NC0089915_Draft Fact Sheet_20200212

Fact Sheet
NPDES Permit No. NCOOXXXXX
Permit Writer/Email Contact: [e-mail]
Date: February 12, 2020
Division/Branch: NC Division of Water Resources / NPDES Complex Permitting
Fact Sheet Template: Version 09Jan2017
Permitting Action:
❑ Renewal
❑ Renewal with Expansion
❑X New Discharge
❑ Modification (Fact Sheet should be tailored to mod
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 C rrect analytical re uirements based
on industry category.
Complete applicable sections below. If not applicable, enter
1. Basic Facility Information 2%h�
Facility Information
Applicant/Facility Name:
The Chemours Company / Chemours Fayetteville Works
Applicant Address:
1007 Market Street, Wilmington, DE 19899
Facility Address:
22828 NC Highway 87 W, Fayetteville, NC 28306-7332
Permitted Flow:
1.58 MGD .,
Facility Type/Waste:
MAJOR Industrial
Facility Class:
III
Treatment Units:
influent oxidation, coagulation, and pH adjustment, ultrafiltration,
granular activated carbon (GAC) adsorption
Pretreatment Program (Y/N):
N/A
County:
Bladen
Region:
Fayetteville
Page 1 of 18

Briefly describe the proposed permitting action and facility background. -
This is a new NPDES wastewater permit for the existing Major Industrial facility. This permit will be issued
to expedite groundwater remediation at the Old Outfall 002. This Outfall will be named Outfall 003 in the
new permit, this will allow to combine the permits in the future without creating confusion with. The Old
Outfall 002 is no longer used due to the relocation upstream. However, there is a channel that collects
groundwater baseflow. The dry weather baseflow is estimated to be 540 gpm (gallons per minute), the
facility will build a capture dam that collects baseflow and be able to collect some additional flow from
stormwater up to the total capacity of 640 gpm. The groundwater treatment system is also designed to treat
an additional flow from the seeps for a total a maximum flow of 750 gpm. Future flows from on -site seeps
and groundwater are expected to be an additional 350 gpm (Phase II).
lak
The system is will be able to remove numerous per- and polyfluorinated alkyl (PFAS) compounds,
including HFPO — DA (GenX) and PFMOAA. The Consent Order between State of North Carolina and
Chemours requires that the facility remove at least 99% of Gen-X and PFMOAA. Tests conducted by the
facility demonstrate that the GAC system proposed for the site is capable of removing 99% of all PFAS
compounds, even short -chained compounds such as - Short -chained c pounds are more difficult to
treat and remove.
This system is expected to significantly reduce overall loading of PFAS compounds to Cape Fear River.
Currently, daily average PFAS concentration at the Old Outfall 002 is estimated to be 6,462 ng/L, after
the GAC system is installed the loading,'Will be reduced by 6,397 ng/L.
This proposed groundwater system will consist of the following components:
1) Influent Oxidation, Coagulation & pH Adjustment
This treatment system includes an influent oxidation/coagulation /pH adjustment tank for pretreatment of
the ultrafiltration (UF) feed (pH adjustment/oxidation/coagulation). The pH adjustment will be done using
sodium hydroxide. Additional iron oxidation will be done with sodium hypochlorite. Poly -aluminum
chloride (PAC) will be used for coagulation and contribute to help maintain the OF membranes. Partially
treated water will be conveyed to the OF units via dual booster pumps. Safety Data Sheets (SDSs) are
attached for the chemicals to be utilized at the wastewater treatment system.
Iron hydroxide particles precipitated in the oxidation process and total suspended solids (TSS) will be
coagulated and settled in the tank. The settled solids will be transferred by a solids transfer pump to a weir
tank (back pulse waste recycle tank) and filtered in downstream removal processes (thickener and rotary -
fan filter press)
2) Ultrafiltration
This design includes OF pretreatment before the Granular Activated Carbon (GAC) stage. The OF will
perform the role of solids removal upstream of the GAC units. The OF will provide an absolute barrier to
solids at 0.04 - 0.1 µm range. Per the manufacturing vendor, the OF membrane will provide additional TOC
removal as well.
The OF back pulse waste recycle will be captured in a weir tank to allow solids to settle and then will be
recycled through the system after being pumped back to the influent oxidation/coagulation /pH adjustment
tank. The settled solids in the weir tank (the back -pulse waste recycle tank) will be drawn off by a sludge
pump and filtered in downstream removal processes (thickener and rotary -fan filter press).
The OF units will intermittently need to be cleaned with a low concentration of citric acid. The cleaning
solution will be captured in a Clean -In Place (CIP) tank and neutralized in it. Following neutralization, the
CIP water will be recycled through the treatment system after being pumped back by CIP neutralization
pumps to the influent oxidation/coagulation /pH adjustment tank.
Page 2 of 18

