NC0025445_fact sheet_20160908

Fact Sheet
NPDES Permit No. NCOO25445
Permit Writer/Email Contact: David Hill, [e-mail]
Date: February 28,2017
Division/Branch:NC Division of Water Resources/NPDES Complex Permitting
Fact Sheet Template:Version 08Sept2016
Permitting Action:
X 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 2'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
City of Randleman/Randleman WWTP
204 South Main St.,Randleman,NC 27317
3475 Applewood Road,Randleman,NC 27317
1.745 MGD
MAJOR Municipal, 79%domestic&21%Industrial
Class III
Grit removal&bar screen,extended aeration basins, secondary
clarifiers,gas chlorination/dechlorination, cascade aerator,traveling
bridge vacuum tertiary filter, aerobic digesters
Yes
Randolph
Winston-Salem
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Briefly describe the proposed permitting action and facility background: The City of Randleman has
applied for NPDES permit renewal,and submitted a renewal application dated March 21,2016.
This facility serves a population of 4,332 residents and operates a pretreatment program with 2
Significant non-categorical Industrial Users(SIUs).
2. Receiving Waterbody Information:
Outfall 001-Deep River
17-(10.5)
C
180
5
12
23
171
35
No
No
Deep River/03030003
D19SE
3. Effluent Data Summary
Effluent data is summarized below for the period September 2012 through
February 2017.
Table. Effluent Data Summary
Flow MGD 0.8 2.2 0.2 1.745
BOD summer mg/1 2.6 18 <2 5.0
BOD winter mg/1 3.4 21 <2 10.0
NH3N summer mg/1 0.2 1.8 <0.1 2.0
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NH3N winter mg/1 0.3 1.5 <0.1 4.0
TSS mg/l 5.2 58 <1 30.0
pH SU 6.9 7.3 6 6-9
Temperature °C 23 33 10
DO mg/1 7.97 14 5.0 5.0
Conductivity umhos/cm 700 2010 25
TN mg/1 3.16 13.6 0.61
TP mg/1 2.54 13.7 0.25
Fecal Coliform #/100 ml 85 12000 <1 200
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/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
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 Data are only available through December 2013 (Stations B4800000 (downstream)
and B4770500(upstream)).
Instream data shows that the facility has little impact on instream dissolved oxygen (DO)with the
instream standard of 5.0 mg/L being maintained. See figure below.
Additional instream parameters are summarized in the following table. Direct comparison between
upstream and downstream values is made difficult as most samples between the stations were taken
on different days. However,the average, maximum,and minimum ranges for upstream and
downstream temperature are within the 2.8°C temperature differential water quality standard.
Parameter Average Max. Min
Conductivity-U(umhos/cm) 176.5 197 160
Conductivity-D 171.8 206 75
Tem erature-U(°C) 18.1 26.8 4.6
Temperature-D 19.9 29.6 7
U=upstream, D=downstream
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Figure. Upstream and Downstream DO.
Upstream VS Downstream Dissolved oxygen
12
10
s • • • .�
•
E 6 •
O t UP
0
4 •• DOWN
2
0
N N N N N N N M M M M M M M M M M M M
a-i a—I a-i ci a-i ci a-i ci ci a-i ci a-i ci a-i ci ci ci ci ci
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
c-I c-I c-I rl c-I a—I c-I rl ri c-I rl c-I rl c-I rl ri rl ri rl
l0 I" 00 M O -1 N c-I N M 'T Ln 00 M O -1 N
c-I ci c-I c-I c-I c-I
Is this facility a member of a Monitoring Coalition with waived instream monitoring(YIN): Yes
Name of Monitoring Coalition: Upper Cape Fear River Basin Association.
Parameters monitored: Temp,DO,pH,Conductivity, TSS,Turbidity
5. Compliance Summary
Summarize the compliance record with permit effluent limits (past 5 years): The facility had one total
residual chlorine violation in 2012 and two BOD violations in 2013.
Summarize the compliance record with aquatic toxicity test limits and any second species test results
(past 5 years): The facility passed 19 of 19 quarterly chronic toxicity tests, as well as all 4 second
species chronic toxicity tests.
Summarize the results from the most recent compliance inspection: The last facility inspection
conducted in 2016 reported that the facility had no compliance issues and suggested to issue permit
renewal.
6. Water Quality-Based Effluent Limitations (WQBELs)
Dilution and MixingZones
ones
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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/l for Municipals)may be appropriate if deemed more stringent based on dilution and
model results.
If permit limits are more stringent than TBELs, describe how limits were developed: Limitations for
BOD are based on a Streeter Phelps model(Level B)for instream DO protection. No changes are
proposed from the previous permit limits.
Ammonia and Total Residual Chlorine Limitations
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: There are no
proposed changes.
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/z detection limit for"less than"values; and 4) streamflows used for dilution
consideration based on 15A NCAC 213.0206. 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
2012 and February 2017.Pollutants of concern included toxicants with positive detections and
associated water quality standards/criteria and are the following: Arsenic,Cadmium, Chromium,
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Copper,Cyanide,Fluoride,Lead,Molybdenum,Nickel, Selenium, and Zinc. 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: Lead.
• 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: Copper.
• 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, Chromium,Cyanide,Fluoride,Molybdenum,Nickel,
Selenium, and Zinc.
• Summary of new limits added based on RPA: Lead.
