NC0023973_Fact Sheet_20180207

Fact Sheet
NPDES Permit No. NCO023973
Permit Writer/Email Contact: Gary Perlmutter, [e-mail]
Date: February 7, 2018
Division/Branch: NC Division of Water Resources/NPDES Complex Permitting
Fact Sheet Template: Version 09Jan2017
Permitting Action:
® Renewal
❑ Renewal with Expansion
❑ New Discharge
❑ 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:
Cape Fear Public Utility Authority (CFPUA) / M'Kean Maffitt
(Southside) WWTP
Applicant Address:
235 Government Center Drive, Wilmington, NC 28403
Facility Address:
3436 River Road, Wilmington NC 28412
Permitted Flow:
12.0 MGD, 16.0 MGD, 20.0 MGD, and 24.0 MGD
Facility Type/Waste:
MAJOR Municipal: 98.2 % Domestic, 1.8 % Industrial'
Facility Class:
Class 4
Treatment Units:
Bar Screens, Grit Removal, Clarifiers, Filtration, Anaerobic Digestion,
Aeration, Activated Sludge, Chlorine Disinfection, De -chlorination
Pretreatment Program (Y/1)
Yes
County:
New Hanover
Region
Wilmington
'Calculated from actual flows from March 2014 through March 2017 provided by PERCS in pretreatment
request form. Permitted industrial flow is 0.35 MGD or 2.9% of total permitted flow.
Briefly describe the proposed permitting action and facility background: The CFPUA has applied for
NPDES permit renewal, and submitted a renewal application dated July 1, 2016 for its Southside WWTP.
The facility serves a population of 62,851 residents and operates a pretreatment program with one
Page 1 of 14

Significant Industrial User (SIU): New Hanover Regional Medical Center (medical healthcare facility —
hospital).
2. Receiving Waterbody Information
Receiving Waterbody Information
Outfalls/Receiving Stream(s):
Outfall 001 — Cape Fear River
Stream Segment:
18-(71)
Stream Classification:
SC-PNA
Drainage Area (mi):
NA
Summer 7Q 10 (cfs)
Tidal
Winter 7Q10 (cfs):
Tidal
30Q2 (cfs):
Tidal
Average Flow (cfs):
Tidal
IWC (% effluent):
NA for RPA; for WET test: 3% at 12 MGD, 4% at 16 MGD,
5% at 20 MGD, 6% at 24 MGD
303(d) listed/parameter:
This segment is listed as impaired for Copper (3 µg/L, AL,
SW) and DO (5 mg/L, AL, SW) on the final 2014 list.
Subject to TMDL/parameter:
Statewide TMDL for Mercury
Subbasm/HUC:
03-06-17 / 03030005 Lower Cape Fear
USGS Topo Quad:
K 27 NW / Wilmington, NC
3. Effluent Data Summary
Effluent data for the period October 2013 through September 2017 is summarized in Table 1.
Table 1. Effluent Data Summary
Parameter
Units
Average
Max
Min
Limit 1
Flow
MGD
8.059
18.062
3.922
12.000
CBOD5
mg/L
5.9
36.0
3.0
MA = 25.0
WA = 40.0
CBOD5 removal
%
96.8
97.7
93.9
>— 85
Total Suspended Solids
mg/L
5.2
83.0
< 2.5
MA = 30.0
(TSS)
WA = 45.0
TSS removal
%
97.5
98.9
90.6
> 85
NH3-N
mg/L
19.8
35.3
3.1
Monitor
only
Enterococci
#/100 mL
6.0
> 600
< 1
MA= 35
(geometric mean)
WA = 276
Page 2 of 14