3) Granular Activated Carbon (GAC) Adsorption
Based on GAC adsorption studies, PFAS removal to meet discharge requirements (per the CO), is expected
to be accomplished using GAC adsorption. The system design for this application includes a total of six (6)
12' diameter x 5' diameter straight side vessels in a three (3) pass configuration capable of swapping
lead/middle/lag. Each GAC vessel can hold up to 20,000 lbs. of GAC. The GAC beds will be sluiced out
upon exhaustion and the new bed sluiced back into the vessel. The GAC vessels have backwashing
capability. Sizing, quantities and configuration may be modified during process optimization.
4) Solids Handling and Treatment
The treatment system includes a containerized sludge handling system with sludge pump, polymer make
down/injection system, in -line mixer and a thickener unit and rotary fan press skid. The rotary fan press
will be mounted on a sump with a pump to return filtrate from the process to the head of the plant into the
influent oxidation/coagulation /pH adjustment tank. Additionally, the solids handling system will include
a screw conveyor to move the sludge out of the container/press and into a roll off for storage, until the
sludge accumulates enough to be hauled off site.
5) Discharge A916!FX
The treated water will be discharged and reintroduced to Outfall 003. The discharge location will be
downstream of the capture dam. 1\
Facility background.
Chemours is a major industrial facility. Chemours operates an ion exchange monomers process and a
polymer processing aid process. Also on -site, DuPont operates a polyvinyl fluoride process, and Kuraray
operates Butacite and en processes.
Beginning in mid-201 S co pounds were found in the Cape Fear River. One specific compound of
concern, GenX or HF mer acid (HFPA-DA), was traced back to Chemours. Health effects of PFAS
are currently not well-known, but some possibly linked health effects include kidney disease,
developmental cts to fetuses, and some forms of cancer. To -date, EPA and the state of NC have not
released/approved of any regulatory standards for these compounds. EPA has released a drinking water
health advisory of 70 ng/L for the sum of PFOA and PFOS. NC Department of Health and Human
Services (DHHS) has released a drinking water health goal (for the most vulnerable population) of 140
ng/L for GenX.
NAL
The current NPDES permit expired on Octob 31, 2016. A renewal application was submitted in May
2016, prior to the permit expiring, and the permit was administratively continued; however, on August 18,
2017 the Division requested additional information, an updated, more detailed application in light of the
newfound PFAS discharge and contamination. On September 5, 2017, the Division notified Chemours of
the intent to suspend the NPDES permit for "obtaining a permit by misrepresentation or failure to disclose
fully all relevant facts," particularly related to the discharge of GenX and related compounds. The
Division would not suspend the permit provided Chemours comply with actions such as preventing
discharge of all GenX compounds, cease Chemours' discharge of process wastewater containing Nafion
byproducts 1 and 2, cease Chemours' discharge of any other per and poly -fluorinated compounds without
effluent limits in the permit, and provide complete responses to all prior additional information requests.
In October 2017, Chemours failed to report a spill at the facility that caused a significant increase in the
concentration of GenX to be discharged. Due to misrepresentations and inadequate disclosure by
Chemours, the Division partially suspended the permit, effective November 30, 2017. Chemours was
prohibited from discharging process wastewater from the Chemours Fluoromonomers/Nafion Membrane
manufacturing area. Chemours has been shipping Chemours process wastewater offsite for disposal,
Page 3 of 18

