NC0004944_Fact Sheet_20190401

Fact Sheet
NPDES Permit NC0004944
Permit Writer (email address): Sergei Chernikov, Ph.D. ([e-mail])
Date: October 1, 2018
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)
1. Basic Facility Information
Facility Information
Applicant/Facility
Salisbury Investments I, LLC / Edge Water Treating, LLC
Name:
(formerly DuraFiber Technologies, Inc.; Performance Fibers
Operations, Inc.; INVISTA, S.a.r.l; KOSA; and Hoechst
Celanese)
Applicant Address:
5320 Old Pineville Rd., Charlotte, NC 28217
Facility Address:
7401 Statesville Blvd., Salisbury, NC 28147
Permitted Flow:
2.305 MGD
Facility Type/Waste:
MAJOR Industrial; 10% domestic, 90% industrial
Facility Class:
Class WW-3
Treatment Units:
• Bar screen and grit removal;
• Chlorine contact (sanitary wastes)
• Two covered equalization tanks;
• Three aeration basins (one out -of —service);
• Anaerobic groundwater treatment unit (out -of -service);
• Three secondary clarifiers (one out -of -service);
• Three aerated polishing ponds;
• Chemical additional facilities;
• Aerobic digestion;
• Sludge dewatering; and
• Instrumented flow measurement.
Pretreatment Program?
N/A
County:
Rowan
Region
Mooresville
Edge Water Treating, LLC is a proposed Centralized Waste Treatment (CWT) facility. As such,
40 CFR 437 Subpart D Federal guidelines are applicable. This is a former OCPSF facility
Page 1 of 22

Fact Sheet
NPDES Permit NC0004944
that recently discontinued production at this site. The facility will accept numerous waste
stream from different clients, the limits in the permit were calculated based on the EPA
development documents for CWT facilities that contained the list of pollutants and their
concentrations typically present in CWT treatment plants.
The facility was originally permitted in 1980 at a flow of 1.2 MGD. In 1992 a flow
modification request accompanied the permit renewal application. At that time, Hoechst
Celanese requested an increase in total flow from 1.2 MGD to 2.305 MGD to accommodate
the discharge of remediated groundwater associated with a RCRA site stabilization plan.
During the same period, USGS was requested to evaluate critical low flows and the
average flow of the receiving stream. The flows provided by USGS were half what they
had been when the permit was developed at 1.2 MGD. DWQ modeled the wastewaters in
1993 and established water quality based limits for BOD and ammonia nitrogen.
The facility requested 3 tiers based on the different flow volumes to allow for potential
growth. The facility has a separate stormwater permit.
2. Receiving Waterbody Information:
Receiving Waterbody Information
Outfalls/Receiving Stream(s):
001 / North Second Creek
Stream Segment:
12-108-21
Stream Classification:
C
Drainage Area (mi2):
116
Summer 7Q10 (cfs)
6.9
Winter 7Q10 (cfs):
23
30Q2 (cfs):
Average Flow (cfs):
116
IWC (% effluent):
34
303(d) listed? / parameter:
No
Subject to TMDL? / parameter:
No
Subbasin/HUC:
Yadkin -Pee Dee 03-07-06; 03040102
USGS Topo Quad:
Salisbury, N.C.
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Fact Sheet
NPDES Permit NC0004944
3. Effluent Data Summary
Effluent data is summarized below for 2011-2016. However, the facility has
discontinued production of the OCPSF materials and this summary might not be
representative of the future discharges.
Table. Effluent Data Summary
Parameter
Units
Average
Max
Min
Permit
Limit
Flow
MGD
1.189
2.188
2.305
BOD
pounds/day
9.9
73.0
60.0/149.0
NH3N
pounds/day
1.8
77.0
23.0/46.0
TSS
pounds/day
31.0
246.0
96.0/294.0
pH
SU
8.8
6.4
6.0-9.0
Temperature
°C
25.0
7.0
DO
mg/l
14.4
5.9
>5.0
TN
pounds/day
1.5
2.3
TP
pounds/day
0.5
0.9
Fecal Coliform
#/100 ml
14.4
240
MA -Monthly Average, WA -Weekly Average, DM -Daily Maximum
4. Instream Data Summary
The facility discharges to North Second Creek in the Yadkin -Pee Dee River Basin. It is not listed
on the 303(d) list of impaired waters. As a member of the Yadkin Pee Dee River Basin Association
(YPDRBA), Edge Water Treating collects instream data at two stations. The upstream station,
Q4030000, is located on Second Creek at Highway 81 and Sherrills Ford Road upstream of both
Edge Water Treating and the Second Creek WWTP. The downstream station, Q4165000, is located
on Second Creek at US 61 near Salisbury and is downstream of both facilities.
This permit requires instream monitoring for temperature, conductivity, and dissolved oxygen. The
monitoring is provisionally suspended due to the facility's membership in the YPDRBA.
Review of instream data for the period 1/2006 — 12/2010 indicates that the dissolved oxygen
standard of 5 mg/1 and pH standard of 6.0 — 9.0 were maintained, and there were no apparent
differences between upstream and downstream stations.
Is this facility a member of a Monitoring Coalition with waived instream monitoring (YIN). YES
Name of Monitoring Coalition: Yadkin Pee Dee River Basin Association
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Fact Sheet
NPDES Permit NC0004944
5. Compliance Summary
The facility reported 1 NH3-N limit violation in 2012.
The facility passed 20 of 20 quarterly chronic toxicity tests.
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 -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):
N/A
If applicable, describe any mixing zones established in accordance with 15A NCAC 2B.0204(b):
N/A
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.
If permit limits are more stringent than TBELs, describe how limits were developed: water quality
based limits for BOD were determined for the 1993 permit application based on DWQ's draft
wasteload allocation dated May 24, 1993. DWQ's modeling analysis predicted a minimum DO of 5
mg/L based on a discharge of 1.574 MGD, 131 pounds/day BOD5, and 17 pounds/day ammonia
nitrogen. The modeling used a typical CBOD decay rate and a CBOD/BOD ratio. These values
were adjusted using site specific information, and a Monthly Average BOD limit of 150 pounds/day
was established for the summer months with ammonia nitrogen limits of 23 pounds/day monthly
average and 46 pounds/day daily maximum. BOD limitations determined using the technology
based effluent guidelines were used to set winter BOD limitations. However, given the current
level of production and the decreased process and sanitary flows BOD limitations for this permit
were limited by the technology based effluent guidelines.
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 µg/L) and capped at 28 µg/L (acute impacts). Due to analytical issues,
all TRC values reported below 50 µg/L are considered compliant with their permit limit.
Limitations for ammonia were based on a model. The limits were not changed in this permit
renewal.
Page 4 of 22

