
[#/100mL]
1 /11 /2017
250
220
3/20/2019
42
36
2/7/2017
54
52
4/15/2019
8500
8300
3/16/2017
66
165
5/15/2019
691
550
4/11 /2017
72
56
6/10/2019
6700
4200
5/3/2017
2400
58
7/15/2019
90
106
6/22/2017
330
600
8/12/2019
390
490
7/24/2017
92
98
9/27/2019
139
112
8/21 /2017
98
169
10/17/2019
2900
891
9/14/2017
510
84
11 /14/2019
891
873
10/26/2017
745
600
12/26/2019
197
116
11 /9/2017
270
169
1 /23/2020
62
90
12/14/2017
149
100
2/24/2020
20
28
1 /30/2018
400
1100
3/18/2020
64
68
2/28/2018
116
106
4/7/2020
60
50
3/26/2018
360
460
5/4/2020
92
88
4/25/2018
1300
1700
6/17/2020
1700
1500
5/22/2018
6000
6000
Geomean
267.3
246.7
6/7/2018
280
340
Max
8500
8300
7/5/2018
118
370
Min
20
28
8/24/2018
664
560
p-value
> .05
9/6/2018
782
873
10/8/2018
42
41
11 /12/2018
52
48
12/10/2018
2400
4400
1 /7/2019
82
96
2/6/2019
42
50

Instream DO Summary NC0025453 Little Creek WRF
Date
Upstream
[mg/L]
Downstream
[mg/L]
Date
Upstream
[mg/L]
Downstream
[mg/L]
1 /11 /2017
10.3
10.2
4/15/2019
7.3
7.3
2/7/2017
9.6
9.5
5/15/2019
8
7.8
3/16/2017
10.1
10
5/29/2019
6.3
6.5
4/11 /2017
7.1
7.2
6/10/2019
7.9
6.4
5/3/2017
6.9
6.9
6/25/2019
6.5
6.3
5/24/2017
7
6.9
7/15/2019
6.8
6.2
6/7/2017
6.7
6.7
7/30/2019
6.3
6.1
6/22/2017
6.7
6.6
8/12/2019
7.7
6.1
7/13/2017
6.4
6.4
8/22/2019
6.3
5.8
7/24/2017
6.5
6.4
9/5/2019
6.7
7
8/21 /2017
6.1
5.8
9/27/2019
6.7
6.1
8/31 /2017
6.3
6.3
10/17/2019
8
7.7
9/14/2017
6.5
6.7
11 /14/2019
10.2
9.9
9/25/2017
6.8
6.9
12/26/2019
10.2
10.3
10/26/2017
7.6
7.5
1 /23/2020
11.3
11.2
11 /9/2017
8.1
8
2/24/2020
11.2
11.1
12/14/2017
10
9.9
3/18/2020
9.3
9.2
1 /30/2018
9.5
9.3
4/7/2020
8.9
8.8
2/28/2018
8.6
8.3
5/4/2020
8.3
8.1
3/26/2018
9.4
9.3
5/19/2020
7.2
7.3
4/25/2018
7.4
7.4
6/17/2020
7.8
8.5
5/10/2018
6.6
6.7
Average
7.9
7.8
5/22/2018
6.6
6.7
Max
11.3
11.2
6/7/2018
6.4
6.5
Min
5.81
5.8
6/21/2018
6.5
6.4
p-value
> .05
7/5/2018
6.4
6.4
7/19/2018
6.6
6.5
8/8/2018
5.8
5.9
8/24/2018
6.5
6.5
9/6/2018
6.5
6.3
9/18/2018
8
8.3
10/8/2018
7
7
11 /12/2018
9.5
9.6
12/10/2018
10.6
11
1 /7/2019
10.5
10.6
2/6/2019
10.8
11
3/20/2019
101
10

Reduction in Frequency Evalaution
Facility:
Little Creek WRF
Permit No.
NC0025453
Review period (use
9/2017 - 9/2020
3 yrs)
Approval Criteria: Y/N?
1. Not currently under SOS
Y
2. Not on EPA Quarterly noncompliance
report
Y
3. Facility or employees convicted of CWA
violations
N
# of non -
Weekly
Monthly
3-yr mean
# daily
# daily
Reduce
50%
200%
200%
monthly
# civil penalty
Data Review
Units
average
average
(geo mean
< 50%?
samples
<15?
samples
< 20?
limit
> 2?
> 1?
Frequency?
limit
limit
MA
for FC)
MA
>200%
WA
>200%
asessment
(Yes/No)
violations
BOD (summer)
mg/L
7.5
5
2.5
2.1774359
Y
10
2
Y
2
N
0
N
Y
BOD (winter)
mg/L
15
10
5
2.0261538
Y
20
0
Y
0
N
0
N
Y
TSS
mg/L
45
30
15
2.3821317
Y
60
0
Y
0
N
0
N
Y
Ammonia (summer)
mg/L
3
1
0.5
0.2407424
Y
2
6
Y
0
N
0
N
Y
Ammonia (winter)
mg/L
6
2
1
0.4794656
Y
4
0
Y
0
N
0
N
Y
Fecal Coliform
#/100
400
200
100
1.3235144
Y
800 0 Y
0
N
0
N
Y

NCO025453
Little Creek WRF
BOD monthly removal rate
Month
RR (%)
Month
RR (%)
September-16
99.15
March-19
98.84
October-16
98.98
April-19
98.07
November-16
99.09
May-19
99.04
December-16
99.31
June-19
99.20
January-17
99.04
July-19
99.24
February-17
99.22
August-19
99.24
March-17
99.09
September-19
99.30
April-17
98.81
October-19
99.26
May-17
98.92
November-19
99.44
June-17
99.19
December-19
99.25
July-17
99.04
January-20
99.19
August-17
99.30
February-20
99.03
September-17
99.14
March-20
99.04
October-17
99.14
April-20
98.72
November-17
99.25
May-20
99.15
December-17
99.31
June-20
99.37
January-18
98.99
July-20
98.92
February-18
99.15
August-20
98.40
March-18
99.00
September-20
April-18
99.06
October-20
May-18
99.38
November-20
June-18
99.12
December-20
July-18
99.36
January-21
August-18
99.24
February-21
September-18
99.17
March-21
October-18
99.33
April-21
November-18
98.82
May-21
December-18
99.07
June-21
January-19
99.02
July-21
February-19
99.16
August-21
Overall BOD removal rate 99.09
10/14/2020
TSS monthly removal rate
Month
RR (%)
Month
RR (%)
September-16
99.01
March-19
99.08
October-16
98.86
April-19
96.48
November-16
99.04
May-19
99.04
December-16
99.08
June-19
99.06
January-17
98.40
July-19
99.09
February-17
98.87
August-19
99.16
March-17
99.12
September-19
99.06
April-17
98.08
October-19
99.18
May-17
99.07
November-19
99.13
June-17
99.06
December-19
99.01
July-17
99.07
January-20
98.74
August-17
99.28
February-20
98.81
September-17
99.16
March-20
98.99
October-17
99.02
April-20
98.55
November-17
99.03
May-20
98.88
December-17
99.10
June-20
99.08
January-18
98.60
July-20
98.77
February-18
99.04
August-20
98.23
March-18
98.58
September-20
April-18
98.78
October-20
May-18
99.19
November-20
June-18
99.29
December-20
July-18
99.17
January-21
August-18
98.99
February-21
September-18
98.97
March-21
October-18
99.07
April-21
November-18
97.99
May-21
December-18
98.37
June-21
January-19
98.14
July-21
February-19
98.85
August-21
Overall TSS removal rate
98.85

10/14/20 WQS = 12 ng/L
Facility Name
Little Creek WRF/NC0025453
/Permit No.
Total Mercury 1631E PQL = 0.5 ng/L
Date Modifier Data Entry Value
MERCURY WQBEL/TBEL EVALUATION V:2013-6
No Limit Required
No MMP Required
7Q10s = 186.000 cfs WQBEL = 588.00 ng/L
Permitted Flow = 2.500 47 ng/L
9/27/16
<
1
0.5
12/15/16
<
1
0.5
0.5 ng/L
- Annual Average for 2016
3/8/17
<
1
0.5
6/13/17
<
1
0.5
9/26/17
<
1
0.5
12/7/17
<
1
0.5
0.5 ng/L
- Annual Average for 2017
3/6/18
<
1
0.5
6/5/18
<
1
0.5
9/10/18
<
1
0.5
12/11/18
<
1
0.5
0.5 ng/L
- Annual Average for 2018
3/5/19
<
1
0.5
6/4/19
<
1
0.5
9/12/19
<
1
0.5
12/3/19
<
1
0.5
0.5 ng/L
- Annual Average for 2019
3/3/20
<
1
0.5
6/2/20
<
1
0.5
0.5 ng/L
- Annual Average for 2020

Little Creek WRF/NC0025453
Mercury Data Statistics (Method 1631E)
2016
2017
2018
2019
# of Samples
2
4
4
4
Annual Average, ng/L
0.5
0.5
0.5
0.50
Maximum Value, ng/L
0.50
0.50
0.50
0.5
TBEL, ng/L
47
WQBEL, ng/L
588.0
2020
0.5
0.5