Total Residual Chlorine
(TRC)
µg2
14 5
47.0
< 10.0
DM= 13.0 z
Temperature
°C
21.8
29.0
12.0
Monitor
only
pH
SU
7.2
7.8
6.8
6.8-8.5
Dissolved Oxygen (DO)
mg/L
6.8
8.3
4.8
Monitor
only
Total Phosphorus
mg/L
3.6
5.0
0.9
Monitor
only
Total Nitrogen
mg/L
27.9
34.8
13.5
Monitor
only
Total Copper
µg/L
6.1
9.0
< 2
Monitor
only
' MA -Monthly Average, WA -Weekly Average, DM -Daily Maximum.
'TRC compliance level of 50 µg/L approved by EPA effective March 1, 2008 to address analytical
difficulties with TRC measurements.
4. Instream Data Summary
Instream monitoring may be required in certain situations, for example: 1) to venfy model predictions when
model results for instream DO are within 1 mg/L 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 mstream
concerns. Instream monitoring may be conducted by the Permittee, and there are also Monitoring Coalitions
established in several basins that conduct mstream 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 proposedfor thispermit
action: The current permit requires mstream monitoring for Dissolved Oxygen (DO) and Temperature.
While sampling is currently waived because the Permittee is a member of a monitoring coalition, data are
available for review. Samples were collected by the Lower Cape Fear River Program (monitoring coalition)
at stations B9820000, upstream of the WWTP's outfall, and B9795000, downstream of it. Instream data
evaluated from January 2013 through July 2016 revealed that samples were not collected on the same days
at the two locations, so direct upstream -downstream pairwise compansons could not be made. However,
averages and data ranges were similar between the two locations, and visual patterns of instream and
effluent DO concentrations and temperatures suggest that the effluent is not affecting the receiving
waterbody substantially. Dissolved oxygen values were seasonally low at both locations, below the water
quality standard of 5 mg/L, and is naturally occu=g. Temperature seasonal maxima were below the
standard of 32°C at both locations. No changes are proposed.
Is this facility a member of a Monitoring Coalition with waived instream monitoring (YIN) - YES
Name of Monitoring Coalition. Lower Cape Fear River Program (LCFRP)
Page 3 of 14

5. Compliance Summary
Summarize the compliance record with permit effluent limits (past 5 years): The facility reported no limit
violations other than numerous Total Residual Chlorine, all of which are below the compliance level of 50
gg/L, approved by the EPA in 2008.
Summarize the compliance record with aquatic toxicity test limits and any second species test results (past
5 years). The facility passed 21 of 22 quarterly WET tests, as well as all four 2" a species toxicity tests,
collected on 5/31/2015 (acute), 9/14/2015, (acute), 12/6/2015 (chronic), and 03/06/2016 (chronic). The
previous permit, issued in 2012, required acute toxicity testing; a modification issued in 2015 changed the
toxicity test type from acute to chronic, and added a requirement of four 2" species toxicity tests, acute or
chronic as specified in the permit.
Summarize the results from the most recent compliance inspection: The most recent facility inspection
(compliance evaluation), conducted on May 17, 2016, reported that the facility appeared to be well
maintained and operated. "Data collection and reporting very reliable historically."
6. Water Quality -Based Effluent Limitations (WQBELs)
Dilution and Mixing Zones
In accordance with 15A NCAC 2B.0206, the following streamflows are used for dilution considerations
for development of WQBELs: 1Q10 streamflow (acute Aquatic Life); 7Q10 streamflow (chronic Aquatic
Life; non-carcmogen HH); 30Q2 streamflow (aesthetics); annual average flow (carcinogen, W.
If applicable, describe any other dilution factors considered (e.g., based on CORMIX model results). The
permit modification issued in 2015 included a dilution factor of 33.1 (IWC = 3% at 12 MGD) for chronic
toxicity based on the 2001 Environmental Fluid Dynamics Cody (EFDC) model. A dilution study
(CORMIX model or equivalent) is required to be performed within one year after expansion to 16 MGD in
the existing permit. As of November 9, 2017, the expansion has been delayed.
In consideration of more stringent toxicant limits, in particular Copper, as determined via Reasonable
Potential Analysis using the High Quality Water safety factor for the receiving water's PNA designation
(see below), the option to perform a dilution study prior to expansion was discussed with the Permittee. It
was recognized that performing a dilution study at 12 MGD as well as at higher expansion flows may result
in adjusting toxicant limits based on more accurate dilution factors. The modeling requirement will be
modified to include an optional dilution study at 12 MGD and/or before expansion.
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 mstream DO water quality standard. Secondary TBEL limits (e.g., BOD = 30 mg/L
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- CBOD limits were
set based on a wasteload allocation (WLA) conducted in 1996. BOD limits for expansion phases (to 16, 20
and 24 MGD) were set to 5 mg/L summer/10 mg/L winter in the 2015 permit modification, based on BAT
for the receiving water, which is impaired for DO, as recommended by the in Chapter 30 of the 2005 Cape
Fear River Basmwide Water Quality Plan. Coincidentally, the receiving stream is also designated a Primary
Nursery Area (PNA), in which BOD limitations for new and expanded discharges of this High Quality
Water (HQW) shall be 5 mg/L per 15A NCAC 02B .0224. No changes are proposed.
Page 4 of 14