Fact Sheet
NPDES Permit NC0004944
Reasonable Potential Analysis (RPA) for Toxicants
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 1/ 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 from the EPA
development documents for CWT facilities. The RPA was conducted for 3 different tiers, please see
attached. 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. In some cases, these limits were substituted
with the production based limits (TBELS) if the TBELS were more stringent: Total
Arsenic, Total Cadmium, Total Chlorinated Phenolic Compounds (based on 2,4,6
trichlorophenol), Total Phenolic Compounds, Trivalent Chromium, Hexavalent Chromium,
Total Copper, Total Lead, Total Nickel, Total Selenium, Total Silver, Total Zinc, Total
Antimony, Carbazole, Bis(2-ethylhexyl) phthalate, Butylbenzyl phthalate, and
Fluoranthene.
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 Industrial Facility and a chronic WET
limit at 34.0% effluent will continue on a quarterly frequency (2.305 MGD flow). Two additional
tiers for 0.5 MGD (10% effluent) and 1.0 MGD (18% effluent) were added to the permit.
Page 5 of 22

Fact Sheet
NPDES Permit NC0004944
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 pounds/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/l
Based on the potential mercury concentration of 17 µg/L (extracted from the EPA development
document), the TBEL of 47 ng/L was added to the permit.
Other TMDL/Nutrient Management Strategy Considerations
If applicable, describe any other TMDLs/Nutrient Management Strategies and their
implementation within this permit: NA.
Other WQBEL Considerations
If applicable, describe any other parameters of concern evaluated for WQBELs: N/A.
If applicable, describe any special actions (HQW or ORW) this receiving stream and classification
shall comply with in order to protect the designated waterbody: N/A.
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: N/A
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: N/A
7. Technology -Based Effluent Limitations (TBELs)
Industrials (if not applicable, delete and skip to next Section)
Describe what this facility produces: CWT wastewater treatment.
List the federal effluent limitations guideline (ELG) for this facility: 40 CFR 437 Subpart D for
New Sources.
If the ELG is based on production or flow, document how the average production/flow value was
calculated: This ELG is based on flow. Limits were calculated for 3 tiers: 0.2285 MGD, 0.5285
MGD, and 1.2335 MGD. Please see attached.
For ELG limits, document the calculations used to develop TBEL limits: Please see attached.
If any limits are based on best professional judgement (BPJ), describe development: N/A
Document any TBELs that are more stringent than WQBELs: N/A
Document any TBELs that are less stringent than previous permit: N/A
Page 6 of 22

Fact Sheet
NPDES Permit NC0004944
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: N/A
9. Antibacksliding Review:
Sections 402(o)(2) and 303(d)(4) of the CWA and federal regulations at 40 CFR 122.44(l) 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 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 A. (1.).
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 Permitting Actions:
Current Permit Conditions and Changes from the previous permit. Two
additional tiers were added to the permit. The CWT TBELS were compared to
the WQBELS and the more stringent limits were used.
Page 7 of 22