Whole Effluent Toxicity Testing and Self Monitoring Summary
Clariant Corp. -Mt. Holly Plant
NC0004375/001
County:
Mecklenburg
Ceri7dPF
Begin:
1/1/2018
Chr Lim: 0.8
NonComp:
Single
J
F M
A
M
2016
-
- Pass
-
-
2017
-
- Pass
-
-
2015
-
- Pass
-
-
2019
-
- Pass
-
-
2020
-
- Pass
-
-
Clarkton WWTP
NCO021610/001
County:
Bladen
Ceri7dPF
Begin:
6/1/2010
chr lim: 90%
NonComp:
Single
J
F M
A
M
2016
Pass
- -
Pass
-
2017
Pass
- -
Pass
-
2015
Pass
- -
Pass
-
2019
Pass
- -
Pass
-
2020
Pass
- -
Pass
-
Clayton WWTP - Little Creek WRF
NCO025453/001
County:
Johnston
Ceri7dPF
Begin:
5/1/2014
chr lim: 2.0% @2.5 M
NonComp:
Single
J
F M
A
M
2016
-
- Pass
-
-
2017
-
- Pass >S(P)
-
-
2015
-
- Pass
-
-
2019
-
- Pass
-
-
2020
-
- Pass
-
-
Cleveland County WTP
NCO051918/001
County:
Cleveland
Fthd24PF
Begin:
2/1/2015
Acu Monit: 90% arm
NonComp:
J
F M
A
M
2016
H
H
2017
H
H
2018
2019
Cleveland WWTP
NCO049867/001
County:
Rowan
Ceri7dPF
Begin:
4/1/2009
chr lim: 3.0%
NonComp:
Single
J
F M
A
M
2016
-
- Pass
-
-
2017
-
- Pass
-
-
2015
-
- Pass >6(P)
-
-
2019
-
- Pass
-
-
2020
-
- Pass
-
-
Region:
MRO
Basin: CTB34
Mar Jun Sep Dec
SOC JOC:
7Q10: 329
PF: 3.9 IWC:
1.8 Freq: Q
J
J
A
5
O
N
Pass
-
-
Pass
-
-
Pass
-
-
Pass
-
-
Pass
-
-
Pass
-
-
Pass
-
-
Pass
-
-
Pass
-
Region:
FRO
Basin: LUM58
Jan Apr Jul Oct
SOC JOC:
7Q10: 0.0
PF: 0.24 IWC:
100 Freq: Q
J
J
A
5
O
N
-
Pass
-
-
Pass
-
-
Pass
-
-
Pass
-
-
Pass
-
-
Pass
-
-
Pass
-
-
Pass
-
Region:
RRO
Basin: NEU02
Mar Jun Sep Dec
SOC JOC:
7Q10: 186
PF: 2.5 IWC:
1.6 Freq: Q
J
J
A
5
O
N
Pass
-
-
Pass >S(P)
-
-
Pass >S(P)
-
-
Pass
-
-
Pass
-
-
Pass
-
-
Pass
-
-
Pass
-
-
Pass
-
Region:
MRO
Basin: BRD04
Jan Apr Jul Oct
SOC JOC:
7Q10:
PF: 0.485 IWC:
Freq: A
J
J
A
5
O
N
H
H
Pass
Pass
Region: MRO Basin: YAD06 Mar Jun Sep Dec
70,10: 14.0 PF: 0.27 IWC: 3.0 Freq: Q
J
J
A
5 O
Pass
-
-
Pass -
Pass
-
-
Pass >12(P) -
Pass
>6(P)
-
Pass -
Pass
-
-
Pass -
Pass
D
Pass
Pass
Pass
Pass
0
D
Pass >S(P)
Pass
Pass
Pass
0
SOC_JOC:
N D
Pass
- >12(P) Pass
Pass
Pass
Legend: P= Fathead minnow (Pimphales promelas), H=No Flow (facility is active), s = Split test between Certified Labs Page 21 of 122

United States Environmental Protection Agency
Form Approved.
EPA Washington, D.C. 20460
OMB No. 2040-0057
Water Compliance Inspection Report
Approval expires 8-31-98
Section A: National Data System Coding (i.e., PCS)
Transaction Code NPDES yr/mo/day Inspection Type Inspector Fac Type
1 IN 1 2 15 1 3 I NC0025453 I11 121 19/06/03 I17 18 n 19 L G j 201
2111111�-1111111111111111111111111111111111111 f6
Inspection
Work Days Facility Self -Monitoring Evaluation Rating B1 CA ---------------------- Reserved -------------------
67
I 71 I I 72 L n, � 73 LLI74 71 I I I I I I I80
70 Iu ty LJ
Section B: Facility Data
Name and Location of Facility Inspected (For Industrial Users discharging to POTW, also include
Entry Time/Date
Permit Effective Date
POTW name and NPDES permit Number)
01:OOPM 19/06/03
14/05/01
Little Creek WRF
1000 Durham St
Exit Time/Date
Permit Expiration Date
Clayton NC 27520
03:30PM 19/06/03
18/03/31
Name(s) of Onsite Representative(s)/Titles(s)/Phone and Fax Number(s)
Other Facility Data
James O Warren/ORC/919-553-1536/
Name, Address of Responsible Official/Title/Phone and Fax Number
Contacted
Timothy S Simpson,PO Box 879 Clayton NC 27520//919-553-1530/9195531541
Yes
Section C: Areas Evaluated During Inspection (Check only those areas evaluated)
Permit 0 Flow Measurement Operations & Maintenar 0 Records/Reports
Sludge Handling Dispos 0 Effluent/Receiving Wate Laboratory
Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary)
(See attachment summary)
Name(s) and Signature(s) of Inspector(s) Agency/Office/Phone and Fax Numbers Date
Jason T Robinson DWR/RRO WQ/919-791-4200/
Signature of Management Q A Reviewer Agency/Office/Phone and Fax Numbers Date
EPA Form 3560-3 (Rev 9-94) Previous editions are obsolete.
Page#

NPDES yr/mo/day Inspection Type
31 NCO025453 I11 121 19/06/03 117 18 ICI
Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary)
Page#

Permit: NCO025453
Inspection Date: 06/03/2019
Owner - Facility: Little Creek WRF
Inspection Type: Compliance Evaluation
Laboratory
Are field parameters performed by certified personnel or laboratory?
Are all other parameters(excluding field parameters) performed by a certified lab?
# Is the facility using a contract lab?
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 degrees
Celsius)?
Incubator (Fecal Coliform) set to 44.5 degrees Celsius+/- 0.2 degrees?
Incubator (BOD) set to 20.0 degrees Celsius +/- 1.0 degrees?
Comment:
Permit
(If the present permit expires in 6 months or less). Has the permittee submitted a new
application?
Is the facility as described in the permit?
# Are there any special conditions for the permit?
Is access to the plant site restricted to the general public?
Is the inspector granted access to all areas for inspection?
Yes
No
NA
NE
•
❑
❑
❑
•
❑
❑
❑
•
❑
❑
❑
•
❑
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❑
■
❑
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■
❑
❑
❑
Yes No NA NE
■ ❑ ❑ ❑
■ ❑ ❑ ❑
❑ ■ ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
Comment: Permit expired on March 31, 2018. Permit renewal applicaiton submitted on September 29.
2017.
Record Keeping
Yes
No
NA
NE
Are records kept and maintained as required by the permit?
0
❑
❑
❑
Is all required information readily available, complete and current?
0
❑
❑
❑
Are all records maintained for 3 years (lab. reg. required 5 years)?
0
❑
❑
❑
Are analytical results consistent with data reported on DMRs?
0
❑
❑
❑
Is the chain -of -custody complete?
0
❑
❑
❑
Dates, times and location of sampling
❑
Name of individual performing the sampling
❑
Results of analysis and calibration
❑
Dates of analysis
❑
Name of person performing analyses
❑
Transported COCs
❑
Are DMRs complete: do they include all permit parameters?
❑
❑
❑
Has the facility submitted its annual compliance report to users and DWQ?
❑
❑
❑
(If the facility is = or > 5 MGD permitted flow) Do they operate 24/7 with a certified operatc
❑
❑
❑
on each shift?
Page#
3

Permit: NCO025453 Owner - Facility: Little Creek WRF
Inspection Date: 06/03/2019 Inspection Type: Compliance Evaluation
Record Keeping Yes No NA NE
Is the ORC visitation log available and current?
0
❑
❑
❑
Is the ORC certified at grade equal to or higher than the facility classification?
0
❑
❑
❑
Is the backup operator certified at one grade less or greater than the facility classification'
0
❑
❑
❑
Is a copy of the current NPDES permit available on site?
0
❑
❑
❑
Facility has copy of previous year's Annual Report on file for review?
0
❑
❑
❑
Comment:
Operations & Maintenance Yes No NA NE
Is the plant generally clean with acceptable housekeeping? 0 ❑ ❑ ❑
Does the facility analyze process control parameters, for ex: MLSS, MCRT, Settleable ❑ ❑ ❑
Solids, pH, DO, Sludge Judge, and other that are applicable?
Comment:
Grit Removal
Yes
No
NA
NE
Type of grit removal
a.Manual
❑
b.Mechanical
Is the grit free of excessive organic matter?
0
❑
❑
❑
Is the grit free of excessive odor?
0
❑
❑
❑
# Is disposal of grit in compliance?
0
❑
❑
❑
Comment:
Bar Screens
Yes
No
NA
NE
Type of bar screen
a.Manual
b.Mechanical
Are the bars adequately screening debris?
0
❑
❑
❑
Is the screen free of excessive debris?
0
❑
❑
❑
Is disposal of screening in compliance?
0
❑
❑
❑
Is the unit in good condition?
0
❑
❑
❑
Comment:
Flow Measurement - Influent Yes No NA NE
Page# 4

Permit: NCO025453 Owner - Facility:
Inspection Date: 06/03/2019 Inspection Type:
Little Creek WRF
Compliance Evaluation
Flow Measurement - Influent
Yes
No
NA
NE
# Is flow meter used for reporting?
❑
0
❑
❑
Is flow meter calibrated annually?
0
❑
❑
❑
Is the flow meter operational?
0
❑
❑
❑
(If units are separated) Does the chart recorder match the flow meter?
0
❑
❑
❑
Comment: -Effluent Flow Reported
Pump Station - Influent
Yes
No
NA
NE
Is the pump wet well free of bypass lines or structures?
0
❑
❑
❑
Is the wet well free of excessive grease?
0
❑
❑
❑
Are all pumps present?
0
❑
❑
❑
Are all pumps operable?
0
❑
❑
❑
Are float controls operable?
0
❑
❑
❑
Is SCADA telemetry available and operational?
0
❑
❑
❑
Is audible and visual alarm available and operational?
0
❑
❑
❑
Comment:
Nutrient Removal
Yes
No
NA
NE
# Is total nitrogen removal required?
0
❑
❑
❑
# Is total phosphorous removal required?
0
❑
❑
❑
Type
Biological
# Is chemical feed required to sustain process?
❑
0
❑
❑
Is nutrient removal process operating properly?
0
❑
❑
❑
Comment:
Oxidation Ditches
Yes
No
NA
NE
Are the aerators operational?
0
❑
❑
❑
Are the aerators free of excessive solids build up?
0
❑
❑
❑
# Is the foam the proper color for the treatment process?
0
❑
❑
❑
Does the foam cover less than 25% of the basin's surface?
0
❑
❑
❑
Is the DO level acceptable?
0
❑
❑
❑
Are settleometer results acceptable (> 30 minutes)?
❑
❑
❑
Is the DO level acceptable?(1.0 to 3.0 mg/1)
❑
❑
❑
Are settelometer results acceptable?(400 to 800 ml/I in 30 minutes)
❑
❑
❑
Page# 5

Permit: NCO025453 Owner - Facility: Little Creek WRF
Inspection Date: 06/03/2019 Inspection Type: Compliance Evaluation
Oxidation Ditches Yes No NA NE
Comment:
Secondary Clarifier
Yes
No
NA
NE
Is the clarifier free of black and odorous wastewater?
0
❑
❑
❑
Is the site free of excessive buildup of solids in center well of circular clarifier?
0
❑
❑
❑
Are weirs level?
0
❑
❑
❑
Is the site free of weir blockage?
0
❑
❑
❑
Is the site free of evidence of short-circuiting?
0
❑
❑
❑
Is scum removal adequate?
0
❑
❑
❑
Is the site free of excessive floating sludge?
0
❑
❑
❑
Is the drive unit operational?
0
❑
❑
❑
Is the return rate acceptable (low turbulence)?
0
❑
❑
❑
Is the overflow clear of excessive solids/pin floc?
0
❑
❑
❑
Is the sludge blanket level acceptable? (Approximately'/4 of the sidewall depth)
0
❑
❑
❑
Comment:
Pumps-RAS-WAS
Yes
No
NA
NE
Are pumps in place?
0
❑
❑
❑
Are pumps operational?
0
❑
❑
❑
Are there adequate spare parts and supplies on site?
0
❑
❑
❑
Comment:
Filtration (High Rate Tertiary)
Yes
No
NA
NE
Type of operation:
Down
flow
Is the filter media present?
❑
❑
❑
Is the filter surface free of clogging?
❑
❑
❑
Is the filter free of growth?
❑
❑
❑
Is the air scour operational?
❑
❑
❑
Is the scouring acceptable?
❑
❑
❑
Is the clear well free of excessive solids and filter media?
❑
❑
❑
Comment:
Disinfection - UV Yes No NA NE
Page# 6