• Summary of existing limits deleted based on RPA: 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.
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: This is a Major POTW, and a chronic WET limit at
35% effluent will continue at a quarterly frequency.
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/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
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Table. Mercury Data Statistics(Method 1631E)
2012 2013 2014 2015 2016
#of Samples 10 8 1 1 9
Annual Average,ng/L 12.8 8.9 6.0 3.3 3.0
Maximum Value,ng/L 26.30 26.10 6.0 3.3 4.58
TBEL, ng/L 47
WQBEL, ng/L 34.2
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 is<2 MGD, a mercury minimization plan(MMP)is not
needed
Other TMDL/Nutrient Management Strategy Considerations
If applicable, describe any other TMDLs/Nutrient Management Strategies and their implementation
within this permit: N/A
Other WQBEL Considerations
If applicable, describe any other parameters of concern evaluated for WQBELs: NA
If applicable, describe any compliance schedules proposed for this permit renewal in accordance with
1 SA NCAC 2K 0107(c)(2)(B), 40CFR 122.47, and EPA May 2007 Memo: A compliance schedule is
included for the new lead limit based on the recently adopted hardness-dependent metals standard.
The schedule requires the permittee to submit a Corrective Action Plan (CAP)within the first year
of the permit with annual updates of the CAP implementation. Total compliance with the new limit
will be required within five years of the permit effective date.
If applicable, describe any water quality standards variances proposed in accordance with NCGS 143-
215.3(e) and 1 SA 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/1 for BOD5/TSS for Weekly Average). YES
If NO, provide a justification for alternative limitations(e.g., waste stabilization pond).
Are 85%removal requirements for BOD5/TSS included in the permit? YES
If NO, provide a justification (e.g., waste stabilization pond). NA
8. Antidegradation Review (New/Expanding Discharge):
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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: NA
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(YES/NO): NO
If YES, confirm that antibacksliding provisions are not violated: NA
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 213.0500; 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.
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:
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Table. Current Permit Conditions and Proposed Changes
Flow MA 1.745 MGD No change 15A NCAC 2B .0505
BOD5 Summer: No change WQBEL. Based on protection of DO
MA 5 mg/1 standard. 15A NCAC 2B .0200
WA 7.5 mg/1
Winter: Model performed 12/4/1995
MA 10 mg/l
WA 15 mg/1
NH3-N Summer: No change WQBEL. Based on protection of
MA 2 mg/l State WQ criteria.
WA 6 mg/1
Winter:
MA 4 mg/l
WA 12 mg/l
TSS MA 30 mg/l No change TBEL. Secondary treatment
WA 45 mg/l standards/40 CFR 133 / 15A NCAC
2B .0406
Fecal coliform MA 200/100m1 No change WQBEL. State WQ standard, 15A
WA 400/100m1 NCAC 2B .0200
DO >5 mg/l No change WQBEL. State WQ standard, 15A
NCAC 2B .0200
pH 6—9 SU No change WQBEL. State WQ standard, 15A
NCAC 2B .0200
Total Nitrogen Monitor Only No change 15A NCAC 2B .0500
Total Phosphorus Monitor Only No change 15A NCAC 2B .0500
Total Copper Quarterly Monitoring No change WQBEL. State WQ standard, 15A
NCAC 2B .0200&reasonable
potential analysis results.
Total Lead Quarterly Monitoring 16 µg/L MA WQBEL. State WQ standard, 15A
381 µg/L DM NCAC 2B .0200 and reasonable
potential to violate State WQ
standard
Conductivity Monitor 3/week No change 15A NCAC 2B .0500
TRC 28 µg/L DM No change WQBEL. State WQ standard, 15A
NCAC 2B .0200
Temperature Monitor Only No change 15A NCAC 2B .0200& 15A NCAC
2B .0500
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Total Cyanide Monitor Only Removed WQBEL. 15A NCAC 2B .0200 and
no reasonable potential to violate
State WQ standard
Total Zinc Monitor Only Removed WQBEL. 15A NCAC 2B .0200 and
no reasonable potential to violate
State WQ standard
Toxicity Test Chronic limit, 35% No change WQBEL. No toxics in toxic
effluent amounts. 15A NCAC 2B .0200 &
15A NCAC 213 .0500
Effluent Pollutant Three per permit cycle No change 40 CFR 122
Scan
Hardness No requirement Quarterly monitoring 15A NCAC 2B .0200. Revised water
quality standards and EPA
guidelines on hardness-dependent
metals
Electronic No requirement Add Electronic In accordance with EPA Electronic
Reporting Reporting Special Reporting Rule 2015.
Condition
MGD—Million gallons per day,MA- Monthly Average,WA—Weekly Average,DM—Daily Max
13. Fact Sheet Addendum (if applicable):
Were there any changes made since the Draft Permit was public noticed(Yes/No): YES
If Yes, list changes and their basis below: At the facility's request, effluent temperature monitoring
was reduced from daily to 3/week consistent with their previous permit. Temperature is not
currently water quality limited and the frequency is consistent with 15A NCAC 2H .0508.The table
in section A. (1.)was reformatted for greater clarity in monitoring requirements. Specific dates
were set in the compliance schedule(section A. (5.)with respect to the permit effective date
14. Fact Sheet Attachments (if applicable):
• RPA Spreadsheet Summary
• Dissolved Metals Implementation/Freshwater or Saltwater
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