Fact Sheet
NPDES Permit NC0004944
Tier I (0.5 MGD), New Tier
Parameter
Current Permit
Proposed Change
Basis for
Condition/Change
Flow
No requirement
0.5 MGD
15A NCAC 2B .0505
BOD5
No requirement
MA 101.0 lb/day
MA-TBEL, based on 40 CFR
DM 300.0 lb/day
437 Subpart D NSPS.
DM -based on WQ model.
NH3-N
No requirement
MA 23.0 lb/day
WQBEL. Based on the WQ
DM 46.0 lb/day
model.
TSS
No requirement
MA 21.5 lb/day
TBEL, based on 40 CFR 437
DM 56.4 lb/day
Subpart D NSPS.
Oil and Grease
No requirement
MA 72.4 lb/day
TBEL, based on 40 CFR 437
DM 242.0 lb/day
Subpart D NSPS.
Fecal coliform
No requirement
MA 200 /100mL
WQBEL. State WQ standard,
DM 400 /100mL
15A NCAC 2B .0200
DO
No requirement
> 5 mg/L
WQBEL. State WQ standard,
15A NCAC 2B .0200
pH
No requirement
6.0 — 9.0 SU
WQBEL. State WQ standard,
15A NCAC 2B .0200
DO, Temp.,
No requirement
Instream monitoring.
15A NCAC 2B .0500
Conductivity,
Total Mercury
No requirement
47.0 ng/L - annual
Based on statewide TMDL
average.
implementation strategy.
Toxicity Test
No requirement
Chronic limit, 10.0%
WQBEL. No toxics in toxic
effluent.
amounts. 15A NCAC 2B.0200
and 15A NCAC 2B.0500
CWT
No requirement
Add limits.
40 CFR 437 Subpart D NSPS
parameters
Chromium III
No requirement
MA 1,166 µg/L
Limits are based on RPA.
DM 7,609 µg/L
Chromium VI
No requirement
MA 108.9 µg/L
Limits are based on RPA.
DM 134.5 µg/L
Total Hardness
No requirement
Monitoring upstream
Needed to implement
and in the effluent
dissolved metal standards.
added
WQBEL. State WQ standard,
15A NCAC 2B .0200.
MGD — Million gallons per day, MA - Monthly Average, WA — Weekly Average, DM — Daily Max
Page 8 of 22

Fact Sheet
NPDES Permit NC0004944
Tier II (1.0 MGD), New Tier
Parameter
Current Permit
Proposed Change
Basis for
Condition/Change
Flow
No requirement
1.0 MGD
15A NCAC 2B .0505
BOD5
No requirement
MA 150.0 lb/day
WQBEL. Based on WQ
DM 300.0 lb/day
model.
NH3-N
No requirement
MA 23.0 lb/day
WQBEL. Based on the WQ
DM 46.0 lb/day
model.
TSS
No requirement
MA 49.8 lb/day
TBEL, based on 40 CFR 437
DM 130.5 lb/day
Subpart D NSPS.
Oil and Grease
No requirement
MA 167.5 lb/day
TBEL, based on 40 CFR 437
DM 559.8 lb/day
Subpart D NSPS.
Fecal coliform
No requirement
MA 200 /100mL
WQBEL. State WQ standard,
DM 400 /100mL
15A NCAC 2B .0200
DO
No requirement
> 5 mg/L
WQBEL. State WQ standard,
15A NCAC 2B .0200
pH
No requirement
6.0 — 9.0 SU
WQBEL. State WQ standard,
15A NCAC 2B .0200
DO, Temp.,
No requirement
Instream monitoring.
15A NCAC 2B .0500
Conductivity,
Total Mercury
No requirement
47.0 ng/L - annual
Based on statewide TMDL
average.
implementation strategy.
Toxicity Test
No requirement
Chronic limit, 18.0%
WQBEL. No toxics in toxic
effluent.
amounts. 15A NCAC 2B.0200
and 15A NCAC 2B.0500
CWT
No requirement
Add limits.
40 CFR 437 Subpart D NSPS
parameters
Chromium III
No requirement
MA 641.8 µg/L
Limits are based on RPA.
DM 4,257 µg/L
Chromium VI
No requirement
MA 60.0 µg/L
Limits are based on RPA.
DM 75.3 µg/L
Total Hardness
No requirement
Monitoring upstream
Needed to implement
and in the effluent
dissolved metal standards.
added
WQBEL. State WQ standard,
15A NCAC 2B .0200.
MGD — Million gallons per day, MA - Monthly Average, WA — Weekly Average, DM — Daily Max
Page 9 of 22