Permit: NC0025453
Inspection Date: 06/03/2019
Owner - Facility: Little Creek WRF
Inspection Type: Compliance Evaluation
Disinfection - UV
Yes
No
NA
NE
Are extra UV bulbs available on site?
0
❑
❑
❑
Are UV bulbs clean?
0
❑
❑
❑
Is UV intensity adequate?
0
❑
❑
❑
Is transmittance at or above designed level?
0
❑
❑
❑
Is there a backup system on site?
0
❑
❑
❑
Is effluent clear and free of solids?
0
❑
❑
❑
Comment:
Flow Measurement - Effluent
Yes
No
NA
NE
# Is flow meter used for reporting?
0
❑
❑
❑
Is flow meter calibrated annually?
0
❑
❑
❑
Is the flow meter operational?
0
❑
❑
❑
(If units are separated) Does the chart recorder match the flow meter?
0
❑
❑
❑
Comment: Reclaimed water subtracted from effluent flow for reportinq
Effluent Pipe
Yes
No
NA
NE
Is right of way to the outfall properly maintained?
0
❑
❑
❑
Are the receiving water free of foam other than trace amounts and other debris?
0
❑
❑
❑
If effluent (diffuser pipes are required) are they operating properly?
0
❑
❑
❑
Comment:
Pump Station - Effluent
Yes
No
NA
NE
Is the pump wet well free of bypass lines or structures?
0
❑
❑
❑
Are all pumps present?
0
❑
❑
❑
Are all pumps operable?
0
❑
❑
❑
Are float controls operable?
0
❑
❑
❑
Is SCADA telemetry available and operational?
0
❑
❑
❑
Is audible and visual alarm available and operational?
0
❑
❑
❑
Comment:
Standby Power
Yes
No
NA
NE
Is automatically activated standby power available?
0
❑
❑
❑
Is the generator tested by interrupting primary power source?
0
❑
❑
❑
Page# 7

Permit: NC0025453
Inspection Date: 06/03/2019
Standby Power
Is the generator tested under load?
Was generator tested & operational during the inspection?
Owner - Facility: Little Creek WRF
Inspection Type: Compliance Evaluation
Do the generator(s) have adequate capacity to operate the entire wastewater site?
Is there an emergency agreement with a fuel vendor for extended run on back-up power?
Is the generator fuel level monitored?
Comment: -
Aerobic Digester
Is the capacity adequate?
Is the mixing adequate?
Is the site free of excessive foaming in the tank?
# Is the odor acceptable?
# Is tankage available for properly waste sludge?
Comment:
Solids Handling Equipment
Is the equipment operational?
Is the chemical feed equipment operational?
Is storage adequate?
Is the site free of high level of solids in filtrate from filter presses or vacuum filters?
Is the site free of sludge buildup on belts and/or rollers of filter press?
Is the site free of excessive moisture in belt filter press sludge cake?
The facility has an approved sludge management plan?
Comment:
Yes
No
NA
NE
■
❑
❑
❑
❑
■
❑
❑
■
❑
❑
❑
■
❑
❑
❑
■
❑
❑
❑
Yes
No
NA
NE
■
❑
❑
❑
•
❑
❑
❑
•
❑
❑
❑
•
❑
❑
❑
❑
❑
❑
■
Yes
No
NA
NE
•
❑
❑
❑
•
❑
❑
❑
•
❑
❑
❑
•
❑
❑
❑
■
❑
❑
❑
■
❑
❑
❑
❑
❑
❑
■
Page# 8

MONITORING REPORT(MR) VIOLATIONS for:
Permit: NCO025453 MRS Betweel 9 - 2016 and 9 - 2020 Region: %
Facility Name:% Param Name% County: %
Major Minor: %
Report Date: 10/08/2C Page 1 of 1
Violation Category:Limit Violation Program Category: %
Subbasin:% Violation Action: %
PERMIT: NCO025453
FACILITY: Town of Clayton -Little Creek WRF
COUNTY: Johnston
REGION: Raleigh
Limit Violation
MONITORING
VIOLATION
UNIT OF
CALCULATED
%
REPORT
OUTFALL
LOCATION
PARAMETER
DATE
FREQUENCY
MEASURE
LIMIT
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
04 -2017
001
Effluent
BOD, 5-Day (20 Deg. C) -
04/29/17
2 X week
mg/I
7.5
8.43
12.3
Weekly Average
Proceed to NOV
Concentration
Exceeded
04-2017
001
Effluent
BOD, 5-Day (20 Deg. C) -
04/30/17
2 X week
mg/I
5
5.19
3.8
Monthly Average
Proceed to NOV
Concentration
Exceeded
04 -2019
001
Effluent
BOD, 5-Day (20 Deg. C) -
04/13/19
2 X week
mg/I
7.5
11.25
50
Weekly Average
Proceed to NOV
Concentration
Exceeded
05-2017
001
Effluent
Oxygen, Dissolved (DO)
05/22/17
5 X week
mg/I
6
5.7
5
Daily Minimum Not
Proceed to NOD
Reached
05-2017
001
Effluent
Oxygen, Dissolved (DO)
05/25/17
5 X week
mg/I
6
5.8
3.3
Daily Minimum Not
Proceed to NOD
Reached
05-2017
001
Effluent
Oxygen, Dissolved (DO)
05/26/17
5 X week
mg/I
6
5.6
6.7
Daily Minimum Not
Proceed to NOD
Reached

TOWN OF CLAYTON
"SERVICE" OPERATIONS CENTER "ENVIRONMENT"
ELECTRIC SERVICE a
PUBLIC WORKS
[phone] [phone]
VEHICLE MAINTENANCE WATER RECLAMATION
[phone] [phone]
September 21, 2020
SEP 2 5 1010
NCDEQ/DWR/NPDES
Michael Montebello
NC DEQ, DWR
Water Quality Permitting Section
1617 Mail Service Center
Raleigh, NC 27699-1617
Re: Winter Limits, Town of Clayton NC, NPDES NCO025453
Mr. Montebello:
The Town of Clayton is submitting a request to have winter limits for 3QD5 and Ammonia-N added to
the permit limits to the current permit modification under review by the permitting group. A speculative
limits letter was issued by DWR on September 4, 2020 that indicated that winter limits would be
considered after a modeling effort indicated that seasonal limits would be protective of water quality.
The Town and Dewberry Engineers have completed the additional river modeling and by our
interpretation water quality would remain protected in the Neuse River. The additional model runs were
submitted to NC DEQ DWR modeling group on 09/18/2020.The model runs are carried out under the
most severe flow scenarios and are very unlikely to occur when the flow in the river is controlled by Falls
dam. See attached Technical Memorandum addressing the modeling effort.
As you are aware the majority of the wastewater treatment facilities in North Carolina are of a biological
nature and experience some amount of inhibition during extended period of cold weather. The majority
of these facilities and particularly in the Neuse River have been given winter limits in their NPDES
permits. The nitrification process is especially affected when temperatures drop into the lower teens
(C*). In order to account for this inhibition when appropriate, regulatory agencies on the federal and
state level have issued winter limits to prevent nuisance compliance issues.
Also in support of our request the following facts are indicative of water bodies in our temperature
zone. During the winter months the ambient dissolved oxygen levels in the river are higher and increase
the assimilative capacity of the water body. Lower temperatures also inhibit the growth of algae and
therefore reducing oxygen depletion in the river.
653 Highway 42 West • P.O. Box 879 • Clayton, North Carolina 27520 • [phone] • Fax [phone]

As requested by the permitting group, please see the attached graph showing the monthly averages for
the Little Creek WRF 2017-2020. The data shows the effects of the cooler temperatures in the ammonia
removal efficiency of the current facility.
The Town of Clayton requests NC DEQ DWR's assistance in this matter as we are currently on tight
schedule to have this facility operational in 2023 to meet our residential and industrial needs. Please
contact me at 919-553-1536 if you have any questions.
Sincerely
e / 'Z'—
ames Warren
Wastewater Operations Superintendent
Town of Clayton, NC

) Dewberry
Date: September 18, 2020
To: Adugna Kebede- DWR, NC DEQ
Pam Behm- DWR, NC DEQ
From: Laura Crisman, P.E.- Dewberry
James Warren- Town of Clayton
Subject:
►,1:4 �,Mif- i!10111►,
Neuse River QUAL21K Model: Falls Dam to Goldsboro, Winter Limits
For Little Creek WRF Expansion
[Addendum to Neuse River QUAL2K Final Model Report, 8/17/2020]
MEMORANDUM
Introduction
The Neuse River QUAL2K model was developed to support the Little Creek Water Reclamation Facility (WRF)
expansion for handling future industrial and residential loads. NC DEQ has issued speculative NPDES limits for the
WRF expansion based on the modeling results submitted August 17, 2020. The speculative limits indicated additional
modeling was necessary to evaluate inclusion of seasonal, winter limits for BOD5 and NH3-N, both of which are
included in the current NPDES permit. This memo summarizes additional Neuse River QUAL2K models that were
developed to evaluate winter NPDES limits for Little Creek WRF's expansion from 2.5 MGD to 6 MGD and 10 MGD.
Approach
Four additional QUAL2K models were developed to evaluate the potential impact of Little Creek WRF's expansion on
the Neuse River under winter conditions and winter NPDES permit limits. The winter Neuse River QUAL2K models
discussed in this memo were developed from the calibrated QUAL2K models previously submitted. A summary of the
four Neuse River winter models is presented in the table below:
No.
Model Description
Little Creek WRF Discharge
Neuse River Model Inputs
1
Low Flow, Winter:
Current NPDES flow at 2.5 MGD,
• NPDES discharge at winter, daily max limits
Current WRF
• Tributary water quality (temperature, DO,
Current NPDES daily max, winter permit limits
phosphorus and nitrogen species) estimated
2
Low Flow, Winter:
Future flow at 6 MGD
from winter AMS data and winter NPDES
Expansion WRF
daily max limits to tributaries.
6 MGD
Current NPDES daily max, winter permit limits
3
Low Flow, Winter:
Future flow at 10 MGD
Expansion WRF
10 MGD
Current NPDES daily max, winter permit limits
4
Low Flow, Winter:
Future flow at 10 MGD
• NPDES discharge at winter, monthly average
limits
Expansion WRF
Current NPDES monthly average, winter permit
10 MGD
limits
0Tributary water quality estimated from winter
AMS data and winter NPDES monthly
average limits to tributaries.
Neuse River QUAL2K Model: Winter Limits Memorandum 1 1 of 5

