NC0023736_Fact Sheet_20240219

Fact Sheet
NPDES Permit No. NCO023736
Permit Writer/Email Contact Gary Perlmutter, [e-mail]:
Date Initiated: February 19, 2024
Division/Branch: NC Division of Water Resources / NPDES Municipal Permitting Unit
Fact Sheet Template: Version 09Jan2017
Permitting Action:
❑ Renewal
❑ Renewal with Expansion
❑ New Discharge
® Modification (Fact Sheet should be tailored to mod request)
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 Form 2C with correct analytical requirements based
on industry category.
Complete applicable sections below. If not applicable, enter NA.
1. Basic Facility Information
Facility Information
Applicant/Facility Name:
City of Lenoir — Gunpowder Creek WWTP
Applicant Address:
P.O. Box 958, Lenoir, NC 28645
Facility Address:
450 Pine Mountain Rd, Hudson, NC 28638
Permitted Flow:
2.0 MGD
Facility Type/Waste:
MAJOR Municipal; 55% domestic, 45% industrial'
Facility Class:
Grade III
Treatment Units:
Screening, Grit Removal, Sequence Batch Reactors, Post
Equalization, Chlorination, Dechlorination, Step Aeration
Pretreatment Program (Y/N)
Yes
County:
Caldwell
Region
Asheville
' From permitted industrial flow of 0.899 MGD.
Briefly describe the proposed permitting action and facility background: The City of Lenoir had requested
a modification to the NPDES permit for its Gunpowder WWTP, submitting an application on January 2,
2024. The permit renewal was issued in February 2021 and included Total Copper limits of 15.4 µg/L
monthly average and 18.8 µg/L daily maximum. In August 2021, a modification to the permit was issued
for the addition of a three-year compliance schedule to meet the Total Copper limits by April 1, 2024. Prior
to the current modification request, the City submitted a Water Effects Ratio (WER) study report, dated
Page 1 of 5

September 2023, which recommends changing the Total Copper limits to 75.3 µg/L monthly average and
98.5 µg/L daily maximum. The City also submitted a WER Checklist for review.
This 2.0 MGD facility serves the communities of Hudson, Lenoir and Sawmill. The WWTP treats a
combination of domestic and industrial wastewater with a pretreatment program involving one non -
categorical Significant Industrial User (SIU): BeoCare Inc. (medical textiles) and one Categorical Industrial
User (CIU): Lenoir Mirror #1 (413.74-G - electroless plating).
2. Receiving Waterbody Information
Receiving Waterbody Information
Outfalls/Receiving Stream(s):
Outfall 001/Gunpowder Creek
Stream Segment:
11-55-(1.5)
Stream Classification:
WS-Iv
Drainage Area (mi):
12.9
Summer 7Q 10 (cfs)
2.9
Winter 7Q10 (cfs):
4.0
30Q2 (cfs):
5.8
Average Flow (cfs):
17.4
IWC (% effluent):
52%
303(d) listed/parameter:
Benthos
Subject to TMDL/parameter:
State-wide Mercury TMDL
Basin/Sub-basin/HUC:
Catawba/03-08-32/03050101
USGS Topo Quad:
D13SW/Granite Falls, NC
3. Effluent Data Summary and WER study review
Effluent data for Outfall 001 is summarized in Table 1 for the period of April 2021 (effective date of the
current permit) — October 2023.
Table 1. Effluent Data Summary Outfall 001.
Parameter
Units
Average
Max
Min
Permit Limit'
Total Copper
µg/L
15.2
30
6
MA = 15.4
DM = 18.7
1 MA = Monthly Average, DM = Daily Maximum.
From the data review, 14 samples or 42% of samples collected exceeded the monthly average limit and 8
or 24% of samples collected exceeded the daily average limit. From this review, it is likely that the Permittee
is incapable of consistently meeting the Total Copper limit and thus justifying the current compliance
schedule. The data also justify the City's conducting the WER study, which has the potential of providing
less stringent limits as the report recommends.
Page 2 of 5

Review of the WER study report and accompanying checklist found them to be complete and properly
conducted. Four rounds of WER studies were conducted, three using Ceriodaphnia dubia and one using
Fathead Minnow (Pimephales promelas) as a second species. Study species used are consistent with the
permit toxicity testing requirements [see permit conditions A. (3.) Chronic Toxicity Permit Limit and A.
(4.) Effluent Pollutant Scan (2.0 MGD); section "Additional Toxicity Testing Requirements for Municipal
Permit Renewal."]. No issues were found in the review and the recommended WER-based copper limits
were found to be appropriately derived.
4. Water Quality -Based Effluent Limitations (WQBELs)
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 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 '/2 detection limit for "less than" values; and 4) streamflows used for dilution
consideration based on 15A NCAC 213.0206. 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.
An RPA was run on effluent copper data sampled from April 2021 October 2023, yielding a reasonable
potential to exceed the current permit copper limits of 15.4 µg/L monthly average and 18.8 µg/L daily
maximum. The WER study recommended 75.3 µg/L chronic and 98.5 µg/L acute limits were then
compared against the effluent data. The maximum predicted value of 33.3 µg/L is less than half of the
allowable effluent concentration to meet the WER-based chronic limit, thus neither limits nor monitoring
are required. As a result, the copper limits and monitoring requirements have been removed from the permit.
In addition, the compliance schedule for the copper limits has been removed. For continued consideration
of WER-based copper limits during the next permit cycle, a special condition has been added requiring the
Permittee to run a confirmation WER study for submittal with the permit renewal application.
5. 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): Yes.
If YES, confirm that antibacksliding provisions are not violated: Total Copper limits and monthly
monitoring requirements as well as the copper limit compliance schedule have been removed from the
permit based on an RPA evaluation of the data against the submitted WER-based recommended chronic
limit, finding no reasonable potential to exceed the allowable concentration.
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6. Summary of Proposed Permitting Actions
Table 6. Current Permit Conditions and Proposed Changes.
Parameter
Current Permit'
Proposed Change
Basis for Condition/Change
Flow
MA 2.0 MGD
No change
15A NCAC 213.0505
MA = 15.4 µg/L
No reasonable potential to exceed
DM = 18.8 µg/L
Remove from
allowable WER-based discharge
Total Copper
Monitor monthly
concentration found after evaluation of
3-year compliance
permit.
WER study report and submitted
schedule
effluent data.
WER confirmation
No requirement
Add special
To verify continued use of WER
condition
consideration in next permit renewal
1MGD = Million gallons per day, MA = Monthly Average, WA = Weekly Average, DM = Daily Maximum.
13. Public Notice Schedule:
Permit to Public Notice: 01/06/2024.
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.
14. NPDES Division Contact:
If you have questions regarding any of the above information or on the attached permit, please contact Gary
Perlmutter at [phone] or via email at gary_perlmutterkncdenr.gov.
15. Fact Sheet Addendum (if applicable):
Were there any changes made since the Draft Permit was public noticed (Yes/No): Comments were
received from Lisa Triplett (ORC), questioning the addition of Chlorinated Phenols quarterly monitoring
in the permit. Comments were also received from the Catawba Riverkeeper, recommending PFAS language
be added to the permit as well as adding E. coli requirements. While the riverkeeper's comments are
appreciated, they are not specific to this permit's modification, which is for total copper limits. These
comments can be addressed upon the next permit renewal.
If Yes, list changes and their basis below:
• Quarterly monitoring for Chlorinated Phenols was removed as this was added by mistake.
16. Fact Sheet Attachments (if applicable):
Page 4 of 5

• WER study report
• WER checklist
• Request to modify permit
• Effluent copper data, Apr 2021 - Nov 2023
• Comments from ORC
• Comments from Catawba Riverkeeper
• Affidavit of Public Notice
Page 5 of 5

E T
environmental, Inc.
P.O. Box 16414, Greenville, SC 29606
[phone] . FAX [phone]
Craftsman Court, Greer, SC 29650
WATER EFFECT RATIO STUDY
City of Lenoir Gunpowder Creek WWTP
NPDES Permit #NC0023736
Metal: Copper
Issued: September 2023
Lenoir Gunpowder WER Study -Cu
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ETT Environmental, Inc.; 9/23

SUMMARY OF RESULTS
The results of the Water Effect Ratio modify the copper limits as follows;
Average Copper Limit
Revised Limit Using WER: 75.3 ug/L
Maximum Copper Limit
Revised Limit Using WER: 98.5 ug/L
EPA or state regulators may adjust the limits based on "what is needed", derived from
historical reported values for copper in site effluent.
Lenoir Gunpowder WER Study -Cu
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ETT Environmental, Inc.; 9/23

1.0 INTRODUCTION
The City of Lenoir Gunpowder Creek Wastewater Treatment Plant (WWTP) discharges effluent to North
Gunpowder Creek southeast of the town. ETT Environmental has been retained to conduct a Water
Effect Ratio for the facility to determine if permitted copper limits for the effluent discharge are
unnecessarily overprotective of aquatic life. This is to be accomplished through the calculation of a water
effect ratio (WER), comparing the chronic effects of copper upon surrogate aquatic test organisms (the
water flea Ceriodaphnia dubia and the Fathead Minnow) living in laboratory dilution water to the chronic
effects of copper to the same test species in simulated downstream receiving water.
The Gunpowder Creek WWTP discharges effluent to Gunpowder Creek under NPDES permit # NC
0023736.
At sites with very low metal limits, a permittee may conduct a site -specific study to determine if the
permit limit for copper should be modified to account for the unique characteristics of the receiving
stream. This is done by determining a Water Effect Ratio (WER), which is multiplied against the national
water quality criterion to calculate a site -specific criterion. Methodology for determining a WER is
provided in the Interim Guidance on Determination and Use of Water -Effect Ratios for Metals (EPA-823-
B-94-001).
This report presents the results of three rounds of WER primary test determinations using acute tests with
the invertebrate Ceriodaphnia dubia and a single round of WER secondary test determinations using
acute tests with the vertebrate Pimephales promelas (Fathead Minnow). Using the Interim Guidance, a
Final WER is determined and the site specific criterion is calculated.
Lenoir Gunpowder WER Study -Cu
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ETT Environmental, Inc.; 9/23

2.0 METHODS
2.1 Overview
As delineated in the EPA Interim Guidance, a minimum of three rounds of side -by -side tests with the
primary test organism (Ceriodaphnia dubia) are required. Each round includes a 48 Hour acute definitive
test in which copper is spiked into laboratory dilution water (13% DMW - 50 mg/L hardness) alongside a
test where copper is spiked into simulated downstream water. A 48 Hour LC50 is calculated for each test,
and a WER is determined based upon the ratio of the LC50 in simulated downstream water divided by the
LC50 in laboratory dilution water. A final WER (EWER) is determined based upon all three individual
WER values. A WER is also determined for a secondary species, which in this case is the Fathead
Minnow - Pimephales promelas. Acute definitive tests (48 Hour) with the secondary species also are
conducted as acute tests, with the endpoint being an LC50.
2.2 Simulated Downstream Water
Simulated downstream water was prepared using proportional flow at the time of sampling.
2.3 Measured Concentrations
All calculations were based upon measured concentrations of copper in the laboratory water and
downstream water. In acute tests with Ceriodaphnia dubia and Pimephales promelas measured
concentrations of total copper were conducted for each test concentration at test initiation and at test
termination. Dissolved copper also was measured at test initiation and test termination.
2.4 Laboratory Water
Due to the relatively low hardness of the receiving stream and effluent, 13% DMW (diluted mineral water
at —50 mg/L hardness) was used as the laboratory water into which copper was spiked.
Lenoir Gunpowder WER Study -Cu
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ETT Environmental, Inc.; 9/23

2.5 Determination of Final Water Effect Ratio
Type I WERs most accurately simulate design -flow conditions, so these values are used directly in
determination of the fWER.
Type II WERs are not representative of the design flow conditions, but can be used in two ways. First, a
Type II WER can be considered a conservative estimate of the WER at design flow conditions, since the
WER will typically be lower for higher stream flows. Type II WERs are also used to calculate the highest
WER (hWER) that would provide adequate protection under design flow conditions. The hWER
incorporates the highest concentration of metal in the effluent (HCME) which will not cause the site
specific criterion to be exceeded downstream. The HCME is then used to predict the hWER at design
flow conditions. The HCME is calculated as follows;
HCME= [CCC x WER x (eFLOW+uFLOW)] - [(uCONC)(uFLOW)]
eFLOW
where; CCC= criterion continuous concentration
WER= the Type II WER which is experimentally determined
eFLOW= effluent flow at time of sampling
uFLOW= upstream flow at time of sampling
uCONC= copper concentration upstream at time of sampling
The hWER is calculated as follows;
hWER= (HCME) x (eFLOWdf) + (uCONCdf) x (uFLOWdf)
(CCC) x (eFLOWdf+ uFLOWdf)
where df indicates the value under design flow conditions.
In this study two of the primary WERs were Type II WERs and the third was a Type I WER. According
to the Interim Guidance, with this combination, the final water effect ratio (fWER) is the lowest of a) the
Type I WER, b) the lowest hWER, or c) the geometric mean if the Type I and Type II WERs.. Method 1
(determining WERs for areas in or near plumes), was used.
Lenoir Gunpowder WER Study -Cu
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ETT Environmental, Inc.; 9/23

3.0 RESULTS
3.1 Determination of Type 1 vs. Type 2 Conditions
Type I tests are tests conducted when downstream flow is <2 times the design flow. Type 1I tests
are tests conducted when downstream flow is >2 times the design flow.
The flows for this study are summarized as follows;
Upstream flow
Effluent Flow
Design 1.843 mgd
2.0 mgd
Round 1 1.4189 mgd
1.0672 mgd
Round 2 1.2130 mgd
0.8170 mgd
Round 3 3.2844 mgd
2.2250 mgd
3.2 Water Effect Ratios for Each Round of Tests
Downstream Flow
3.843 mgd
2.4861 mgd Type 1
2.0300 mgd Type 1
5.5094 mgd Type 1
The experimentally derived (hardness adjusted) WERs for total recoverable copper for acute
testing with Ceriodaphnia dubia and Pimephales promelas are summarized as follows;
Total Cu Dis. Cu
Date Species WER WER
Round 1.
8/18/22
primary
13.6250
13.5937
Round 2
10/12/22
primary
10.9036
10.0017
Round 3
2/01/23
primary
6.0449
6.4179
Round 4
2/01/23
secondary
2.0912
3.1797
Because the WER for the secondary test was within a factor of three of the low Type I value in
the primary test, the secondary test is considered to confirm the primary test results.
Lenoir Gunpowder WER Study -Cu
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ETT Environmental, Inc.; 9/23

3.3 Calculation of Highest Concentration of Metal in Effluent (HOME) Values
Calculations of HCME values are provided in Tables 1 and 2. HCME (total recoverable) values
ranged from 38.1301 ug/L in Round 3 to 77.5767 ug/L in Round 1.
3.4 Calculation of hWER Values
Calculations of hWER values are provided in Tables 1 and 2. hWER (total recoverable) values
ranged from 7.7897 ug/L in Round 3 to 16.5184 ug/L in Round 1.
3.5 Calculation of Final Water Effect Ratio (fWER)
As noted above, when all rounds of testing are Type I, the Interim Guidance requires that the
fWER be calculated as the lowest of the Type I WERs. The results are summarized as follows;
Type 1 WER fWER
Total Rec. Cu 6.0449 6.0449
Dissolved Cu 6.4179 6.4179
The WER values for acute tests with fathead minnows were not used in the calculations.
Lenoir Gunpowder WER Study -Cu
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ETT Environmental, Inc.; 9/23

3.6 Calculation of Site Specific Average Limit for Copper
The site specific criterion (S) is adjusted by multiplying the hardness adjusted CCC times the
fWER.
Site Specific CCC = S = [(ccc) x (fWER)]
[2.3470A x 6.0449B ] = 14.187 ug/L
A: recalculated CCC (ug/L) at site hardness (20..86 mg/L)
B: lowest WER
The site specific CCC (S) is then adjusted using EPA procedures and incorporating the
effluent IWC as follows;
Effluent Limit
ct
Effluent Limit Adjusted for
4 I 3 I Kpb = Kp I Cp I Kp ct Effluent rWC
Chronic (mo. average) 14.187 0.96 13.6200 1 10 1 1040000 1 -0.743E 187686.E 16.17627 187686.E 1 39.2 75.3
Acute [daily maxi 1 18.55E 1 0.96 17.8138 1 10 1 1040000 1 -0.743E 187686.E 21.1571E 1187686.6 1 61.2 98.5
Proposed effluent average limit — 75.3 µg/L (using Total Recoverable Copper EWER)
Lenoir Gunpowder WER Study -Cu
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ETT Environmental, Inc.; 9/23

3.7
Calculation of Site Specific Maximum Limit for Copper
The site specific criterion (S) is adjusted by multiplying the hardness adjusted CCC times the
fWER.
Site Specific CMC = S = [(cmc) x (fWER)]
[3.0697A x 6.0449B ] = 18.556 ug/L
A: recalculated CMC (ug/L) at site hardness (20..86 mg/L)
B: lowest WER
The site specific CMC (S) is then adjusted using EPA procedures and incorporating the
effluent IWC as follows;
ct
Effluent Limit Adjusted for
0 3 = ct Effluent WC
Chronic fmn. averaoei 14.187 0.9E 13.6200 10 1040000 -0.743E 187686.E 16.17627 187686.E 392 75.3
Acute
Proposed effluent maximum limit = 98.5 µg/L (using Total Recoverable Copper fWER)
Lenoir Gunpowder WER Study -Cu
Page 9 of 120
ETT Environmental, Inc.; 9/23