Fact Sheet
NPDES Permit NC0004944
Tier III (2.305 MGD)
Parameter
Current Permit
Proposed Change
Basis for
Condition/Change
Flow
2.305 MGD
No change
15A NCAC 2B .0505
BOD5
MA 60.0 lb/day
MA 150.0 lb/day
MA -based on WQ model. The
DM 149.0 lb/day
DM 300.0 lb/day
DM-TBEL, based on 40 CFR
437 Subpart D NSPS.
NH3-N
MA 23.0 lb/day
MA 23.0 lb/day
WQBEL. Based on the WQ
DM 46.0 lb/day
DM 46.0 lb/day
model.
TSS
MA 96.0 lb/day
MA 49.8 lb/day
TBEL, based on 40 CFR 437
DM 294.0 lb/day
DM 130.5 lb/day
Subpart D NSPS.
Oil and Grease
No requirement
MA 167.5 lb/day
TBEL, based on 40 CFR 437
DM 559.8 lb/day
Subpart D NSPS.
Fecal coliform
MA 200 /100mL
MA 200 /100mL
WQBEL. State WQ standard,
DM 400 /100mL
DM 400 /100mL
15A NCAC 2B .0200
DO
> 5 mg/L
> 5 mg/L
WQBEL. State WQ standard,
15A NCAC 2B .0200
pH
6.0 - 9.0 SU
6.0 - 9.0 SU
WQBEL. State WQ standard,
15A NCAC 2B .0200
DO, Temp.,
Instream monitoring.
Instream monitoring.
15A NCAC 2B .0500
Conductivity,
Total Mercury
No requirement
47.0 ng/L - annual
Based on statewide TMDL
average.
implementation strategy.
Toxicity Test
Chronic limit, 34.0%
Chronic limit, 34.0%
WQBEL. No toxics in toxic
effluent.
effluent.
amounts. 15A NCAC 2B.0200
and 15A NCAC 2B.0500
CWT
No requirement
Add limits.
40 CFR 437 Subpart D NSPS
parameters
Chromium III
No requirement
MA 1,166 µg/L
Limits are based on RPA.
DM 7,609 µg/L
Chromium VI
No requirement
MA 108.9 µg/L
Limits are based on RPA.
DM 134.5 µg/L
Total Nitrogen
No requirement
90.41b/day - annual
Limits are added to freeze
average
nitrogen load and prevent
deterioration of the nutrient
impaired stream.
Page 10 of 22

Fact Sheet
NPDES Permit NC0004944
Total Hardness
No requirement
Monitoring upstream
Needed to implement
and in the effluent
dissolved metal standards.
added
WQBEL. State WQ standard,
15A NCAC 2B .0200.
MGD — Million gallons per day, MA - Monthly Average, WA — Weekly Average, DM — Daily Max
All tiers also contain an Electronic Reporting Special Condition based on the EPA Electronic
Reporting Rule of 2015.
13. Fact Sheet Addendum (if applicable):
Were there any changes made since the Draft Permit was public noticed (Yes/No): No
14. Fact Sheet Attachments (if applicable):
• RPA Spreadsheet Summary
• CWT calculation
15. Comparison of TBELs and WQBELs
Tier I (0.5 MGD)
TBEL's are based on a Process flow of 0.2285 MGD
Parameter
WQBEL
TBEL
Permit Limit
BOD5
MA 150.0 lb/day
MA 101.0 lb/day
MA 101.0 lb/day
DM 300.0 lb/day
DM 310.6 lb/day
DM 300.0 lb/day
NH3-N
MA 23.0 lb/day
N/A
MA 23.0 lb/day
DM 46.0 lb/day
DM 46.0 lb/day
Cr(III)
MA 1,166 µg/L
N/A
MA 21.6 µg/L
DM 7,609 µg/L
DM 74.7 µg/L
Cr(III)/Total Cr ratio:
Calculations are based on
the Cr(III)/Total Cr ratio
MA 0.91
and TBEL Total Cr limit
DM 0.98
Cr(VI)
MA 108.9 µg/L
N/A
MA 2.1 µg/L
DM 134.5 µg/L
DM 1.6 µg/L
The limits are calculated by
subtracting Cr(III) limits
from TBEL Total Cr limit
Total Cr
N/A
MA 23.7 µg/L
MA 23.7 µg/L
DM 76.3 µg/L
DM 76.3 µg/L
Page 11 of 22