y Dewberry
MEMORANDUM
Model Inputs
The QUAL2K modeled geography and hydraulic inputs reflect those of the previously submitted models. Descriptions
of inputs to the winter models are below:
1. Low (7Q10) flow at the headwater was used in the winter models as Falls Dam typically regulates to a lower
flow during winter.' The 7Q10 flow was also used in the summer models as a conservative model of drought
conditions. Thus, flow estimates in the winter models are the same as in the calibrated, low flow summer
models. The flows for tributaries and diffuse sources were calibrated using a December 2012 model, thus, it
is expected this is a good estimate of low, winter flow conditions in the Neuse River.
2. Water quality parameters (temperature, DO, nitrogen species and phosphorus) of the headwater and the 25
tributaries were derived from ambient monitoring station (AMS) data and NPDES dischargers to the tributaries.
Specifically, AMS data along the river was determined for November -March for the last four years of available
data, within the past ten years (attached to this memo). Where tributaries have NPDES dischargers, the water
quality of the tributary was estimated by a flow -weighted average of the nearest AMS and the NPDES permit
limits.
3. Sediment oxygen demand (SOD), ammonia and phosphorus sediment flux were estimated from data used in
the previously submitted models (EPA Project 18-0362). The field values were temperature corrected for the
winter models using a Van't Hoff Equation and an average winter water temperature at the nearest AMS, using
3-4 years of data in the past ten years. There is little data on winter SOD rates in the Neuse River. Some
studies have indicated that SOD rates may be three times higher in the summer compared to winter (Eric
Akomeah, 2017). This is in line with the temperature corrected estimate of winter SOD rates compared to the
summer model estimate.
4. Rate parameters in the water column (e.g. reaeration rate, BOD oxidation, nitrification, denitrification, algae
growth and respiration) were estimated as the same inputs as previously developed calibrated low flow model
rate inputs. Note: the rate values are not the same in the winter model due to the lower temperature. QUAL2K
contains an internal Arrhenius correction for temperature for the first order rate reactions.
5. Ambient air temperature was estimated from winter weather data at the Raleigh RDU weather station. The
dew point was estimated at 80% relative humidity.
6. Wind speed and cloud cover were conservatively assumed to be zero and the calibrated inputs for shade
along the river were used in the winter model (45-60% shade).
7. Temperature input for diffuse sources used AMS data from the nearest station, estimating temperature as 95th
percentile temperature of winter data at the nearest AMS. The DO for diffuse sources in the winter is estimated
at 8.5 mg/L (90% of DO saturation at 18C).
8. NPDES point sources used winter permit limits (daily max for three models and monthly average for one
model) for flow and water quality inputs. For temperature and other water quality inputs that do not have
specific NPDES permit limits, discharge monitoring report data was used from the winter, low flow calibration
model.
t U.S. Army Corps of Engineers, in agreement with the Town of Smithfield, is required to release a minimum of 100 cfs (64.6 MGD)
from the dam during the summer months (April -October) and 65 cfs (42 MGD) during winter months (November -March).
Neuse River QUAL2K Model: Winter Limits Memorandum 1 2 of 5

Dewberry
MEMORANDUM
Complete details on the model approach, geography, hydraulic and kinetic inputs may be found in the previously
submitted report. All inputs and notes specific to the winter models may be found in the QUAL2K model files submitted
with this memorandum.
Calibration
Details of model calibration may be found in the previous report, specifically for the Dec 2012 flow calibration model.
Results and Discussion
Figure 1 contains a summary graph of DO results for the four 7Q10, winter models of the Neuse River (attached).
The general shape of the DO curve from previous Neuse River models is also observed in these winter model DO
profile results. DO is increasing at the location of Little Creek WRF; in fact the models predict an increase in DO from
the WRF expansion for about 3 km downstream of the discharge. Additionally, as in previous model results, the winter
models do not predict a discernable, characteristic DO drop due to the Little Creek WRF. Again, likely due to effects of
overriding discharge and withdrawals modeled near the discharge that dwarf the impact of Little Creek WRF near the
point of discharge. The maximum difference in DO prediction with the expansion is observed 75 km downstream of the
discharge: where the DO is predicted to be 4.55 mg/L in the 2.5 MGD model; 4.45 mg/L in the 6 MGD model; and 4.34
mg/L in the 10 MGD model. These model predictions assume all the point sources between Falls Dam and Goldsboro
discharge at their winter, daily maximum NPDES limits and that the river is at 7Q10 low flow, which is a deliberately
conservative scenario with highest potential for maximum DO suppression. At these conditions, the QUAL2K model
predicts the DO is above the minimum instantaneous in stream water quality standard of 4.0 mg/L.
Interestingly, the winter model of daily maximum NPDES limits results in a lower absolute minimum DO (4.34 mg/L, 10
MGD model) compared to the previously run, higher temperature model (4.92 mg/L, 10 MGD model). One generally
expects a higher DO profile during lower temperature, winter months in a waterway. However, the Neuse River has
dam -controlled flow, thus the low flow conditions may, and often do, occur during the winter months. Thus, it is due to
the increased nutrient load from the winter NPDES limits that QUAL2K predicts minimum DO lower in winter than in
the higher temperature model under the 7Q10 flow conditions.
Little Creek WRF is one of four major municipal WWTP's along the Neuse River between Falls Dam and Goldsboro,
and it is currently the smallest.2 The expansion to 6 MGD would bring it to the same size as the next largest WWTP,
Smith Creek RRF. The summer and winter discharge limits for flow, ammonia, phosphorus, and DO from the four
WWTPs are shown in tables below. The QUAL21K model predicts the river is impacted by the WWTPs' increased
maximum nutrient loading in the winter. Notably, WWTP nutrient removal is sensitive to low winter temperatures where
nitrification slows; thus it may be expected that at higher winter temperatures the WWTPs' actual (not modeled)
discharge may be nearer to the summer NPDES limits. In this way, the QUAL21K winter model is a worst case scenario
of highest winter temperatures, to reflect conditions where DO saturation value is lowest, and maximum winter NPDES
discharges to the River. These two conditions are not likely to occur simultaneously in the field, but are modeled as
most potentially limiting to DO in the Neuse River.
2 A total of fifteen NPDES dischargers were modeled to the Neuse River. A complete list of their summer and winter permit limits
may be found in the previous model report, as well limits for NPDES dischargers to Neuse River tributaries.
Neuse River QUAL21K Model: Winter Limits Memorandum 1 3 of 5

f Dewberry
MEMORANDUM
Though the winter model predicts DO could theoretically be lower than in the high, summer temp model, it takes an
extraordinary confluence of circumstances to reflect the model conditions of 7Q10 flow, highest winter temperature,
and maximum daily discharge rates. The ambient monitoring station data appear to reflect that DO in the River in the
winter months has not been subject to these extreme conditions simultaneously: the nearest AMS to the location of
model -predicted DO low point is J5250000, where the 5ch percentile of winter DO data is 8.6 mg/L (2010-2013). The
DO graph in Figure 1 includes AMS data, average winter and 51h percentile of the last 3-4 years at each AMS for
comparative purposes.
Perhaps a more realistic representation of the Neuse River is the QUAL2K winter model of monthly NPDES discharge
limits. As shown on Figure 1, the DO in this model scenario remains above 6.5 mg/L at all points downstream of Little
Creek WRF, modeled at 10 MGD, maximum expansion. This prediction is above the daily average water quality
standard of 5.0 mg/L in the Neuse River for the entire model geography.
Summer
DO
Facility Name
Flow
BOD5, 20°C m /L
NH3-N m /L
TP m /L
m /L
Min
Monthly
Daily
Monthly
Daily
Quarterly
Daily
MGD
Avg
Max0)
Avg
Max0)
Avg
Avg
Smith Creek WWTP
RRF
6
5.0
7.5
1
3
2
5.0
Neuse River RRF
75
5.0
7.5
1
3
2
5.0
Little Creek WRF
2.5
5.0
7.5
1
3
2
6.0
Central Johnston County
Regional WWTF
13.5
1 5.0
7.5
1
3
2
6
Winter
DO
Facility Name
Flow
BOD5, 20°C m /L
NH3-N m /L
TP
m /L
Min
Monthly
Daily
Monthly
Daily
Quarterly
Daily
MGD
Avg
Maze)
Avg
Maxi')
Avg
Avg
Smith Creek WWTP
RRF
6
10.0
15.0
2
6
2
5.0
Neuse River RRF
75
10.0
15.0
2
6
2
5.0
Little Creek WRF
2.5
10.0
15.0
2
6
2
6.0
Central Johnston County
Re ional WWTF
13.5
10.0
15.0
2
6
2
1 6
Neuse River QUAL2K Model: Winter Limits Memorandum 1 4 of 5

10 Dewberry
MEMORANDUM
Conclusions
The QUAL2K models predict the Neuse River DO would stay above the minimum instantaneous water quality standard
of 4.0 mg/L at conservatively critical conditions in the Neuse River (low flow, high winter temperature. and all NPDES
discharges at winter daily maximum limits). The models also predict the DO would stay above the daily average water
quality standard of 5.0 mg/L when NPDES dischargers are modeled at winter monthly average limits. Ambient
monitoring station data from winter months indicate the QUAL21K model predictions of DO are highly conservative (lower
than observed AIMS data), which is as the models designed. Based on the results of the four winter models, the Neuse
River has sufficient assimilative capacity to accept the additional flow and loading from Little Creek WRF expansion
with winter NPDES limits; showing a relatively small impact between 2.5 MGD to 10 MGD discharge from the Little
Creek WRF (0.2 mg/L).
Attachments:
Figure 1. Neuse River QUAL2K Model DO Profile at 7Q10 Flow, Winter
Ambient Monitoring Station Data- Winter Monthly Summary
cc:
David Hill, NC DEQ
Mike Templeton, NC DEQ
Michael Montebello, NC DEQ
Rich Cappola, Town of Clayton
Neuse River QUAL2K Model: Winter Limits Memorandum 1 5 of 5