TABLE 1.
DERIVATION OF TOTAL COPPER fWERS WITH HARDNESS ADJUSTMENT (Using Acute Tests)
Facility: Lenoir Gunpowder T-Cu
WEIR #
1: 8/18/22
2: 10/12/22
3: 2/1/23
adj EC50= e(0.9422[ln(site water hard-In(lab water hard)])
Assigned effluent hardness: 22.20421 mg/L
Upstream Design Flow: 1.843 mgd 48.0%
Effluent Design Flow: 2 mgd 52.0%
Upstream Design Conc.: 0 ppb
Infarim
WEIR
Type
Lab Water
Hardness LC50 Adj LC50
Site Water
Hardness EC50
Hard. Adj.
WER
MC @ CCC @
rstehardsite hard
Upstream Effluent
Flow (mgd) Flow (mgd)
Upstream Effluent
Hardness Hardness
HCME hWER
Type 1
51.0000
9.1201
4.1083
21.87711
55.9758
13.62501
3.21001
2.4441
1.41891
1.0672
18.40001
26.5000
77.5767
16.5184
Type 1
47.1000
7.63841
4.0265
23.87201
43.9036
10.90361
3.48511
2.6334
1.29301
0.8170
20.0000
1 30.0000
74.1548
14.6552
Type 1
55.1000
23.01441
9.2175
20.86351
55.7186
6.04491
3.06971
2.3470
3.28441
2.2250
18.4000
24.5000
35.1301
7.7897
Lowest Type 1 W ER 6.044866
CCC= 2.578 = e (0.8545[In(hard ness)]-1.702)
CMC= 3.391 = e (0.9422[ln(hardness)]-1.70)
Ct (acute) = CMC * CF * [1+(Kp * (TSS^(1+_)) * 1000000)]
Ct (chronic) = CCC * CF * [1+(Kp * (TSS^(1+_)) * 1000000)]
low average
3.0697 2.3470
Effluent Limit
Ct
Effluent Limit Adjusted for
S CF Cd TSS a K b= K C K Ct Effluent IWC
Chronic (mo. average) 14.187 0.9E 13.6200 10 -0.743E 187686.E 16.17627 187686.E 39.2 75.3
Acute (dailv max) 18.55E 0.9E 17.8138 10 -0.743E 187686.E 21.1571E 187686.E 51.2 98.5
Page 10 of 120

TABLE 1.
DERIVATION OF DISSOLVED COPPER fWERS WITH HARDNESS ADJUSTMENT (Using Acute Tests)
Facility: Lenoir Gunpowder Dis-Cu
WER #
1: 8/18/22
2: 10/12/22
3: 2/1/23
adj EC50= e(0.9422[ln(site water hard-In(lab water hard)])
Assigned effluent hardness: 22.20411 mg/L
Upstream Design Flow: 1.843 mgd 48.0%
Effluent Design Flow: 2 mgd 52.0
Upstream Design Conc.: 0 ppb
Infarim
WER
Type
Hardness
Lab Water
LC50
Adj LC50
Site Water
Hardness EC50
Hard. Adj.
WER
C @
Fscitm,�hard
CCC @
site hard
Upstream
Flow (mgd)
Effluent
Flow (mgd)
Upstream
Hardness
Effluent
Hardness
HCME
hWER
Type 1
51.0000
7.56831
3.4093
21.87711
46.3447
13.59371
3.21001
2.4441
1.4189
1.0672
18.4000
26.5000
77.3984
16.4805
Type 1
47.1000
7.48171
3.9439
23.87201
39.4457
10.00171
3.48511
2.6334
1.2930
0.8170
20.0000
30.0000
68.0207
13.4429
Type 1
55.1000
18.19701
7.2880
20.86321
46.7735
6.41791
3.06971
2.3470
2.1231
1.4380
18.4000
24.5000
37.3019
8.2714
Lowest Type 1 WER 6.417884
CCC= 2.578 = e (0.8545[In (hard ness)]-1.702)
CMC= 3.391 = e (0.9422[ln(hardness)]-1.70)
Ct (acute) = CMC * CF * [1+(Kp * (TSS^(1+_)) * 1000000)]
Ct (chronic) = CCC * CF * [1+(Kp * (TSS^(1+_)) * 1000000)]
average average
3.0697 2.3470
Effluent Limit
Ct
Effluent Limit Adjusted for
S CF Cd TSS a K b= Kp Cp Kp Ct ]Effluent IWC
Chronic (mo. average) 15.063 0.96 14.4603 10 -0.743E 1187686.6 117.17428 1187686.6 41.6 79.9
Acute (daily max) 19.701 0.96 18.9128 10 -0.743E 1187686.6 122.46243 1187686.6 54.4 104.5
ua/L ua/L
Page 11 of 120

E T
environmental, Inc.
P.O. Box 16414, Greenville, SC 29606
APPENDIX A
[phone] . FAX [phone]
Craftsman Court, Greer, SC 29650
WATER EFFECT RATIO STUDY
City of Lenoir, N.C.
Gunpowder WWTP
Primary Species - Round 1
Metal: Copper
August 2022
Gunpowder WWTP - WER 1 Cu ETT Environmental; 8/22
Page 12 of 120

TABLE OF CONTENTS
1.0 INTRODUCTION
2.0 METHODS
2.1 Experimental Design
2.2 Laboratory Dilution Water
2.3 Upstream and Effluent Sample Collection
2.4 Chemical Analyses
2.5 Preparation of Test Solutions
2.6 Test Organisms
3.0 RESULTS
3.1 Laboratory Water
3.2 Simulated Downstream Water
3.3 Upstream Waters
4.0 CALCULATION OF WATER EFFECT RATIO
5.0 DISCUSSION
LIST OF APPENDICES
Appendix Al. Reference Toxicant Quality Control Chart for Ceriodaphnia dubia
Appendix A2. Survival Data for Acute Definitive Tests
Appendix A3. Measured Concentrations of Total Recoverable Copper in Test Solutions
Appendix A4. Water Chemistry Measurements for Acute Definitive Tests
Appendix A5. Chain of Custody Records
Appendix A6. Statistical Analysis Results
Gunpowder WWTP - WER 1 Cu
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ETT Environmental; 8/22

1.0 INTRODUCTION
The City of Lenoir, N.C. Gunpowder wastewater treatment plant (WWTP) discharges effluent into
Gunpowder Creek under NPDES Permit NC0023736. ETT Environmental has been retained to conduct a
"site specific study" to determine if permitted copper limits for each effluent discharge are unnecessarily
overprotective of aquatic life. This is to be accomplished through the calculation of a water effect ratio
(WER), comparing the acute effects of copper upon the surrogate aquatic test organism Ceriodaphnia
dubia living in laboratory dilution water to the acute effects of copper to the same test species in
simulated downstream receiving water. The study used the methodology provided in the Interim
Guidance on Determination and Use of Water -Effect Ratios for Metals (EPA-823-B-94-001).
On August 16-17, 2022, Gunpowder WWTP personnel collected a composite effluent water sample.
Acute toxicity tests for the Water Effect Ratio study were initiated on August 18, 2022.
Laboratory Location:
NCDNR Certification #
Study Director:
Study Scientist:
Study Technicians:
Study Dates:
ETT Environmental, Inc.
4 Craftsman Court
Greer, SC 29650
022
Robert W. Kelley, Ph.D.
Amy McMahon
Jennifer Christian
August 18-20, 2022
Gunpowder WWTP - WER 1 Cu
Page 14 of 120
ETT Environmental; 8/22

2.0 METHODS
2.1
2.2
Experimental Design
The design of the study involved spiking copper into test solutions and assessing the
acute toxicity of the test solutions with 48 Hour Acute Definitive tests using the surrogate
test organism Ceriodaphnia dubia. The two test solutions assessed were 1) laboratory
dilution water, and 2) simulated downstream water at measured conditions on the day of
sampling (42.9% effluent). Acute toxicity tests were set according to U.S. EPA protocols
(EPA 821-R-02-012 Method 2002), modified according to the following parameters;
Test type:
Temperature:
Light:
Test Chambers:
Test Solution Volume:
Renewal of Test Solutions:
Test Organism Age:
# Neonates/Cup:
# Replicates/Concentration:
Feeding Regime:
Aeration:
Dilution Factor:
Test Duration:
Endpoints:
Laboratory Dilution Water
Acute Static
250C fl
100 ft.-candles; 16 hr light/8 hr dark
30 mL plastic cups
25 mL
None
< 24 hr
5
4
None
None
0.7
48 Hours
Survival
The laboratory dilution water used in all tests was diluted mineral water (DMW). In this
first round of tests the DMW was prepared at a hardness of 51.0 mg/L. This dilution
water was prepared by adding Perrier water to ultra -pure water to obtain the desired final
hardness. The procedure for the preparation of this water may be found in the EPA
manual Short Term Methods for Estimating the Chronic Toxicity of Effluents and
Receiving Waters to Freshwater Organisms (EPA 821-R-02-013).
* Dilution water during the period of testing was prepared as follows;
Amount Hardness Conductivity Alkalinity pH
20 L 51.0 mg/L 112 µmhos/cm 48.9 mg/L 7.6
Gunpowder WWTP - WER 1 Cu ETT Environmental; 8/22
Page 15 of 120

2.3 Sample Collection
Sampling Locations
The effluent discharges into Gunpowder Creek. The effluent samples were collected as
composite samples. As received the effluent had no measureable residual chlorine (<0.05
mg/L). Effluent flow in the 24 hour period preceding sample collection was 1.067 mgd.
Upstream water samples were collected as grab samples upstream from the effluent
discharge point. Upstream flow was estimated based on flow at the USGS station located
at (USGS0214183368 Upper Little R at SR1740) (the closest USGS station to the
WWTP). This estimate was calculated as follows. On the day of sample collection the
flow at the USGS monitoring station was 20 cfs (12.9 mgd). The 25th percentile flow at
the USGS station (26 cfs = 16.8 mgd) was assumed to be the 7Q10 flow. Thus, on the
day of sample collection, the Gunpowder Creek flow was 0.77 times the 7Q10 flow (20
cfs / 26 cfs). The 7Q10 upstream flow at the discharge point of the WWTP on
Gunpowder Creek is 2.856 cfs. When the factor of 0.77 is applied to the Gunpowder
Creek 7Q10 flow, it is thereby estimated that the upstream flow on Gunpowder Creek on
the day of sample collection was 0.77 x 2.856 cfs = 2.195 cfs.
All samples were collected in half gallon plastic jugs and preserved in coolers at 0-6°C.
Samples were transferred to an ETT courier by WWTP personnel.
2.4 Chemical Analyses
Dissolved oxygen and pH were measured in one surrogate of each test concentration at
the beginning and end of the test. Temperature was monitored in three surrogate test cups
in the incubator daily. Dissolved Oxygen and pH were measured with the use of a Orion
4 Star meter. The meter is calibrated daily.
Alkalinity, hardness, total suspended solids (TSS), total organic carbon (TOC), and
specific conductance were measured on each laboratory water and effluent sample
collected.
Gunpowder WWTP - WER 1 Cu
Page 16 of 120
ETT Environmental; 8/22

Total recoverable copper was measured on each test solution at the beginning and end of
the test. Dissolved copper also was measured for each test concentration at the beginning
and end of the test. Copper analyses were conducted by ETT Environmental of Greer,
SC using Standard Methods 18a' Edition Method 3111B (flame atomic absorption), and
concentrated to achieve a detection limit of 10 ug/L (or lower with concentration).
2.5 Preparation of Test Solutions
2.5.1 Simulated Downstream Water
Based upon the measured effluent flow (1.067 mgd = 1.651 cfs) and the estimated
upstream flow (2.195 cfs) , a simulated downstream sample was prepared using 42.9%
effluent and 57.1% upstream water.
2.5.2 Copper Spiking
Copper was spiked as copper sulfate (CUSO4.5112O) into laboratory water and the
simulated downstream water. Prior to spiking the total recoverable copper in each
effluent sample was measured. Each day a batch of simulated downstream water was
prepared. A 12.72 mg/L stock solution of copper sulfate was prepared by adding 0.05 g
Of CUSO4.5H2O to one liter of demineralized water. A microliter syringe was used to add
the correct volumes of the stock solution to each simulated effluent or control
concentration to achieve the desired nominal concentration of copper.
2.6 Test Organisms
The test organism used for this study was the daphnid Ceriodaphnia dubia. Test
organisms were neonates of less than 24 hours in age which were obtained from
individual cultures at ETT Environmental, Inc. These cultures are set weekly with
reproduction of the first three broods tracked for all culture organisms. Only neonates
from broods of eight or larger, produced by culture trays demonstrating less than 10%
mortality and greater than a mean of 15 young per female (3 broods) are used for testing.
Culture sensitivity is monitored through the use of semi-monthly reference toxicant
testing. Voucher specimens from the culture are set aside on a monthly basis and
taxonomically verified by a staff macroinvertebrate taxonomist. Culture organisms are
subject to the same light, temperature, and feeding regimes as used for testing.
Gunpowder WWTP - WER 1 Cu
Page 17 of 120
ETT Environmental; 8/22

3.0 RESULTS
3.1 Laboratory Water
3.1.1 Acute Toxicity Testing Results
The acute definitive test with Ceriodaphnia dubia in laboratory water spiked with copper
showed a 48 Hour LC50 of 9.1201 ug/L Total Recoverable Copper and a 48 Hour
LC50 of 7.5683 ug/L Dissolved Copper. Due to the pattern of the data, the values were
calculated using the logistic method. The survival data at each concentration are
summarized as follows;
Nominal Concentration
of Total Recoverable Cu
Measured Concentration
of Total Recoverable Cu
and (Dissolved Cu)
48 Hour
Mortality
0 ug/L
<1.0 ug/L (<1.0)
0%
4.2 ug/L
3.1 ug/L (2.8)
0%
6.0 ug/L
4.9 ug/L (4.5)
0%
8.6 ug/L
6.9 ug/L (6.2)
0%
12.3 ug/L
10.0 ug/L (8.1)
85%
17.5 ug/L
11.8 ug/L (11.6)
100%
25.0 ug/L
20.0 ug/L (19.0)
100%
Survival data for the test may be found in Appendix A2. Results of measured
concentrations of total recoverable and dissolved copper are provided in Appendix A3.
Statistical analysis results are found in Appendix A6.
3.1.2 Chemical Anal
The pH in the spiked dilution water test ranged from a minimum of 7.6 to a maximum of
8.1. Dissolved oxygen was generally at the saturation point in all treatments throughout
the test.
Gunpowder WWTP - WER 1 Cu
Page 18 of 120
ETT Environmental; 8/22

3.2 Simulated Downstream Water
3.2.1 Acute Toxicity Testing Results
The acute definitive test with Ceriodaphnia dubia in downstream water spiked with
copper showed a 48 Hour LC50 of 55.9758 ug/L Total Recoverable Copper and a 48
Hour LC50 of 46.3447 ug/L of Dissolved Copper. Due to the pattern of the data, the
value was calculated using the logistic method. The survival data at each concentration
are summarized as follows;
Nominal Concentration
of Total Recoverable Cu
Measured Concentration
of Total Recoverable Cu
and (Dissolved Cu)
48 Hour
Mortality
0 ug/L
6.0 ug/L (5.4)
0%
17.5 ug/L
19.9 ug/L (16.9)
0%
25 ug/L
29.5 ug/L (22.5)
0%
35 ug/L
39.0 ug/L (31.0)
0%
50 ug/L
53.5 ug/L (44.5)
20%
71.4 ug/L
68.0 ug/L (55.5)
100%
102 ug/L
99.5 ug/L (74.0)
100%
Measured concentrations were generally higher than nominal concentrations. A
significant suppression in survival was noted at a nominal concentration of 71.4 ug/L of
total copper.
Survival data for the test may be found in Appendix A2. Results of measured
concentrations of total recoverable and dissolved copper are provided in Appendix A3.
Statistical analysis results are found in Appendix A6.
Gunpowder WWTP - WER 1 Cu
Page 19 of 120
ETT Environmental; 8/22

3.2.2 Chemical Anal
The pH in the simulated downstream water ranged from a minimum of 7.0 to a maximum
of 7.8. Dissolved oxygen was generally near the saturation point in all treatments
throughout the test. Other water chemistry parameters are summarized as follows;
Parameter
Effluent
Total Recoverable Copper (ug/L)
11.0
Dissolved Copper (ug/L)
10.0
Alkalinity (mg/L)
No data
Conductivity (umhos/cm)
235
Hardness (mg/L)
26.5
Total Organic Carbon (mg/L)
4.6
Total Suspended Solids (mg/L)
3.9
It may be seen that the effluent water was characterized by low alkalinity, hardness, TOC
and TSS.
3.3 Upstream Waters
Water quality parameters measured on upstream waters are provided in the following table;
Parameter
Result
Total Recoverable Copper (µg/L)
<5.0
Dissolved Copper (µg/L)
<5.0
Total Organic Carbon (mg/L)
1.3
Alkalinity (mg/L)
No data
Hardness (mg/L)
18.4
Conductivity (µmhos/cm)
63
Total Suspended Solids (mg/L)
4.5
Gunpowder WWTP - WER 1 Cu
Page 20 of 120
ETT Environmental; 8/22