Fact Sheet
NPDES Permit NC0004944
As
MA 1,486 µg/L
MA 19.9 µg/L
MA 19.9 µg/L
DM 2,858 µg/L
DM 99.3 µg/L
DM 99.3 µg/L
Cd
MA 5.84 µg/L
MA 10.2 µg/L
MA 5.84 µg/L
DM 27.2 µg/L
DM 17.2 µg/L
DM 17.2 µg/L
Total Phenol
MA 9,203 µg/L
MA 1,080 µg/L
MA 1,080 µg/L
DM 9,203 µg/L
DM 3,650 µg/L
DM 3,650 µg/L
Chlorinated
MA 30.7 µg/L
MA 106 µg/L
MA 30.7 µg/L
Phenol
DM N/A
DM 155 µg/L
DM 155 µg/L
Cu
MA 78.0 µg/L
MA 216 µg/L
MA 78.0 µg/L
DM 88.0 µg/L
DM 659 µg/L
DM 88.0 µg/L
CN
MA 49.5 µg/L
MA 178 mg/L
MA 49.5 µg/L
DM 184.9 µg/L
DM 500 mg/L
DM 184.9 µg/L
Pb
MA 29.1 µg/L
MA 160 µg/L
MA 29.1 µg/L
DM 634.6 µg/L
DM 350 µg/L
DM 350 µg/L
Hg
Limits are based on Statewide Mercury TMDL - 47.0 ng/L Annual average
Sb
MA 6,338 µg/L
MA 31.2 µg/L
MA 31.2 µg/L
DM 6,338 µg/L
DM 111 µg/L
DM 111 µg/L
Mo
MA 19,806 µg/L
MA 965 µg/L
MA 965 µg/L
DM 19,806 µg/L
DM 1,010 µg/L
DM 1,010 µg/L
Ni
MA 368.7 µg/L
MA 309 µg/L
MA 309 µg/L
DM 2,818 µg/L
DM 794 µg/L
DM 794 µg/L
Se
MA 49.5 µg/L
MA 69.8 µg/L
MA 49.5 µg/L
DM 470.8 µg/L
DM 176 µg/L
DM 176 µg/L
Ag
MA 0.594 µg/L
MA 12.2 µg/L
MA 0.594 µg/L
DM 2.49 µg/L
DM 31.8 µg/L
DM 2.49 µg/L
Zn
MA 1,057 µg/L
MA 252 µg/L
MA 252 µg/L
DM 1,057 µg/L
DM 657 µg/L
DM 657 µg/L
Sn
MA 7,625 µg/L
MA 36.7 µg/L
MA 36.7 µg/L
DM 7,625 µg/L
DM 95.5 µg/L
DM 95.5 µg/L
Acetone
MA 19,806 µg/L
MA 7,970 µg/L
MA 7,970 µg/L
DM 19,806
DM 30,200 µg/L
DM 19,806 µg/L
Acetophenone
MA 80,216 µg/L
MA 56.2 µg/L
MA 56.2 µg/L
DM 80,216 µg/L
DM 114 µg/L
DM 114 µg/L
2-Butanone
MA 257,483 µg/L
MA 1,850 µg/L
MA 1,850 µg/L
Page 12 of 22

Fact Sheet
NPDES Permit NC0004944
DM 257,483 µg/L
DM 4,810 µg/L
DM 4,810 µg/L
Carbazole
MA 11.9 µg/L
MA 276 µg/L
MA 11.9 µg/L
DM N/A
DM 598 µg/L
DM 598 µg/L
Pyridine
MA 12,874 µg/L
MA 182 µg/L
MA 182 µg/L
DM 12,874 µg/L
DM 370 µg/L
DM 370 µg/L
Bis(2-
MA 3.66 µg/L
MA 101 µg/L
MA 3.66 µg/L
ethylhexyl)phthal
DM N/A
DM 215 µg/L
DM 215 µg/L
ate
Butylbenzyl
MA 0.99 µg/L
MA 88.7 µg/L
MA 0.99 µg/L
Phthalate
DM N/A
DM 188 µg/L
DM 88.7 µg/L
Fluoranthene
MA 198 µg/L
MA 26.8 µg/L
MA 26.8 µg/L
DM 198 µg/L
DM 53.7 µg/L
DM 53.7 µg/L
Tier II (1.0 MGD)
TBEL's are based on a Process flow of 0.5285 MGD
Parameter
WQBEL
TBEL
Permit Limit
BOD5
MA 150.0 lb/day
MA 233.6 lb/day
MA 150.0 lb/day
DM 300.0 lb/day
DM 718.5 lb/day
DM 300.0 lb/day
NH3-N
MA 23.0 lb/day
N/A
MA 23.0 lb/day
DM 46.0 lb/day
DM 46.0 lb/day
Cr(III)
MA 641.8 µg/L
N/A
MA 25.1 µg/L
DM 4,256.8 µg/L
DM 86.4 µg/L
Cr(III)/Total Cr ratio:
Calculations are based on
MA 0.91
the Cr(III)/Total Cr ratio
and TBEL Total Cr limit
DM 0.98
Cr(VI)
MA 60.0 µg/L
N/A
MA 2.5 µg/L
DM 75.3 µg/L
DM 1.8 µg/L
The limits are calculated by
subtracting Cr(III) limits
from TBEL Total Cr limit
Total Cr
N/A
MA 27.6 µg/L
MA 27.6 µg/L
DM 88.2 µg/L
DM 88.2 µg/L
As
MA 758.4 µg/L
MA 19.9 µg/L
MA 19.9 µg/L
DM 1,599 µg/L
DM 99.3 µg/L
DM 99.3 µg/L
Cd
MA 3.22 µg/L
MA 10.2 µg/L
MA 3.22 µg/L
DM 15.2 µg/L
DM 17.2 µg/L
DM 15.2 µg/L
Page 13 of 22

