NC0048151_Fact Sheet_20230331 (2)

FACT SHEET - NCO048151
FOR PERMIT RENEWAL - SEAFOOD 40CFR REGULATED
Basic Information
Permit Writer/Date Joe R. Corporon L.G. / 31Mar2023
Permittee Etheridge Seafood Company, Inc.
Willie R. Etheridge, III, President/Owner
Etheridge Seafood Company
Facility/Address/Outfalls 4561 Mill Landing Road, Wanchese,NC 27981
Three (3) outfalls: 002 (packing ice-melt); 003 (fish
processing); 004 (packing only).
40CFR 408.210 Subpart U, Non Alaskan
Conventional Bottom Fish Processing Subcategory.
Federal/State Regulations Fish-Packing monitored in accord with DWQ memo
05Janl993.
No declared change in production since last
renewal.
Regional Office/Contact WaRO/Robert Tankard, Supervisor
Basin Name/Hydrological Unit Pasquotank/03-01-51
Receiving Stream Mill Landing Creek [segment 30-21-8]
Stream Classification in Permit/Verified SC /Yes
Does permit need Daily Max NH3 limits? No
Does permit need TRC limits/language? Yes—added TRC; footnote says monitor only used
to disinfect during cleanup.
Does permit have toxicity testing? No
Does permit have Special Conditions? Yes— Seafood production BMPs/Restricted Biocides
Does permit have instream monitoring? No
Is the stream impaired [303(d)listed]? No [facility does not discharge sanitary sewer].
Any obvious compliance concerns? No—no NOVs/no assessments (per BIMS
Any permit MODS since last permit? No
Current expiration date December 31, 2022
New expiration date December 31, 2027
Comments received on Draft Permit? Peer Review: 24Mar2023 Em2
Facility Description:
Etheridge purchases seafood from vessels and wholesale venders. They filet seafood,package, and
sell products to restaurants, seafood markets, and wholesale dealers.
40CFR Renewal Review Summary:
Renewal considered effluent limits relative to production in accord with 40CFR 408.210 Subpart U,
Non-Alaskan Conventional Bottom Fish Processing Subcategory. Updated permit text. Parameter
limits based on stated production in accord with renewal-application.
• Production—The Permittee's renewal application declares no changes in seafood production
since last renewal, therefore there are no changes in permit limits [see A. (1.)].
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Compliance Evaluation:
• Effluent data reported within the bounds of permit limits.
• Compliance Record- good, no assessments/no NOVs (Jan2019-Mar2023).
• Effluent flow consistently reported(per DMRs Jan2019-Mar2023) for:
■ Outfall 002 (Annual) as 0.0003 MGD
■ Outfall 003 (Monthly) as 0.0003 MGD (46 sample events)
■ Outfall 004 (Annual) = 0.000084 MGD
PROPOSED SCHEDULE FOR PERMIT ISSUANCE
Draft Permit to Public Notice: April 5, 2023
[Tentative] Permit Scheduled to Issue: May 12, 2023
[Tentative] Effective date June 1, 2023
NPDES Division Contact
If you have questions about any of the above information or on the attached permit,please email Joe R.
Corporon,P.G. [e-mail]].
NAME. 141 DATE: 31 MAR2023
1
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NPDES Im lementatio of Instream Dissolved Metals Standards—Freshwater Standards
The NC 20 -2015 Water uality 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, µg/1 Acute SW, µg/1 Chronic SW, µg/l
(Dissolved) (Dissolved) (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
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. Falculation=Hardness dependent standard
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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, /l
Cadmium,Acute WER*It.136672-[ln hardness](0.041838)} eA10.9151 [ln hardness]-3.14851
Cadmium,Acute Trout waters WER*11.136672-[ln hardness](0.041838)} eA10.9151[In hardness]-3.623 61
Cadmium,Chronic WER*{1.101672-[1n 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 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-[In hardness](0.145712)} • e^{1.273[ln hardness]-1.460)
Lead,Chronic WER*{1.46203-[In 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 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 e^{0.8473[ln hardness]+0.884}
General Information on the Reasonable Potential AnalysisRPA)
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/WOBELs 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 a 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.
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 = 1
Ctotal 1 + { [Kpo] [ss(l+a)] [10-6] }
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 proeram under a
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.
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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.
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)
Qv,
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)
*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.
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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) Not Applicable.
[Total as, CaCO3 or(Ca+Mg)] No metals monitoring
Average Upstream Hardness(mg/L) Not Applicable.
[Total as, CaCO3 or(Ca+Mg)] No metals monitoring
7Q10 summer(cfs) Tidal Conditions NPDES Files and BIMS
1Q10(cfs) Tidal Conditions NPDES Files and BIMS
Permitted Flow(MGD) Not Limited
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