Ammonia and Total Residual Chlorine Limitations
Limitations for ammonia-N (NH3-N) 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 NH3-N 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 µg/L) and capped at 28 gg/L (acute impacts). Due to analytical issues, all TRC values
reported below 50 gg/L are considered compliant with the permit limit.
Describe any proposed changes to ammonia and/or TRC limits for this permit renewal: Wasteload
Allocation (WLA) calculations for TRC and NH3-N cannot be run because the receiving water experiences
tidal flow. The TRC limit, set at 13.0 gg/L per the EPA NRWQC for saltwater aquatic life protection, will
be maintained. Ammonia-N limits for saltwater protection can be determined from using EPA's Ambient
Water Quality Criteria for Ammonia (Saltwater) — 1989 guidance document (EPA 1989). Ambient
Monitoring data (Temperature, pH and Salinity spanning from October 2013 — July 2016) from Station
B9820000, located upstream of the facility's discharge, were entered to the Department of Oregon's
Saltwater Ammonia Calculator developed from the EPA's 1989 document. The calculator yielded Mean
Total NH3-N Acute and Chronic Criteria of 98.9 and 14.86 mg/L prior to dilution. The modified permit
issued in 2015 includes an IWC of 3% at 12 MGD; the Ammonia Criteria under dilution are 3297 mg/L
(acute) and 495 mg/L (chronic). No changes are proposed.
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 (RP), 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 %Z detection lunit 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.
An RPA was conducted on effluent toxicant data collected between October 2013 and September 2017 for
the current 12.0 MGD flow and the tiered 16.0, 20.0, and 24.0 MGD expansion flows. For the expansion
flows a %z safety factor is applied in recognition of the PNA of the receiving water (this is not applied to the
12 MGD flow as that predates the stream PNA designation). 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 Monitorm . 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: Copper (at all flows). To allow time and actions to meet Copper limits,
a four year compliance schedule will be added to the permit.
• Monitoring Oaly. 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.
o Total Phenolic Compounds (at expanded flows), to be added to the permit
Page 5 of 14

o Nickel monitoring will continue at all flows as part of the Pretreatment Long Term
Monitoring Program (LTMP) and shall be reported to the lower detection level of < 2
,ug/L.
o Silver is sampled quarterly as part of the LTMP, but may not be required due to the type
of SIU (hospital) input Quarterly monitoring will be added to the permit at all flows with
reporting to the lower detection level of < I ,ugIL.
o Zinc (at expanded flows), to continue as part of the LTMP
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 concentration: Arsenic,
Cadmium, Total Chromium, Cyanide, Lead, Molybdenum, Selenium (at all flows), Total Phenolic
Compounds (at 12 MGD only).
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: None
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: None.
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
Toxicity 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: Southside WWTP is a Mayor POTW that discharges complex
wastewater with chronic Ceriodaphma dubia WET limits at 3.0% effluent at 12 MGD, 4.0% at 16 MGD,
5.0% at 20 MGD, and 6.0% at 24 MGD, all to be sampled for quarterly per the 2015 permit modification.
(Ceriodaphnia dubia was introduced as the test organism in the 2004 permit modification at the Permittee's
request to change it from Daphnia duplex with no objection from the Division. The C. dubia WET test has
been maintained in the permit since that change.) A dilution study (CORMIX or equivalent model) is
required to be performed within one year after expansion to 16 MGD. Modification to the dilution study
requirement to include the current 12 MGD flow is addressed in the Dilution and Mixing Zones subsection
above; results may affect IWC levels at any or all flow scenarios.
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
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/L) 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/L) and/or if any individual value exceeds a TBEL value of 47 ng/L.
Page 6 of 14

