NC0088838_Fact Sheet_20240202

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Renewal Fact Sheet
NPDES Permit No. NC0088838

Permit Writer/Email Contact Joe R. Corporon, P.G. [[e-mail]]
Date: 02Feb2024
Division/Branch: NCDEQ/DWR/NPDES Expedited Permitting

Permitting Action:
☒ Renewal – Note: This discharge is currently dormant / New owner is:
Patrick Pierce of 600 Radiator Road, LLC [[e-mail]], (704) 343–2965
605 Lexington Avenue, Suite 100
Charlotte, North Carolina 28203

Table 1. Basic Facility Information
Facility Information
Applicant/Facility Name: Radiator Specialty Company (RSC) /Radiator Specialty Company
Applicant Address: 605 Lexington Ave Ste 100
Facility Address: 600 Radiator Road, Indian Trail, NC 28709
Permitted Flow: 0.090 MGD (Average discharge 0.042 MGD over previous permit cycle)
Facility Type/Waste: MINOR Industrial, Groundwater Remediation
Facility Class: WPCS Class PC-I
Treatment Units: EQ collection tank, air stripper, integral pump, gravity flow to outfall
Pretreatment Program (Y/N) No
County: Union
Region Mooresville

Table 2 - Receiving Waterbody Information
Receiving Waterbody Information
Outfall / Receiving Stream(s): Outfall 001- UT to South Fork Crooked Creek
Stream Segment / River Basin: 13-17-20-2 / Yadkin River Basin
Stream Classification: C
Drainage Area (mi2): 2.2
Summer 7Q10 (cfs) 0.0
Winter 7Q10 (cfs): 0.0
30Q2 (cfs): 0.07
Average Flow (cfs): -
IWC (% effluent): 100%
303(d) listed/parameter: This segment is impaired for Benthos and Fish Community
on the Final 2014 303(d) list, first listed in 1998.
Subject to TMDL/parameter: No
Hydrological Unit /HUC: 03-07-12 / 030401050702
State Grid / USGS Topo Quad: G16SW / Matthews, NC

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1.0 Site History - Radiator Specialty Company (RSC) operates a 0.090 MGD groundwater
remediation facility [air-stripping system supported by four (4) recovery wells] located at its Indian
Trail site. DWR received their renewal application on 04Oct2022. This site is part of a 1994 RCRA
post-closure remediation requirement. Although treated discharge was initially accepted by a local
utility, the utility denied this discharge in 2009, and Radiator Specialty Company applied for an
individual NPDES permit, granted by the Division on 14Sep2009.
1,4-Dioxane - In 2012 the Division’s Hazardous Waste Section was advised that environmentally
significant levels of 1,4-Dioxane were detected in local area monitoring wells. Because of the
potential to influence RSC’s treatment system, the Division asked the Permittee to sample onsite
monitoring wells and report analyses of 1,4-Dioxane. However, these analyses did not detect 1,4
Dioxane above 80 µg/L due to an insufficiently low laboratory PQL [See all influent parameters
(Table 3). 1,4-Dioxane was reported in the effluent [See effluent parameters, Table 4].

Table 3. Influent Data Summary - Aug2014 thru Dec2014

Parameter Unit of Measure Average Maximum Minimum
Benzene µg/L 1.11 1.4 0.77
Chloroethane µg/L 13.3 15 9.4
2-Chlorotouluene µg/L 2.98 3.3 0.81
4-Chlorotouluene µg/L < 1 < 1 < 0.5
1,1-Dichloroethane µg/L 49.0 60 41
1,2-Dichloroetheane µg/L 0.678 0.75 0.56
1,1-Dichloroethene µg/L 27.0 31 23
Cis-1,2-Dichlorothene µg/L 22.8 30 20
Trans-1,2-Dichloroethene µg/L 2.52 3.0 2.0
Dichlorodifluoromethane µg/L 4.50 6.1 3.2
1,4 Dioxane * µg/L < 80 * < 80 * < 80 *
Ethylbenzene µg/L < 1 < 1 < 0.5
Methyl ethyl ketone µg/L < 5 < 5 < 5
Methylene Chloride µg/L < 2 < 2 < 1
Methyl isobutyl ketone (MIBK) µg/L < 5 < 5 < 5
Tetrachloroethene µg/L 84.4 100 70
Toluene µg/L < 1 < 1 < 0.5
1,1,1-Trichloroethane µg/L 1.98 2.6 1.7
Trichloroethene µg/L 5.94 7.4 4.4
Vinyl chloride µg/L 4.72 6.5 3.2
Xylenes (Total) µg/L < 2 < 2 < 1

* NOTE: Although Table 2 indicates 1,4 Dioxane as “not detected” in influent, subsequent treatment
system discharge data (DMR Jan2018-Jul2023) indicate levels exceeding 800 ug/L in onsite
monitoring wells. Significant levels of 1,4 Dioxane suggest that this remains a contaminant of
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concern (COC), currently untreatable by the previously applied air-stripper remediation system. A
redesign of the treatment system is recommended.