while continuing to treat and discharge Kuraray and DuPont process wastewater through Outfall 002.
Chemours resubmitted the renewal application on July 10, 2019.
On February 26, 2019, the Consent Order was signed by Bladen County Superior Court Judge Sasser, and
Chemours has since begun fulfilling its obligations. Work has begun in the following areas: planning for
Old Outfall 002 groundwater remediation, sampling of site wastewater for PFAS compounds, planning
for reduction of on -site non -process wastewater. The Paragraph 11(b) Sampling Plan was approved by
DWR on June 19, 2019. For full details see the Consent Order, Section D. Compliance Measures —
Surface Water, Paragraphs 10-15.
Chemours process wastewater (currently pumped and hauled) contains the following:
1. 2,2-difluoro-2-sulfoacetic acid (CASRN 422-67-3)
2. MMF — Difluoromalonic acid (CASRN 1514-85-8) AW
3. MTP Acid — Methyl 2,2,3,3-tetrafluoro-3-methoxypropionate 2,2,3,3-tetrafluoro-3-methoxy-
propanoic acid (CASRN 93449-21-9)
4. PPF Acid — Perfluoropropionic acid (CASRN 422-64-0)
5. PFMOAA — 2,2-difluoro-2-(trifluoromethoxy)acetic acid (CASRN 674-13-5)
6. 4-(2-carboxy-1,1,2,2-tetrafluoroethoxy)-2,2,3,3,4,5,5,5-octafluoropentanoic acid (no listed
CASRN)
7. 2,2,3,3,4,5,5,5-octafluoro-4-(1,1,2,2-tetrafluoro-2-(fluorosu onyl)ethox tanoic acid (no
listed CASRN)
8. 2-fluoro-2-(1,1,2,3,3,3-hexafluofb-2-(1,1,2,2-tetrafluoro- lfoethoxy)propo cetic acid (no
listed CASRN)
9. PMPA — Perfluoro-2-(perfluoromethoxy)propanoic acid (CASRN 13140-29-9)
10. PF02HxA — Perfluoro-3,5-dioxahexanoic acid (CASRN 39492-88-1)
11. NVHOS — Sodium 1,1,2,2-tetrafluoroethoxy)ethane-l-sulfonate (CASRN 1132933-86-8)
12. PEPA — Perfluoroethoxypropyl carboxylic acid (CASRN 267239-61-2)
13. PF030A — Perfluoro(3,5,7-trioxaoctanoic) acid (CASRN 39492-89-2)
14. PES — Perfluoro(2-ethoxyethane)sulfonic acid (CASRN 113507-82-7)
15. PFECA B — Perfluorq 3,6-dioxaheptanoic acid (CASRN 151772-58-6)
16. HFPO DA (GenX) — 2,3,3,3-tetrafluoro-2-(1,1,V,3,3,3-heptafluoropropoxy) propanoic acid
(CASRN 13252-13-6)
17. PFECA G — 2,2,3,3,4,4-hexafluoro-4-[(heptafluoropropan-2-yl)oxy]butanoic acid (CASRN
801212-59-9)
18. PF04DA — 2-[[[difluoro(trifluoromethoxy)methoxy]-difluoromethoxy]-difluoromethoxy]2,2-
difluoroacetic acid (CASRN 39492-90-5)
19. Hydro -EVE Acid — 2,2,3,3-tetrafluoro-3-((1,1,1,2,3,3-hexafluoro-3-(1,2,2,2-
tetrafluoroethoxy)propan-2-yl)oxy)propanoic acid (CASRN 773804-62-9)
20. EVE Acid — 3-[1-[Difluoro[(trifluoroethenyl)oxy]methyl]-1,2,2,2-tetrafluoroethoxy]-2,2,3,3-
tetrafluoropropanoic acid (CASRN 69087-46-3)
21. 1,1,2,2-tetrafluoro-2-((1,1,1,2,3,3,4,4-octafluorobutan-2-yl)oxy)ethanesulfonic acid (no listed
CASRN)
22. Nafion Byproduct 1— 2-[1-[difluoro[(1,2,2-trifluoroethenyl)oxy]methyl]-1,2,2,2-
tetrafluoroethoxy]-1,1,2,2-tetrafluoro-ethanesulfonic acid (CASRN 29311-67-9)
23. PF05DA — 3,5,7,9,11-pentaoxatridecafluorododecanoic acid (CASRN 39492-91-6)
24. PFOA — Perfluorooctanoic acid (CASRN 335-67-1)
[**Note: "No listed CASRN" compounds likely R-EVE, Byproduct 4, Byproduct 5, Byproduct 6]
Page 4 of 18