4.0 CALCULATION OF WATER EFFECT RATIO
As noted in the results section, acute testing indicated an LC50 of 9.1201 ug/L of total recoverable
copper in laboratory dilution water and an LC50 of 55.9758 ug/L of total recoverable copper in
42.9% Gunpowder Creek WWTP effluent. The laboratory dilution water LC50 values must be
adjusted to downstream water hardness in order to calculate the Water Effect Ratio, using the
EPA formula, as follows;
LC50 x (downstream hardness/laboratory water hardness)0.9422
T-Cu: 9.1201 ug/L x (21.88/51)0.9422 = 4.1083 ug/L
Dis-Cu: 7.5683 ug/L x (21.88/51)0.9422 = 3.4093 ug/L
The Water Effect Ratio can thus be calculated as follows;
Water Effect Ratio (WER)
(Total Recoverable Copper)
Water Effect Ratio (WER)
(Dissolved Copper)
LC50 in Effluent = 55.9758 ug/L = 13.6250
LC50 in Lab Water 4.1083 ug/L
LC50 in Effluent = 46.3447 ug/L = 13.5937
LC50 in Lab Water 3.4093 ug/L
A final water effect ratio (FWER) will be calculated using the individual WERs from three
rounds of testing.
Gunpowder WWTP - WER 1 Cu
Page 21 of 120
ETT Environmental; 8/22

ROUND 1 - APPENDIX Al
Reference Toxicant Quality Control Chart
Ceriodaphnia dubia
See Round 3 Appendix C.
Gunpowder WWTP - WER 1 Cu
Page 22 of 120
ETT Environmental; 8/22

Gunpowder WWTP - WER 1 Cu
ROUND 1 -APPENDIX A2
Survival Data for Acute Definitive Tests
ETT Environmental; 8/22
Page 23 of 120

Mortality
24 hr 48 hr
I
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Facility: DMW
Metal: Cu
Sample ID:
Start Date: 08/18/22 Time:
12:30 By: AM
End Date: 08/20/22 Time:
I2:00 By: iC
Eff. Log #:
Upstream Log 4:
TEST ORGANISMS
Test Organism:
Cerioda hnia dubia
for Ceriodaphnia dubia
Date Removed:
Between 1700
Source: , G-L 8-4, M-R 8-4.
02/03/22
hrs 2200 hrs
for fathead minnows or mysids
Source:
-26 C. Light 16 hr It 18 hr dk; 50-100 ft-candles
Water DMW / SSF 50 m L hardness
t Water Preparation
I% effluent I Ivolume Prcp nice:
% upstream I I volume 11r,.i, 11%.
Test Solution Preparation:
Date: 08/18/22
Prep By
AM
Metal Salt: CuSO4
Stock. Soln: 12.72 m L
Nominal Conc.
mL Stock Soln.
Volume Prepared
4 u L
0.16 mL
500 mL
6.2 u L
0.24 mL
500 mL
8.6 u L
0.34 mL
500 mL
12.3 u L
0.48 mL
500 mL
17.5 u
0.69 ML
500 mL
25 ll
0.98 mL
500 mL
u L
mL
mL
u
mL
mL
Water Chemistry Time: n,;ivsr.
D.O. (mg/L)
pH
DMW Start
Final
8.2 m L
76 S.u.
8.9 mg/L
S.U.
Downstream Start
Final
m
S.U.
mg1Ls.u.
Upstream Start
ma
Effluent Start
ma/L
s.u.
Test solution volume: 25 mL. Test vessels 1 oz. plastic cups. Transfer volume 0.05 mL.
Page 24 of 120
Test Method: per EPA Interim Guidance

saga
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WER 48 Hour Acute Toxicity Test
Facility:
LENOIR
etal: C U
t
Sample 1D:
GUNPOWDER
Start Date:
08/I8/22 Time: 12:30 By: AM
End Date:
08/20/22 Time: 12.30 By-, 1C
EM Log #:
T62780 11111SUDstream. Log 9: T62781
TEST ORGANISMS
Test Organism: Cerioda hnia dubia
for Ceriodaphnia duhia Source: , G-L 8-4, M-R 8-4,
Date Removed: 08/15/22
Between 1700 hrs 2200 hrs
for fathead minnows or mysids
Source:
Temperature 24-26 C. Light 16 hr It / 8 hr dk. 50-100 ft-candles
Laboratory Water DMW / SSF @ 50 m hardness
Downstream Water Preparation
% effluent
upstream
42.9%
volume 1501.5
Prep. Date: 08/16/22
57.1 %
volume 1998.5
Prep. 13y: AM
Test Solution Preparation:
Date: 08/16/22
Prep By
AM
CuSO4
[=stocksotn:
12.72 m L
Nominal Cone.
mL Stock Soln,
Volume Prepared
t 7.5
U
0.69
mL
500 mL
25
ll L
0.98
mL
500 mL
35
u L
1.38
mL
500 mL
50
u L
1.97
mL
500 mL
71
u
2.79
mL
500 mL
102
u L
4.01
mL
500 mL
ugL
mL
mL
uQ L
mL
mL
Water Chemistry
Time:
analyst:
D.O. (mg/L)
PH
DMW
Start
Final
8,2
MEL
7.6 S.U.
8.9 MEL
e.1 S.U.
Downstream
Start
Final
8.4
m
7.0 S.U.
9.3 m L
TS S.U.
Upstream
Start
8.4
m
TO S.U.
Effluent
Start
8.3
ma
6.9 s.u.
Test solution volume: 25 mL. Test vessels 1 oz. plastic cups. Transfer volume 0.05 mL. Test Method: per EPA Interim Guidance
Page 25 of 120

ROUND I - APPENDIX A3
Measured Concentrations of Total Recoverable Copper in Test Solutions
Gunpowder WWTP - WER 1 Cu
ETT Environmental; 8/22
Page 26 of 120

Measured Total Recoverable and Dissolved Copper
Lenoir Gunpowder - Primary Species Site Specific Study
August 2022
Sample: Spiked Dilution Water (Diluted DMV Initial Date: 8/18/22
Nominal
Total Cu
Measured Total Recoverable Copper (µg/L)
Initial Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Mean
Rio of
Nominal
0
<1.0
<1.0
<1.0
4.2
3.8
2.4
3.1
74%
6.0
5.5
4.2
4.9
82%
8.61
7.0
6.8
6.9
80%
12.3
10.2
9.7
10.0
81%
17.5
13.8
9.8
11.8
67%
25.0
20.0
20.0
20.0
80%
Sample: Simulated Downstream Initial Date: 8/18/22
Nominal
Total Cu
Measured Total Recoverable Copper (µg/L)
Initial Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Mean
% of
Nominal
0.0
6.0
6.0
6.0
17.5
20.5
19.3
19.9
114%
25.0
29.0
30.0
29.5
118%
35.01
38.0
40.0
39.0
111%
50.0
52.0
55.0
53.5
107%
71.0
65.0
71.0
68.0
96%
102.0
98.0
101.0
99.5
98%
Measured Dis. Cu (µg/L)
Initial Day 2 Mean
%
Dissolved
<1.0
<1.0
1.8
3.7
2.8
90%
4.6
4.3
4.5
1 92%
5.8
6.6
6.2
90%
7.5
8.7
8.1
81%
11.9
11.2
11.6
98%
17.0
21.0
19.0
95%
Measured Dis. Cu (µg/L)
Initial Day 2 Mean
%
Dissolved
5.3
5.5
5.4
17.6
16.2
16.9
85%
22.0
23.0
22.5
76%
32.0
30.0
31.0
79%
47.0
42.0
44.5
83%
55.0
56.0
55.5
82%
76.0
72.0
74.0
74%
Page 27 of 120

ROUND 1 - APPENDIX A4
Water Chemistry Measurements for Acute Definitive Tests
Gunpowder WWTP - WER 1 Cu
See Appendix Al
ETT Environmental; 8/22
Page 28 of 120

Gunpowder WWTP - WER 1 Cu
ROUND 1 - APPENDIX A5
Chain of Custody Documentation
ETT Environmental; 8/22
Page 29 of 120

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PO Box 16414, Greenville, SC 29606-7414
[phone], [phone]
Shipping Address: 4 Craftsman Ct, Greer, SC 29650
www.ettleb.org
CHAIN OF CUSTODY RECORD
Paae of
Client: C . 1
Program
Containers
Preservative
Parameters
Facility: G &Ln r
whole Effluent Toxicity
0
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State: /1/6 IVPDE$ #: /► `�� 3
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Sample Custody Transfer Record
Secure
Receipt
Sample
Date Time Relinquished By/ Oranization e' ed By! Owanization
Area
Temp °C
Preserved?
V17/-z
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11192-
COMPOSITE SAMPLING PROCEDURES TEMPERATURE MONITORING PROCEDURES HOLD TIME PROCEDURES
Composite samples must be collected over a 24 hour period. Sample temperature during collection and transport must be between For toxicity testing the sample must first be used within 36 hours
Time Proportional: I sample each (tour for 24 hours. Equal volut 0.0 and 6.0 °C. Samples must not be frozen. Use water ice in sealed bags. of sample collection (completion of composite sample).
or at minimum t sample every 4 hours over 24 hours. Sample may not be used after 72 hours front sample collection.
Flow Proportional: As per instructions in NPDES permit.
Page 30 of 120

Gunpowder WWTP - WER 1 Cu
ROUND 1 - APPENDIX A6
Statistical Analysis Results
ETT Environmental; 8/22
Page 31 of 120

LOGISTIC MODEL Survival
Test: DMW
Date: 811812022 T U
predicted
num denominator y
gamma 0
1E-05
100 1 100
alpha
0.98
4,9 1.000009152 99,99908
beta
-43 sury
denom 6.9 1,005464465 99.45652
0
100
10 6.584528464 15,18712
test conc
4.9
100
11.6 123.8453582 0.807459
5.9
100
20 2336793.484 4.28E-05
10
15
11.8
0
IC25 2 50 actual mean
20
0
predicted reproduction
LC50 9.12010839
0
100
90
80
70
—_ _ -
60-
50
40
30
20
10
00 4 8 12 16 20
■ actual mean predicted
reproduction
Page 32 of 120

LOGISTIC MODEL
Survival
Test: DMW
Date: B118/2022
Dis Cu
gamma 0
1 E-05
alpha
0.879
beta
-57
sury
0
100
test conc
4.5
100
6.2
100
8.1
15
11,6
0
19
0
LC50 7.56832895
0
predicted
num denominator y
100 1 100
4.5 1.000002574 99A9974
denom 6.2 1.007178436 99.28727
8.1 6.369023649 15.70099
11.6 38992.75084 0.002565
19 7867099299 1.27E-08
IC25 2 50 actual mean
predicted reproduction
100
90
71
80
70
'
60
50
40
30-
20
10
00
4 8 12 16 20
-E actual mean o predicted
reproduction
Page 33 of 120

LOGISTIC MODEL Survival
Test: Lenoir Gunpowder
Date: 8118/2022 T Cu
gamma 0
1E-05
alpha
1.748
beta
-70
sury
0
100
test corc
29.5
100
39
100
53.5
80
6a
0
99.5
0
LC50 55.9757601
0
predicted
num denominator y
100 1 100
29,5 1.000000003 100
denom 39 1.000016946 99.99831
53,5 1.25278012 79.82247
68 371.7855598 0.268972
99.5 39334622.85 2.54E-06
1C25 2 50 actual mean
predicted reproduction
100
90
80-
70 -
60 - -
50
40
30
20
10 1
00 20 40 60 80 100
actual mean predicted
reproduction
Page 34 of 120

LOGISTIC MODEL
Survival
Test: Lenoir Gunpowder
Date: 8/18/2022
Dis Cu
gamma 0
1 E-05
alpha
1.666
beta
-77
sury
0
100
test conc
22.5
100
31
100
44.5
80
55.5
0
74
0
LC50
46.344692
0
0
predicted
num denominator y
100 1 100
22.5 1 100
denom 31 1.000001445 99.99986
44.5 1.257102831 79.54799
55.5 416.1167062 0,240317
74 6254692.745 1.6E-05
IC25 2 50 actual mean
predicted reproduction
10011�— ■ — -
90 - -
80 - - - -
70 --
60
50
40
30
20 — — — - -
10
00 10 20 30 40 50 60 70 80
-a actual mean
predicted
reproduction
Page 35 of 120

E T
environmental, Inc.
P.O. Box 16414, Greenville, SC 29606
APPENDIX B
[phone] . FAX [phone]
Craftsman Court, Greer, SC 29650
WATER EFFECT RATIO STUDY
City of Lenoir, N.C.
Gunpowder WWTP
Primary Species - Round 2
Metal: Copper
October 2022
Gunpowder WWTP - WER 2 Cu ETT Environmental; 10/22
Page 36 of 120

TABLE OF CONTENTS
1.0 INTRODUCTION
2.0 METHODS
2.1 Experimental Design
2.2 Laboratory Dilution Water
2.3 Upstream and Effluent Sample Collection
2.4 Chemical Analyses
2.5 Preparation of Test Solutions
2.6 Test Organisms
3.0 RESULTS
3.1 Laboratory Water
3.2 Simulated Downstream Water
3.3 Upstream Waters
4.0 CALCULATION OF WATER EFFECT RATIO
5.0 DISCUSSION
LIST OF APPENDICES
Appendix B 1. Reference Toxicant Quality Control Chart for Ceriodaphnia dubia
Appendix B2. Survival Data for Acute Definitive Tests
Appendix B3. Measured Concentrations of Total Recoverable Copper in Test Solutions
Appendix B4. Water Chemistry Measurements for Acute Definitive Tests
Appendix B5. Chain of Custody Records
Appendix B6. Statistical Analysis Results
Gunpowder WWTP - WER 2 Cu
Page 37 of 120
ETT Environmental; 10/22

1.0 INTRODUCTION
The City of Lenoir, N.C. Gunpowder wastewater treatment plant (WWTP) discharges effluent into
Gunpowder Creek under NPDES Permit NC0023736. ETT Environmental has been retained to conduct a
"site specific study" to determine if permitted copper limits for each effluent discharge are unnecessarily
overprotective of aquatic life. This is to be accomplished through the calculation of a water effect ratio
(WER), comparing the acute effects of copper upon the surrogate aquatic test organism Ceriodaphnia
dubia living in laboratory dilution water to the acute effects of copper to the same test species in
simulated downstream receiving water. The study used the methodology provided in the Interim
Guidance on Determination and Use of Water -Effect Ratios for Metals (EPA-823-B-94-001).
On October 10-11, 2022, Gunpowder WWTP personnel collected a composite effluent water sample.
Acute toxicity tests for the Water Effect Ratio study were initiated on October 12, 2022.
Laboratory Location:
NCDNR Certification #
Study Director:
Study Scientist:
Study Technicians:
Study Dates:
ETT Environmental, Inc.
4 Craftsman Court
Greer, SC 29650
022
Robert W. Kelley, Ph.D.
Amy McMahon
Jennifer Christian
October 12-14, 2022
Gunpowder WWTP - WER 2 Cu
Page 38 of 120
ETT Environmental; 10/22

2.0 METHODS
2.1
2.2
Experimental Design
The design of the study involved spiking copper into test solutions and assessing the
acute toxicity of the test solutions with 48 Hour Acute Definitive tests using the surrogate
test organism Ceriodaphnia dubia. The two test solutions assessed were 1) laboratory
dilution water, and 2) simulated downstream water at measured conditions on the day of
sampling (38.7% effluent). Acute toxicity tests were set according to U.S. EPA protocols
(EPA 821-R-02-012 Method 2002), modified according to the following parameters;
Test type:
Temperature:
Light:
Test Chambers:
Test Solution Volume:
Renewal of Test Solutions:
Test Organism Age:
# Neonates/Cup:
# Replicates/Concentration:
Feeding Regime:
Aeration:
Dilution Factor:
Test Duration:
Endpoints:
Laboratory Dilution Water
Acute Static
250C fl
100 ft.-candles; 16 hr light/8 hr dark
30 mL plastic cups
25 mL
None
< 24 hr
5
4
None
None
0.7
48 Hours
Survival
The laboratory dilution water used in all tests was diluted mineral water (DMW). In this
first round of tests the DMW was prepared at a hardness of 47.1 mg/L. This dilution
water was prepared by adding Perrier water to ultra -pure water to obtain the desired final
hardness. The procedure for the preparation of this water may be found in the EPA
manual Short Term Methods for Estimating the Chronic Toxicity of Effluents and
Receiving Waters to Freshwater Organisms (EPA 821-R-02-013).
* Dilution water during the period of testing was prepared as follows;
Amount Hardness Conductivity Alkalinity pH
20 L 47.1 mg/L 112 µmhos/cm 48.4 mg/L 7.8
Gunpowder WWTP - WER 2 Cu ETT Environmental; 10/22
Page 39 of 120

2.3 Sample Collection
Sampling Locations
The effluent discharges into Gunpowder Creek. The effluent samples were collected as
composite samples. As received the effluent had no measureable residual chlorine (<0.05
mg/L). Effluent flow in the 24 hour period preceding sample collection was 0.817 mgd.
Upstream water samples were collected as grab samples upstream from the effluent
discharge point. Upstream flow was estimated based on flow at the USGS station located
at (USGS0214183368 Upper Little R at SR1740) (the closest USGS station to the
WWTP). This estimate was calculated as follows. On the day of sample collection the
flow at the USGS monitoring station was 14 cfs (9.05 mgd). The 25th percentile flow at
the USGS station (20 cfs = 12.9 mgd) was assumed to be the 7Q10 flow. Thus, on the
day of sample collection, the Gunpowder Creek flow was 0.7 times the 7Q 10 flow (14 cfs
/ 20 cfs). The 7Q10 upstream flow at the discharge point of the WWTP on Gunpowder
Creek is 2.856 cfs. When the factor of 0.77 is applied to the Gunpowder Creek 7Q10
flow, it is thereby estimated that the upstream flow on Gunpowder Creek on the day of
sample collection was 0.7 x 2.856 cfs = 2.0 cfs.
All samples were collected in half gallon plastic jugs and preserved in coolers at 0-6°C.
Samples were transferred to an ETT courier by WWTP personnel.
2.4 Chemical Analyses
Dissolved oxygen and pH were measured in one surrogate of each test concentration at
the beginning and end of the test. Temperature was monitored in three surrogate test cups
in the incubator daily. Dissolved Oxygen and pH were measured with the use of a Orion
4 Star meter. The meter is calibrated daily.
Alkalinity, hardness, total suspended solids (TSS), total organic carbon (TOC), and
specific conductance were measured on each laboratory water and effluent sample
collected.
Gunpowder WWTP - WER 2 Cu
Page 40 of 120
ETT Environmental; 10/22

