NC0089109_Fact Sheet_20230525

NCDEQ/DWR
FACT SHEET FOR NPDES PERMIT DEVELOPMENT
RENEWAL
Befesa Zinc Metal, LLC
NC0089109
Facility Information
1. Facility Name: Befesa Zinc Metal,Li,C
(2.)Permitted Flow(MGD): 0.98 (6.)County: Rutherford
(3.)Facility Class: _II 1 (7.)Regional Office: Asheville
(4.)Pretreatment Program: N/A (8.)USGS Topo Quad F11SW
(5.) Permit Status: Renewal (9.)USGS Quad Name:
Stream Characteristics
(1.) Receiving Stream: ............_.._......................fi..._Broad River.._.._....._... (7.)Drainage AreaAmi)..... 575 _
2. Sub-basin . 03-08-02 (8.)Summer 7Q10 cfs : 167
(3.)Stream Index Number: 9-(36.5) (9)Winter 7Q10(cfs): _334
4. Stream Classification: I WS-IV 10. 30Q 2 cfs : 403
(5.))303(d)Status:......................_......................................... ' Not listed _..._._..._.........................__(11.)Average Flow...(cfsl: 914..........................____...._.-.........
(6.)305(b)Status: (12.) IWC%: 0.9
Summary
This is a renewal for the Befesa Zinc Metal,LLC permit. The facility is located in the
southern portion of the Rutherford County.The facility uses the impure zinc oxide that is
generated from the parent company's (AZR) recycle plants,which recycle Electric Arc
Furnace (EAF) dust.The EAF dust is a zinc containing waste generated by the North
American steel mini mills. The facility produces approximately 55,000 tons of Special High
grade Zinc metal.The process includes zinc oxide leaching,extraction of zinc with an
organic ligand electrowinning,and casting. The facility achieves significant degree of
recycling of the reagents that are used in the process. This is a first facility of this type in the
USA,and there are no effluent guidelines for Zinc recycling facilities.
The facility went through a bankruptcy in 2016 and now reorganized. It has undergone
through substantial changes and improvements to the production and wastewater facilities.
Potable water and sanitary sewer service for the facility is provided by the Forrest City.
Antidegradation review
Per NC antidegradation policy (15A NCAC 2B.0201,each applicant for an NPDES permit
expansion must document an effort to consider non-discharge alternatives pursuant to 15A
NCAC 2H.0105(c)(2).The original estimates for the wastewater flow submitted by the
facility prior to the beginning of the production were incorrect. The facility employs a new
technology that has not been used for Zinc production in this country.Therefore,it was
difficult to correctly calculate a flow limit for the new facility, the re-calculated flow estimate
is 0.98 MGD.The updated EAA was submitted by the facility on September 6, 2017. The
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NPDES Permit Fact Sheet- 05/25/23 American Zinc Products, LLC
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EAA was approved on September 29,2017,it allows discharge of 0.98 MGD treated
industrial wastewater. The wastewater generated by the facility is essentially a clean brine
solution that has a very high concentration of chlorides (17,000 mg/L). Hence,the non-
discharge options are not viable. If this wastewater is discharged to the soil surface or into
the infiltration galleries,it will contaminate the soil and the aquafer.The Forrest City POTW
is also unable to treat this discharge since it will cause a major toxicity problem and likely
destroy the microbial biomass in the treatment system,which will result in a complete failure
of the POTW.
Therefore,DWR staff concurred with the EAA conclusion that expansion at the current
location was the most environmentally sound alternative from the reasonably cost-effective
options (per 15A NCAC 2H.0105).
Compliance Schedule
Due to the recent changes in the state water quality standards,the new dissolved state
standard for Cadmium has become more stringent. Review of the effluent data indicated that
the facility will not be able to comply with the new permit limit for Cadmium.The facility
conducted a bench-scale testing with the effluent to evaluate various treatment options.
Based on the results of the test the facility proposed a 10-year compliance schedule. The
Division discussed the schedule with the applicant and negotiated a reduced compliance
schedule of 7.5 years,it will be added to the permit.
With this renewal,the facility requested removal of the compliance schedule since it was
able to achieve Final Cadmium Limits prior to the expiration of the compliance schedule.
Compliance History
The facility has experienced numerous production and compliance issues since the start-up,
which led to the bankruptcy in February of 2016.The facility has been purchased by a new
owner and completed several improvement projects.
During the last 5 years the facility violated pH limits 10 times.Although, the majority of
violations were pH measurements of 5.9,which is very close to the limit of 6.0 (8 out of 10).
RPA
The need for toxicant limits is based upon a demonstration of reasonable potential to exceed
water quality standards,a statistical evaluation that is conducted during every permit renewal
utilizing the most recent effluent data for each outfall. The RPA is conducted in accordance
with 40 CFR 122.44 (d) (i). The NC RPA procedure utilizes the following: 1) 95%
Confidence Level/95%Probability;2) assumption of zero background;3) use of
detection limit for"less than"values;and 4) streamflows used for dilution consideration
based on 15A NCAC 2B.0206. Effective April 6,2016,NC began implementation of
dissolved metals criteria in the RPA process in accordance with guidance titled NPDES
Implementation of Instream Dissolved Metals Standards, dated June 10,2016.