Describe proposed permit actions based on mercury evaluation: An evaluation of mercury data was run
for all four flow scenarios, each with the same results (Table 2). Since no annual average mercury
concentration exceeded the WQBEL, and no individual mercury sample exceeded the TBEL, no limit is
required However, since the facility is > 2 MGD and quantifiable levels of mercury were present in the
effluent, a mercury minimization plan (MMP) is required. A MMP requirement will be added to the permit.
Table 2. Mercury Effluent Data Summary
Parameter
2014
2015 2016 2017
No. of Samples
1
11 8 3
Annual Average Conc. ng/L
3.2
4.0 2.8 1.8
Maximum Conc., ng/L
3.15
15.20 4.64 2.29
TBEL, ng/L
47
WQBEL, ng/L
25.0
Other TMDL/Nutnent Management Strategy Considerations
If applicable, describe any other TMDLs/Nutrient Management Strategies and their implementation within
this permit: There is no Nutrient Management Strategy for the Lower Cape Fear River Sub-basm. Total
Nitrogen and Total Phosphorus is monitored monthly per facility size (> 1 MGD) and river sub-basm (Cape
Fear) as specified in 15A NCAC 02B .0508. No changes are proposed.
A special condition (Special Condition A. (9)) is in the current permit that addresses historical permit limits
and calculated mass loads of BOD, TSS and NH3-N to be considered in developing wasteload allocations
resulting from future TMDLs or plant expansions This special condition will be maintained in the permit.
Other WQBEL Considerations
If applicable, describe any other parameters of concern evaluated for WQBELs: NA
If applicable, describe any special actions (HQW or OR W) this receiving stream and classification shall
comply with in order to protect the designated waterbody: The receiving stream, the Lower Cape Fear
River, was designated a primary nursery area (PNA) under 15A NCAC 03R.01 03(19)(a) in 1991, after the
facility expanded its flow to the current 12.0 MGD in 1989. Therefore, the PNA designation does not affect
limitations at the current flow rate. However, to protect this type of HQW, the following effluent limitations
as specified in 15A NCAC 02B .0224 for new or expanded discharges are as follows: BODS = 5 mg/L, TSS
= 10 mg/L, NH3-N = 2 mg/L and DO = 6 mg/L plus a safety factor of %z normal standard is included for
individual toxics. Coincidentally, equivalent BOD and DO limits are already in the current permit for
expanded phases, as well as lower NH3-N limits. TSS limits will be lowered to 10 mg/L and the safety
factor is introduced for the expansion phases.
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: A four-year compliance schedule
will be added to the permit to meet the Total Copper limits.
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)
Page 7 of 14

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/L
BODS/TSS for Monthly Average, and 45 mg/L for BODS/TSS for Weekly Average). YES
If NO, provide ajustification for alternative limitations (e g., waste stabilization pond). NA
Are 85% removal requirements for BODS/TSS included in the permit? YES
If NO, provide alust f cation (e g., wasre stabilization pond). NA
Industrials (if not applicable, delete and skip to next Section). 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 2B.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. NA
9. Anti -backsliding Review:
Sections 402(0)(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 (YES/NO). NO, but Special Condition A.
(10.) was inserted to the permit modification in 2015 that allows for less stringent BODS and NH3-N limits
under listed provisions. No changes are proposed.
If YES, confirm that anti -backsliding provisions are not violated Special Condition A. (10.) in the 2015
permit modification includes provisions for less stringent BODS and NH3-N limits so that anti -backsliding
provisions are not violated. This condition will be maintained in the permit.
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(0) of the Clean Water Act, and therefore anti -backsliding
prohibitions would not be triggered by reductions in monitoring frequencies.
Page 8 of 14