FIGURE 1 NEUSE RIVER QUAL2K MODEL DO PROFILE AT 7Q10 LOW FLOW, WINTER:
LITTLE CREEK WRF DISCHARGE AT 2.5, 6, and 10 MGD
'Note 1: Only major tributaries (>0.25 MGD) and major NPDES sources are identified on the chart. More minor sources are included in the QUAL2K models.
'Note 2: NPDES point source dischargers are modeled at summer maximum daily discharge limits, unless otherwise noted.
• LCWRF 2.5 MGD- winter model
•
• LCWRF 6 MGD- winter model
• • • LCWRF 10 MGD- winter model
•
•
• • • • Winter AMS Data: 5th Percentile
•
12.00
10.00
• ; • Winter AMS Data: Average
•
• 8.00
• LCWRF 10 MGD; •
NPDES sources @ Monthly Limits °p
_ E
c
a
00
6.00 O
..
lilies >
o
Crabtree Creek O
Little Creek WWTP (NPDES) ��A�
Neuse River WWTP (NPDES)
Smith Creek WWTP I
Johnston
Smithfield WTP
- Poplar Creek
Smith Creek ; 'Harris Creek ; Central Johnston County Regional
NP
�- Poplar Branch WWTF (Mocassin Cre k Goldsboro WRF(NPDES)2 00
f Marks Cree Swift Cree e
! Walnut Creek ' Falling Creek
I ) Polecat Branch ---
f Black Creek Mill Creek Little River
\� 0.00
180.00 170.00 160.00 150.00 140.00 130.00 120.00 110.00 100.00 90.00 80.00 70.00 60.00 50.00 40.00 30.00 20.00 10.00 0.00
Neuse River Location- Distance from Model Endpoint in Goldsboro (km)
; r . 9/17/2020 Dewberry" Neuse QUAL2K Model - Winter

Little Creek WRF, Clayton NC
NCO025453
Effluent
Nh3-N
BOD
Minimum
Monthly
Monthly
Temperature
AVG
Average
30
°C
mg/L
Jan-17
14
0.04
2.28
Feb-17
16
0.05
2.47
Mar-17
14
0.29
2.59
Apr-17
18
0.53
5.19
25
May-17
20
0.S1
2.73
Jun-17
22
0.17
2.00
Jul-17
24
0.17
2.45
Aug-17
24
0.41
2.00
Sep-17
24
0.22
2.00
Oct-17
19
0.03
2.00
20
Nov-17
18
0.19
2.00
Dec-17
15
0.58
2.00
Jan-18
12
1.91
2.00
Feb-18
15
0.62
2.04
Mar-18
15
0.12
2.69
'
is
Apr-18
15
0.36
2.31
a
May-18
19
0.06
2.00
E
Jun-18
23
0.2
2.00
Jul-18
24
0.02
2.00
Aug-18
25
0
2.00
Sep-18
26
0.01
2.00
10
Oct-18
20
0
2.00
Nov-18
17
0.14
2.00
Dec-18
15
0.03
2.00
Jan-19
14
0.53
2.08
Feb-19
15
0.01
2.00
Mar-19
15
1.12
2.74
5
Apr-19
15
0.66
1.05
May-19
21
0.26
2.84
Jun-19
24
0.1
4.21
Jul-19
25
0
2
Aug-19
25
0.03
2
Effluent Ammonia/ Temperature
Sep-19
23
0.01
p _ �w . ww ww.. w. a.. ww. ww w.. w. ww ww w• ww ww.... w_ ww. . _w w , a _.; w. w _.,..,ww ww sw ww. w.....w.. ,.w....• w. ww...wa w_ ww �,.. w.. w.._
2 .n, R m ao m ago oyo °' .O1i
Oct-19
21
0.16
2 c LL n>;- m n t; 'o o �' 'o w c LL `o. i s m a > c a > c
o i
Nov-19
18
0.49
zd a a' z o a i a'
2
Axis Title
Dec-19
15
0.4
2
Jan-20
14
0.07
2 ■ Effluent Minimum Tempe rature°C ■Nh3-N Monthly AVG mg/L
Feb-20
13
0.51
2
Mar-20
17
0.1
2.43
Apr-20
18
0.15
3.22
May-20
19
0.09
2.06
Jun-20
22
0.02

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
Director
James Warren
Wastewater Operations Superintendent
Town of Clayton
PO Box 879
Clayton, North Carolina
Dear Mr. Warren:
NORTH CAROLINA
Environmental Quality
September 4, 2020
Subject: Speculative Effluent Limits
Little Creek WRF
Permit No. NCO025453
Johnston County
Neuse River Basin
This letter provides speculative effluent limits for expansion to 6.0 and 10.0 MGD at the Little Creek WRF.
The Division received the speculative limits request in a letter dated August 7, 2020. Please recognize that
speculative limits may change based on future water quality initiatives, and it is highly recommended that,
if expansion does not proceed in the near future, the applicant verify the speculative limits with the
Division's NPDES Unit prior to any engineering design work.
Receiving Stream. The Neuse River has a stream classification of WS-IV; NSW at the proposed discharge
location. Waters with this classification have a best usage for all class C criteria: aquatic life propagation
and maintenance of biological integrity, wildlife, secondary recreation, and agriculture; as well as a water
supply source for drinking, culinary, and food -processing purposes. The Neuse River has a regulated flow
of 186 cfs for all permitted critical flows. The river at this location is not listed on the 303(d) list of impaired
waters; however, the entire river basin has been designated nutrient sensitive waters (NSW) because of
multiple algae impairments in the basin.
Based upon a review of information available from the North Carolina Natural Heritage Program Online
Map Viewer, there are not any Federally Listed threatened or endangered aquatic species identified within
a 5-mile radius of the proposed discharge location. If any threatened/endangered species are identified, it
is recommended that the applicant discuss the proposed project with the US Fish and Wildlife Service to
determine whether the proposed discharge location might impact such species.
Speculative Effluent Limits. Based on the Division's review of receiving stream conditions and water
quality modeling results, speculative limits for the proposed -expansions to 6.0 MGD and 10.0 MGD are
presented in Tables 1 and 2. A complete evaluation of these limits, limits and monitoring requirements for
metals and other toxicants, as well as potential instream monitoring requirements, will be conducted upon
receipt of a formal NPDES permit application. Some features of the speculative limit development include
the following:
North Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 1 1617 Mail Service Center I Raleigh, North Carolina 27b99 1617
919.707.9000

Speculative Effluent Limits
Little Creek WRF
Permit No. NCO025453
September 4, 2020
• BOD/NH3 Limits. Biochemical oxygen demand (BOD) and ammonia -nitrogen limits are based on
review of a 2020 QUALM model which demonstrated that the proposed limits are protective of the
dissolved oxygen water quality standard. If future modeling indicates that seasonal limits at the expanded
flows would be protective of water quality, and if such limits are justified per 15A NCAC 02B .0404(b),
the Division may develop seasonal limits for oxygen -consuming wastes.
Nutrients: Total Nitrogen (TN) and Total Phosphorus (TP) limits are in accordance with the Neuse River
nutrient management strategy (see 15A NCAC 213 .0700). TN mass limits are the sum of the Town's
initial allocation and its additional allocation and offset credit purchases, the last of which is pending
approval through permit modification (public noticed July 23, 2020). The additional allocation and
credits will continue to be held in reserve until expansion to 6.0 MGD. At that time, they will be activated,
and the resulting limit (63,842 lb/yr) will be equivalent to 3.5 mg/L TN at the permitted flow.
If the offset credits (31,816 lb/yr) are not purchased as planned, the TN limit will be the sum of the initial
and added allocations only. The resulting limit (32,0261b/year) would be equivalent to 1.75 mg/L at 6.0
MGD and 1.05 mg/L at 10 MGD. Even if the credits are purchased, the TN limit (63,842 lb/yr) would
only be equivalent to 2.10 mg/L at 10 MGD. In each of these cases, the required level of treatment is
beyond typical treatment capabilities, and the Town will have to demonstrate in its application for
expansion how it will achieve the required level of treatment.
The 2.0 mg/L TP limit applies as long as the permittee remains a member of a compliance association,
otherwise a limit of 1.0 mg/L Quarterly Average applies.
TABLE 1. Speculative Limits for Little Creek WRF (6.0 MGD)
Effluent Characteristic
Effluent Limitations
Monthly Average
Weekly Average
Daily Maximum
Flow
6.0 MGD
BOD5
5.0 m
7.5 m
NH3 asN
I.0m
3.0m
Dissolved Oxygen
Daily Average > 6.0 m
TSS
30.0 m
45.0 m
TRC if used for disinfection
28 L
TN Load'
63,8421bs/ ear
TP
2.0 mg/L Quarterly Average
Fecal coliform (geometric
mean
200/100 mL
400/100 mL
Chronic Toxicity, Pass/Fail
(Quarterly test
4 8%
Notes:
1. With the proposed credits, equivalent to a concentration of 3.5 mg/L.
Page 2 of 3

Speculative Effluent Limits
Little Creek WRF
Permit No. NCO025453
September 4, 2020
TABLE 2. Speculative Limits for Little Creek WRF (10.0 MGD)
Effluent Characteristic
Effluent Limitations
Monthly Average
Weekly Average
Daily Maximum
Flow
10.0 MGD
BOD5
5.0 m
7.5 m
NH3 asN
1.0m
3.0m
Dissolved Oxygen
Daily
Average >_ 6.0 m
TSS
30.0 m
45.0 m
TRC if used for disinfection
28 g/L
TN Load
63,842 lbs/ ear
TP
2.0 mg/L Quarterly Average
_T
Fecal coliform (geometric
mean)
200/100 mL
400/100 mL
Chronic Toxicity, Pass/Fail
(Quarterly test
7.7%
Notes:
1. With the proposed credits, equivalent to a concentration of 2.1 mg/L.
Engineering Alternatives Analysis (EAA). Please note that the Division cannot guarantee that an NPDES
permit for a new or expanding discharge will be issued with these speculative limits. Final decisions can
only be made after the Division receives and evaluates a formal permit application for the new/expanded
discharge. In accordance with North Carolina Administrative Code 15A NCAC 2H.0105(c), the most
environmentally sound alternative should be selected from all reasonably cost-effective options. Therefore,
as a component of all NPDES permit applications for new or expanding flow, a detailed engineering
alternatives analysis (EAA) must be prepared. The EAA must justify requested flows and provide an
analysis of potential wastewater treatment alternatives. A copy of the Division guidance for preparing the
EAA can be found at: httvs:Hdea.nc.gov/about/divisions/water-resources/water-(ivality-t)ermittinsJnydes-
wastewater/npdes-permitting=process
Should you have any questions about these speculative limits or NPDES permitting requirements, please
feel free to contact David Hill at david.hill(a)ncdenr.gov [phone].
Sincerely,
Michael E. Templeton, P.E.
Water Quality Permitting Section
Hardcopy: NPDES Permit File
Electronic Copy: NC Wildlife Resources Commission, Inland Fisheries,
[e-mail]
US Fish and Wildlife Service, [e-mail]
DWR/Water Quality Regional Operations/Raleigh
DWRBasinwide Planning, Ian McMillan
DWR/NPDES Server>Specs
Page 3 of 3