Fact Sheet
NPDES Permit NC0004944
Total Phenol
MA 4,752 µg/L
MA 1,080 µg/L
MA 1,080 µg/L
DM 4,752 µg/L
DM 3,650 µg/L
DM 3,650 µg/L
Chlorinated
MA 15.8 µg/L
MA 106 µg/L
MA 15.8 µg/L
Phenol
DM N/A
DM 155 µg/L
DM 155 µg/L
Cu
MA 42.9 µg/L
MA 216 µg/L
MA 42.9 µg/L
DM 49.2 µg/L
DM 659 µg/L
DM 49.2 µg/L
CN
MA 27.3 µg/L
MA 178 mg/L
MA 27.3 µg/L
DM 103.5 µg/L
DM 500 mg/L
DM 103.5 µg/L
Pb
MA 16.0 µg/L
MA 160 µg/L
MA 16.0 µg/L
DM 355 µg/L
DM 350 µg/L
DM 350 µg/L
Hg
Limits are based on Statewide Mercury TMDL - 47.0 ng/L Annual average
Sb
MA 3,489 µg/L
MA 31.2 µg/L
MA 31.2 µg/L
DM 3,489 µg/L
DM 111 µg/L
DM 111 µg/L
Mo
MA 10,903 µg/L
MA 965 µg/L
MA 965 µg/L
DM 10,903 µg/L
DM 1,010 µg/L
DM 1,010 µg/L
Ni
MA 203 µg/L
MA 309 µg/L
MA 203 µg/L
DM 1,577 µg/L
DM 794 µg/L
DM 794 µg/L
Se
MA 27.3 µg/L
MA 69.8 µg/L
MA 27.3 µg/L
DM 263.4 µg/L
DM 176 µg/L
DM 176 µg/L
Ag
MA 0.327 µg/L
MA 12.2 µg/L
MA 0.327 µg/L
DM 1.394 µg/L
DM 31.8 µg/L
DM 1.394 µg/L
Zn
MA 591.2 µg/L
MA 252 µg/L
MA 252 µg/L
DM 591.2 µg/L
DM 657 µg/L
DM 591.2 µg/L
Sn
MA 4,197 µg/L
MA 36.7 µg/L
MA 36.7 µg/L
DM 4,197 µg/L
DM 95.5 µg/L
DM 95.5 µg/L
Acetone
MA 10,903 µg/L
MA 7,970 µg/L
MA 7,970 µg/L
DM N/A
DM 30,200 µg/L
DM 30,200 µg/L
Acetophenone
MA 44,158 µg/L
MA 56.2 µg/L
MA 56.2 µg/L
DM 44,158 µg/L
DM 114 µg/L
DM 114 µg/L
2-Butanone
MA 141,741 µg/L
MA 1,850 µg/L
MA 1,850 µg/L
DM 141,741 µg/L
DM 4,810 µg/L
DM 4,810 µg/L
Carbazole
MA 6.54 µg/L
MA 276 µg/L
MA 6.54 µg/L
DM N/A
DM 598 µg/L
DM 598 µg/L
Pyridine
MA 7,087 µg/L
MA 182 µg/L
MA 182 µg/L
Page 14 of 22