Reduced monitoring is in place for CBOD5, TSS, and Enterococci at 12.0 MGD; none are in place at the
higher flow tiers. Reductions were granted in September 2013 with 2/week for all three parameters.
Reduction in monitoring frequencies for these and NH3-N were received by the Division on September 9,
2013. The Division responded that all but NH3-N were eligible for review; NH3-N was not eligible as it was
a monitored toxicant of concern.
Table 3. Monitoring Frequency Reduction (MFR) Analysis and Assessment.
Parameter
Three-year
Monthly Average
Percent of Limit
Is Mean < 50%
Parameter
Average
Limit,
results > 200% of
of Limit?
CBOD5
5.7 mg/L
25.0 mg/L
23%
YES
TSS
4.9 mg/L
30 0 mg/L
16%
YES
Enterococci
(geometric mean)
7/100 mL
35/100 mL
20%
YES
' Greater than 20 results for Enterococci.
Review of effluent data from October 2014 — September 2017 for CBOD5, TSS, and Enterococci revealed
that they met criteria of 1) three-year average below 50% of the monthly average limit, 2) no more than 15
sampling results for CBOD5 and TSS were greater than 200% of their monthly average limits, and 3) no
more than 20 results for Enterococci were greater than 200% of its monthly average limit (Table 3).
Therefore, the reduced monitoring frequencies will be maintained for CBOD5, TSS, and Enterococci at
12.0 MGD permitted flow. No changes are proposed.
For instream monitoring, refer to Section 4.
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. Effective December 21, 2020, NPDES regulated facilities will be required to submit
additional NPDES reports electronically. This permit contains the requirements for electronic reporting,
consistent with Federal requirements.
12. Summary of Proposed Permitting Actions:
Current permit conditions and proposed changes are summarized in Table 4 for the current 12.0 MGD flow
rate and in Table 5 for higher tiered flow rates (16.0, 20.0 and 24.0 MGD) upon expansion phases.
Page 9 of 14
200% of
Are > 151 sample
Parameter
Monthly
Number of
results > 200% of
Are MFR'Criteria
Average Limit
Occurrences
Limit?
Met?
CBOD5
50.0 mg/L
0
NO
YES
TSS
60.0 mg/L
1
NO
YES
Enterococci
70/100 mL
12
NO
YES
(geometnc mean)
' Greater than 20 results for Enterococci.
Review of effluent data from October 2014 — September 2017 for CBOD5, TSS, and Enterococci revealed
that they met criteria of 1) three-year average below 50% of the monthly average limit, 2) no more than 15
sampling results for CBOD5 and TSS were greater than 200% of their monthly average limits, and 3) no
more than 20 results for Enterococci were greater than 200% of its monthly average limit (Table 3).
Therefore, the reduced monitoring frequencies will be maintained for CBOD5, TSS, and Enterococci at
12.0 MGD permitted flow. No changes are proposed.
For instream monitoring, refer to Section 4.
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. Effective December 21, 2020, NPDES regulated facilities will be required to submit
additional NPDES reports electronically. This permit contains the requirements for electronic reporting,
consistent with Federal requirements.
12. Summary of Proposed Permitting Actions:
Current permit conditions and proposed changes are summarized in Table 4 for the current 12.0 MGD flow
rate and in Table 5 for higher tiered flow rates (16.0, 20.0 and 24.0 MGD) upon expansion phases.
Page 9 of 14

Table 4. Current Permit Conditions and Proposed Changes until expansion above 12.0 MGD.
Parameter
Current Permit 1
Proposed Change
Basis for Condition/Change
Flow
12.0 MGD
No change
15A NCAC 2B .0505.
CBOD5
MA 25.0 mg/L
No change
WQBEL. Determined via WLA
WA 40.0 mg/L
conducted in 1996.
MA 30.0 mg/L
TBEL. Secondary treatment
TSS
WA 45.0 mg/L
No change
standards / 40 CFR 133 / 15A
NCAC 2B.0406.
NH3-N
Monitor 3/week
No change
15A NCAC 02B .0508.
Enterococci
MA 35 /100 mL
No change
WQBEL. State WQ standard, 15A
(geometric mean)
WA 276 /100 mL
NCAC 2B.0220.
WQBEL. EPA Nationally
TRC
DM 13.0 µg/L
No change
Recommended Water Quality
Criteria for Salt Water, 2006.
Temperature
Monitor daily
No change
WQBEL. State WQ standard, 15A
NCAC 2B.0508.
pH
6.8 — 8.5 SU
No change
WQBEL. State WQ standard, 15A
NCAC 2B .0200.
Dissolved Oxygen
Monitor daily
No change
15A NCAC 02B .0508.
Total Nitrogen
Monitor monthly
No change
15A NCAC 02B.0508.
Total Phosphorus
Monitor monthly
No change
15A NCAC 02B .0508.
MA 3.7 µg/L
Total Copper
Monitor quarterly
WA 5.8 µg/L
WQBEL. Reasonable potential to
Add four-year
exceed WQS found in RPA.
compliance schedule
Continue quarterly
Dissolved Metal Standards guidance
monitoring via
memo, 6/10/2016. RPA resulted in
Total Nickel
No requirement
Pretreatment LTMP;
Max. Predicted Cw < 50% of
sample to lower
Allowable Cw. All nondetects (14
detection level.
out of 16 results) > Allowable Cw.
Total Mercury
No requirement
Add mercury
mmimization plan
Statewide mercury TMDL, based on
(MMP)
plant size (> 2 MGD).
Add quarterly
Dissolved Metal Standards
monitoring; use
permitting guidance memo,
Total Silver
No requirement
"clean" sampling and
6/10/2016. RPA resulted in all non -
report to lower
detects. 14 of 16 non -detects < 2
detection level
µg/L > Allowable Cw (0.10 µg/L)
and P L < 1
Q ( µms)•
Page 10 of 14