STATE OF NORTH CAROLINA
DEPARTMENT OF ADMINISTRATION
Roy Cooper
GOVERNOR
January 5, 2021
Jennifer Haynie
NC Department of Environmental Quality
Division of Water Infrastructure
1633 Mail Service Center
Raleigh, NC 27699-1633
Machelle Sanders
Secretary
Re: SCH File 9 21-E-4300-0789 Proposed project will expand the Town of Clayton's wastewater
treatment capacity in phases up to 10 MGD.
Dear Jennifer Haynie:
The above referenced environmental impact information has been reviewed through the State Clearinghouse
under the provisions of the North Carolina Environmental Policy Act.
Attached to this letter are comments made in the review of this document. Because of the nature of the
comments, it has been determined that no further State Clearinghouse review action on your part is needed
for compliance with the North Carolina Environmental Policy Act. The attached comments should be taken
into consideration in project development.
Sincerely,
CRYSTAL BEST
State Environmental Review Clearinghouse
Attachments
Mailing Address: Telephone: [phone] Location:
NC DEPARTMENT OF ADMINISTRATION Fax: [phone] WEST JONES STREET
1301 MAIL SERVICE CENTER COURIER: #51-01-00 RALEIGH, NORTH CAROLINA
RALEIGH, NC 27699-1301 Email: [e-mail]
Wehsite: www.ncadmin.nc.gov

FINDING OF NO SIGNIFICANT IMPACT
AND ENVIRONMENTAL ASSESSMENT
TOWN OF CLAYTON
WATER RECLAMATION FACILITY CAPACITY EXPANSION
RESPONSIBLE AGENCY: NORTH CAROLINA DEPARTMENT OF
ENVIRONMENTAL QUALITY
CONTACT: JON RISGAARD, SECTION CHIEF
STATE REVOLVING FUND SECTION
DIVISION OF WATER INFRASTRUCTURE
1633 MAIL SERVICE CENTER
RALEIGH, NORTH CAROLINA 27699-1633
[phone]
November 18, 2020

(This page intentionally left blank.)

FINDING OF NO SIGNIFICANT IMPACT
Article I, Chapter 113A of the North Carolina General Statutes requires an action to be subject to
the requirements of the North Carolina Environmental Policy Act (NCEPA) if it involves the
expenditure of public funds and if a potential impact is anticipated to the environment. The
project has been evaluated for compliance with the NCEPA and is determined to be a major
agency action, which will affect the environment.
Project Applicant: Town of Clayton, North Carolina
Project Description: The proposed project will expand the Town of Clayton's
wastewater treatment capacity in phases up to 10 MGD with the
following components: (1) a 6 million gallon per day (MGD)
five -stage biological nutrient removal water reclamation facility
(WRF) at the site of the Town's Neuse River pump station; (2)
conversion of the existing Little Creek WRF to a pump station
and forcemain to convey raw wastewater to the proposed WRF
site; (3) expansion of the existing East Clayton Industrial Area
(ECIA) pump station and construction of a new forcemain to
convey flows from the ECIA to the proposed WRF site; (4)
expansion of the existing Neuse River outfall; and (5)
construction of an access road from O'Neil Street to the proposed
WRF site with a parallel water main along the existing utility
transmission easement. The new WRF will initially operate at 6
MGD and will be expanded in phases to the full 10 MGD. The
Little Creek pump station will include pumps sized to meet the
initial peak and average daily flow requirement for 6 MGD and is
designed for expansion to accommodate future flows. The
forcemain will be sized for the full 10 MGD treatment capacity.
The Finding of No Significant Impact applies to the full
expansion to 10 MGD.
Project Number: CS370431-07
Project Cost: $153,000,000
Clean Water State $30,000,000 (Note that the Town has been awarded $30 million
Revolving Loan Fund: in CWSRF loans at this time and intends to apply for an
additional $60 million in future funding rounds)
Local Funds: $63,000,000 in operating revenue, bonds, and low -interest loans
The review process indicated that significant adverse environmental impacts should not occur if
mitigative measures are implemented, and an environmental impact statement will not be
required. The decision was based on information in the Engineering Report/Environmental
Information Document (ER/EID) submitted by the applicant and reviews by governmental
agencies. The attached Environmental Assessment (EA), prepared by the Division based on the
ER/EID, supports this action and outlines mitigative measures that must be followed. This
Finding of No Significant Impact (FONSI) completes the environmental review record, which is
available for inspection at the State Clearinghouse.

No administrative action will be taken on the proposed project for at least 30 days after
notification that the FONSI has been published in the North Carolina Environmental Bulletin.
Sincerely,
?e- /6�
Jon Risgaard, Section Chief
State Revolving Fund Section
Division of Water Infrastructure

ENVIRONMENTAL ASSESSMENT
A. Proposed Facilities and Actions
The proposed project will expand the Town of Clayton's wastewater treatment capacity in
phases to 10 MGD with the following components: (1) a 6 million gallon per day (MGD) five -
stage biological nutrient removal (BNR) water reclamation facility (WRF) at the site of the
Town's Neuse River pump station; (2) conversion of the existing Little Creek WRF to a pump
station and forcemain to convey raw wastewater to the proposed WRF site; (3) expansion of the
existing East Clayton Industrial Area (ECIA) pump station and construction of a new forcemain
to convey flows from the ECIA to the proposed WRF site; (4) expansion of the existing Neuse
River outfall; and (5) construction of an access road from O'Neil Street to the proposed WRF
site with a parallel water main along the existing utility transmission easement. The new WRF
will include an influent pump station, odor control, headworks for screening and grit removal,
flow equalization, five -stage BNR for nitrogen and phosphorus, supplemental carbon for
enhanced nitrogen removal, supplemental metal salts for backup and polishing of phosphorus
removal, cloth media (disc) tertiary filtration, UV disinfection, and cascade re -aeration. The new
WRF will initially operate at 6 MGD and will be expanded in phases to the full 10 MGD. The
Little Creek pump station will include pumps sized to meet the initial peak and average daily
flow requirement for 6 MGD and is designed for expansion to accommodate future flows. The
forcemain will be sized for the full 10 MGD treatment capacity. Solids treatment at the new
WRF will include thickening with rotary drum thickeners, 30-day aerated sludge holding, and
dewatering with screw press with solids to be disposed through contract composting and/or
landfill. This environmental assessment evaluates the environmental impacts associated with the
full expansion to 10 MGD.
FundingStatus: tatus: The estimated total cost for the project is $153,000,000. The Town is applying
for a Clean Water State Revolving Fund (CWSRF) loan of $30,000,000 and intends to apply for
an additional $60,000,000 in future CWSRF funding rounds. The remaining project costs will be
funded through a combination of local bonds, low -interest loans, and operating revenues.
B. Existing Environment
Topography and Soils. Clayton is the Piedmont Physiographic Province, with topography
gradually sloping toward the Coastal Plain and floodplains along streams. Elevations in the study
are range from 130 to 370 feet above mean sea level, with a range from 140 to 220 feet above
mean sea level at the proposed WRF site.
The dominant soil types in the project area are Wedowee sandy loam, Pacolet loam, Norfolk
loamy sand, and Cecil loam. Typical soils in floodplains and adjacent to streams are Wehadkee
and Chewacla. Soils throughout the project area have been impacted by development, grading
activities, and other soil disturbances.
Surface Water. The project area is located in the Upper Neuse River Subbasin (HUC 03020201).
Surface waters in project area include the Neuse River and Little Creek. Reaches of the Neuse
River in the project area are designated as Water Supply -IV and Water Supply-V and classified

as nutrient sensitive waters. Some portions of the Neuse River in the study area are impaired for
copper and zinc. Little Creek is classified as Class C and nutrient sensitive waters, with some
portions impaired for benthos.
Water Supply. The Town of Clayton purchases drinking water from Johnston County, which
draws water from the Neuse River.
C. Existing Wastewater Facilities
The Town provides wastewater conveyance and treatment services to residential users within
town limits and its extra -territorial jurisdiction as well as several industrial and commercial
customers. The Town owns and operates the 2.5 MGD Little Creek WRF, which discharges to
the Neuse River under NPDES Permit NC0025453. The Little Creek WRF was constructed in
the 1950s as a trickling filter plant and has undergone major upgrades and modifications since
then. In 1990, the plant was converted to an oxidation ditch facility, and a second oxidation ditch
was added in the mid-1990s. In the mid-2000s, anaerobic and anoxic zones were added. The
current biological treatment process includes two oxidation ditches with additional anaerobic and
anoxic ones for biological nutrient removal. Many of the processes at the WRF are in good
condition, but much of the mechanical and electrical equipment is approaching the end of its
useful life. Although the plant is permitted at 2.5 MGD, current operation is limited to
approximately 2 MGD due to treatment limitations and total nitrogen restrictions.
The Town has an additional 2.4 MGD in treatment capacity through regional partnerships: 1.4
MGD through the City of Raleigh's Neuse River Wastewater Treatment Plant (WWTP) and 1.0
MGD through Johnston County's WWTP. The Town has a pump station at the ECIA that to
conveys most of the flow from the ECIA to the County's WWTP, with the remainder going to
the Little Creek WRF. The Town sends a portion of its flow to Raleigh through the Neuse 2
pump station. These partnerships, combined with the Little Creek WRF, give the Town a total of
4.9 MGD in treatment capacity. In 2028, the Town's average daily flow was 3.2 MGD.
The Town's collection system includes almost 160 miles of gravity sewer lines and forcemains
and 28 pump stations with capacities ranging from 40 to 2,100 gallons per minute. Most of the
pump stations are in moderate to very good condition. The Town is working to replace older pipe
sections in the collection system as funding allows.
D. Need for Proposed Facilities and Actions
The Town's wastewater flow from residential, industrial, and commercial customers has been
growing. New housing units are being built to support the growing population, and facilities in
the ECIA are expanding. The Town is nearing 89 percent of its available capacity, with an
increase in flow from an ECIA facility expected in 2023 that will push the Town's wastewater
treatment demands close to the current capacity of 4.9 MGD before 2025. In addition, the Little
Creek WRFs' infrastructure is aging and susceptible to flooding. Historically, the Town has
utilized regional partnerships to delay major capital investments, but Johnston County and City
of Raleigh have indicated their intent to increase fees to treat the Town's wastewater, and the