2.0 Receiving Stream Evaluation - UT to South Fork Crooked Creek
Note: The receiving-stream segment is listed as impaired for Benthos and Fish Community on the
Final 2014 303(d) list, first listed in 1998.
Instructions: …if not applicable, indicate NA.
1. If applicable, summarize any instream data and what instream monitoring will be proposed for this
permit action: NA
2. Is this facility a member of a Monitoring Coalition with waived instream monitoring (Y/N): NA
3. Name of Monitoring Coalition: NA
3.0. Effluent Data Reported - Rationale for Limits and Monitoring
1. If data show RP => limited in permit
2. Detected or limited dataset, but data show no RP => Monitor and Report as
contaminant of concern (COC)
3. Not detected => discontinue monitoring
Table 4. Summary of Effluent Data - * MA = Monthly Average, DM = Daily Maximum.
Parameter Units ɳ Ave Max Min Limits* &
Monitoring
RP
Yes/ No
Flow MGD 601 0.0422 0.453 0.0001 MA 0.090 ~
Total Suspended Solids (TSS) mg/L 14 2.5 < 2.6 < 2.5 DM 45.0
MA 30.0 ~
1,4 Dioxane µg/L 9 71.62 230 15.2 DM 80.0
MA 80.0 Yes
Tetrachloroethene (PCE) µg/L 23 2.42 6.7 < 1 DM 3.0
MA 3.0 Yes
1,1-Dichloroethane (1,1 DCA) µg/L 10 1.5 2.1 <0.5 Monitor
Quarterly No
Vinyl Chloride µg/L 23 All non-detects, < 1 to < 2 Monitor
Quarterly No
Methylene Chloride
(Chloroethane) µg/L 8 All non-detects, < 2 to < 5 Monitor
Quarterly No
Trichloroethene (TCE) µg/L 10 All non-detects, < 0.5 to < 2 Monitor
Quarterly No
Benzene µg/L 10 All non-detects, < 0.5 to < 2 Monitor
Quarterly No
Toluene µg/L 10 All non-detects, < 0.5 to < 2 Monitor
Quarterly No
1,1-Dichloroethlyene (1,1, DCE) µg/L 2 All non-detects, < 0.5 to < 1 Discontinue
Monitoring No
1,2-Dichloroethene (1,2, DCE) µg/L 2 All non-detects, < 1 to < 5 Discontinue
Monitoring No
1,2-Dichloroethane (1,2 DCA) µg/L 2 All non-detects, < 0.5 to < 1 Discontinue
Monitoring No
1,1,1-Trichloroethane (1,1,1
TCA) mg/L 2 All non-detects, < 4 to < 4 Discontinue
Monitoring No

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4.0 Compliance Summary

Compliance Record - Effluent Limits &Whole Effluent Toxicity:
• There were no reported permit limit exceedances during this timeperiod.
• The permittee was issued a Notice of Violation (NOV) for a WET-test failure on 30Dec2019.
• See Monitoring Report Violations Export Jan2019-Jul2023).

Most recent compliance inspection: This facility discontinued reporting a treatment-system
discharge on 14Jul2020 (BIMS). The last facility inspection (23Sep2020) reported that there were no
restrictions in the permit, and that monitoring for 1,4 Dioxane and chlorinated solvents are still
required.

5.0 Proposed Schedule for Permit Issuance
Draft Permit to Public Notice: October 26, 2023
Redrafted for review February 2, 2024
[Tentative] Permit Scheduled to Issue: March 14, 2024
[Tentative] Effective date April 1, 2024

6.0 NPDES Division Contact
If you have questions on any of the above information or in the attached permit, please email Joe R.
Corporon, P.G. [[e-mail]].

NAME: DATE: 02FEB2024

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)
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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
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 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/l
Cadmium, Acute WER*{1.136672-[ln hardness](0.041838)} ∙ e^{0.9151 [ln
hardness]-3.1485}
Cadmium, Acute Trout
waters
WER*{1.136672-[ln hardness](0.041838)} ∙ e^{0.9151[ln
hardness]-3.6236}
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}
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Chromium III, Chronic WER*0.860 ∙ e^{0.8190[ln hardness]+0.6848}
Copper, Acute WER*0.960 ∙ e^{0.9422[ln hardness]-1.700}
Copper, Chronic WER*0.960 ∙ e^{0.8545[ln hardness]-1.702}
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)} ∙ 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}

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.
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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, 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
• 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 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 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. 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.
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_______________
Ctotal 1 + { [Kpo] [ss(1+a)] [10-6] }
Where:
ss = in-stream suspended solids concentration [mg/l], 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 sheet labeled
DPCs.

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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.

3. 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) (Cwqs) – (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.
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

4. 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.

5. 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.

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6. 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.

7. 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.

8. 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+Mg)]
Ave 216 mg/L ~
Average Upstream Hardness
(mg/L)
[Total as, CaCO3 or (Ca+Mg)]
~ ~
7Q10 summer (cfs) 0.0 Zero-flow conditions
[7Q10 and 30Q2 = 0.0 cfs
1Q10 (cfs) 0.0 Zero-flow conditions
[7Q10 and 30Q2 = 0.0 cfs
Permitted Flow (MGD) 0.090 Average for previous
permit cycle 0.042 MGD