2. Receiving Waterbody Information
Receiving Waterbody Information
Outfalls/Receiving Stream(s):
Outfall 003 — Cape Fear River
Stream Segment:
18-(26.25)
Stream Classification:
C, WS-Iv
Drainage Area (mi2):
4852
Summer 7Q10 (cfs):
467 (17.14 — used in limit calculations, the number is based on
the modeling)
603
900
Winter 7Q10 (cfs):
30Q2 (cfs):
Average Flow (cfs):
4220
IWC (% effluent):
14.7% (based on the model)
303(d) listed/parameter:
No, the segment is not listed on the 2018 303(d) list
Subject to TMDL/parameter:
Yes — State-wide Mercury TMDL implementation.
Sub-basin/HUC:
Outfall 002: 03-06-16 /
USGS Topo Quad:
Duart fir 'Isk I
3. Effluent Data Summar
N/A
This is a new permit for groundwater remediation, the facility did not engage in the groundwater remediation
under the previous permit. Outfall 003 is located at the former Chemours Old Outfall 002.
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: The current permit requires instream monitoring for dissolved oxygen and temperature.
Review of instream data for the past three years indicates that the dissolved oxygen standard of 5.0 mg/L
was maintained, and there were no substantial differences between upstream and downstream stations.
This draft permit maintains the same instream monitoring requirements.
Is this facility a member of a Monitoring Coalition with waived instream monitoring (YIN): N
Page 5 of 18

Name of Monitoring Coalition: N/A.
5. Compliance Summary
Summarize the compliance record with permit effluent limits (past 5 years): The facility received 3
Notices of Violation:
1) for release of the C3 Dimer Acid on 10/06/2017.
2) For 2 daily BOD violation and monthly BOD violation in October 2014.
Summarize the compliance record with aquatic toxicity test limits and any second species test results
(past 5 years): The facility passed 20 of 20 quarterly chronic toxicity ests, as well as all 4 second species
chronic toxicity tests. Please see attached.
Summarize the results from the most recent compliance inspection: The last facility inspection conducted
on June 2, 2016 reported that the facility was adequately ntained and operated.
'A& A6,
6. Water Quality -Based Effluent Limitations (WQBELs)
Dilution and MixingZones
ones
In accordance with 15A NCAC 213.0206, the following Xstream 4flosre used for
for development of WQBELs: 1Q10 streamflow (acute Aquatic Life); 7Q10 streamflow (chronic Aquatic
Life; non -carcinogen HH); 30Q2 streamflow (aestheti ), annual average flow (carcinogen, HH).
ILI
If applicable, describe anyffit ion factors considered (e.g., based o CORMIX model results):
N/A.
If applicable, describe any mixing
uming W
I5A NCAC 2B. 0204(b): N/A.
Limitations for oxygen -consuming waste (e. ar nerally based on water quality modeling to
ensure protection of the instream dissolved oxyge water quality standard. Secondary TBEL limits
(e.g., BOD= 30 mg/1 for Municipals) may e appropriate if deemed more stringent based on dilution and
model results. Vk
If permit limits are more stringent than TBELs, describe how limits were developed:
Geosyntec Consulta s of NC has MLitted CORMIX model results on behalf of The Chemours
Company FC, LLC for the primary discharge outfall 002 of their Fayetteville Works site discharging to
the Cape Fear River, classified WS-IV, approximately 1,500 feet above the William O Huske Dam aka
Lock and Dam 3 in Bladen County. This outfall discharges process wastewaters from the Kurary and
DuPont facilities, non -contact cooling water and boiler blowdown from Chemours, excess river intake
water, and stormwater for the industrial complex. The discharge was modeled because of concerns over
incomplete mixing due to the presence of the lock and dam system and background concentrations from
site runoff, aerial deposition, seepage, and groundwater flow into the river of per -and polyfluoralkyl
substances (PFAS).
The CORMIX model river schematization used The Army Corps of Engineers 2016 bathymetric survey
data which showed a consistent river cross-section profile from the point of discharge to just above Lock
and Dam 3. Critical river flows were obtained from the USGS in June 2019, which showed a marked
decrease in critical flow statistics from those used in prior permits. The lower flows reflect changes in the
Page 6 of 18

