NC0085871_Fact Sheet_20240312

DEQ/DWR/NPDES
FACT SHEET FOR NPDES PERMIT RENEWAL
PERMIT NC0085871
Table 1 - Facility Information
Applicant/Facility Flakt Product, Inc. /Former Flakt Products Site
Name:
Applicant Address: 131 Pheonix Crossing, Bloomfield, Connecticut 06002
Keith Knauerhase, Chief Counsel,ABB, Inc.
Vance Litz, Environmental Project Leader[[e-mail]]
Facility Contacts: 45 Griffin Road,Bloomfield,CT 06022
Joe Deatherage, Lead Consultant—Environmental Engineer,
WSP USA,2030 Falling Waters Road, Suite 300,Knoxville, TN 37922
oe.deathera e ws .com ; Mobil: 865-414-0351
Facility Address: 2000 Lowery Street; Winston-Salem,NC 27101
Permitted Flow: 0.0864 MGD
Type of Waste: Groundwater-remediated to remove chlorinated solvents
Facility/Permit Status: WPCS Class PC-I/Renewal - Dormant discharge, sampling and
repo in waved 04Au 2017
County: Fors th County
Miscellaneous
Receiving Stream: Brushy Fork I Stream Class: C
Drainage Basin Yadkin Pee-Dee (Upper Yadkin
Hydrological Unit: 03-07-04 Index No.: 12-94-12-6
Drainage Area (mil : 7.3 HUC: 03040101
Summer 7Q 10 cfs : 2.9 303 d Listed? No
Winter 7Q10 cfs : - Regional Office: Winston-Salem
30Q2 (cfs): - USGS Quad: Winston-Salem East
Average Flow cfs : - Permit Writer: Joe R. Corporon, P.G.
IWC (%): 4.5% Date: Updated 12Mar2024
Background --Flakt Products Inc. (Flakt)manufacturing plant ceased operations in 1986. A
subsequent site assessment indicated soil and groundwater contamination likely resulting from
metal fabrication activities employing solvent degreasing baths, an above ground storage tank
(7,000 gallons), and other sources. Soil remediation began in January 1993 and ceased once
volatile organic compounds (VOCs) concentrations dropped below established target levels.
In January 1997, the Division issued an NPDES permit for proposed groundwater-treatment and
discharge. The Permittee was permitted to discharge to Brushy Fork at a flow rate not to exceed
0.0288 MGD. DWR approved an Authorization to Construct(ATC), and after receiving the
Permittee's Engineer's Certification (November 1997), discharge commenced in July 1998.
In March 2016, an influent scan for Volatile Organic Compounds (VOCs) detected the following:
Table 2: Initial Influent VOCs Detected
Compounds UoM Concentration
1,1,1-tichloroethane /L 40.8
1,1-dichloroethane /L 9.00
1,1-dichloroethene /L 219
1,2-dichloroethane /L 4.60
Chloroform /L 1.64
Trichloroethene /L 45.6
Trichlorofluoromethane /L 1.57
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Treatment facilities consisted of:
• 60 initial extraction wells, [later reduced to 7 extraction wells]
• an equalization tank,
• air stripper,
• chemical feed system (iron sequestering-citric acid)
• flow meter
• bag filter and/or activated carbon filter [optional]
NOTE: Bag filter and activated-carbon filter were subsequently judged"not
required,"therefore never installed.
DWR modified the permit in 1998 to expand the permitted flow to its current limit of 0.0864
MGD. Later in 2000, the Division reduced the monitoring frequencies to current levels of
Quarterly based on"no detects." The permit was renewed in June 2009 to remove monitoring for
metals based on the absence of reasonable potential [MAX predicted or non-detect value less
than 50% of the standard/EPA criteria]. In August 2017, DWR granted a Waiver of Monthly
Reporting although the Permittee continues to pay annual permit fees.
Receiving Stream -- This facility discharges to Brushy Fork, currently a Class C stream,
within the Upper Yadkin, Yadkin-Pee Dee River Basin. Brushy Fork has a summer 7Q 10 flow of
2.9 cfs [defined in 1997] and it joins Salem Creek downstream approximately 1,500 ft. Brushy
Fork is not listed as impaired [303 (d) list].
Compliance-BIMS lists no permit limit violations or civil penalties for this permit. Whole
Effluent Toxicity(WET) testing [Chronic, Ceriodaphnia at 4.5% effluent concentration]
consistently passed and monitoring will continue Quarterly for this renewal. WSRO
complimented the facility's operation and maintenance [Compliance Inspection Report, 2016].
Data Evaluation -When active, this facility discharged"intermittently"ranging from 11 to
21 consecutive days in a given month. Because there have been no discharges since 2017, this
permit renewal will reflect the previous permit's parameters of concern.
Table 3: DMR Data Summary [Jan2009 to Jun2017]
Parameter UoM Average Maximum Minimum Count
(
Flow, MGD MGD 0.021 0.207 < 0.000003 1,441
TSS m /L 1.56 6.53 < 1 32
Benzene /L No Detects < 1 33
Carbon tetrachloride /L No Detects < 1 33
Chloroform /L No Detects < 1 33
1,1-dichloroethene /L 1.16 3.54 1 33 33
1,2-dichloroethane /L No Detects < 1 33
Methylene chloride /L No Detects < 5 33
Trichloroethene /L No Detects < 1 33
Tetrachloroethene /L No Detects < 1 33
1,1,2,2-tetrachloroethane /L No Detects < 1 33
1,1,2-trichloroethane µg/L No Detects < 1 33
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Renewal Summary:
1. No changes to parameters of concern (POC).
2. RPA suggests we discontinue monitoring for some parameters intermittently detected.
Instead, DWR judges it prudent to reduce monitoring from Quarterly to Annually
[best professional judgment(BPJ)] as these remain contaminants of concern (COCs).