Total recoverable copper was measured on each test solution at the beginning and end of
the test. Dissolved copper also was measured for each test concentration at the beginning
and end of the test. Copper analyses were conducted by ETT Environmental of Greer,
SC using Standard Methods 18"' Edition Method 3111B (flame atomic absorption), and
concentrated to achieve a detection limit of 10 ug/L (or lower with concentration).
2.5 Preparation of Test Solutions
2.5.1 Simulated Downstream Water
Based upon the measured effluent flow (0.817 mgd = 1.264 cfs) and the estimated
upstream flow (2.0 cfs) , a simulated downstream sample was prepared using 38.7%
effluent and 61.3% upstream water.
2.5.2 Copper Spiking
Copper was spiked as copper sulfate (CUSO4.5112O) into laboratory water and the
simulated downstream water. Prior to spiking the total recoverable copper in each
effluent sample was measured. Each day a batch of simulated downstream water was
prepared. A 12.72 mg/L stock solution of copper sulfate was prepared by adding 0.05 g
Of CUSO4.5H2O to one liter of demineralized water. A microliter syringe was used to add
the correct volumes of the stock solution to each simulated effluent or control
concentration to achieve the desired nominal concentration of copper.
2.6 Test Organisms
The test organism used for this study was the daphnid Ceriodaphnia dubia. Test
organisms were neonates of less than 24 hours in age which were obtained from
individual cultures at ETT Environmental, Inc. These cultures are set weekly with
reproduction of the first three broods tracked for all culture organisms. Only neonates
from broods of eight or larger, produced by culture trays demonstrating less than 10%
mortality and greater than a mean of 15 young per female (3 broods) are used for testing.
Culture sensitivity is monitored through the use of semi-monthly reference toxicant
testing. Voucher specimens from the culture are set aside on a monthly basis and
taxonomically verified by a staff macroinvertebrate taxonomist. Culture organisms are
subject to the same light, temperature, and feeding regimes as used for testing.
Gunpowder WWTP - WER 2 Cu
Page 41 of 120
ETT Environmental; 10/22

3.0 RESULTS
3.1 Laboratory Water
3.1.1 Acute Toxicity Testing Results
The acute definitive test with Ceriodaphnia dubia in laboratory water spiked with copper
showed a 48 Hour LC50 of 7.6384 ug/L Total Recoverable Copper and a 48 Hour
LC50 of 7.4817 ug/L Dissolved Copper. Due to the pattern of the data, the values were
calculated using the logistic method. The survival data at each concentration are
summarized as follows;
Nominal Concentration
of Total Recoverable Cu
Measured Concentration
of Total Recoverable Cu
and (Dissolved Cu)
48 Hour
Mortality
0 ug/L
<1.0 ug/L (<1.0)
0%
4.2 ug/L
2.7 ug/L (2.0)
0%
6.0 ug/L
5.3 ug/L (4.3)
0%
8.6 ug/L
5.9 ug/L (6.1)
10%
12.3 ug/L
9.0 ug/L (8.5)
80%
17.5 ug/L
12.9 ug/L (12.2)
100%
25.0 ug/L
20.0 ug/L (18.5)
100%
Survival data for the test may be found in Appendix B2. Results of measured
concentrations of total recoverable and dissolved copper are provided in Appendix B3.
Statistical analysis results are found in Appendix B6.
3.1.2 Chemical Anal
The pH in the spiked dilution water test ranged from a minimum of 7.8 to a maximum of
7.9. Dissolved oxygen was generally at the saturation point in all treatments throughout
the test.
Gunpowder WWTP - WER 2 Cu
Page 42 of 120
ETT Environmental; 10/22

3.2 Simulated Downstream Water
3.2.1 Acute Toxicity Testing Results
The acute definitive test with Ceriodaphnia dubia in downstream water spiked with
copper showed a 48 Hour LC50 of 43.9036 ug/L Total Recoverable Copper and a 48
Hour LC50 of 39.4457 ug/L of Dissolved Copper. Due to the pattern of the data, the
value was calculated using the logistic method. The survival data at each concentration
are summarized as follows;
Nominal Concentration
of Total Recoverable Cu
Measured Concentration
of Total Recoverable Cu
and (Dissolved Cu)
48 Hour
Mortality
0 ug/L
5.1 ug/L (3.9)
0%
17.5 ug/L
19.7 ug/L (16.6)
0%
25 ug/L
29.0 ug/L (21.5)
0%
35 ug/L
36.0 ug/L (32.5)
10%
50 ug/L
48.5 ug/L (43.5)
75%
71.4 ug/L
65.5 ug/L (59.5)
100%
102 ug/L
90.5 ug/L (82.5)
100%
Measured concentrations were generally higher than nominal concentrations. A
significant suppression in survival was noted at a nominal concentration of 50 ug/L of
total copper.
Survival data for the test may be found in Appendix B2. Results of measured
concentrations of total recoverable and dissolved copper are provided in Appendix B3.
Statistical analysis results are found in Appendix B6.
Gunpowder WWTP - WER 2 Cu
Page 43 of 120
ETT Environmental; 10/22

3.2.2 Chemical Anal
The pH in the simulated downstream water ranged from a minimum of 6.9 to a maximum
of 7.8. Dissolved oxygen was generally near the saturation point in all treatments
throughout the test. Other water chemistry parameters are summarized as follows;
Parameter
Effluent
Total Recoverable Copper (ug/L)
<5.0
Dissolved Copper (ug/L)
<5.0
Alkalinity (mg/L)
26.9
Conductivity (umhos/cm)
278
Hardness (mg/L)
30.0
Total Organic Carbon (mg/L)
5.0
Total Suspended Solids (mg/L)
<1.0
It may be seen that the effluent water was characterized by low alkalinity, hardness, TOC
and TSS.
3.3 Upstream Waters
Water quality parameters measured on upstream waters are provided in the following table;
Parameter
Result
Total Recoverable Copper (µg/L)
<5.0
Dissolved Copper (µg/L)
<5.0
Total Organic Carbon (mg/L)
<1.0
Alkalinity (mg/L)
18.1
Hardness (mg/L)
20.0
Conductivity (µmhos/cm)
65
Total Suspended Solids (mg/L)
1.2
Gunpowder WWTP - WER 2 Cu
Page 44 of 120
ETT Environmental; 10/22

4.0 CALCULATION OF WATER EFFECT RATIO
As noted in the results section, acute testing indicated an LC50 of 7.6384 ug/L of total recoverable
copper in laboratory dilution water and an LC50 of 43.9036 ug/L of total recoverable copper in
38.7% Gunpowder Creek WWTP effluent. The laboratory dilution water LC50 values must be
adjusted to downstream water hardness in order to calculate the Water Effect Ratio, using the
EPA formula, as follows;
LC50 x (downstream hardness/laboratory water hardness)0.9422
T-Cu: 7.6384 ug/L x (23.9/47.1)0-9422 = 4.0265 ug/L
Dis-Cu: 7.4817 ug/L x (23.9/47.1)0.9422 = 3.9439 ug/L
The Water Effect Ratio can thus be calculated as follows;
Water Effect Ratio (WER)
(Total Recoverable Copper)
Water Effect Ratio (WER)
(Dissolved Copper)
LC50 in Effluent = 43.9036 ug/L = 10.9036
LC50 in Lab Water 4.0265 ug/L
LC50 in Effluent = 39.4457 ug/L = 10.0017
LC50 in Lab Water 3.9439 ug/L
A final water effect ratio (FWER) will be calculated using the individual WERs from three
rounds of testing.
Gunpowder WWTP - WER 2 Cu
Page 45 of 120
ETT Environmental; 10/22

ROUND 2 -APPENDIX B1
Reference Toxicant Quality Control Chart
Ceriodaphnia dubia
See Round 3 Appendix C.
Gunpowder WWTP - WER 2 Cu
Page 46 of 120
ETT Environmental; 10/22

Gunpowder WWTP - WER 2 Cu
ROUND 2 -APPENDIX B2
Survival Data for Acute Definitive Tests
ETT Environmental; 10/22
Page 47 of 120

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WER 48 Hour Acute Toxicity Test
Facility:
DMW
kletal: Cu
Sample ID:
Start Date:
10/12/22 Time: 2:30 By: AM
End Date:
10/14/22 Time: 2:10 By: AM
Eff. Log #:
Upstream Log #:
TEST ORGANISMS
Test organism: Cerioda hnia dubia
for Ceriodaphnia dubia Source: 29, M-R 9-29, S-X 9
Date Removed: 02/03/22
Between 1700 hrs 2200 hrs
for fathead minnows or mysids
Source:
Temperature 24-26 C. Light 16 hr It 18 hr dk; 50-100 ft-candles
Laboratory Water DMW / SSF @ 50 ma hardness
Downstream Water Preparation
% effluent
% upstream
volume
Prep. Date:
volume
Prep. By:
Test Solution Preparation:
Date: 10,111/22
Prep By
is
Metal Salt:
CuSO4
Stock. Sol.:
12.72 m L
NominalConc.
mL Stock Soln,
Volume Prepared
4
u L
0.16
mL
500 mL
6.2
u
0.24
mL
500 ml.
8.6
u L
0.34
mL
500 mL
12.3
u L
0.48
mL
500 mL
17.5
u
0.69
mL
500 mL
25
u L
0.98
mL
500 mL
u L
mL
[Ill.
u
mL
mL
Water Chemist
Time:
Analyst:
D.O. (mg/L)
pH
DMW
Start
Final
8.4
ma
7.8 S.U.
8.2 ma
7.9 S.U.
Downstream
Start
Final
m L
SAL
m L
s.u.
U stream
Start
m
S.U.
Effluent
Start
mpq
S.u.
Test solution volume: 25 mL. Test vessels 1 oz. plastic cups. Transfer volume 0.05 mL. Test Method: per EPA Interim Guidance
Page 48 of 120

Nominal
Cone.
Rep.
lnitiala
or aristns
Mortality
24 hr 48 lir
WER 48 Hour Acute Toxicity Test
Facility: LENOIR GUNPOWDER
Metal: CU
1.
0.0
u
A
5
0
Sample ID: EFFLUENT
B
5
0
Start Date: 10/12/22 Time: 2:30 By: AM
C
5
0
jEnd Date: 10/14/22 Time: 2:45 By: AM
D
5
0
EfF. Log #: 63180 Upstream Log #: 63181
17.5
ug/L
A
5
0
TEST ORGANISMS
B
5
0
Test Organism: Cerioda hnia dubia
C
5
0
for Ceriodaphnia dubia Source: 29, M-R 9-29, S-X 9
Date Removed: 02/03/22
Between 1700 hrs 2200 hrs
D
5
0
25.
AA
0
ug/L
B
5
0
for fathead minnows or mysids
Source:
C
5
0
D0
Temperature 24-26 C. Light 16 hr It 1$ hr dic; 50-1001t-candles
35.0
A
0
Laboratory Water DMW / SSF @ 50 mgj hardness
ug/L
B
5
1
Downstream Water Preparation
C
5
0
% effluent
% u stream
38.7%
volume 1354.5
rrep. Date: 10/12/22
D
5
I
61.3%
volume 2145.5
,,. l;,: AM
50.0
A
5
3
u11,1L
B
5
3
Test Solution Preparation:
Date: 10/11/22
Prep By
11C
Metal Salt: CuSO4
C
5
4
Stock. Soln: 12.72 m L
1)
5
5
Nominal Cone.
mL Stock Soin.
Volume Prepared
71.0
ug/L
A
5
5
17.5 u
0.69 ml,
500 mL
13
5
5
25 ug/L
0,98 mL
500 mL
C
5
35 ug/L
1,38 mL
500 mL
D
5
5
50 ug/L
1.97 mL
500 mL
102.0
u
A
5
5
71 u
2.79 mL
500 mL
B
5
5
102 ug/L
4.01 mL
500 mL
C
5
5
ug/L
mL
mL
D
5
5
u 1-
mL
mL
ug/L
A
Water Chemist Time: Analyst:
B
D.O. (mg/L)
H
C
DMW Start
Final
8.4 m
; s S.U.
D
8.2 m
S.U.
ug/L
A
Downstream Start
Final
9.2 m
S.U.
B
8.0 m
H S.U.
C
Upstream Start
9.3 m L
t.9 S.u.
D
Efftluent Start
8.2 ma
6.6 S.u.
Test solution volume: 25 mL. Test vessels 1 oz. plastic cups. Transfer volume 0.05 mL. Test Method: per EPA Interim Guidance
Page 49 of 120

ROUND 2 - APPENDIX B3
Measured Concentrations of Total Recoverable Copper in Test Solutions
Gunpowder WWTP - WER 2 Cu
ETT Environmental; 10/22
Page 50 of 120

Measured Total Recoverable and Dissolved Copper
Lenoir Gunpowder - Primary Species Site Specific Study
October 2022
Sample: Spiked Dilution Water (Diluted DMV Initial Date: 10/12/22
Nominal
Total Cu
Measured Total Recoverable Copper (µg/L)
Initial Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Mean
Rio of
Nominal
0
<1.0
<1.0
<1.0
4.2
2.6
2.7
2.7
64%
6.0
5.3
5.3
5.3
88%
8.61
5.7
6.1
5.9
69%
12.3
8.7
9.2
9.0
73%
17.5
13.0
12.8
12.9
74%
25.0
20.0
20.0
80%
Sample: Simulated Downstream Initial Date: 10/12/22
Nominal
Total Cu
Measured Total Recoverable Copper (µg/L)
Initial Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Mean
% of
Nominal
0.0
4.6
5.5
5.1
17.5
18.5
19.8
19.2
110%
25.0
26.0
32.0
29.0
116%
35.01
34.0
38.0
36.0
103%
50.0
46.0
51.0
48.5
97%
71.0
65.0
66.0
65.5
92%
102.0
89.01
1 2.0
90.5
89%
Measured Dis. Cu (µg/L)
Initial Day 2 Mean
%
Dissolved
<1.0
<1.0
<1.0
1.4
2.5
2.0
74%
4.0
4.6
4.3
1 81%
6.3
5.8
6.1
103%
8.5
8.5
94%
11.2
1 13.2
12.2
95%
16.0
21.0
18.5
93%
Measured Dis. Cu (µg/L)
Initial Day 2 Mean
%
Dissolved
3.6
4.2
3.9
16.7
16.4
16.6
86%
20.0
23.0
21.5
74%
32.0
33.0
32.5
90%
44.0
43.0
43.5
90%
56.0
63.0
59.5
91%
80.0
85.0
82.5
91 %
Page 51 of 120

ROUND 2 - APPENDIX B4
Water Chemistry Measurements for Acute Definitive Tests
Gunpowder WWTP - WER 2 Cu
See Appendix B1
ETT Environmental; 10/22
Page 52 of 120

Gunpowder WWTP - WER 2 Cu
ROUND 2 -APPENDIX B5
Chain of Custody Documentation
ETT Environmental; 10/22
Page 53 of 120

ETT
PO Box 16414, Greenviae, SC 29608-7414
[phone], [phone] Fax:[phone]
Shipping Address: 4 Craftsman Ct, Greer, SC 29650
W W W.6TTENVIR0NMENTAL.V 0M
CHAIN OF CUSTODY RECORD
Page ---L- of
Client: C; bA 4
Parameters
D r
Program
Containers
Preservative
Facility:
p
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Sample Custody Transfer Record
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Sample
Dote. Time —,-0fivquished By / Or ani tin ceived PV/ Organization
Area
Temp °C
Preserved?
d11
k
COMPOSITE SAMPLING PROCEDURES TEJUPERATURE i1101VITORING PROCEDURES HOLD TIME PROCEDURES
Composite samples must be collected over a 24 hour period. Sample temperature during collection and transport must be between For toxicity testing the sample must first be used within 36 hours
Time Proportional: 1 sample each hour for 24 hours. Equal volui 0.0 and 6.0 *C. Samples must not be frozen. Use water ice in sealed bags. of sample collection (completion of composite sample).
or at minimum 1 sample every 4 hours over 24 hours. Sample may not be used after 72 hours from sample collection.
Flow Proportional: As Der instructions in NPDES aermit.
age J4 0

Gunpowder WWTP - WER 2 Cu
ROUND 2 - APPENDIX B6
Statistical Analysis Results
ETT Environmental; 10/22
Page 55 of 120

LOGISTIC MODEL
Survival
Test: DMW
Date: 10/12/2022
T Cu
gamma 01
1 E-05
alpha
0.883
beta
-19.5
1 sury
0
100
test conc
2.7
100
5.3
100
5.9
90
9
20
12.9
0
LC50
7.63835784
0
predicted
num denominator y
100 1 100
2.7 1.000149696 99.98503
denom 5.3 1.045269555 95.6691
5.9 1.112265826 89.90657
9 5.011755532 19.95309
12.9 85.6055063 1.168149
IC25 2 50
actual mean
predicted reproduction
100
90
80
-
-
70
j
60
---i
50
-
40
30
___..._..__.....
10
00
2 4 6
8 10 12 14
® actual mean
® predicted
reproduction
Page 56 of 120