B. Everett Jordan Lake Drought Contingency Plan formally approved in 2008 and operationally in effect
since 2007. Water levels in the model were determined from the continuous record USGS stream gage
(Station 02105500) located at the lock and dam. Outfall parameters in the model were based on the
existing outfall configuration.
Model results and sensitivity analysis were first received in July 2019. The Division requested that the
model be updated with critical flow values and a second modeling report was submitted in November
2019. The Division again disagreed with facility's choice of modeled critical conditions and asked them
to resubmit results at critical flow including the facility's maximum discharge concentration of
hexafluoropropylene oxide dimer acid (HFPO-DA) since their cessation of discharging process
wastewater. Model results with the requested information were received in December 2019.
The modeled pollutant of concern is HFPO-DA at a concentration of 710 ng/L. The final model results
predict the NC Department of Health and Human Services HFPO-DA health goal of 140 ng/L is met at
15.8 meters from the outfall. Mixing continues till 21.2 in from the outfall where the plume begins to
exhibit passive ambient diffusion with little additional dilution. At this point the effluent plume dilution is
8:1 until model end. Though model results indicate the NC DHHS provisional health goal is met,
additional onsite and downstream loading of the target compound is not accounted for in the model and
dilution model should not be used to establish final water quality -based effluent limitations. Mass based
loading from all sources should be used to establish a water quality -based wasteload allocation for HFPO-
DA and associated PFAS. The model results can be used, however, to establish dilution based effluent
limitations for parameters with little to no background concentrations. The 8:1 dilution is both more
conservative than and supported over instream waste concentration (IWC) based limitations normally
performed under 15A NCAC 2B. The IWC from using standard procedures under 7Q10 flow conditions
of 467 cubic feet per second (cfs) would be 9% versus 12.5% at an 8:1 dilution.
h,
Applying EPA criteria for sizing mixing zones in their Technical Support Document for Water Quality -
based Toxics Control 1991 section 4.3.2, with the most limiting factor of sizing an acute mixing zone
based on 10% of the size of the regulatory mixing zone, an 8:1 chronic dilution zone at 21.2 in would
result in an acute mixing zone with a dilution of 2.3:1 at 2.1 in from the outfall.
Target Dilution- 8:1 chronic, 2.3:1 acute
AMW "%IX
Chronic IWC%- 12.5%
IEL
Chronic Mixing Zone- 21.2 in downstream of the outfall.
Acute Mixing Zone- 2.1 in downstream of the outfall.
Outfall Characteristics- Existing structure: Single port submerged 60 inch RCP, invert at 17.14 feet above
river bottom, oriented perpendicular to flow, angled down-1.655'
Although the CORMIX dilution model was developed for Outfall 002, the Division will also use it for
Outfall 003. The model produced the effective 7Q10s of 17.14 cfs. This is a very conservative
assumption, which is substantially lower than the USGS estimate of 467.0 cfs. Therefore, using the
CORMIX model provides a very high level of protection for the receiving stream and the downstream
water users, it will be used in the Reasonable Potential Analysis (RPA).
This dilution model is based on the best available information, the Division will re-evaluate it if the more
comprehensive information becomes available. In addition, the Division implemented TBEL limits for
PFAS compounds in the permit and the dilution model has no impact on the calculation of these limits.
The Dilution model has in impact on the metal limits only.
Page 7 of 18

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: The facility
conducted a comprehensive evaluation of the dry weather flow in the eek bed and submitted results on
the EPA Form 2D to the Divisions. The analysis indicates that they ammonia or TRC.
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 ential 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) sumption of zero
background; 3) use of/2 detection limit for "less than" values; and 4) stream flows a for dilution
consideration based on 15A NCAC 2B.0206. Effective April 6, 2016, NC began imple ntation 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 provided by the facility in the
permit application. Pollutants of concern included toxicants with positive detections and associated water
quality standards/criteria. Based on is 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: Silver, Cobalt, Selenium, Mercury.
• 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: Cadmium,
Copper, Cyanide, Lead, Thallium. 10
• 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: Aluminum, Arsenic, Barium, Beryllium, Total Phenolic Compounds, Total
Chromium, Fluoride, Molybdenum, Nickel, Sulfate, Zinc, Nitrate/nitrite.
Attached are the RPA results and a copy of the guidance entitled NPDES Implementation oflnstream
Dissolved Metals Standards Freshwater Standards. "
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
Page 8 of 18