Fact Sheet
NPDES Permit NC0004944
DM 7,087 µg/L
DM 370 µg/L
DM 370 µg/L
Bis(2-
MA 2.02 µg/L
MA 101 µg/L
MA 2.02 µg/L
ethylhexyl)phthal
DM N/A
DM 215 µg/L
DM 215 µg/L
ate
Butylbenzyl
MA 0.545 µg/L
MA 88.7 µg/L
MA 0.545 µg/L
Phthalate
DM N/A
DM 188 µg/L
DM 188 µg/L
Fluoranthene
MA 109 µg/L
MA 26.8 µg/L
MA 26.8 µg/L
DM 109 µg/L
DM 53.7 µg/L
DM 53.7 µg/L
Tier III (2.305 MGD)
TBEL's are based on a Process flow of 1.2335 MGD
Parameter
WQBEL
TBEL
Permit Limit
BOD5
MA 150.0 lb/day
MA 545.4 lb/day
MA 150.0 lb/day
DM 300.0 lb/day
DM 1,574 lb/day
DM 300.0 lb/day
NH3-N
MA 23.0 lb/day
N/A
MA 23.0 lb/day
DM 46.0 lb/day
DM 46.0 lb/day
Cr(III)
MA 345.1 µg/L
N/A
MA 25.4 µg/L
DM 2,359 µg/L
DM 88.1µg/L
Cr(III)/Total Cr ratio:
Calculations are based on
the Cr(III)/Total Cr ratio
MA 0.91
and TBEL Total Cr limit
DM 0.98
Cr(VI)
MA 32.2 µg/L
N/A
MA 2.5 µg/L
DM 41.7 µg/L
DM 1.5 µg/L
The limits are calculated by
subtracting Cr(III) limits
from TBEL Total Cr limit
Total Cr
N/A
MA 27.9 µg/L
MA 27.9 µg/L
DM 89.6 µg/L
DM 89.6 µg/L
As
MA 334.7 µg/L
MA 19.9 µg/L
MA 19.9 µg/L
DM 886.2 µg/L
DM 99.3 µg/L
DM 99.3 µg/L
Cd
MA 1.73 µg/L
MA 10.2 µg/L
MA 1.73 µg/L
DM 8.44 µg/L
DM 17.2 µg/L
DM 8.44 µg/L
Total Phenol
MA 2,231 µg/L
MA 1,080 µg/L
MA 1,080 µg/L
DM N/A
DM 3,650 µg/L
DM 3,650 µg/L
Chlorinated
MA 7.4 µg/L
MA 106 µg/L
MA 7.4 µg/L
Phenol
DM N/A
DM 155 µg/L
DM 155 µg/L
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Fact Sheet
NPDES Permit NC0004944
Cu
MA 23.1 µg/L
MA 216 µg/L
MA 23.1 µg/L
DM 27.3 µg/L
DM 659 µg/L
DM 27.3 µg/L
CN
MA 14.7 µg/L
MA 178 mg/L
MA 14.7 µg/L
DM 57.3 µg/L
DM 500 mg/L
DM 57.3 µg/L
Pb
MA 8.62 µg/L
MA 160 µg/L
MA 8.62 µg/L
DM 196.8 µg/L
DM 350 µg/L
DM 196.8 µg/L
Hg
Limits are based on Statewide Mercury TMDL - 47.0 ng/L Annual average
Sb
MA 1,876 µg/L
MA 31.2 µg/L
MA 31.2 µg/L
DM 1,876 µg/L
DM 111 µg/L
DM 111 µg/L
MO
MA 5,863 µg/L
MA 965 µg/L
MA 965 µg/L
DM 5,863 µg/L
DM 1,010 µg/L
DM 1,010 µg/L
Ni
MA 109.1 µg/L
MA 309 µg/L
MA 109.1 µg/L
DM 873.8 µg/L
DM 794 µg/L
DM 794 µg/L
Se
MA 14.7 µg/L
MA 69.8 µg/L
MA 14.7 µg/L
DM 146 µg/L
DM 176 µg/L
DM 146 µg/L
Ag
MA 0.176 µg/L
MA 12.2 µg/L
MA 0.176 µg/L
DM 0.773 µg/L
DM 31.8 µg/L
DM 0.773 µg/L
Zn
MA 327.7 µg/L
MA 252 µg/L
MA 252 µg/L
DM 327.7 µg/L
DM 657 µg/L
DM 327.7 µg/L
Sn
MA 2,257 µg/L
MA 36.7 µg/L
MA 36.7 µg/L
DM 2,257 µg/L
DM 95.5 µg/L
DM 95.5 µg/L
Acetone
MA 5,863 µg/L
MA 7,970 µg/L
MA 5,863 µg/L
DM N/A
DM 30,200 µg/L
DM 30,200 µg/L
Acetophenone
MA 23,743 µg/L
MA 56.2 µg/L
MA 56.2 µg/L
DM 23,743 µg/L
DM 114 µg/L
DM 114 µg/L
2-Butanone
MA 76,213 µg/L
MA 1,850 µg/L
MA 1,850 µg/L
DM 76,213 µg/L
DM 4,810 µg/L
DM 4,810 µg/L
Carbazole
MA 3.52 µg/L
MA 276 µg/L
MA 3.52 µg/L
DM N/A
DM 598 µg/L
DM 598 µg/L
Pyridine
MA 3,811 µg/L
MA 182 µg/L
MA 182 µg/L
DM 3,811 µg/L
DM 370 µg/L
DM 370 µg/L
Bis(2-
MA 1.08 µg/L
MA 101 µg/L
MA 1.08 µg/L
ethylhexyl)phthal
DM N/A
DM 215 µg/L
DM 215 µg/L
ate
Page 16 of 22