LOGISTIC MODEL
Survival
Test: DMW
Date: 10/1212022
Dis Cu
gamma 0
1E-05
alpha
0.874
beta
-25
sury
0
100
test conc
2
100
4.3
100
6.1
90
8.5
20
12.2
0
LC50 7.48169501
predicted
num denominator y
100 1 100
2 1.000000601 99.99994
denom 4.3 1.002446031 99.75599
6.1 1.108962213 90.1744
8.5 4.996716475 20.01314
12.2 203.1471236 0.492254
IC25 2 50 actual mean
predicted reproduction
100 -�
90 ® -
80
70
60-
50
40
30
20
10
00 2 4 6 8 10 12 14
® actual mean o predicted
reproduction
Page 57 of 120

LOGISTIC MODEL
Survival
Test: Gunpowder
Date: 10112/2022
T Cu
gamma 0
1E-05
alpha
1.6425
beta
25.5 sury
0
100
test conc
3.8
100
29
100
36
90
48.5
25
65.5
0
LC50 43.9035866
predicted
num denominator y
100 1 100
3.8 1 100
denom 29 1.010126485 98.9975
3G 1.111020954 90.0073
48.5 4.012180799 24.9241
65.5 84.96626067 1.176952
IC25 2 50
100E a
actual mean
predicted reproduction
10 20 30 40 50 60 70
® actual mean
predicted
reproduction
Page 58 of 120

LOGISTIC MODEL
Survival
Test: Gunpowder
Date: 10/12/2022
Dis Cu
gamma 0
1E-05
alpha
1.596
beta
-26
sury
0
100
test conc
16.6
100
21.5
100
32.5
90
43.5
25
59.5
0
LC50 39.4457302
predicted
num denominator y
100 1 100
16.6 1.000056958 99.9943
denom 21.5 1.001056705 99.89444
32.5 1.112249342 89.9079
43.5 4.018381259 24.88564
59.5 104.6936738 0.955168
IC25 2 50 actual mean
predicted reproduction
100
90 �
80
70
60
50
40
30
20 .........
10
00 10 20 30 40 50 60
mi actual mean I
predicted
reproduction
Page 59 of 120

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Mortality
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WER 48 Hour Acute Toxicity Test
Facility:
DMW
kletal: Cu
Sample ID:
Start Date:
10/12/22 Time: 2:30 By: AM
End Date:
10/14/22 Time: 2:10 By: AM
Eff. Log #:
Upstream Log #:
TEST ORGANISMS
Test organism: Cerioda hnia dubia
for Ceriodaphnia dubia Source: 29, M-R 9-29, S-X 9
Date Removed: 02/03/22
Between 1700 hrs 2200 hrs
for fathead minnows or mysids
Source:
Temperature 24-26 C. Light 16 hr It 18 hr dk; 50-100 ft-candles
Laboratory Water DMW / SSF @ 50 ma hardness
Downstream Water Preparation
% effluent
% upstream
volume
Prep. Date:
volume
Prep. By:
Test Solution Preparation:
Date: 10,111/22
Prep By
is
Metal Salt:
CuSO4
Stock. Sol.:
12.72 m L
NominalConc.
mL Stock Soln,
Volume Prepared
4
u L
0.16
mL
500 mL
6.2
u
0.24
mL
500 ml.
8.6
u L
0.34
mL
500 mL
12.3
u L
0.48
mL
500 mL
17.5
u
0.69
mL
500 mL
25
u L
0.98
mL
500 mL
u L
mL
[Ill.
u
mL
mL
Water Chemist
Time:
Analyst:
D.O. (mg/L)
pH
DMW
Start
Final
8.4
ma
7.8 S.U.
8.2 ma
7.9 S.U.
Downstream
Start
Final
m L
SAL
m L
s.u.
U stream
Start
m
S.U.
Effluent
Start
mpq
S.u.
Test solution volume: 25 mL. Test vessels 1 oz. plastic cups. Transfer volume 0.05 mL. Test Method: per EPA Interim Guidance
Page 60 of 120

Nominal
Cone.
Rep.
lnitiala
or aristns
Mortality
24 hr 48 lir
WER 48 Hour Acute Toxicity Test
Facility: LENOIR GUNPOWDER
Metal: CU
1.
0.0
u
A
5
0
Sample ID: EFFLUENT
B
5
0
Start Date: 10/12/22 Time: 2:30 By: AM
C
5
0
jEnd Date: 10/14/22 Time: 2:45 By: AM
D
5
0
EfF. Log #: 63180 Upstream Log #: 63181
17.5
ug/L
A
5
0
TEST ORGANISMS
B
5
0
Test Organism: Cerioda hnia dubia
C
5
0
for Ceriodaphnia dubia Source: 29, M-R 9-29, S-X 9
Date Removed: 02/03/22
Between 1700 hrs 2200 hrs
D
5
0
25.
AA
0
ug/L
B
5
0
for fathead minnows or mysids
Source:
C
5
0
D0
Temperature 24-26 C. Light 16 hr It 1$ hr dic; 50-1001t-candles
35.0
A
0
Laboratory Water DMW / SSF @ 50 mgj hardness
ug/L
B
5
1
Downstream Water Preparation
C
5
0
% effluent
% u stream
38.7%
volume 1354.5
rrep. Date: 10/12/22
D
5
I
61.3%
volume 2145.5
,,. l;,: AM
50.0
A
5
3
u11,1L
B
5
3
Test Solution Preparation:
Date: 10/11/22
Prep By
11C
Metal Salt: CuSO4
C
5
4
Stock. Soln: 12.72 m L
1)
5
5
Nominal Cone.
mL Stock Soin.
Volume Prepared
71.0
ug/L
A
5
5
17.5 u
0.69 ml,
500 mL
13
5
5
25 ug/L
0,98 mL
500 mL
C
5
35 ug/L
1,38 mL
500 mL
D
5
5
50 ug/L
1.97 mL
500 mL
102.0
u
A
5
5
71 u
2.79 mL
500 mL
B
5
5
102 ug/L
4.01 mL
500 mL
C
5
5
ug/L
mL
mL
D
5
5
u 1-
mL
mL
ug/L
A
Water Chemist Time: Analyst:
B
D.O. (mg/L)
H
C
DMW Start
Final
8.4 m
; s S.U.
D
8.2 m
S.U.
ug/L
A
Downstream Start
Final
9.2 m
S.U.
B
8.0 m
H S.U.
C
Upstream Start
9.3 m L
t.9 S.u.
D
Efftluent Start
8.2 ma
6.6 S.u.
Test solution volume: 25 mL. Test vessels 1 oz. plastic cups. Transfer volume 0.05 mL. Test Method: per EPA Interim Guidance
Page 61 of 120

ETT
PO Box 16414, Greenviae, SC 29608-7414
[phone], [phone] Fax:[phone]
Shipping Address: 4 Craftsman Ct, Greer, SC 29650
W W W.6TTENVIR0NMENTAL.V 0M
CHAIN OF CUSTODY RECORD
Page ---L- of
Client: C; bA 4
Parameters
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Dote. Time —,-0fivquished By / Or ani tin ceived PV/ Organization
Area
Temp °C
Preserved?
d11
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COMPOSITE SAMPLING PROCEDURES TEJUPERATURE i1101VITORING PROCEDURES HOLD TIME PROCEDURES
Composite samples must be collected over a 24 hour period. Sample temperature during collection and transport must be between For toxicity testing the sample must first be used within 36 hours
Time Proportional: 1 sample each hour for 24 hours. Equal volui 0.0 and 6.0 *C. Samples must not be frozen. Use water ice in sealed bags. of sample collection (completion of composite sample).
or at minimum 1 sample every 4 hours over 24 hours. Sample may not be used after 72 hours from sample collection.
Flow Proportional: As Der instructions in NPDES aermit.
age nz o

LOGISTIC MODEL
Survival
Test: DMW
Date: 10/12/2022
T Cu
gamma 01
1 E-05
alpha
0.883
beta
-19.5
1 sury
0
100
test conc
2.7
100
5.3
100
5.9
90
9
20
12.9
0
LC50
7.63835784
0
predicted
num denominator y
100 1 100
2.7 1.000149696 99.98503
denom 5.3 1.045269555 95.6691
5.9 1.112265826 89.90657
9 5.011755532 19.95309
12.9 85.6055063 1.168149
IC25 2 50
actual mean
predicted reproduction
100
90
80
-
-
70
j
60
---i
50
-
40
30
___..._..__.....
10
00
2 4 6
8 10 12 14
® actual mean
® predicted
reproduction
Page 63 of 120

LOGISTIC MODEL
Survival
Test: DMW
Date: 10/1212022
Dis Cu
gamma 0
1E-05
alpha
0.874
beta
-25
sury
0
100
test conc
2
100
4.3
100
6.1
90
8.5
20
12.2
0
LC50 7.48169501
predicted
num denominator y
100 1 100
2 1.000000601 99.99994
denom 4.3 1.002446031 99.75599
6.1 1.108962213 90.1744
8.5 4.996716475 20.01314
12.2 203.1471236 0.492254
IC25 2 50 actual mean
predicted reproduction
100 -�
90 ® -
80
70
60-
50
40
30
20
10
00 2 4 6 8 10 12 14
® actual mean o predicted
reproduction
Page 64 of 120

LOGISTIC MODEL
Survival
Test: Gunpowder
Date: 10112/2022
T Cu
gamma 0
1E-05
alpha
1.6425
beta
25.5 sury
0
100
test conc
3.8
100
29
100
36
90
48.5
25
65.5
0
LC50 43.9035866
predicted
num denominator y
100 1 100
3.8 1 100
denom 29 1.010126485 98.9975
3G 1.111020954 90.0073
48.5 4.012180799 24.9241
65.5 84.96626067 1.176952
IC25 2 50
100E a
actual mean
predicted reproduction
10 20 30 40 50 60 70
® actual mean
predicted
reproduction
Page 65 of 120

LOGISTIC MODEL
Survival
Test: Gunpowder
Date: 10/12/2022
Dis Cu
gamma 0
1E-05
alpha
1.596
beta
-26
sury
0
100
test conc
16.6
100
21.5
100
32.5
90
43.5
25
59.5
0
LC50 39.4457302
predicted
num denominator y
100 1 100
16.6 1.000056958 99.9943
denom 21.5 1.001056705 99.89444
32.5 1.112249342 89.9079
43.5 4.018381259 24.88564
59.5 104.6936738 0.955168
IC25 2 50 actual mean
predicted reproduction
100
90 �
80
70
60
50
40
30
20 .........
10
00 10 20 30 40 50 60
mi actual mean I
predicted
reproduction
Page 66 of 120

E T
environmental, Inc.
P.O. Box 16414, Greenville, SC 29606
APPENDIX C
[phone] . FAX [phone]
Craftsman Court, Greer, SC 29650
WATER EFFECT RATIO STUDY
City of Lenoir, N.C.
Gunpowder WWTP
Primary Species - Round 3
Metal: Copper
February 2023
Gunpowder WWTP - WER 3 Cu
Page 67 of 120
ETT Environmental; 2/23

TABLE OF CONTENTS
1.0 INTRODUCTION
2.0 METHODS
2.1 Experimental Design
2.2 Laboratory Dilution Water
2.3 Upstream and Effluent Sample Collection
2.4 Chemical Analyses
2.5 Preparation of Test Solutions
2.6 Test Organisms
3.0 RESULTS
3.1 Laboratory Water
3.2 Simulated Downstream Water
3.3 Upstream Waters
4.0 CALCULATION OF WATER EFFECT RATIO
5.0 DISCUSSION
LIST OF APPENDICES
Appendix C1. Reference Toxicant Quality Control Chart for Ceriodaphnia dubia
Appendix C2. Survival Data for Acute Definitive Tests
Appendix C3. Measured Concentrations of Total Recoverable Copper in Test Solutions
Appendix C4. Water Chemistry Measurements for Acute Definitive Tests
Appendix C5. Chain of Custody Records
Appendix C6. Statistical Analysis Results
Gunpowder WWTP - WER 3 Cu
Page 68 of 120
ETT Environmental; 2/23

1.0 INTRODUCTION
The City of Lenoir, N.C. Gunpowder wastewater treatment plant (WWTP) discharges effluent into
Gunpowder Creek under NPDES Permit NC0023736. ETT Environmental has been retained to conduct a
"site specific study" to determine if permitted copper limits for each effluent discharge are unnecessarily
overprotective of aquatic life. This is to be accomplished through the calculation of a water effect ratio
(WER), comparing the acute effects of copper upon the surrogate aquatic test organism Ceriodaphnia
dubia living in laboratory dilution water to the acute effects of copper to the same test species in
simulated downstream receiving water. The study used the methodology provided in the Interim
Guidance on Determination and Use of Water -Effect Ratios for Metals (EPA-823-B-94-001).
On January 30-31, 2023, Gunpowder WWTP personnel collected a composite effluent water sample.
Acute toxicity tests for the Water Effect Ratio study were initiated on February 1, 2023.
Laboratory Location:
NCDNR Certification #
Study Director:
Study Scientist:
Study Technicians:
Study Dates:
ETT Environmental, Inc.
4 Craftsman Court
Greer, SC 29650
022
Robert W. Kelley, Ph.D.
Amy McMahon
Jennifer Christian
February 1-3, 2023
Gunpowder WWTP - WER 3 Cu
Page 69 of 120
ETT Environmental; 2/23

2.0 METHODS
2.1
2.2
Experimental Design
The design of the study involved spiking copper into test solutions and assessing the
acute toxicity of the test solutions with 48 Hour Acute Definitive tests using the surrogate
test organism Ceriodaphnia dubia. The two test solutions assessed were 1) laboratory
dilution water, and 2) simulated downstream water at measured conditions on the day of
sampling (40.4% effluent). Acute toxicity tests were set according to U.S. EPA protocols
(EPA 821-R-02-012 Method 2002), modified according to the following parameters;
Test type:
Temperature:
Light:
Test Chambers:
Test Solution Volume:
Renewal of Test Solutions:
Test Organism Age:
# Neonates/Cup:
# Replicates/Concentration:
Feeding Regime:
Aeration:
Dilution Factor:
Test Duration:
Endpoints:
Laboratory Dilution Water
Acute Static
250C fl
100 ft.-candles; 16 hr light/8 hr dark
30 mL plastic cups
25 mL
None
< 24 hr
5
4
None
None
0.7
48 Hours
Survival
The laboratory dilution water used in all tests was diluted mineral water (DMW). In this
first round of tests the DMW was prepared at a hardness of 50.0 mg/L. This dilution
water was prepared by adding Perrier water to ultra -pure water to obtain the desired final
hardness. The procedure for the preparation of this water may be found in the EPA
manual Short Term Methods for Estimating the Chronic Toxicity of Effluents and
Receiving Waters to Freshwater Organisms (EPA 821-R-02-013).
* Dilution water during the period of testing was prepared as follows;
Amount Hardness Conductivity Alkalinity pH
20 L 55.1 mg/L 113 µmhos/cm 49.2 mg/L 7.8
Gunpowder WWTP - WER 3 Cu ETT Environmental; 2/23
Page 70 of 120

2.3 Sample Collection
Sampling Locations
The effluent discharges into Gunpowder Creek. The effluent samples were collected as
composite samples. As received the effluent had no measureable residual chlorine (<0.05
mg/L). Effluent flow in the 24 hour period preceding sample collection was 2.225 mgd.
Upstream water samples were collected as grab samples upstream from the effluent
discharge point. Upstream flow was estimated based on flow at the USGS station located
at (USGS0214183368 Upper Little R at SR1740) (the closest USGS station to the
WWTP). This estimate was calculated as follows. On the day of sample collection the
flow at the USGS monitoring station was 30 cfs (19.4 mgd). The 25th percentile flow at
the USGS station ( 26 cfs = 16.8 mgd) was assumed to be the 7Q10 flow. Thus, on the
day of sample collection, the Gunpowder Creek flow was 1.15 times the 7Q10 flow (30
cfs / 26 cfs). The 7Q10 upstream flow at the discharge point of the WWTP on
Gunpowder Creek is 2.856 cfs. When the factor of 1.15 is applied to the Gunpowder
Creek 7Q10 flow, it is thereby estimated that the upstream flow on Gunpowder Creek on
the day of sample collection was 2.856 cfs x 1.15 = 3.2844 cfs.
All samples were collected in half gallon plastic jugs and preserved in coolers at 0-6°C.
Samples were transferred to an ETT courier by WWTP personnel.
2.4 Chemical Analyses
Dissolved oxygen and pH were measured in one surrogate of each test concentration at
the beginning and end of the test. Temperature was monitored in three surrogate test cups
in the incubator daily. Dissolved Oxygen and pH were measured with the use of a Orion
4 Star meter. The meter is calibrated daily.
Alkalinity, hardness, total suspended solids (TSS), total organic carbon (TOC), and
specific conductance were measured on each laboratory water and effluent sample
collected.
Gunpowder WWTP - WER 3 Cu
Page 71 of 120
ETT Environmental; 2/23