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 14.7% with quarterly frequency is established in the permit.
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.
Describe proposed permit actions based on mercury evaluation: This is a lepe mit and the Division
has no historic data to conduct a comprehensive evaluation. A RPA indicates th ed for a standard of
96.0 ng/L. However, State Implementation Strategy specifies Technology Based Effluent Limit for
mercury of 47.0 ng/L. This limit is mor ingent and will be im lemented in the per
Other TMDL/Nutrient Management Strategy Considerations
If applicable, describe any other TMDLs/Nutrient Management Stra egies and their implementation
within this permit: N/A.
Other WQBEL Considerations
If applicable, describe any o er param tens oYconcealuatedfor 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.
If applicab 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.
If applicable, describe any water quality standcds variances proposed in accordance with NCGS 143-
215.3(e) and 15A V
2B. 0226 for this permit renewal: N/A.
7. Technology -Based Effluent Limitations (TBELs)
Describe what this facility pr ces: This is a groundwater remediation permit for the facility that
produces organic chemicals.
List the federal effluent limitations guideline (ELG) for this facility: N/A.
If the ELG is based on production or flow, document how the average production/flow value was
calculated. N/A.
For ELG limits, document the calculations used to develop TBEL limits: N/A.
If any limits are based on best professional judgement (BPJ), describe development: N/A.
Page 9 of 18

Document any TBELs that are more stringent than WQBELs: The TBELs for GenX and PFMOAA were
calculated in accordance with the Consent Order requirements, it requires that the groundwater treatment
system removes 99% of the both compounds.
The calculation was based on the permit application data, the data indicates that influent contains the
following amounts: GenX= 6.0 µg/L; PFMOAA = 85 µg/L.
The Division is unable to calculate WQBELs for the compounds due to the absence of the State standards
or EPA criteria for these parameters. When EPA develops PFAS criteria for any of the compounds
generated by the Chemours, the Division will conduct RPA analysis and reopen the permit to introduce
the new limits (if necessary).
lak
The TBELs for both compounds will be implemented in the permit: GenX = 0.06 µg/L, PFMOAA = 0.85
µg/LAw
-
Document any TBELs that are less stringent than previous permit: Nl
8. Antidegradation Review (New/Expanding Discharge)
The objective of an antidegradation review is to ensure that a new or increased pollutant loading will not
degrade water quality. Permitting actions for new or expanding discharges require an antidegradation
review in accordance with 15A NCAC 213.0201. Each applicant for a new/expanding NPDES permit
must document an effort to consider non -discharge alternatives per 15A NCAC 2H.0105(c)(2). In all
cases, existing instream water uses and the level of water quality necessary to protect the existing use is
maintained and protected.
If applicable, describe the results of the antidegradation review, including the Engineering Alternatives
Analysis (EAA) and any water quality modeling results- The facility provided an EAA to justify new
discharge, please see the plication for details.
The facility reviewed the ing avai able alterna :Connection to the Existing Publically Owned
Treatment 0. W), La licatio ante Reuse in the Facility, Trucking Offsite, and
Direct D
was not available since the nearest Rockfish Creek Water Reclamation
Facility rNValto
accept this wastewater.I%
The PresCosts for the next 20 years was calculated using EPA discount factor of 3.5%, the
Costs are presented below: 10
Land Application — $86,
Wastewater Reuse in the Fa
Trucking Offsite - $8,710,OOO)
Direct Discharge- $67,000,000
9,600,000 (including riparian restoration)
The Analysis indicates that the direct discharge is the most environmentally friendly economically
feasible alternative. The Division has given a significant consideration to the fact that even with the 99%
removal efficiency, the groundwater treatment system will discharge effluent with GenX concentration of
60 ng/L. Although this concentration is lower than the state health goal of 140 ng/L, it is above some of
the standards established by other states. It is important to emphasize that the health goal is neither a state
standard nor an EPA criterion and is based on a limited data set, it is likely to be reduced in a future after
more research is conducted.
Page 10 of 18

Therefore, the Division cannot allow the groundwater to be contaminated with GenX and other PFAS,
this resource is used by numerous households adjacent to the facility.
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 O): N/A.
If YES, confirm that antibacksliding provisions are not violated.'
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 trigg reductions . on.toring frequencies.
For instream monitoring, refer to Section
11. Electronic
The US EPA NPD
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 ederai re uirements.
12. Summary of Proposed Permitting Actions
Parameter
Current Permit
Proposed Change
Basis for Condition/Change
Flow
MA 1.58 MGD
N/A
15A NCAC 213.0505
BOD5
MA 30.0 mg/L
N/A
WQBEL. Based on protection of DO
DM 45.0 mg/L
standard. 15A NCAC 213.0200
TSS
MA 30.0 mg/L
N/A
TBEL. Secondary treatment
WA 45.0 mg/L
standards/40 CFR 133 / 15A NCAC
2B .0406
Temperature
The ambient water
WQBEL. State WQ standard, 15A
temperature to exceed
NCAC 213.0200
320C
Page 11 of 18