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A reasonable potential analysis was conducted on effluent toxicant data collected between
during the last 5 years. Pollutants of concern included toxicants with positive detections and
associated water quality standards/criteria. Based on this analysis, the following permitting
actions are proposed for this permit:
• Effluent Limit with Monitoring. The following parameters will receive a water
quality-based effluent limit (WQBEL) since they demonstrated a reasonable
potential to exceed applicable water quality standards/criteria: Total Cadmium.
• 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: Total Arsenic,Chlorides,
Chromium (VI),Total Copper,Total Lead,Total Nickel,Total Selenium,Total
Silver,and Total Zinc.
• 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: Total Phenolic
Compounds,Total Cyanide,Total Fluoride,Total Mercury,Total Tin,Total
Antimony,Total Aluminum,and Total Thallium.
Attached is a spreadsheet of the RPA results as well as a copy of the Dissolved Metals Implementation Fact
Sheet for freshwater/saltwater to this Fact Sheet.
Toxicity Testing Limitations
Permit limits and monitoring requirements for Whole Effluent Toxicity (WET) have been
established in accordance with Division guidance (per WET Memo, 8/2/1999). Per WET
guidance,all NPDES permits issued to Major facilities or any facility discharging"complex"
wastewater (contains anything other than domestic waste)will contain appropriate WET
limits and monitoring requirements,with several exceptions. The State has received prior
EPA approval to use an Alternative WET Test Procedure in NPDES permits,using single
concentration screening tests,with multiple dilution follow-up upon a test failure.
Describe proposed toxicity test requirement This facility discharges complex wastewater, and a
chronic WET limit at 0.9% effluent will continue.
During the last 5 years the facility passed all WET test with one exception,test in January
2022 failed.
Fish Tissue Monitoring
The facility performed fish tissue sampling for 3 fish species at upstream and downstream
locations in accordance with the plan approved by the DWR.The fish tissue samples were
analyzed for Arsenic,Cadmium,and Zinc.All the results were below the fish tissue
screening levels established by the NC DHHS.The only exception was Arsenic in one
upstream sample of redhorse tissue.This Arsenic measurement exceeded the NC DHHS
screening level. But even that sample was qualified by the laboratory as "an estimate".
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Summary of Permitting Actions
Parameter Current Permit Proposed Basis for Condition/Change
Change
Flow 0.98 MGD No change 15A NCAC 2H.0105
NH3-N Quarterly monitoring No change Parameter of concern
TSS Monitoring-2/Month Monthly Based on the review of data
monitoring Parameter of concern
Total Aluminum, Quarterly monitoring Removed Based on the RPA results
Total Tin,Total
Antimony,Total
Fluoride
Total Selenium, No monitoring Quarterly Based on the RPA results
Total Silver monitoring
Total Nickel, Monthly monitoring Quarterly Based on the RPA results
Total Lead monitoring
Total Cadmium MA 90.4 µg/L No change WQBEL. State WQ standard, 15A
DM 454.4 µg NCAC 2B .0200.Based on the RPA
results.
Intermediate standards and compliance
schedule eliminated due to the early
achievement of the final standards.
Chlorides Quarterly monitoring No change WQBEL. State WQ standard, 15A
NCAC 2B .0200.Based on the RPA
results.
Chromium (VI) Quarterly monitoring No change WQBEL. State WQ standard, 15A
NCAC 2B .0200.Based on the RPA
results.
Total Cobalt Quarterly monitoring Removed Based on the review of the data
Total Copper Quarterly monitoring No change WQBEL. State WQ standard, 15A
NCAC 2B .0200.Based on the RPA
results.
Total Arsenic Quarterly monitoring No change WQBEL. State WQ standard, 15A
NCAC 2B .0200.Based on the RPA
results.
Total Zinc Monthly monitoring No change WQBEL. State WQ standard, 15A
NCAC 2B .0200. Based on the RPA
results.
Total Iron Quarterly monitoring Removed Based on the elimination of the state
Iron standard
pH 6.0—9.0 SU No change WQBEL. State WQ standard, 15A
NCAC 2B .0200
Toxicity Test Chronic limit,0.9% No change WQBEL. No toxics in toxic amounts.
effluent. 15A NCAC 2B.0200 and 15A NCAC
2B.0500
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Turbidity Monitoring in the No change Parameter of concern
effluent,upstream and
downstream
Fish tissue Sampling one time No change Added to address a comment from the
monitoring during the permit cycle regional office
Priority Pollutant Sampling one time No change Added to address a comment from the
Scan during the permit cycle regional office
MA-monthly average
DM-Daily Maximum
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/NO): NO
If YES,confirm that antibacksliding provisions are not violated: N/A
Proposed Schedule for Permit Issuance
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-day comment period indicating the interest
of the party filing such request and the reasons why a hearing is warranted.