I MGD — Million gallons per day, MA - Monthly Average, WA — Weekly Average, DM — Daily
Maximum.
Table 5. Current Permit Conditions and Proposed Changes at expansion phases above 12.0 MGD.
Parameter
Current Permit I
Proposed Change
Request to change from acute to
Whole Effluent
Chronic 7 -day pass/fail
chronic with IWC of 3% approved
Toxicity
test using Ceriodaphnia
No change
by DWR Aquatic Toxicity Branch in
dubia at 3.0% effluent
2015. IWC based on 33:1 dilution
Summer
MA 5.0 mg/L
from modeling conducted in 2001.
Effluent Pollutant
Three times per permit
No change
40 CFR 122
Scan
cycle
No change
for DO, as recommended in Ch. 30
Electronic
Electronic Reporting
Special Condition in
Update Electronic
Reporting Special
In accordance with EPA Electronic
Reporting
permit
Condition with current
Reporting Rule 2015.
TSS
MA 30.0 mg/L
language
WQBEL. HQW standards for PNAs
Dissolved Oxygen
Instream monitoring,
No change
Facility a member of a monitoring
provisionally waived
coalition.
Temperature
Instream monitoring,
No change
Facility a member of a monitoring
NH3-N
provisionally waived
No change
coalition.
I MGD — Million gallons per day, MA - Monthly Average, WA — Weekly Average, DM — Daily
Maximum.
Table 5. Current Permit Conditions and Proposed Changes at expansion phases above 12.0 MGD.
Parameter
Current Permit I
Proposed Change
Basis for Condition/Change
16.0 MGD, 20.0 MGD,
Flow
24.0 MGD expansion
No change
15A NCAC 2B.0505.
phases
Summer
MA 5.0 mg/L
WQBEL. BAT for the receiving
WA 7.5 mg/L
stream segment, which is impaired
BODS
Winter
No change
for DO, as recommended in Ch. 30
MA 10.0 mg/L
of the 2005 Cape Fear River
WA 15.0 mg/L
Basinwide Water Quality Plan.
TSS
MA 30.0 mg/L
MA 10.0 mg/L
WQBEL. HQW standards for PNAs
WA 45.0 mg/L
WA 15.0 mg/L
in 15A NCAC 02B .0224.
Summer
MA 1.0 mg/L
WQBEL. BAT for the receiving
WA 3.0 mg/L
stream segment, which is impaired
NH3-N
Winter
No change
for DO, as recommended in Ch. 30
MA 2.0 mg/L
of the 2005 Cape Fear River
WA 6.0 mg/L
Basinwide Water Quality Plan.
Enterococci
MA 35 /100 mL
No change
WQBEL. State WQ standard, 15A
(geometric mean)
WA 276 /100 mL
NCAC 2B.0220.
WQBEL. EPA Nationally
TRC
DM 13.0 gg/L
No change
Recommended Water Quality
Criteria for Salt Water, 2006.
Temperature
Monitor daily
No change
15A NCAC 2B .0508.
Page 11 of 14