Total recoverable copper was measured on each test solution at the beginning and end of
the test. Dissolved copper also was measured for each test concentration at the beginning
and end of the test. Copper analyses were conducted by ETT Environmental of Greer,
SC using Standard Methods 18a' Edition Method 3111B (flame atomic absorption), and
concentrated to achieve a detection limit of 10 ug/L (or lower with concentration).
2.5 Preparation of Test Solutions
2.5.1 Simulated Downstream Water
Based upon the measured effluent flow (0.1.438 mgd) and the estimated upstream flow
(2.123 mgd) , a simulated downstream sample was prepared using 40.4% effluent and
59.6% upstream water.
2.5.2 Copper Spiking
Copper was spiked as copper sulfate (CuSO4.51-12O) into laboratory water and the
simulated downstream water. Prior to spiking the total recoverable copper in each
effluent sample was measured. Each day a batch of simulated downstream water was
prepared. A 12.72 mg/L stock solution of copper sulfate was prepared by adding 0.05 g
Of CuSO4.51-12O to one liter of demineralized water. A microliter syringe was used to add
the correct volumes of the stock solution to each simulated effluent or control
concentration to achieve the desired nominal concentration of copper.
Gunpowder WWTP - WER 3 Cu
Page 72 of 120
ETT Environmental; 2/23

2.6 Test Organisms
The test organism used for this study was the daphnid Ceriodaphnia dubia. Test
organisms were neonates of less than 24 hours in age which were obtained from
individual cultures at ETT Environmental, Inc. These cultures are set weekly with
reproduction of the first three broods tracked for all culture organisms. Only neonates
from broods of eight or larger, produced by culture trays demonstrating less than 10%
mortality and greater than a mean of 15 young per female (3 broods) are used for testing.
Culture sensitivity is monitored through the use of semi-monthly reference toxicant
testing. Voucher specimens from the culture are set aside on a monthly basis and
taxonomically verified by a staff macroinvertebrate taxonomist. Culture organisms are
subject to the same light, temperature, and feeding regimes as used for testing.
Gunpowder WWTP - WER 3 Cu
Page 73 of 120
ETT Environmental; 2/23

3.0 RESULTS
3.1 Laboratory Water
3.1.1 Acute Toxicity Testing Results
The acute definitive test with Ceriodaphnia dubia in laboratory water spiked with copper
showed a 48 Hour LC50 of 22.9615 ug/L Total Recoverable Copper and a 48 Hour
LC50 of 18.1552 ug/L Dissolved Copper. Due to the pattern of the data, the values were
calculated using the logistic method. The survival data at each concentration are
summarized as follows;
Nominal Concentration
of Total Recoverable Cu
Measured Concentration
of Total Recoverable Cu
and (Dissolved Cu)
48 Hour
Mortality
0 ug/L
<2.0 ug/L (<2.0)
0%
4.2 ug/L
5.7 ug/L (4.9)
0%
6.0 ug/L
7.1 ug/L (6.2)
0%
8.6 ug/L
8.3 ug/L (7.4)
0%
12.3 ug/L
11.9 ug/L (10.3)
0%
17.5 ug/L
17.5 ug/L (14.4)
0%
25.0 ug/L
25.0 ug/L (19.5)
85%
3 5. 0 ug/L
32 ug/L (27.5)
100%
Survival data for the test may be found in Appendix C2. Results of measured
concentrations of total recoverable and dissolved copper are provided in Appendix C3.
Statistical analysis results are found in Appendix C6.
3.1.2 Chemical Anal
The pH in the spiked dilution water test ranged from a minimum of 7.2 to a maximum of
8.3. Dissolved oxygen was generally at the saturation point in all treatments throughout
the test.
Gunpowder WWTP - WER 3 Cu
Page 74 of 120
ETT Environmental; 2/23

3.2 Simulated Downstream Water
3.2.1 Acute Toxicity Testing Results
The acute definitive test with Ceriodaphnia dubia in downstream water spiked with
copper showed a 48 Hour LC50 of 55.9758 ug/L Total Recoverable Copper and a 48
Hour LC50 of 46.7735 ug/L of Dissolved Copper. Due to the pattern of the data, the
value was calculated using the logistic method. The survival data at each concentration
are summarized as follows;
Nominal Concentration
of Total Recoverable Cu
Measured Concentration
of Total Recoverable Cu
and (Dissolved Cu)
48 Hour
Mortality
0 ug/L
3.6 ug/L (10.2)
0%
17.5 ug/L
19.9 ug/L (18.8)
0%
25 ug/L
30.5 ug/L (25.5)
0%
35 ug/L
36.5 ug/L (32.0)
0%
50 ug/L
50.0 ug/L (43.5)
10%
71.4 ug/L
74.0 ug/L (55.5)
100%
102 ug/L
98.0 ug/L (73.5)
100%
143 ug/L
144.5 ug/L (100.5)
100%
Measured concentrations were generally higher than nominal concentrations. A
significant suppression in survival was noted at a nominal concentration of 71.4 ug/L of
total copper.
Survival data for the test may be found in Appendix C2. Results of measured
concentrations of total recoverable and dissolved copper are provided in Appendix C3.
Statistical analysis results are found in Appendix C6.
Gunpowder WWTP - WER 3 Cu
Page 75 of 120
ETT Environmental; 2/23

3.2.2 Chemical Anal
The pH in the simulated downstream water ranged from a minimum of 7.2 to a maximum
of 8.3. Dissolved oxygen was generally near the saturation point in all treatments
throughout the test. Other water chemistry parameters are summarized as follows;
Parameter
Effluent
Total Recoverable Copper (ug/L)
9.0
Dissolved Copper (ug/L)
9.0
Alkalinity (mg/L)
No data
Conductivity (umhos/cm)
No data
Hardness (mg/L)
24.5
Total Organic Carbon (mg/L)
3.9
Total Suspended Solids (mg/L)
2.7
It may be seen that the effluent water was characterized by low alkalinity, hardness, TOC
and TSS.
3.3 Upstream Waters
Water quality parameters measured on upstream waters are provided in the following table;
Parameter
Result
Total Recoverable Copper (µg/L)
<5.0
Dissolved Copper (µg/L)
<5.0
Total Organic Carbon (mg/L)
<1.0
Alkalinity (mg/L)
No data
Hardness (mg/L)
18.4
Conductivity (µmhos/cm)
No data
Total Suspended Solids (mg/L)
<1.0
Gunpowder WWTP - WER 3 Cu
Page 76 of 120
ETT Environmental; 2/23

4.0 CALCULATION OF WATER EFFECT RATIO
As noted in the results section, acute testing indicated an LC50 of 12.3027 ug/L of total
recoverable copper in laboratory dilution water and an LC50 of 13.8038 ug/L of total recoverable
copper in 5.5% Gunpowder Creek WWTP effluent. The laboratory dilution water LC50 values
must be adjusted to downstream water hardness in order to calculate the Water Effect Ratio, using
the EPA formula, as follows;
LC50 x (downstream hardness/laboratory water hardness)0,9422
T-Cu: 23.0144 ug/L x (20.86/55.1)0.9422 = 9.2175 ug/L
Dis-Cu: 18.1970 ug/L x (20.86/55.1)0.9422 = 7.2880 ug/L
The Water Effect Ratio can thus be calculated as follows;
Water Effect Ratio (WER)
(Total Recoverable Copper)
Water Effect Ratio (WER)
(Dissolved Copper)
LC50 in Effluent = 55.7186 ug/L = 6.0448
LC50 in Lab Water ug
LC50 in Effluent = 46.7735 ug/L = 6.4179
LC50 in Lab Water 7.2880 ug/L
A final water effect ratio (FWER) will be calculated using the individual WERs from three
rounds of testing.
Gunpowder WWTP - WER 3 Cu
Page 77 of 120
ETT Environmental; 2/23

ROUND 3 -APPENDIX C1
Reference Toxicant Quality Control Chart
Ceriodaphnia dubia
Gunpowder WWTP - WER 3 Cu
Page 78 of 120
ETT Environmental; 2/23

2
J
2.4
0
2.2
o
cc
ACUTE FEFTX - 2022 -23 dubia; Toxicant NaCl-. Fight to Left
x 2.5 2.5 2.6 2.5— — — — — — 2,� 2.5 2.� 2.� 2.� 2.5 2.5 2.5 2,5
----- — — — — —
— ----
a� 226 226 228 228 9 229 230 230 23 229 22 '
2}2.12.12.1
1 2.1
2-1
f
MEAN
❑
LC56
❑
UPPER
❑
LOWER
l ICL & LCL ARE +1- 2 STD ❑ FROM MEAN
Page 79 of 120

48 Hour Acute Toxicity Test Benchsheet
Test Method: EPA 821 R-02-012 Method 2002 Ceriodaphnia dubia
Client:
ETT
I Sample ID:
NaCI Lab ID# 2-6-23 AD REF TOX C
Start Date:
02/06/23
Time: 03:15 PM dl
Set By:
Ended By:
AM
AM
End Date: 02/08/23 Time: 03:17 PM
Test Vessel
Test Solution Volume
Incubator
Transfer Volume
Dilution Water
Ceriodaphnia dubia
30 mL plastic cup
25 mL
#1
0.05 mL
MHSF
Randomization pattern per SOP lNeonates from common holding vessel
Light: 50 -100 ft-c. 16 hr light / 8 hr dark
TEST ORGANISMS
for Ceriodaphnia dubia
Date Removed: 2-5-23 Between: 1700 and: 2200
Pime hales promelas Source: Days old:
M sido sis Bahia Source: a s old:
Test Organisms Pre Fed by: AM Time: 1:00
MORTALITY DATA
®�Cum
lative Mortality
Comments:
Initial
Final
Temp
ID.O. JpH
I
I By:
Temp
24.51
8.51
7.611
AM
24.31
7.91
7.91
JAM
24.51
8.51
7.711
AM
24.31
7.91
7.911
AM
24.51
8.51
7.71
1 AM
24.31
7.91
8.011
AM
24.51
8.61
7.711
AM
24.31
8.11
8.011
AM
24.5
8.61
7. 811
AM
24.3
8.11
8.011
AM
24.5
8.61
7.811
AM
24.]1
8.01
8.011
AM
°C
m L I
IT
I°C
I m
48 Hour Acute Toxicity Test Statistics
Statistical Method: Spearman Karber
48 Hour LC50 = 2.12 g/L NaCl Lower Confidence Limi 2.03
Upper Confidence Limit 2.23
Page 80 of 120

Gunpowder WWTP - WER 3 Cu
ROUND 3 - APPENDIX C2
Survival Data for Acute Definitive Tests
ETT Environmental; 2/23
Page 81 of 120

Nominal
Conc.
Rep.
Initial H
organisms
Mortality
24 hr 48 hr
0.0
u L
A
5
0
0
B
5
0
0
C
5
0
0
D
5
0
0
4.0
A
5
0
0
u L
B
5
0
0
C
5
0
0
D
5
0
0
6.2
A
5
0
0
ug/L
B
5
0
0
C
5
0
0
D
5
0
0
8.6
uIg/L
A
5
0
0
B
5
0
0
C
5
0
0
D
5
0
0
12.3
A
5
0
0
_ ug/L
B
5
0
0
C
5
0
0
D
5
0
0
17.5
A
5
0
0
ua/L
B
5
0
0
C
5
0
0
D
5
0
0
25.0
A
5
1
3
up/f,
B
5
2
4
C
5
3
5
D
5
3
5
35.0
uU'L
A
5
5
5
B
5
5
5
C
5
5
5
D
5
5
5
uc/L
A
B
6.
D
WER 48 Hour Acute Toxicit Test
Facility:
IMW Cu C dubia 2-1-2
Metal: Cu
Sample ID:
Start Date:
02/01/23 Time: 1:30 By: is
End Date:
02/03/23 Time: 1:45 By: JC
Eff. Log #:
Upstream Log #:
TEST ORGANISMS
Test Organism: Cet•ioda hnia dubia
for Ceriodaphnia dubia Source: �- 1-20, G-L 1-19, M-
Date Removed: 02/03/22
Between 1650 hrs 2200 hrs
for fathead minnows or mysids
Source:
Temperature 24-26 C. Light 16 hr It / 8 hr dk, 50-100 ft-candles
Laboratory Water
DMW / SSF @ 50 mil hardness
Downstream Water Preparation
Luent
volume
Prep. Datetream
volume
Prep. By,
Test Solution Preparation:
Date: 02/01 /23
Prep By
1C
Metal salt:
CuSO4 5H2O
Stock. Soln:
12.72 m L
Nominal Conc.
mL Stock Soln.
Volume Prepared
0
U L
0.00
mL
500 mL
4
U
0.16
nil.
500 mL
6.2
u
0.24
mL
500 mL
8.6
u L
0.34
mL
500 mL
12.3
U
0.48
mL
500 mL
17.5
ugil,
0.69
mL
500 mL
25
u
0.98
MI.
500 mL
35
u L
1.38
mL
500 mL
Water Chemistry
Time:
Analyse
D.O. (mg/L)
T pH
DMW
Start
Final
8.3
m L
78 s.U.
8.3 m L
S.U.
Downstream
Start
Final
m L
s.u.
m L
s.u.
-Upstream
Start
m L
s.u.
Effluent
Start
m L
S.U.
Test solution volume: 25 mL. Test vessels 1 oz. plastic cups. Transfer volume 0.05 mL. Test Method: Per EPA Interim Guidance
Page 82 of 120

Nominal
Conc.
Rep.
Initial =
organisms
Mortality
24 hr 48 hr
0.0
A
5
0
0
LW/L
B
5
0
0
C
5
0
0
0
17.5
A
5
0
0
u�xlL
B
5
0
0
C
5
0
0
D
5
0
0
25.0
ukr/L
A
5
0
0
B
5
0
0
C
5
0
0
D
5
0
0
35.0
A
5
0
0
u
B
5
0
0
C
5
0
0
-
D
5
0
0
50.0
A
5
0
1
tie/L.
B
5
0
0
C
5
0
1
D
5
0
0
71.0
A
5
5
ug/L
B
5
5
5
C
5
5
D
5
5
5
102.0
A
5
5
5
u
B
5
5
5
C
5
5
5
D
5
5
5
143.0
A
5
5
5
ug/L
B
5
5
5
-
C
5
5
5
D
5
5
5
A
u gJL
B
Now
C
D
WER 48 Hour Acute Toxic i Test
Facili :
T64030 Cu C dubia
Metal: CU
Sample 1D:
GUNPOWDER
Start Date:
02/01/23 Time: 1:30 By: JC.
End Date:
02/03/23 Time: 1:50 By: is
Eff. Log ##:
64029 U stream Log #: 64030
TEST ORGANISMS
Test Organism: Cerioda hnia dubia
for Ceriodaphnia dubia Source: ' 1-20, G-L 1-19, M-
Date Removed: 02/03/22
Between 1650 hrs 2200 hrs
for fathead minnows or mysids
Source:
Temperature 24-26 C. Light 16 hr It / 8 hr dk; 50-100 R-candles
Laboratory Water
DMW / SSF 50 m hardness
Downstream Water Preparation
uent
L
40.4%
volume 1616
Pre .Date: 02I01/23tream
59.6%
volume 2384
Pre . By; JC
Test Solution Preparation:
Date: 02/01/23
Prep By
JC
Metal Salt:
CuSO4 5 H2O
Stock, Soln:
12.72 m
Nominal Conc.
mL Stock Soln.
Volume Prepared
0
u
0.00
mL
500 mL
17.5
u
0.69
mL
500 mL
25
u
0.98
mL
500 mL
35
u
1.38
mL
500 mL
50
u
1.97
mL
500 mL
71
u
2.79
mL
500 mL
102
U911,
4.01
mL
500 mL
143
u
5.62
ml,
500 mL
Water Chemist
Time:
Analyst:
D.O. m )
pH
DMW
Start
Final
8.3
m
7.8 S.U.
m
S.U.
Downstream
Start
Final
8.1
m
7.2 S.U.
8.4 m
8.3 S.U.
U stream
Start
8.4
ma
7.3 S.U.
Effluent
Start
8.1
m L
7.0 S.U.
Test solution volume: 25 mL. Test vessels 1 oz. plastic cups. Transfer volume 0.05 mL. Test Method: per EPA Interim Guidance
Page 83 of 120

ROUND 3 - APPENDIX C3
Measured Concentrations of Total Recoverable Copper in Test Solutions
Gunpowder WWTP - WER 3 Cu
ETT Environmental; 2/23
Page 84 of 120

Measured Total Recoverable and Dissolved Copper
Lenoir Gunpowder - Primary Species Site Specific Study
February 2023
Sample: Spiked Dilution Water (Diluted DMV Initial Date: 2/1/23
Nominal
Total Cu
Measured Total Recoverable Copper (µg/L)
Initial Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Mean
Rio of
Nominal
0
1.7
<2.0
4.2
6.0
5.4
5.7
136%
6.0
8.2
5.9
7.1
118%
8.61
9.2
7.4
8.3
97%
12.3
12.5
11.3
11.9
97%
17.5
18.7
16.3
17.5
100%
25.0
26.0
24.0
25.0
100%
35.0
33.0
31.0
32.0
Sample: Simulated Downstream Initial Date: 2/1/23
Nominal
Total Cu
Measured Total Recoverable Copper (µg/L)
Initial Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Mean
% of
Nominal
0.0
3.9
3.2
3.6
17.5
21.3
18.4
19.9
114%
25.0
32.0
29.0
30.5
122%
35.01
39.0
34.0
36.5
104%
50.0
52.0
48.0
50.0
100%
71.0
76.0
72.0
74.0
104%
102.0
97.0
99.0
98.0
96%
143.0
146.0
143.0
144.5
Measured Dis. Cu (µg/L)
Initial Day 2 Mean
%
Dissolved
1.0
<2.0
7.2
2.5
4.9
86%
7.8
4.6
6.5
1 92%
8.2
6.6
7.4
89%
11.4
9.1
10.3
87%
15.1
1 13.7
14.4
82%
19.0
20.0
19.5
78%
27.0
28.0
27.5
Measured Dis. Cu (µg/L)
Initial Day 2 Mean
%
Dissolved
11.8
8.5
10.2
20.4
17.2
18.8
94%
25.0
26.0
25.5
84%
33.0
31.0
32.0
88%
46.0
41.0
43.5
87%
57.01
54.0
55.5
75%
78.01
69.0
73.5
75%
106.01
95.0
100.5
Page 85 of 120