Fact Sheet
NPDES Permit NC0004944
Butylbenzyl
MA 0.293 µg/L
MA 88.7µg/L
MA 0.293 µg/L
Phthalate
DM N/A
DM 188 µg/L
DM 188 µg/L
Fluoranthene
MA 58.6 µg/L
MA 26.8 µg/L
MA 26.8 µg/L
DM 58.6 µg/L
DM 53.7 µg/L
DM 53.7 µg/L
16. Changes in the Final Permit
• The limits for barium, molybdenum, aniline, and 2,3-dichloroaniline were removed from the
permit because these compounds were removed from the CWT regulations in 2003.
• The water quality based limits for Ni (Monthly Average) were corrected for all 3 tiers, now
they are based on the appropriate classification of the receiving stream (C-class).
• The annual average nitrogen limit was added to the permit to freeze nitrogen load and
prevent further deterioration of the nutrient impaired waterbody. The limit is based on the
total nitrogen concentration of 4.7 mg/L reported by the previous owner of the facility. The
total nitrogen data was extracted from the following DMRs: 08/1992-08/1993 and 01/2009-
12/2009.
• The permit limits for trivalent and hexavalent chromium were reduced to make them
consistent with the Effluent Guidelines calculations.
Page 17 of 22

Fact Sheet
NPDES Permit NC0004944
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 Quality Standards/Aquatic Life Protection
Parameter
Acute FW, µg/l
(Dissolved)
Chronic FW, µg/l
(Dissolved)
Acute SW, µg/l
(Dissolved)
Chronic SW, µg/l
(Dissolved)
Arsenic
340
150
69
36
Beryllium
65
6.5
---
---
Cadmium
Calculation
Calculation
40
8.8
Chromium I11
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
1 0.1
Zinc
Calculation
Calculation
90
1 81
Table 1 Notes:
1. FW= Freshwater, SW= Saltwater
2. Calculation = Hardness dependent standard
3. 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 2B.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/1
Cadmium, Acute
WER*{1.136672-[ln hardness](0.041838)} e^10.9151 [In hardness]-
3.1485}
Cadmium, Acute Trout
waters
WER*{1.136672-[ln hardness](0.041838)} e^{0.9151[ln hardness] -
3.62361
Cadmium, Chronic
WER*{1.101672-[In 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
Page 18 of 22

Fact Sheet
NPDES Permit NC0004944
Copper, Chronic
WER*0.960 • e^{0.8545[ln hardness]-1.7021
Lead, Acute
WER* { 1.46203- [ln hardness] (0.145712)1 e^ { 1.273 [ln hardness] -
1.460 }
Lead, Chronic
WER* { 1.46203- [ln hardness] (0.145712)) e^ { 1.273 [ln hardness] -
4.705 }
Nickel, Acute
WER*0.998 e^{0.8460[ln hardness]+2.255}
Nickel, Chronic
WER*0.997 e^{0.8460[ln hardness]+0.0584}
Silver, Acute
WER*0.85 • e^{1.72[ln hardness]-6.59}
Silver, Chronic
Not applicable
Zinc, Acute
WER*0.978 e^10.8473[In hardness]+0.884}
Zinc, Chronic
WER*0.986 e^10.8473[In hardness]+0.884}
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/WQBELs 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 1Q10
using the formula 1Q10 = 0.843 (s7Q10, cfs) 0.993
• Effluent hardness and upstream hardness, site -specific data is preferred
Page 19 of 22

Fact Sheet
NPDES Permit NC0004944
• Permitted flow
• Receiving stream classification
2. 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.
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) + (s7O10, cfs *Avg. Upstream Hardness, mg/L)
(Permitted Flow, cfs + s7Q10, cfs)
The Combined Hardness for acute is the same but the calculation uses the 1 Q1 0 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 — 1
Ctota1 1 + { [Kpo] [ss(i+a)] [10-6] }
Where:
ss = in -stream suspended solids concentration [mg/1], minimum of 10 mg/L used,
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.
Page 20 of 22

Fact Sheet
NPDES Permit NC0004944
In some cases, where an EPA default partition coefficient translator does not exist (ie. 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 = (s7010 + Ow) (Cwq) — (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:
1Q10 = used in the equation to protect aquatic life from acute toxicity
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
6. 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.
8. 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
Page 21 of 22

Fact Sheet
NPDES Permit NC0004944
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+M )]
25.0
Default value
Average Upstream Hardness (mg/L)
[Total as, CaCO3 or Ca+M ]
25.0
Default value
7Q10 summer cfs
0
Lake or Tidal
1Q10 cfs
0
Lake or Tidal
Permitted Flow (MGD)
2.1
For dewaterin
Page 22 of 22