DO
Monitor Only
N/A
WQBEL. State WQ standard, 15A
NCAC 2B .0200
Fluoride
Monitor Only
N/A
WQBEL. State WQ standard, 15A
NCAC 2B .0200
GenX
MA 0.06 µg/L
N/A
TBEL, based on the Consent Order
DM 0.06 µg/L
PFMOAA
MA 0.85 µg/L
N/A
TBEL, based on the Consent Order
DM 0.85 µg/L
PFAS compounds
Monitor Only
N/A
Based on the Consent Order
pH
6.0 — 9.0 SU
N/A
WQBEL. State WQ standard, 15A
NCAC 2B .0200
Total Nitrogen
Monitor Only
N/A
State WQ Rule, 15A NCAC 2B
.050
Total Phosphorus
Monitor Only
N/A
State le, 15A NCAC 2B
.0500
Conductivity
Monitor Only iT
/A
State WQ Rule, 15A NCAC 2B
0500
-
Toxicity Test
Chronic limit, 0.47%
/A
QBEL. No toxics in toxic
tounts.
efflu
15A NCAC 2B.0200 and
15A NCAC 2B.0500
Total Hardness
Mon my
N/A
State WQ standard, 15A NCAC 2B
.0200
Statewide Mercury TMDL
Total Mer
47.0 ng/L — An 1
Average Standard
implementation Strategy
Total Selem
MA 40.0
N/A
State WQ standard, 15A NCAC 2B
DM 379.8 µ t
.0200. Based on RPA results.
Total Silver
0.48 µg/L
N/A
State WQ standard, 15A NCAC 2B
2.01 µg/
.0200. Based on RPA results.
Total Cobalt
MA 23.9 µg/L
N/A
State WQ standard, 15A NCAC 2B
DM 23.9 µg/L
.0200. Based on RPA results.
Total Copper
Monitor Only
N/A
State WQ standard, 15A NCAC 2B
.0200
Total Cadmium
Monitor Only
N/A
State WQ standard, 15A NCAC 2B
.0200
Total Cyanide
Monitor Only
N/A
State WQ standard, 15A NCAC 2B
.0200
Page 12 of 18

Electronic
No requirement
N/A
In accordance with EPA Electronic
Reporting
Reporting Rule 2015.
MGD — Million gallons per day, MA — Monthly Average, DM — Daily Max
13. Public Notice Schedule
Permit to Public Notice: xx/xx/20xx
Per 15A NCAC 2H .0109 & .0111, The Division will receive comments for a period of 30 days following
the publication date of the public notice. Any request for a public hearing shall be submitted to the
Director within the 30 days comment period indicating the interest party filing such request and the
reasons why a hearing is warranted.
14. NPDES Division Contact
If you have questions regarding any of the above information or on the attached permit, please contact
Sergei Chernikov at [phone] or via email at [e-mail]
15. Fact Sheet Attachments (if applicable
Xu � .jii%A�w 3
NPDES Implementation of Instream Dissolved
WET Testing and Self -Monitoring
Monitoring Report Violations Sun
Instream Data Analvsis
Page 13 of 18
— [Freshwater / Saltwater]

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 III
Calculation
Calculation
---
---
Chromium VI
16
11
1 LVAM50
Copper
Calculation
Calculation
4.8
3.1
Lead
Calculation
Calculation
210
8.1
Nickel
Calculation
Calculation
74
8.2
Silver
Calculation
0.06
1.9
0.1
Zinc
Calculation
Calculation
90 11W
81
Table 1 Notes: 1%
1. FW= Freshwater, SW= Sal rater
2. Calculation = Hardness dependent standard
Only the aquatic life standards listed above are express dissolved form. Aquatic life
standards for Merry and selenium are still expressed as TotRecoverable Metals due to
bioaccumulative concerns (as are all human health standards for all metals). It is still
necessary to evaluate total rec verable aquatic life and human health standards listed in 15A
NCAC 213.0200 (e.g., arsenic a 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
VThe Water Effects Ratio (WER) is equal to one unless determined otherwise under
15A NCAC 02B .0211 Sutagraph (11) (d)
Metal
NC Dissolved Standard, µg/l
Cadmium, Acute
WER*{1.136672-[ln hardness](0.041838)} e^{0.9151 [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-[ln hardness](0.041838)} e^{0.7998[ln hardness]-
4.4451 }
Chromium III, Acute
WER*0.316 e^{0.8190[ln hardness]+3.7256}
Chromium III, Chronic
WER*0.860 e^{0.8190[ln hardness]+0.6848}
Copper, Acute
WER*0.960 e^{0.9422[ln hardness]-1.7001
Page 14 of 18