ROUND 3 - APPENDIX C4
Water Chemistry Measurements for Acute Definitive Tests
Gunpowder WWTP - WER 3 Cu
See Appendix C2
ETT Environmental; 2/23
Page 86 of 120

Gunpowder WWTP - WER 3 Cu
ROUND 3 -APPENDIX C5
Chain of Custody Documentation
ETT Environmental; 2/23
Page 87 of 120

ETT
PO Box 16414, Greerpriite, SC 23806-7414
[phone], [phone]
Shipping Address: 4 Craftsman Ct, Greer, SC 29650
www.ettleb.org
CHAIN OF CUSTODY RECORD
Page of
Client: /� ,
Ci�"of letw r
Containers
Program
Preservative
Parameters
Facility: Gu�/O�pl��/'
Whole Effluent Toxicity
�
State: /✓VC NPDES # c�j%
Acute
Chronic
Test Organisms
o
c
c
(Composite only)
(Grab or Composite)
<
c
'�
{ j
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,r`p
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Sign, and Print below
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1=1i2SO4
z=Het
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the dotted line
^
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U
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SAMPLE ID
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Compositestart DateTime
SnmplcCollection Date Time
Collected by
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Chemical Analytrts8 Other
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Special Instructions:
Sample Custody Transfer Record
Secure
Receipt
Sample
Date Time Relinquished B / Organization Receiv r i Lion
Area
Temp eC
Preserved?
1-31-�31153
t�
,• o
_
0
COMPOSITE SAMPLING PROCEDURES TEA/PERATURE MONITORING PROCEDURES HOLD TIME PROCEDURES
Composite samples must be collected over a 24 hour period. Sample temperature during collection and transport must be between For toxicity testing the sample must first be used within 36 hours
Time Proportional: 1 sample each hour for 24 hours. Equal volui 0.0 and 6.0'C. Samples must not be frozen. Use water ice in sealed bags. of sample collection (completion of composite sample).
or at minimum I sample every 4 hours over 24 hours. Sample may not be used after 72 hours from sample collection.
Flow Proportional: As per instructions in NPDES permit.
Page 88 of 120

Gunpowder WWTP - WER 3 Cu
ROUND 3 - APPENDIX C6
Statistical Analysis Results
ETT Environmental; 2/23
Page 89 of 120

LOGISTIC MODEL Survival
Test: Gunpowder
Date: 2/1/2023
Dis Cu
gamma 0
1E-05
alpha
1.67
beta
-70 sury
0
100
lest conc
25.5
100
32
100
43.5
90
55.5
0
73.5
0
LC50
46.7735141
O
predicted
num denominator y
100 1 100
25.5 1.00000001 100
denom 32 1.000009738 99.99903
43.5 1.110167647 90.07649
55.5 182,3645 0.548352
73.5 927376.4103 0.000108
IC25 2 50 actual mean
predicted reproduction
100
90
80.-
70 .. __- .. ............. ....
..._. _.-
60 -----------------_-..
50
20_
10
00 10 20 30 40 50 60 70 80
-a actual mean
M. predicted
reproduction
Page 90 of 120

LOGISTIC MODEL
Survival
Test: Gunpowder
Dale: 2l112023
T Cu
gamma 0
1 E-05
alpha
1.746
beta
-47.5
sury
0
100
test conc
30.3
100
36.5
100
50
90
74
0
98
0
LC60
55.7185749
0
predicted
num denominator y
100 1 100
30.3 1.000003487 99.99965
denom 36.6 1.000162296 99.98377
56 1.10710723 90.32549
74 349.4541603 0.286161
98 114490.523 0.000873
IC25 2 s0 actual mean
predicted reproduction
50J.- -
40
�0 20 40
.P.. actual mean
60 80 1
® predicted
reproduction
Page 91 of 120

LOGISTIC MODEL
Survival
Test: DMW
Date: 211/2023
T Cu
gamma 0
1E-05
alpha
1.362
beta
48
sury
0
100
test conc
8.3
100
11.9
100
17.5
100
25
15
32
0
LC50
23.0144182
0
predicted
num denominator y
100 1 100
8.3 1.000000001 100
denom 11.9 1.000001068 99.99989
17.5 1.003312097 99.66988
25 6.613196909 15.12128
32 966.1037944 0.103616
IC25 2 50
1004--- .. a-- ---
.m. actual mean
actual mean
predicted reproduction
predicted
reproduction
Page 92 of 120

LOGISTIC MODEL Survival
Test: DMW
Date: 2/1/2023
Dis Cu
gamma 0
1 E-05
alpha
1.26
beta
-57
sury
0
100
test conc
7.4
100
10.3
100
14.4
100
19.5
15
27.5
0
LC50
18.1970086
0
0
predicted
num denominator y
100 1 100
7.4 1 100
denom 10.3 1.000000761 99,99992
14.4 1,003047792 99.69615
19.5 6.539880043 15.2908
27.5 27501.61229 0.003636
IC25 2 50 actual mean
predicted reproduction
100 ®------�
90
80 --
70
60
50
40 �
30
20 - \ -
10
00 4 8 12 16 20 24 28
r
® actual mean ® reproduction
production
Page 93 of 120

E T
environmental, Inc.
P.O. Box 16414, Greenville, SC 29606
APPENDIX D
[phone] . FAX [phone]
Craftsman Court, Greer, SC 29650
WATER EFFECT RATIO STUDY
City of Lenoir, N.C.
Gunpowder WWTP
Secondary Species - Round 4
Metal: Copper
February 2023
Gunpowder WWTP - WER 4 Cu
Page 94 of 120
ETT Environmental; 2/23

TABLE OF CONTENTS
1.0 INTRODUCTION
2.0 METHODS
2.1 Experimental Design
2.2 Laboratory Dilution Water
2.3 Upstream and Effluent Sample Collection
2.4 Chemical Analyses
2.5 Preparation of Test Solutions
2.6 Test Organisms
3.0 RESULTS
3.1 Laboratory Water
3.2 Simulated Downstream Water
3.3 Upstream Waters
4.0 CALCULATION OF WATER EFFECT RATIO
5.0 DISCUSSION
LIST OF APPENDICES
Appendix D 1. Reference Toxicant Quality Control Chart for Pimephales promelas
Appendix D2. Survival Data for Acute Definitive Tests
Appendix D3. Measured Concentrations of Total Recoverable Copper in Test Solutions
Appendix D4. Water Chemistry Measurements for Acute Definitive Tests
Appendix D5. Chain of Custody Records
Appendix D6. Statistical Analysis Results
Gunpowder WWTP - WER 4 Cu
Page 95 of 120
ETT Environmental; 2/23

1.0 INTRODUCTION
The City of Lenoir, N.C. Gunpowder wastewater treatment plant (WWTP) discharges effluent into
Gunpowder Creek under NPDES Permit NC0023736. ETT Environmental has been retained to conduct a
"site specific study" to determine if permitted copper limits for each effluent discharge are unnecessarily
overprotective of aquatic life. This is to be accomplished through the calculation of a water effect ratio
(WER), comparing the acute effects of copper upon the surrogate aquatic test organism Pimephales
promelas living in laboratory dilution water to the acute effects of copper to the same test species in
simulated downstream receiving water. The study used the methodology provided in the Interim
Guidance on Determination and Use of Water -Effect Ratios for Metals (EPA-823-B-94-001).
On January 30-31, 2023, Gunpowder WWTP personnel collected a composite effluent water sample.
Acute toxicity tests for the Water Effect Ratio study were initiated on February 1, 2023.
Laboratory Location:
NCDNR Certification #
Study Director:
Study Scientist:
Study Technicians:
Study Dates:
ETT Environmental, Inc.
4 Craftsman Court
Greer, SC 29650
022
Robert W. Kelley, Ph.D.
Amy McMahon
Jennifer Christian
February 1-3, 2023
Gunpowder WWTP - WER 4 Cu
Page 96 of 120
ETT Environmental; 2/23

2.0 METHODS
2.1
2.2
Experimental Design
The design of the study involved spiking copper into test solutions and assessing the
acute toxicity of the test solutions with 48 Hour Acute Definitive tests using the surrogate
test organism Pimephales promelas. The two test solutions assessed were 1) laboratory
dilution water, and 2) simulated downstream water at measured conditions on the day of
sampling (40.4% effluent). Acute toxicity tests were set according to U.S. EPA protocols
(EPA 821-R-02-012 Method 2002), modified according to the following parameters;
Test type:
Temperature:
Light:
Test Chambers:
Test Solution Volume:
Renewal of Test Solutions:
Test Organism Age:
# Larvae/Cup:
# Replicates/Concentration:
Feeding Regime:
Aeration:
Dilution Factor:
Test Duration:
Endpoints:
Laboratory Dilution Water
Acute Static
250C fl
100 ft.-candles; 16 hr light/8 hr dark
300 mL plastic cups
200 mL
None
< 24 hr
10
2
None
None
0.7
48 Hours
Survival
The laboratory dilution water used in all tests was diluted mineral water (DMW). In this
first round of tests the DMW was prepared at a hardness of 50.0 mg/L. This dilution
water was prepared by adding Perrier water to ultra -pure water to obtain the desired final
hardness. The procedure for the preparation of this water may be found in the EPA
manual Short Term Methods for Estimating the Chronic Toxicity of Effluents and
Receiving Waters to Freshwater Organisms (EPA 821-R-02-013).
* Dilution water during the period of testing was prepared as follows;
Amount Hardness Conductivity Alkalinity pH
20 L 55.1 mg/L 113 µmhos/cm 49.2 mg/L 7.8
Gunpowder WWTP - WER 4 Cu ETT Environmental; 2/23
Page 97 of 120

2.3 Sample Collection
Sampling Locations
The effluent discharges into Gunpowder Creek. The effluent samples were collected as
composite samples. As received the effluent had no measureable residual chlorine (<0.05
mg/L). Effluent flow in the 24 hour period preceding sample collection was 2.225 mgd.
Upstream water samples were collected as grab samples upstream from the effluent
discharge point. Upstream flow was estimated based on flow at the USGS station located
at (USGS0214183368 Upper Little R at SR1740) (the closest USGS station to the
WWTP). This estimate was calculated as follows. On the day of sample collection the
flow at the USGS monitoring station was 30 cfs (19.4 mgd). The 25th percentile flow at
the USGS station ( 26 cfs = 16.8 mgd) was assumed to be the 7Q10 flow. Thus, on the
day of sample collection, the Gunpowder Creek flow was 1.15 times the 7Q10 flow (30
cfs / 26 cfs). The 7Q10 upstream flow at the discharge point of the WWTP on
Gunpowder Creek is 2.856 cfs. When the factor of 1.15 is applied to the Gunpowder
Creek 7Q10 flow, it is thereby estimated that the upstream flow on Gunpowder Creek on
the day of sample collection was 2.856 cfs x 1.15 = 3.2844 cfs.
All samples were collected in half gallon plastic jugs and preserved in coolers at 0-6°C.
Samples were transferred to an ETT courier by WWTP personnel.
2.4 Chemical Analyses
Dissolved oxygen and pH were measured in one surrogate of each test concentration at
the beginning and end of the test. Temperature was monitored in three surrogate test cups
in the incubator daily. Dissolved Oxygen and pH were measured with the use of a Orion
4 Star meter. The meter is calibrated daily.
Alkalinity, hardness, total suspended solids (TSS), total organic carbon (TOC), and
specific conductance were measured on each laboratory water and effluent sample
collected.
Gunpowder WWTP - WER 4 Cu
Page 98 of 120
ETT Environmental; 2/23

Total recoverable copper was measured on each test solution at the beginning and end of
the test. Dissolved copper also was measured for each test concentration at the beginning
and end of the test. Copper analyses were conducted by ETT Environmental of Greer,
SC using Standard Methods 18a' Edition Method 3111B (flame atomic absorption), and
concentrated to achieve a detection limit of 10 ug/L (or lower with concentration).
2.5 Preparation of Test Solutions
2.5.1 Simulated Downstream Water
Based upon the measured effluent flow (0.1.438 mgd) and the estimated upstream flow
(2.123 mgd) , a simulated downstream sample was prepared using 40.4% effluent and
59.6% upstream water.
2.5.2 Copper Spiking
Copper was spiked as copper sulfate (CuSO4.5H2O) into laboratory water and the
simulated downstream water. Prior to spiking the total recoverable copper in each
effluent sample was measured. Each day a batch of simulated downstream water was
prepared. A 12.72 mg/L stock solution of copper sulfate was prepared by adding 0.05 g
Of CuSO4.5112O to one liter of demineralized water. A microliter syringe was used to add
the correct volumes of the stock solution to each simulated effluent or control
concentration to achieve the desired nominal concentration of copper.
Gunpowder WWTP - WER 4 Cu
Page 99 of 120
ETT Environmental; 2/23

2.6 Test Organisms
The test organism used for this study was the fathead minnow Pimephales promelas. Test
organisms were neonates of less than 24 hours in age which were obtained from Aquatic
Biosystems of Fort Collins, CO. The test organisms were received as eggs and hatched
in ETT DMW dilution water. Culture sensitivity is monitored through the use of
reference toxicant testing on each purchased batch. Voucher specimens from the culture
are set aside and taxonomically verified by a staff macroinvertebrate taxonomist.
Gunpowder WWTP - WER 4 Cu
Page 100 of 120
ETT Environmental; 2/23

3.0 RESULTS
3.1 Laboratory Water
3.1.1 Acute Toxicity Testing Results
The acute definitive test with Pimephales promelas in laboratory water spiked with
copper showed a 48 Hour LC50 of 97.7237 ug/L Total Recoverable Copper and a 48
Hour LC50 of 89.1251 ug/L Dissolved Copper. Due to the pattern of the data, the values
were calculated using the logistic method. The survival data at each concentration are
summarized as follows;
Nominal Concentration
of Total Recoverable Cu
Measured Concentration
of Total Recoverable Cu
and (Dissolved Cu)
48 Hour
Mortality
0 ug/L
<1.0 ug/L (<2.0)
0%
35 ug/L
30.5 ug/L (32)
0%
50 ug/L
47 ug/L (47)
20%
71.4 ug/L
69.5 ug/L (65.5)
30%
102 ug/L
88 ug/L (79)
45%
143 ug/L
135 ug/L (126.5)
65%
204 ug/L
186.5 ug/L (173)
85%
291 ug/L
279 ug/L (279.5)
85%
Survival data for the test may be found in Appendix D2. Results of measured
concentrations of total recoverable and dissolved copper are provided in Appendix D3.
Statistical analysis results are found in Appendix D6.
3.1.2 Chemical Anal
The pH in the spiked dilution water test ranged from a minimum of 7.8 to a maximum of
8.2. Dissolved oxygen was generally at the saturation point in all treatments throughout
the test.
Gunpowder WWTP - WER 4 Cu
Page 101 of 120
ETT Environmental; 2/23

3.2 Simulated Downstream Water
3.2.1 Acute Toxicity Testing Results
The acute definitive test with Pimephales promelas in downstream water spiked with
copper showed a 48 Hour LC50 of 89.1251 ug/L Total Recoverable Copper and a 48
Hour LC50 of 83.1764 ug/L of Dissolved Copper. Due to the pattern of the data, the
value was calculated using the logistic method. The survival data at each concentration
are summarized as follows;
Nominal Concentration
of Total Recoverable Cu
Measured Concentration
of Total Recoverable Cu
and (Dissolved Cu)
48 Hour
Mortality
0 ug/L
8.7 ug/L (8.6)
0%
71.4 ug/L
67.5 ug/L (61)
25%
102 ug/L
91.0 ug/L (75.5)
65%
145 ug/L
124 ug/L (104.5)
65%
208 ug/L
171 ug/L (132.5)
70%
297 ug/L
259 ug/L (193.5)
80%
424 ug/L
376 ug/L (281)
100%
606 ug/L
646 ug/L (397)
100%
Measured concentrations were generally higher than nominal concentrations. A
significant suppression in survival was noted at a nominal concentration of 102 ug/L of
total copper.
Survival data for the test may be found in Appendix D2. Results of measured
concentrations of total recoverable and dissolved copper are provided in Appendix D3.
Statistical analysis results are found in Appendix D6.
Gunpowder WWTP - WER 4 Cu
Page 102 of 120
ETT Environmental; 2/23

3.2.2 Chemical Anal
The pH in the simulated downstream water ranged from a minimum of 7.2 to a maximum
of 8.3. Dissolved oxygen was generally near the saturation point in all treatments
throughout the test. Other water chemistry parameters are summarized as follows;
Parameter
Effluent
Total Recoverable Copper (ug/L)
9.0
Dissolved Copper (ug/L)
9.0
Alkalinity (mg/L)
No data
Conductivity (umhos/cm)
No data
Hardness (mg/L)
24.5
Total Organic Carbon (mg/L)
3.9
Total Suspended Solids (mg/L)
2.7
It may be seen that the effluent water was characterized by low alkalinity, hardness, TOC
and TSS.
3.3 Upstream Waters
Water quality parameters measured on upstream waters are provided in the following table;
Parameter
Result
Total Recoverable Copper (µg/L)
<5.0
Dissolved Copper (µg/L)
<5.0
Total Organic Carbon (mg/L)
<1.0
Alkalinity (mg/L)
No data
Hardness (mg/L)
18.4
Conductivity (µmhos/cm)
No data
Total Suspended Solids (mg/L)
<1.0
Gunpowder WWTP - WER 4 Cu
Page 103 of 120
ETT Environmental; 2/23