County will no longer accept wastewater with characteristics exceeding domestic -strength limits
after 2023. The Town's contract with Raleigh expires in 2027. The Town anticipates higher -
strength wastewater from ECIA as well as more concentrated wastewater from residential users.
Without these partnerships, the Town will lose approximately 2.4 MGD of treatment capacity.
To address the growing residential, industrial, commercial demand for wastewater treatment and
the increasing costs and limitations associated with regional partnerships, the Town has
concluded that constructing a new WRF with a phased approach is the best solution to address
the Town's future wastewater needs. The proposed project will provide 6 MGD of initial
treatment capacity to meet the Town's short-term wastewater treatment needs, and will be
constructed to allow for incremental expansion up to 10 MGD to meet longer -term needs within
the planning period.
E. Alternatives Analysis
Alternative 1 — No -Action: This alternative would rely on existing treatment systems,
infrastructure, and regional interconnections with no significant increase in capacity. This
alternative was rejected because it does not meet the Town's need for increased wastewater
treatment capacity.
Alternative 2 — Construction of a new WRF and continued use of a surface water discharge:
Under this alternative, the Town would (1) build a new 6 MGD WRF with potential for future
expansion to 10 MGD with two sites being considered: the Neuse 2 Pump Station site
(Alternative 2a) and the ECIA Pretreatment Facility site (Alternative 2b); (2) continued operation
of the Little Creek WRF at 2 MGD until the new facility is online; (3) decommissioning that
facility and converting the site use to a new pump station to convey 3 MGD average daily flow;
(4) continued reliance on regional contracts through 2023; (5) retention of regional contracts as
backup after 2023 with minimization of flow to the County and Raleigh; (6) expansion of the
Little Creek WRF surface water discharge to the Neuse River at the Neuse 2 Pump Station site;
and (7) planning for future incremental expansion of the new facility to 10 MGD as flows
increase.
Alternative 2a Neuse 2 Pump Station Site: This site alternative would utilize a Town -owned
parcel, the Neuse 2 Pump Station site. The new facility would utilize five -stage BNR for
nitrogen and phosphorus, supplemental carbon for enhanced nitrogen removal, supplemental
metal salts for backup and polishing of phosphorus removal, cloth media (disc) tertiary filtration,
UV disinfection, and cascade re -aeration. Solids treatment at the new WRF will include
thickening with rotary drum thickeners, 30-day aerated sludge holding, and dewatering with
screw press. Use of this site would require construction of an access road and expanding the
existing outfall. The site is sufficiently sized to allow for construction of the WRF while
maintaining stream and property buffers and avoiding the floodplain along the Neuse River. The
public greenway infrastructure would remain available to the community. Connecting
infrastructure would be required. The site is centrally located to Town operations and expected
areas of development. Potential impacts to the Neuse River from an increased discharge would

be offset by purchase of nitrogen credits. The location, site size, and ability to minimize
environmental impacts make this site more desirable than the Alternative 2b site.
Alternative 2b ECIA Pretreatment Facility: This site alternative would construct the new WRF
adjacent to the R. Steven Biggs Regional Pretreatment Facility with conveyance system work
required to connect existing sewer infrastructure to the new WRF. The treatment process would
be similar to Alternative 2a except that diffused aeration would be used rather than cascade
aeration due to limited elevation changes at the site. This alternative would expand and use the
existing Neuse River outfall. The site is located near industrial and commercial customers but
not in an area expected to see significant residential growth and development. The site is
currently intended for future expansion of the pretreatment facility. Building at this site would
require using the athletic field adjacent to the pretreatment facility and may require additional
land acquisition. The site is unlikely to be large enough to accommodate future facility
expansions, and wetlands bordering the site would likely lead to greater environmental impacts
compared to the Alternative 2a site. For these reasons, Alternative 2b is rejected in favor of
Alternative 2a.
Alternative 2, using site Alternative 2a, meets the Town's needs for long-term resiliency,
expanded treatment capacity, control of treatment costs, and adaptability and phasing for longer
term needs and is the preferred alternative.
Alternative 3 — Expansion of Little Creek WRF and continued use of surface water discharge:
This alternative would rehabilitate the existing Little Creek WRF and expand its capacity to 6
MGD while adding biological nutrient removal to comply with Neuse River discharge limits.
Expansion of the existing Neuse River outfall capacity would be accomplished with a parallel
outfall. Additional infrastructure upgrades would be required, including the discharge forcemain,
pump station, gravity line to discharge location, and Neuse River discharge. Much of the growth
in the Town is projected to be on the Neuse River side rather than the Little Creek side, so a
significant expansion of the Neuse River 2 Pump Station would be required to send flow back
across town. The existing facility is on a steeply graded parcel with limited available space for
expansion without significant site work. The site is also partially located in the floodplain and
not well -suited for treatment infrastructure due to flooding risk. The site would likely involve
greater impacts to streams and buffers compared to the preferred alternative, and the permitting
process for work in the floodplain would pose a significant schedule risk. The complexity of
continuing to operate the existing plant during the expansion would present management
challenges. Site constraints limit the ability to provide cost-effective nitrogen removal with a
future expansion to meet longer term needs. These challenges make this alternative less desirable
than the preferred alternative, so it was rejected.
Alternative 4 — Continued use of Little Creek WRF and maximizing regional connections to
existing wastewater treatment: Under this alternative, the Town would expand existing contracts
with the County and the City of Raleigh while maintaining operation of the Little Creek WRF
with improvements to nitrogen removal to allow the WRF to operate at the permitted capacity of
2.5 MGD. This alternative would likely require construction of additional conveyance
infrastructure to the County or City's treatment facilities. Although this alternative is technically
feasible, the Town has not been able to reach cost-effective agreements with the County or City
E

that will provide the needed treatment capacity at a reasonable cost. This alternative also leaves
the Town vulnerable to flood impacts and reliability concerns associated with the Little Creek
WRF. For these reasons, this alternative was rejected.
Alternative 5 — Construction of a new WRF and use of land application: Similar to Alternative 2,
this alternative would build a new 6 MGD WRF with plans for future expansion to 10 MGD. For
purposes of analysis, the Neuse 2 Pump Station site was considered because the Town already
owns this land. This option would abandon the effluent discharge at the Neuse River and divert
effluent to suitable locations for spray irrigation. The alternative would include construction of
transmission infrastructure to convey effluent to land application site(s). Approximately 1,300
acres would be needed for land application. An advantage of this alternative is that nutrient
removal requirements for land application are less stringent than surface discharge to the Neuse
River, so certain elements of the WRF can be eliminated, including tertiary treatment, and
purchase of nitrogen credits would be reduced or eliminated. Environmental impacts would be
lower than the preferred alternative because of elimination of the surface water discharge, but
spray operation would have to be monitored to ensure that run-off does not impact surface
waters. Disadvantages of this alternative are increased pumping to convey effluent to land
application sites, higher O&M costs to operate spray fields, and feasibility is questionable due to
the high cost and limited availability of suitable land within ten miles of the proposed WRF site.
This alternative was rejected because these disadvantages outweigh the possible benefits of this
alternative.
Alternative 6 — Construction of a new WRF and implementation of larger -scale wastewater
reuse: Similar to Alternative 2, this alternative would build a new 6 MGD WRF with plans for
future expansion to 10 MGD. For purposes of analysis, the Neuse 2 Pump Station site was
considered because the Town already owns this land. The Town has a limited reuse program
available that provides a small amount of reuse water to a local golf course on a seasonal basis.
Two additional golf courses were identified with a total estimated demand of 0.15 MGD. The
Town reached out to industrial customers to investigate the possibility of interest in purchasing
reuse water, but these customers already have environmental sustainability programs in place to
conserve water use and, as a result, the amount of water purchased is minimal and leaves little
opportunity for purchase of reuse water. The limited potential demand for reuse water is not
enough for this alternative to be feasible. If feasible, this alternative would reduce environmental
impacts by eliminating a surface discharge; however, due to limited potential for large-scale
reuse of wastewater, this alternative was rejected because it is not a viable solution to the Town's
wastewater needs.
Alternative 7 — Construction of a new WRF with alternative secondary treatment process: This
alternative would construct a new 6 MGD WRF similar to Alternative 2 but using 4-stage BNR
with metal salt addition. Heavy metal salts would precipitate phosphorus to facilitate removal
during secondary treatment. This alternative would produce similar effluent as the preferred
alternative and slightly lower capital costs; however, this alternative was rejected because
chemicals used for phosphorus removal have the potential to vary in price, leading to uncertainty
of operational cost. The slightly higher capital cost for biological phosphorus removal is offset
by the potential for higher operating costs. In addition, there is an environmental benefit to
5

biological phosphorus removal compared to increased chemical use and delivery truck traffic
associated with chemical phosphorus removal.
Alternative 8 — Construction of a new WRF with alternative biosolids treatment str9M: This
alternative would construct a 6 MGD WRF similar to Alternative 2 but using a physical -
chemical thermal hydrolysis process (Lystek THP®) to produce Class a biosolids. Under this
alternative, the Town would contract with Lystek for management and disposal of biosolids. The
solids treatment process would use the same thickening and dewatering equipment as Alternative
2 and adds Lystek THP® reactors to produce biosolids that can be sold as fertilizer. This
alternative has similar environmental impacts as the preferred alternative and similar long-term
benefit but slightly higher initial costs. This alternative was rejected due to the higher cost, but
the Town could add this biosolids process in the future if desired.
Alternative 9 — Combination of Alternatives: The Town considered whether some combination
of alternatives might meet the project purpose and needs. A possible combination considered was
continuing operating the Little Creek WRF at current capacity and constructing a smaller 4 MGD
WRF at a second site. This combination would have a lower capital cost but would still require
investment in the Little Creek WRF to rehabilitate or replace aging equipment and maintain
operational functionality of this plant. Operational costs for two plants would be higher than one
plant. This combination was rejected because it does not offer any cost -savings or operation
efficiency compared to the preferred alternative.
Another combination that was considered was land applying effluent during the dry season and
discharging via the Little Creek WRF outfall during the wet season. This option would require a
large area for the land application at very high cost. The alternative would also still require
additional treatment to improve effluent quality for surface water discharge. This combination
was also rejected as it offers no cost or operational benefits compared to the preferred alternative.
Finally, a combination of land application and large-scale reuse (Alternatives 5 and 6) was
briefly considered but was rejected because the combination would be no more feasible than
either alternative implemented independently.
Alternative 10 — Decentralized System: This alternative would transition from the Town's
current strategy of collect wastewater at centralized points for transmission to the Little Creek
WRF and regional partners for treatment to a decentralized system. A decentralized approach
would not be efficient or effective for the Town. This alternative was deemed infeasible and
rej ected.
Alternative 11 — Optimum operation of existing facilities: This alternative would involve
optimizing operation of the Little Creek WRF. Normal maintenance at this facility is becoming
costly, and this alternative would require investment to replace or rehabilitate existing
infrastructure. Even with these investments, this alternative would not meet the Town's needs for
additional capacity and improved treatment to meet Neuse River discharge limits; therefore, this
alternative was rejected.
M