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)1 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^{0.8473[ln hardness]+0.884}
Zinc, Chronic
WER*0.986 e^{0.8473[ln hardness]+0.884}
The RPA process itself did not chan e as the result of the new metals standards. ever,
application of the dissolved and haress-dependent standards requires additional consideration in
order to establish the numeric standard for each metal of concern of each individual discharge.
N
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. 04,
Metals limits must b xpressed 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 pos i 1 n i r case-s ific translators developed in accordance with
established methodolo
RPA Permittin-- Guidance/WOBELs for Hardness -Dependent Metals - Freshwater
The RPA is designed to predict the maximum 4ely effluent concentrations for each metal of concern, based
on recent effluent data, and calculate 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 poten[ial 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...s
• Effluent hardness and upstream hardness, site -specific data is preferred
• Permitted flow
Page 15 of 18

• Receiving stream classification
In order to establish the numeric standard for each hardness -dependent metal of concern
and for each individual discharge, the Permit Writer must first determine what effluent and
instream (upstream) hardness values to use in the equations.
The permit writer reviews DMR's, Effluent Pollutant Scans, and Toxicity Test results for any
hardness data and contacts the Permittee to see if any additional data is available for
instream hardness values, upstream of the discharge.
If no hardness data is available, the permit writer may choose to do an initial evaluation
using a default hardness of 25 mg/L (CaCO3 or (Ca + Mg)). Minimum and maximum limits
on the hardness value used for water quality calculations are 25 mg/L and 400 mg/L,
respectively.
If the use of a default hardness value results m ahardness-dependent metal showing
reasonable potential, the permit writer contacts the Permittee and requests 5 site -specific
effluent and upstream hardness samples ov, a period of one week. The RPA is rerun using
the new data. low 11111k
The overall hardness value used in the water quality calculations is calculated as follows:
Combined Hardness (chronic) Akq� X
_ (Permitted Flow, cfs *Avg. Effluent Hardness, mg/L) + (s7Q10, cfs *Avg. Upstream Hardness, mg/L)
jkj 1jPFN% (Permitted Flow, cfs + s7Q10, cfs)
The Combined ness for acute is the same but the calculation uses the 1Q10 flow.
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:
Cai55 - 1
Ctotal 1 + { [Kpo] [ss(1+a)] [10-6] t
Where:
ss = in -stream suspended solids concentration [mg/1], minimum of 10 mg/L used,
Page 16 of 18

4. The numeric standard for each metal of concern is divided by the default partition
coefficient (or site -specific translator) to obtain a Total Recoverable Metal at ambient
conditions.
In some cases, where an EPA default partition coefficient translator does not exist (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 convey on 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 i4ing the\wingeq/ua)tion.
Ca = s7 10 + w Cw s — s7 10
Qw
Where: Ca = allowable effluent concentration (µg/L or mg/L)
Cwqs = NC Water Quality Standard or federal crite a
Cb = background concentration: ass e zero for\fro
except NH3* (µg/L or mg/L)
Qw = permitted effluent flo s, ma 10)
s7Q10 = summer low flow used to protect aquatichronic toxicity and human health
through the consumpticke of water, fish, and shellfish from noncarcinogens (cfs)
* Discussi re on- g with EPA ow best to address background concentrations
s other than s7Q10 may be incorporat pplicable:
1 Q1 0 = used in the equatio o protect aquatic life from acute toxicity
CA used in 3!quation to otect human health through the consumption of water, fish,
and sh llfish from carcinogens
30Q2 din the equation to protect aesthetic quality
6. The permit writer from
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.
Page 17 of 18

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 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.
eoor 'V
10. Hardness and flow values used in the Reasonable Potential Analysis for this permit included:
Parameter
Value
Comments (Data Source)
Average Effluent Hardness (m L)
[Total as, CaCO3 or Ca+M
25.0
Default v e
Average Upstream Hardness
(mg/L)
[Total as, CaCO3 or Ca+M ]
425.0
Default value
%,
7Q10 summer (cfs)
0
Lake or Tidal
1Q10 cfs
0
Lake or Tidal
Permitted Flow (MGD)
2.1
For dewaterin
Page 18 of 18