pH
6.8 — 8.5 SU
No change
WQBEL. State WQ standard, 15A
NCAC 2B.0200.
WQBEL. Cape Fear River
Dissolved Oxygen
> 6 mg/L
No change
Basinwide Water Quality Plan to
—
protect the receiving stream, which
is impaired for DO.
Total Nitrogen
Monitor monthly
No change
15A NCAC 02B .0508.
Total Phosphorus
Monitor monthly
No change
15A NCAC 02B .0508.
Total Phenolic
No reasonable potential found, but
Compounds
No requirement
Monitor quarterly
max. predicted value > 50% of
allowable Cw.
MA 1 8 µg/L
WQBEL. Reasonable potential to
Total Copper
Monitor quarterly
WA 2.9 µg/L
exceed WQS found in RPA with %z
safety factor applied for PNA HQW.
Continue quarterly
Dissolved Metal Standards guidance
monitoring via
memo, 6/10/2016. Reasonable
Total Nickel
No requirement
Pretreatment LTMP;
potential found, all but 2 data were
sample to lower
nondetects < 10 µg/L; detects were
detection level.
below allowable Cw.
Add mercury
Statewide mercury TMDL, based on
Total Mercury
No requirement
minimization plan
plant size (> 2 MGD)
(MMP)
Add quarterly
Dissolved Metal Standards
monitoring; use
permitting guidance memo,
Total Silver
No requirement
"clean" sampling and
6/10/2016. RPA resulted in all non -
detects. 14 of 16 non -detects < 2
report to lower
µg/L > Allowable Cw (0.10 µg/L)
detection level.
and PQL (< 1 µg/L).
Continue quarterly
Dissolved Metal Standards guidance
Total Zinc
No requirement
monitoring via
memo, 6/10/2016. RP not found but
max. predicted value > 50% of
Pretreatment LTMP
allowable Cw.
Chronic 7 -day pass/fail
test using Ceriodaphnia
dubia at:°
• 4.0 /o effluent
IWC calculated from permitted
Whole Effluent
(16.0 MGD)
No change
expansion flows and calculated
Toxicity
• 5.0 %effluent
"S7Q10" of 595.2 cfs, performed in
(20.0 MGD),
2012.
• 6.0% effluent
(24.0 MGD) 2
Effluent Pollutant
Three times per permit
No change
40 CFR 122
Scan
cycle
Electronic Reporting
Update Electronic
Electronic
Condition m
Reporting Special
In accordance with EPA Electronic
Reporting
permitl
Condition with current
Reporting Rule 2015.
language
Page 12 of 14

Dissolved Oxygen
Instream monitoring,
No change
Facility a member of a monitoring
provisionally waived
coalition.
Temperature
Instream monitoring,
No change
Facility a member of a monitoring
provisionally waived
coalition.
'MGD — Million gallons per day, MA - Monthly Average, WA — Weekly Average, DM — Daily Maximum.
2 Tentative concentrations based on 33:1 dilution factor at 12.0 MGD, to be verified with CORMIX or
equivalent modeling no later than 12 months after completion of the 16.0 MGD expansion.
13. Public Notice Schedule:
Permit to Public Notice: 12/23/2017
Per 15A NCAC 2H .0109 & .0 111, 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):
Were there any changes made since the Draft Permit was public noticed (Yes/No): YES. Comments were
received from Dean Hunkele, DWR Wilmington Regional Office, and Beth Eckert, CFPUA. Dean Hunkele
had two questions: how could copper limits be lower than detection limits, and how are items 2 and 3
(annual initial and subsequent annual report in the Compliance Schedule) different, and should Item 3
indicate what "additional" actions since the previous report. DWR's response to Mr. Hunkele's questions
include an explanation that limits are based on science, not detection limits, and that NPDES must enforce
limits, even if they are below detection. Further, DWR acknowledges that the best the Permittee can do is
to sample to the lowest reporting level and show results below detection to demonstrate compliance.
DWR's response to the compliance schedule question resulted in revision in its wording (see below).
Beth Eckert provided three comments: a request for rewording in the TRC footnote, a request to insert a
special condition from the Northside WWTP to the Southside permit to avoid more stringent TSS limits in
the expansion phases, and a question how reclassification of the receiving stream would affect the Permittee
in terms of limits and stream impairment designations. DWR responses involved more investigation and
explanation, and resulted in no changes to the permit. DWR responses are attached.
If Yes, list changes and their basis below:
• Revised text in Copper Compliance Schedule, Step 3 to read: "Within three (3) years from the
effective date of the permit, the Permittee shall submit a report to the Division summarizing actions
taken during the previous year to achieve compliance with the final copper limitations. The actions
shall be in accordance with the Corrective Action Plan submitted and approved by DWR " Based
on comment from regional office.
15. Fact Sheet Attachments (if applicable):
Pretreatment Information Request Form and data summary
Effluent summary tables and charts
Instream summary tables and charts
Page 13 of 14

• Fina12014 NC 303(d) list, page 2
• Saltwater Ammoma Calculator
• WET Testmg and Self Monitoring sheet, page 122
• Compliance Evaluation Report, 05/7/2016
• RPA Spreadsheet Summanes (one for each flow scenario) and data
• Saltwater — Total Recoverable Metal Standards for Aquatic Life Protection table
• Mercury Data Statistics table and data
• CPFUA draft comments and DWR responses
Page 14 of 14