Draft Permit to Public Notice: March 21,2023 (est.)
Permit Scheduled to Issue: May 22,2023 (est.)
State Contact Information
If you have any questions on any of the above information or on the attached permit,please
contact Sergei Chernikov at [phone], or sergei.chernikovencdenr.gov.
Fact Sheet Attachments
• RPA Spreadsheet Summary
• Dissolved Metals Implementation/Freshwater or Saltwater
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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/1 Chronic FW,µg/1 Acute SW,µg/1 Chronic SW,pg/1
(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. 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/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,µg/1
Cadmium,Acute WER*{1.136672-[ln hardness](0.041838)} • e^{0.9151 [ln hardness]-
3.1485}
Cadmium, Acute Trout WER*{1.136672-[ln hardness](0.041838)} • e^{0.9151[In hardness]-
waters 3.6236}
Cadmium, Chronic WER*{1.101672-[/n hardness](0.041838)1 • e^{0.7998[In hardness]-
4.4451}
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Chromium III,Acute WER*0.316 • e^{0.8190[ln hardness]+3.7256}
Chromium III,Chronic WER*0.860 • e^{0.8190[1n hardness]+0.6848}
Copper,Acute WER*0.960 • e^{0.9422[ln hardness]-1.700}
Copper, Chronic WER*0.960 • e^{0.8545[In hardness]-1.702}
Lead,Acute WER*{1.46203-[/n hardness](0.145712)1 • e^{1.273[In hardness]-
1.460}
Lead, Chronic WER*{1.46203-[ln hardness](0.145712)} • e^{1.273[In hardness]-
4.705}
Nickel,Acute WER*0.998 • e^{0.8460[In hardness]+2.255}
Nickel, Chronic WER*0.997 • e^{0.8460[ln hardness]+0.0584}
Silver,Acute WER*0.85 • e^{1.72[In hardness]-6.59}
Silver, Chronic Not applicable
Zinc,Acute WER*0.978 • e^{0.8473[In hardness]+0.884}
Zinc, Chronic WER*0.986 • e^{0.8473[In hardness]+0.884}
General Information on the Reasonable Potential Analysis (RPA)
The RPA process itself did not change as the result of the new metals standards. However,
application of the dissolved and hardness-dependent standards requires additional
consideration in order to establish the numeric standard for each metal of concern of each
individual discharge.
The hardness-based standards require some knowledge of the effluent and instream
(upstream) hardness and so must be calculated case-by-case for each discharge.
Metals limits must be expressed as `total recoverable'metals in accordance with 40 CFR
122.45(c).The discharge-specific standards must be converted to the equivalent total values
for use in the RPA calculations.We will generally rely on default translator values developed
for each metal(more on that below),but it is also possible to consider case-specific
translators developed in accordance with established methodology.
RPA Permitting Guidance/WQBELs for Hardness-Dependent Metals-Freshwater
The RPA is designed to predict the maximum likely effluent concentrations for each metal of concern,based
on recent effluent data,and calculate the allowable effluent concentrations,based on applicable standards and
the critical low-flow values for the receiving stream.
If the maximum predicted value is greater than the maximum allowed value (chronic or
acute),the discharge has reasonable potential to exceed the standard,which warrants a
permit limit in most cases. If monitoring for a particular pollutant indicates that the pollutant
is not present (i.e. consistently below detection level),then the Division may remove the
monitoring requirement in the reissued permit.
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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, 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 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 1Q10 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.
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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")] [101 }
Where:
4. The 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 sheet labeled DPCs.
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) (Cwqs) — (s7Q10) (Cb)
Qw
Where:Ca=allowable effluent concentration(pg/L or mg/L)
Cwqs=NC Water Quality Standard or federal criteria(µg/L or mg/L)
Cb=background concentration:assume zero for all toxicants except NH3* (µg/L or mg/L)
Qw=permitted effluent flow(cfs,match s7Q10)
s7Q10=summer low flow used to protect aquatic life from chronic toxicity and human health
through the consumption of water,fish,and shellfish from noncarcinogens(cfs)
*Discussions are on-going with EPA on how best to address background concentrations
Flows other than s7Q10 may be incorporated as applicable:
1Q10=used in the equation to protect aquatic life from acute toxicity
QA=used in the equation to protect human health through the consumption of water,fish,
and shellfish from carcinogens
30Q2=used in the equation to protect aesthetic quality
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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) 25.0 Default value
[Total as,CaCO3 or (Ca+Mg)]
Average Upstream Hardness
(mg/L) 25.0 Default value
[Total as,CaCO3 or(Ca+Mg)]
7Q10 summer (cfs) 0 Lake or Tidal
1Q10 (cfs) 0 Lake or Tidal
Permitted Flow (MGD) 2.1 For dewatering
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