F. Environmental Consequences and Mitigative Measures
Topography and Soils: Construction activities will have some permanent impacts to topography
and soils for grading and fill, but these impacts are not expected to be significant. Approximately
42 acres will be disturbed for installation of linear infrastructure, and the WRF site will require
grading of approximately 25 acres. Grading and fill will occur at the upland areas of the project
site to avoid disturbance of the Neuse River floodplain, stream buffers, and wetlands. Soil loss
during construction will be minimized by following a DEQ-approved Erosion and Sedimentation
Control Plan. The Little Creek WRF site will be returned to existing grade and stabilized after
demolition. Installation of the transmission main and the Neuse River outfall will have temporary
impacts on floodplains. A Floodplain Development Permit will be obtained from the Town of
Clayton for this work. Secondary and cumulative impacts (SCI) are not expected to be
significant. The proposed expansion supports growth and development that is already in progress
rather than stimulating new development. Impacts from development and construction will be
mitigated through the Town's erosion and sedimentation control program, federal and local
floodplain development requirements, Neuse River watershed stream buffer rules, Johnston
County's stormwater management program, and the Town's stormwater design manual.
Land Use: Impacts to land use are not expected to be significant. The site to be used for the
proposed WRF already includes a pump station, but more of the site will be cleared to for the
WRF. Most of the access road and transmission main will be constructed within existing utility
easements. The Little Creek Pump Station will be constructed at the Little Creek WRF site. SCI
are not expected to be significant and will be mitigated through the Town's 2040 Comprehensive
Plan, Uniform Development Code, General Design Guidelines, and zoning processes. These
programs work together to plan for growth while maintaining open space and natural areas.
Wetlands: Significant impacts to wetlands are not anticipated. Impacts at the proposed WRF site
will avoid impacts to wetlands by doing most construction in the center portion of the site away
from wetlands, implementing an erosion and sedimentation control plan, maintaining a buffer
around the construction site to prevent soil from settling in wetlands, and maintaining the site's
existing natural forested buffers to minimize impacts from stormwater runoff. No wetlands are
present along the access road alignment or near the Little Creek pump station site. Five wetland
areas are located along the transmission route in an existing sewer easement that has been
maintained as herbaceous wetlands through regular mowing and maintenance. Wetland soils be
returned to these areas after construction to support wetland restoration, and all required permits
will be obtained. SCI related to future growth and development will be minimized through water
supply watershed protections, the Neuse River watershed stream buffer requirements, Johnston
County's stormwater management program, the Town's stormwater design manual, and
permitting programs.
Important Farmlands: Significant impacts to important farmlands are not anticipated.
Construction of the WRF, access road, and transmission lines will impact soils classified as
prime farmland and farmland of statewide importance but these lands are not in agricultural use.
SCI on farmlands are not expected to be significant and will be mitigated through the Town's
2040 Comprehensive Plan, Uniform Development Code, General Design Guidelines, and zoning
7

processes. These program work together to plan for growth while protecting agriculture in the
Town and County.
Public Lands and Scenic, Recreational, and State Natural Areas: Significant impacts to public
lands, scenic, recreational, or state natural areas are not expected. The Sam's Branch and Neuse
River greenways are adjacent to the WRF site and will be temporarily closed during
construction, but the greenways will be restored to existing conditions and reopened. Forested
buffers will limit visual and noise impacts from operation of the WRF. SCI are not expected to
be significant and will be mitigated through the Town's 2040 Comprehensive Plan, Uniform
Development Code, General Design Guidelines, and zoning processes. These program work
together to plan for growth while maintaining open space and natural areas.
Cultural Resources: Impacts to cultural and historic resources are not anticipated. The North
Carolina State Historic Preservation Office (SHPO) is not aware of any historic resources that
will be impacted by the project September 22, 2020, ER 20-1074). The Town's downtown
historic district will not be impacted by the project. SCI are not expected to be significant and
will be mitigated through the Town's 2040 Comprehensive Plan, Uniform Development Code,
General Design Guidelines, and zoning processes. The Town's historic downtown area is listed
on the National Register of Historic Places and protected through the Town's Downtown Master
Plan. Any large development activities will require investigation for potential historic value.
Air Quality: No significant impacts to air quality are anticipated. Construction may temporarily
impact air quality. Dust suppression will be used to minimize these impacts. Odor control is
proposed for the new WRF. An air quality permit will be obtained for the generator for the
propose WRF. Truck traffic to and from the site during operations is not expected to have a
significant impact on local air quality. SCI are not expected to be significant. Growth will follow
the Town's 2040 Comprehensive Plan, and the town has attracted industries that are not large air
polluters. Joint planning efforts have resulted in the County's Comprehensive Transportation
Plan to support development while limiting transportation -related SCI through careful planning.
Noise Levels: No significant permanent noise impacts are anticipated. Construction activities
will cause temporary increase in noise, but operation of the WRF will not change overall ambient
noise level in the area. The surrounding area includes industrial activities. The forested buffer
between the WRF and the public greenways will minimize noise for greenway users. will be
limited to normal daytime working hours. SCI are not expected to be significant. Growth will
follow the Town's 2040 Comprehensive Plan, which includes guidelines for noise control with
site planning. Joint planning efforts have resulted in the County's Comprehensive Transportation
Plan to support development while limiting transportation -related SCI through careful planning.
Water Resources: No significant impacts to water resources are anticipated. During construction
of the WRF, the sediment and erosion control plan and a stormwater management plan will be
implemented to minimize impacts from soil and pollution discharge into surface waters. The
proposed WRF will include flow equalization to limit potential for untreated discharge to the
Neuse River. Discharge into the Neuse River will increase from the permitted flow of 2.5 MGD
to 6 MGD initially, with future discharge of 10 MGD planned. Potential water quality impacts
have been evaluated for determination of permit limits for the expansion with modeling

conducted to determine treatment approaches needed to address seasonal variations of dissolved
oxygen and other parameters. The facility will be designed to reliably meet permit limits. The
Town will achieve the total nitrogen limit through treatment technologies and nitrogen credit
purchases, and nitrogen offset credits have been purchased to meet nutrient requirements of the
Neuse & Tar -Pamlico Nutrient Strategy Rules. Compliance with permit limits will protect water
quality in the Neuse River. A cofferdam system will be used for construction of the outfall to
minimize increases in turbidity. The additional effluent flow into the Neuse River will have an
increase of approximately three percent during low flows and is not a measurable increase during
normal and higher flows. This flow is not expected to lead to bank erosion or change the
hydrology of the river downstream of the outfall. Installation of the transmission main will
include crossings of ten perennial streams and six intermittent streams. Construction will likely
be open -cut but measures will be taken to reduce impacts with trenchless technology used where
feasible, and appropriate permits will be obtained. SCI related to future growth and development
will be minimized through water supply watershed protections, the Neuse River watershed
stream buffer requirements, stormwater management programs, and permitting programs.
Forest Resources: Significant impacts to forest resources are not expected. Approximately 24
acres of forest will be cleared for the WRF, and approximately 2.3 acres will be cleared for the
access road. SCI are not expected to be significant and will be mitigated through the Town's
2040 Comprehensive Plan, Uniform Development Code, General Design Guidelines, and zoning
processes. These program work together to plan for growth while maintaining forested and
natural areas.
Shellfish or Fish and Their Habitats: Significant impacts to shellfish, fish, and their habitats are
not expected. Compliance with the permit limits will protect aquatic life in the Neuse River. Soil
and erosion control measures and best management practices will minimize construction
impacts. Suitable habitat for the following protected species may be present: Dwarf
wedgemussel (Alasmidonta heterodon), Tar River spinymussel (Parvaspina steinstansana),
Yellow lance (Elliptio lanceolate), Atlantic pigtoe (Fusconaia masoni), Neuse River waterdog
(Necturus lewisi), and Carolina madtom (Noturus fuiosus). The biological determination
concluded that the project is not likely to adversely affect these species, and the U.S. Fish &
Wildlife Service concurs with the determination (email October 27, 2020). SCI related to future
growth and development will be minimized through water supply watershed protections, the
Neuse River watershed stream buffer requirements, stormwater management programs, and
permitting programs.
Wildlife and Natural Vegetation: No significant impacts to wildlife and natural vegetation are
expected. Construction activities may result in temporary impacts, and some permanent loss of
habitat may occur, but wildlife are expected to relocate to adjacent area with minimal effects.
Potential habitat for Michaux's sumac (Rhus michauxii) was identified, but a survey was
conducted during the growing season with no occurrences located. The Bald Eagle (Haliaeetus
laucocephalus) and Red -Cockaded Woodpecker (Picoides borealis) have been identified within
a mile of the project but are not expected to be impacted. The U.S. Fish & Wildlife Service
concurs with the determination of "no effect'' for these wildlife species. The town plans to create
a corridor of native vegetation along the greenway by reseeding after construction with a native
6

seed mix and will modify mowing protocol to avoid mowing during the flowering spring and
summer seasons to promote pollination, natural reseeding and long-term viability of this area.
Introduction of Toxic Substances: The project is not expected to introduce toxic substances into
the environment. During construction, best practices and regular offsite maintenance will be used
to minimize the risk of leaks or malfunctions from construction equipment. Construction wastes
are not expected to be toxic, and no hazardous wastes will be generated by operation of the
WRF. SCI are not expected to be significant and will be mitigated through the Town's 2040
Comprehensive Plan, Uniform Development Code, General Design Guidelines, and zoning
processes. These program work together to plan for growth while maintaining open space and
natural areas.
The U.S. Fish and Wildlife Service reviewed the proposed project and concurred with the
Town's determinations for listed species (October 27, 2020). The North Carolina Wildlife
Resources Commission, Natural Heritage Program, and DWR Raleigh Regional Office do not
object to the proposed project. The U.S. Army Corps of Engineers was consulted and did not
object to the project. The North Carolina Department of Natural and Cultural Resources is aware
of no historic resources that would be affected by the project (September 22, 2020, ER 20-1074).
G. Public Participation, Sources Consulted
The Town held a public meeting on November 16, 2020 and made the engineering
report/environmental information document available for review by the public through the
Town's website. The meeting included a presentation about the project and an opportunity for
public comment, with two comment received:
Comment: A representative from Gifols Therapeutics expressed support for the project
and noted that Grifols is undergoing expansion and will need additional wastewater
treatment capacity from the Town.
Response: Comment noted.
Comment: A resident expressed support for the WRF overall but concern about cost and
rate impacts to current residents. The resident asked if developers were contributing
project funding and recommended developers pay into a system development program to
reduce burden on existing residents
Response: The Town will consider the comment and noted that the Town must treat
ratepayers fairly.
The current user charge for a typical residential customer is $83.58 per month for water and
sewer service combined, based on consumption of 5,000 gallons per month. The proposed
project will increase the bill by $46.09 (approximately 55%), for a future combined bill of
$129.67 in FY 2025. The Town plans to implement rate increases over the next five years.
Sources consulted about this project for information or concurrence included:
10

1) Town of Clayton
2) City of Raleigh
3) Johnston County
4) North Carolina Department of Environmental Quality
-Wildlife Resources Commission
-Natural Heritage Program
-DEQ Raleigh Regional Office
-Division of Air Quality
-Division of Water Resources
-Division of Forest Resources
-Division of Environmental Assistance and Customer Service
-Division of Waste Management
5) North Carolina Department of Natural and Cultural Resources
6) North Carolina State Clearinghouse
7) North Carolina Department of Public Safety
8) U.S. Fish and Wildlife Service
9) U.S. Army Corps of Engineers
11

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