3. Effluent vs. receiving stream IWC confirmed at 4.5 % (see attached WLA).
4. Added Monthly Average limit for TSS [both limits required by EPA]
5. Updated WET text [section A. (2.)]
6. Updated Special Condition for eDMR compliance [section A. (3.)].
Proposed Permit Issuance Schedule
Draft Permit to Public Notice January 4, 2024
Submittal for signature March 12, 2024
Permit Scheduled to Issue (Tentative) March 22, 2024
Effective Date (Tentative) May 1, 2024
Note: permit issuance was delayed due to State signatory authorization issues.
NPDES Division Contact
If you have questions regarding any of the above information or on the attached permit, please
contact Joe R. Corporon P.G. [[e-mail]].
NAME: DATE: Updated 12Mar2024
NPDES Im 1 mentatio of Instream Dissolved Metals Standards—Freshwater Standards
The NC 2007 2015 Wat&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/1 Chronic FW, Acute SW, µg/l Chronic SW,
(Dissolved) µg/1 (Dissolved) µg/1
(Dissolved) (Dissolved)
Arsenic 340 150 69 36
Beryllium 65 6.5 --- ---
Cadmium Calculation Calculation 40 8.8
Chromium III Calculation Calculation --- ---
Chromium VI 16 11 1100 50
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Copper Calculation Calculation 4.8 3.1
Lead Calculation Calculation 210 8.1
Nickel Calculation Calculation 74 8.2
Silver Calculation 0.06 1.9 0.1
Zinc Calculation Calculation 90 81
Table 1 Notes:
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 213.0200 (e.g., arsenic at 10 µg/1 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, /l
Cadmium, Acute WER*{1.136672-[ln hardness](0.041838)} e^{0.9151 [In
hardness]-3.14851
Cadmium, Acute Trout WER*{1.136672-[ln hardness](0.041838)} eA10.9151[In
waters hardness]-3.623 61
Cadmium, Chronic WER*{1.101672-[In hardness](0.041838)} eA10.7998[ln
hardness]-4.4451}
Chromium III, Acute WER*0.316 • e^{0.8190[ln hardness]+3.7256}
Chromium III, Chronic WER*0.860 eAtO.8190[ln hardness]+0.6848}
Copper, Acute WER*0.960 eAtO.9422[ln hardness]-1.7001
Copper, Chronic WER*0.960 e^{0.8545[ln hardness]-1.7021
Lead, Acute WER*{1.46203-[ln hardness](0.145712)} • e^{1.273[ln hardness]-
1.460}
Lead, Chronic WER*{1.46203-[ln hardness](0.145712)} • eAl1.273[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 All.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 eA10.8473[ln hardness]+0.884}
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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 an RPA on the Freshwater hardness-dependent metals the Permit Writer
compiles the following information:
• Critical low flow of the receiving stream, 7Q 10 (the spreadsheet automatically
calculates the 1 Q 10 using the formula 1 Q 10= 0.843 (s7Q 10, cfs) 0.993
• Effluent hardness and upstream hardness, site-specific data is preferred
• Permitted flow
• Receiving stream classification
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.
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The overall hardness value used in the water quality calculations is calculated as follows:
Combined Hardness (chronic) =
(Permitted Flow, cfs *Avg.Effluent Hardness,mg/L)+(s7Q10, cfs *Avg. Upstream Hardness,mg/L)
(Permitted Flow, cfs+s7Q10,cfs)
The Combined Hardness for acute is the same but the calculation uses the IQ 10 flow.
3. The permit writer converts the numeric standard for each metal of concern to a total
recoverable metal, using the EPA Default Partition Coefficients (DPCs) or site-specific
translators, if any have been developed using federally approved methodology.
EPA default partition coefficients or the "Fraction Dissolved" converts the
value for dissolved metal at laboratory conditions to total recoverable metal
at in-stream ambient conditions. This factor is calculated using the linear
partition coefficients found in The Metals Translator: Guidance for
Calculating a Total Recoverable Permit Limit from a Dissolved Criterion
(EPA 823-B-96-007, June 1996) and the equation:
Cdiss = I
Ctotal 1 + { [Kpo] [ss(i+a)] p of i
4. The Where:
ss =in-stream suspended solids concentration [mg/1], minimum of 10 mg/L
used, and
Kpo and a =constants that express the equilibrium relationship between
dissolved and adsorbed forms of metals. A list of constants used for each
hardness-dependent metal can also be found in the RPA program under a
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 conversion factors see the June,
1996 EPA Translator Guidance Document.
5. The RPA spreadsheet uses a mass balance equation to determine the total allowable
concentration(permit limits) for each pollutant using the following equation:
Ca= (s7Q10+ Qw) (Cwgs)—(s7Q10) (Cb)
Qw
Where: Ca=allowable effluent concentration (µg/L or mg/L)
Cwqs =NC Water Quality Standard or federal criteria(µg/L or mg/L)
Cb=background concentration: assume zero for all toxicants except
NH3* (µg/L or mg/L)
Qw=permitted effluent flow (cfs, match s7Q 10)
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)
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* Discussions are on-going with EPA on how best to address background
concentrations
Flows other than s7Q10 may be incorporated as applicable:
IQ 10 =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 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) Metals monitoring not
[Total as, CaCO3 or(Ca+Mg)] required
Average Upstream Hardness (mg/L)
[Total as, CaCO3 or(Ca+Mg)]
7Q10 summer(cfs) 2.9 IWC 4.5 %
1 Q 10 (cfs) 2.43
Permitted Flow (MGD) 0.0864
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