4.0 CALCULATION OF WATER EFFECT RATIO
As noted in the results section, acute testing indicated an LC50 of 97.7237 ug/L of total
recoverable copper in laboratory dilution water and an LC50 of 89.1251 ug/L of total recoverable
copper in 40.4% Gunpowder Creek WWTP effluent. The laboratory dilution water LC50 values
must be adjusted to downstream water hardness in order to calculate the Water Effect Ratio, using
the EPA formula, as follows;
LC50 x (downstream hardness/laboratory water hardness)0.9422
T-Cu: 97.7237 ug/L x (20.86/55.1)0.9422 = 39.1394 ug/L
Dis-Cu: 89.1251 ug/L x (20.86/55.1)0.9422 = 35.6955 ug/L
The Water Effect Ratio can thus be calculated as follows;
Water Effect Ratio (WER)
= LC50 in Effluent
= 89.1251 ug/L = 2.2771
(Total Recoverable Copper)
LC50 in Lab Water
39.1394 ug/L
Water Effect Ratio (WER)
= LC50 in Effluent
= 83.1764 ug/L = 2.3302
(Dissolved Copper)
LC50 in Lab Water
35.6955 ug/L
A final water effect ratio (FWER) will be calculated using the individual WERs from three
rounds of testing.
Gunpowder WWTP - WER 4 Cu
Page 104 of 120
ETT Environmental; 2/23

ROUND 4 -APPENDIX D1
Reference Toxicant Quality Control Chart
Pimephales promelas
Gunpowder WWTP - WER 4 Cu
Page 105 of 120
ETT Environmental; 2/23

ACUTE F EFTO - 2022/2
Fathead Minnow, Toxicant NaCl-. Fight to Left
f
MEAN
❑
LC50
f
UPPER
❑
LOWER
a
U
+
06
6
DF
Ur
G
p
m
r
Date
UCL & LCL ARE +1- 2 STD D FROM MEAN
Page 106 of 120

48 Hour Acute Toxicity Test Benchsheet
Test Method: EPA 821 R-02-012 ; Method 2000 Pimephales promelas
Client:
ETT
Sample ID:
NaCI Lab ID# 2-2-23 AD REF TOX P
Start Date:
02/02/23
Time: 02:30 PM
Set By:
Ended By:
AM
JC
End Date: 02/04/23 Time: 01:45 PM
Test Vessel
Test Solution Volume
Incubator
Transfer Volume
Dilution Water
Fathead Minnows
500 mL plastic cup
200 mL
#1
0.5 mL
MHSF
Randomization pattern per SO lNeonates from common holding vessel
Light: 50 -100 ft-c. 16 hr light / 8 hr dark
TEST ORGANISMS
for Ceriodaphnia dubia
Date Removed: Between: and:
Pime hales promelas Source: ABS Days old: 7
M sido sis Bahia Source: a s old:
Test Organisms Pre Fed b AM Time: 11:30
MORTALITY DATA
®�Cumulative
Mortality
- hr 48 hr 72 hr 96 lir
Comments:
Initial
Final
Temp
ID.O. IpH
I
I By:
JpH
I
I By:
24.71
8.01
7.711
AM
24.71
9.1
7.8
JC
24.71
8.01
7.711
AM
24.71
9.11
7.91
JJC
24.71
8.01
7.71
1 AM
24.71
9OF
8.01
JJC
24.71
8.11
7.811
AM
24.71
8.61
8.111
JC
24.71
8.11
7.911
AM
24.71
8.41
8.1
JC
24.71
8.11
7.911
AM
24.71
8.41
8. 111.1
C
°C
I mg/L
°C
mg;'L
48 Hour Acute Toxicity Test Statistics
Statistical Method: Spearman Karber
48 Hour LC50 = 8.39 g/L NaCl Lower Confidence Limi 7.98
Upper Confidence Limit 8.83
Page 107 of 120

Gunpowder WWTP - WER 4 Cu
ROUND 4 - APPENDIX D2
Survival Data for Acute Definitive Tests
ETT Environmental; 2/23
Page 108 of 120

Mortality
24 hr 48 hr
II
e�aa
®®aa
e�aa
e®®a
e�®a
OEM��
®
as
WER 48 Hour Acute Toxicity Test
Facility: 1W Cu P promelas 2-1-23
Metal: Cu
Sample ID:
Start Date: 02/01/23 Time; 1:30 By: JC
End Date: 02/03/23 Time: 2:00 By: 7C
Eff. Log #: U stream Log ##:
TEST ORGANISMS
Test Organism: Cerioda hnia dub771
for Ceriodaphnia dubia Source:
Date Removed:
Between hrs hrs
for fathead minnows or mysids
Source: ABS 2/l/23
Temperature 24-26 C. Light 16 hr It / 8 hr dk; 50-100 ft-candles
Laboratou Water
DMW / SSF A 50 m hardness
Downstream Water Preparation
Lfluent
Stream
volume
Pre . bate:
Volume
Prep. By:
Test Solution Preparation:
Date: 02/01/23
Prep By
JC
Metal Salt:
CuSO4 5H2O
Stock. Soln:
12.72 m
Nominal Cone.
mL Stock Soln.
Volume Preared
0
u
0.00
mL
600 mL
35
ug/L
1.65
mL
600 ML
50
u(,/L
2.36
mL
600 mL
71.4
u,/L
3.37
mL
600 mL
102
u L
4.81
mL
600 mL
143
U
6.75
mL
600 mL
204
u9jL
9.63
mL
600 mL
291
u
13.73
mL
600 mL
Water Chemist
Time:
Analyst:
D.O.(m )
PH
DMW
Start
Final
8.3
m
7.8 S.U.
7.7 m
8.2 S.U.
Downstream
Start
Final
m
S.U.
m
S.U.
U stream
Start
m
S.U.
Effluent
Start
m
S.U.
Test solution volume: 25 mL. Test vessels 9 oz. plastic cups. Transfer volume 0.05 mL. Test Method: Per EPA Interim Guidance
Page 109 of 120

om®Mortality
era®
era®
e�sa
e®®a
WER 48 Hour Acute Toxici Test
Facility:
T64030 Cu P promelas
Metal: Cu
Sample ID:
GUNPOWDER
Start Date:
02/01/23 Time: 1:30 By: JC
End Date:
02/03/23 Time: 2:10 By: JC
Eff Lo #:
64029 U stream Log #: 64030
TEST ORGANISMS
Test Organism: Cerioda hnia dubia
for Ceriodaphnia dubia Source:
Date Removed:
Between hrs hrs
for fathead minnows or mysids
Source: ABS 2/l/23
Temperature 24-26 C. Light 16 hr It / 8 hr dk; 50-100 ft-candles
Laboratory Water DMW / SSF A 50 m4 hardness
Downstream Water Preparation
effluent 1 40.4% 1 volume 2020 1 Prep. Date: 02/01/23
uDstreaml 59.6% 1 volume 2980 1 Prev, Bv: JC
Test Solution Preparation:
Date: 02/01/23
Prep By
JC
Metal Salt:
CuSO4 5H2O
I Stock, Soln:
12.72 m L
Nominal Cone.
mL Stock Soln.
Volume Prepared
0
u L
0.00
mL
600 mL
71.4
u
3.37
mL
600 mL
102
u L
4.81
mL
600 mL
145
u
6.84
mL
600 mL
208
11911,
9.81
mL
600 mL
297
u
14.01
mL
600 mL
424
u
20.01
mL
600 mL
606
u
28.60
mL
600 mL
Water Chemist
Time:
Analyst:
D.O.(m )
PH
DMW
Start
Final
8.3
m
7.9 S.U.
m
S.U.
Downstream
Start
Final
8.1
m
7.2 S.U.
7.9 m
7.8 S.U.
U stream
Start
8.4
m L
7,3 S.u.
Effluent
Start
8.1
mulL
7n S.u.
Test solution volume: 25 mL. Test vessels 1 oz. plastic cups. Transfer volume 0.05 mL.
Page 110 of 120
Test Method: per EPA Interim Guidance

ROUND 4 - APPENDIX D3
Measured Concentrations of Total Recoverable Copper in Test Solutions
Gunpowder WWTP - WER 4 Cu
ETT Environmental; 2/23
Page 111 of 120

Measured Total Recoverable and Dissolved Copper
Lenoir Gunpowder - Secondary Species Site Specific Study
February 2023
Sample: Spiked Dilution Water (Diluted DMV Initial Date: 2/01/23
Nominal
Total Cu
Measured Total Recoverable Copper (µg/L)
Initial Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Mean
Rio of
ominal
0
<1.0
<1.0
<1.0
35.0
33.0
28.0
30.5
87%
50.0
48.0
46.0
47.0
94%
71.41
67.0
72.0
69.5
97%
102.0
86.0
90.0
88.0
86%
143.0
129.0
141.0
135.0
94%
204.0
188.0
1274.0
185.0
186.5
91%
291.0
1
1284.0
279.0
Sample: Simulated Downstream Initial Date: 2/01/23
ominal
Total Cu
Measured Total Recoverable Copper (µg/L)
Initial Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Mean
% of
Nominal
0.0
9.5
7.9
8.7
71.4
71.0
64.0
67.5
95%
102.0
100.0
82.0
91.0
89%
145.01
135.0
113.0
124.0
86%
208.0
190.0
152.0
171.0
82%
297.0
286.0
232.0
259.0
87%
424.0
415.0
331.0
375.5
89%
606.0
541.0
750.0
646.0
Measured Dis. Cu (µg/L)
Initial Day 2 Mean
%
Dissolved
<1.0
1.3
1.2
34.0
30.0
32.0
105%
48.0
46.0
47.0
1 100%
63.0
68.0
65.5
94%
84.0
74.0
79.0
90%
120.0
1 133.0
126.5
94%
170.0
176.0
173.0
93%
291.0
268.0
279.5
Measured Dis. Cu (µg/L)
Initial Day 2 Mean
%
Dissolved
8.6
8.6
8.6
70.0
52.0
61.0
90%
81.0
70.0
75.5
83%
109.0
100.0
104.5
84%
143.0
122.0
132.5
77%
206.0
181.0
193.5
75%
296.0
265.0
280.5
75%
407.0
386.o
391.5
Page 112 of 120

ROUND 4 - APPENDIX D4
Water Chemistry Measurements for Acute Definitive Tests
Gunpowder WWTP - WER 4 Cu
See Appendix D2
ETT Environmental; 2/23
Page 113 of 120

Gunpowder WWTP - WER 4 Cu
ROUND 4 -APPENDIX D5
Chain of Custody Documentation
ETT Environmental; 2/23
Page 114 of 120

ETT
PO Box 16414, Greemntle, SC 29606-7414
[phone], [phone]
Shipping Address: 4 Craftsman Ct, Greer, SC 29650
www.ettleb.org
CHAIN OF CUSTODY RECORD
Page of
Client:
V' Ci(
Program
Containers
Preservative
Parameters
Facility: G&0(po,,,deo-
\1`holcemucntTozicity
State: /✓C— NPDES #: C 373
Acute
Chronic
Test Organisms
=
fl
0
C
E
V
(Composite only)
(Grab or Composite)
<
o
c
U
t j
O
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i
o
y
(S]
U
Sign, and Print below
3
w
v
c
2=14CL
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no
-
7
=
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<
g
Oledotted line
u
'�
G
=
aaFtNoa
u
fl
>:
•
j
L
ID
U
composite start Dsle Time
sample Collection Dme Time
Collected by
U
£
to
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OO
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Special Instructions:
Sample Custody Transfer Record
Secure
Receipt
Sample
Date Time Relinquished B / Or anization Receiv r tion
Area
Temp °C
Preserved?
1-31-�31153
t�
,• o
_
3r
s
o
COMPOSITE SAMPLING PROCEDURES TEMPERATURE AlONITORING PROCEDURES HOLD TIME PROCEDURES
Composite samples must be collected over a 24 hour period. Sample temperature during collection and transport must be between For toxicity testing the sample must first be used within 36 hours
Time Proportional: 1 sample each hour for 24 hours. Equal volui 0.0 and 6.0 *C. Samples must not be frozen. Use water ice in sealed bags. of sample collection (completion of composite sample).
or at minimum 1 sample every 4 hours over 24 hours. Sample may not be used after 72 hours from sample collection.
Flow Proportional: As per instructions in NPDES permit.
Page 115 of 120

Gunpowder WWTP - WER 4 Cu
ROUND 4 - APPENDIX D6
Statistical Analysis Results
ETT Environmental; 2/23
Page 116 of 120

DMb)
LOGISTIC MODEL
Survival
Test:6uopewder
Fish
Date:21112023
T-Cu
gamma 0
1E-05
alpha
1.99
beta
-4.4
sury
0
100
test conc
47
80
69.5
70
88
55
135
35
186.5
15
LC50
97.7237221
0
0
predicted
num denominator y
100 1 100
47 1.246900607 80.19885
denom 69.5 1.521384837 65.72959
88 1.818504616 54.99024
135 2.854228268 35,03574
186.5 4.438333406 22,53098
IC25 2 50 actual mean
predicted reproduction
100
90 --- -
80 - --- -- --- _-._
70 �.
60
50 m
40
30
20
10 °
00 40 80 120 160 200
in actual mean
® predicted
reproduction
Page 117 of 120

pow
LOGISTIC MODEL
Survival
Test:-G4apaurde -
Fish
Date: 2/1/2023
Dis Cu
gamma 0
1E-05
alpha
1.95
beta
4
sury
0
100
test conc
47
80
65.5
70
79
55
126.5
35
173
15
LC50 69.1250938
0
predicted
num denominator y
100 1 100
47 1.329029269 75.24289
denom 65,5 1.585648909 63.06566
79 1.810996424 55-21822
126.5 2.837419427 35.24329
173 4.165099246 24.00903
IC25 2 50 actual mean
predicted reproduction
I
100 i
90 - - - - --
80
70
_ _ ..._..
60
50
40
30
20
10 _®
00 20 40 60 80 100 120 140 160 180
i
® actual mean ® predicted
reproduction
Page 118 of 120

LOGISTIC MODEL
Survival
Test: Gunpowder
Fish
Date: 2/1/2023
T Cu
gamma 0
1 E-05
alpha
1.95
beta
-4
sury
0
100
test conc
67.5
75
91
35
124
35
171
30
259
20
LC50
89.1250938
0
0
1C
predicted
num denominator y
100 1 100
67.5 1.617062534 61.84063
denom 91 2.036827499 49.09596
124 2.774798225 36.03866
171 4.101805749 24.37951
259 7.380197521 13.54977
IC25 2 50
actual mean
predicted reproduction
0 40 80 120 160 200 240 280
® actual mean
® predicted
reproduction
Page 119 of 120

LOGISTIC MODEL
Survival
Test: Gunpowder
Fish
Date: 2/1/2023
Dis Cu
gamma 0
1E-05
alpha
1.92
beta
-4
sury
0
100
test cone
67.5
75
75.5
35
104.5
35
132.5
30
193.5
20
l-050
83.1763771
predicted
num denominator y
100 1 100
67.5 1.695736064 58.97144
denom 75.5 1.845174475 54.19542
104.5 2.486560648 40.21619
132.5 3.24535472 30.81327
193.5 5.335009828 18.74411
IC25 2 50 actual mean
predicted reproduction
Page 120 of 120

Cu WER: 2023
Water Effect Ratio (WER) Study Review Checklist
Permittee: City of Lenoir - Gunpowder Creek Permit No.:
Date reviewed:
Reviewer:
NCO023736
This checklist is based upon the 1994 Interim Guidance on Determination and Use of Water -Effect Ratios for Metals and applies to Method 1
described therein. The purpose of this checklist is to serve as a useful tool in reviewing Method I WER studies. The checklist does not
supercede the 1994 Interim Guidance document. In reviewing a WER study, the acceptability of each toxicity test will be evaluated
individually based upon the procedures described in the 1994 Interim WER Guidance. Page 57 of the 1994 guidance states that, "If the
procedures used deviated from those specified in the guidance, particularly in terms of acclimation, randomization, temperature control,
measurement of metal, and/or disease or disease -treatment, the test should be rejected; if deviations were numerous and/or substantial, the
test must be rejected. " Guidance concerning the calculation of the results of each test and the derivation of the individual test WERs and the
FWER is also provided in the 1994 Interim WER Guidance. Review of these results will be in accordance with the guidance document.
General Information
#
Question
(If yes, place a "Y" in box; if no, place an "N" in box. If question cannot be
answered in yes/no format, then place answer in "Comments " section.)
Workplan
Comments
1994
Guidance
page #, part
1.
Is the name, location, and description of the discharger provided?
j
62, J(3)
2.
Is the name of the study investigator provided?
62, J(1)
3.
Is the purpose for conducting the study described?
—
4.
Are requirements that are in the existing permit concerning WET testing,
TIE, and/or THE being met?
9
5.
Is pretreatment, waste minimization, or source reduction an option?
9
6.
Are applicable technology -based limits being met?
9
7.
Is a description of each sampling station provided?
62, J(4)
Page 1

Permittee:_ City of Lenoir - Gunpowder Creek
Individual Studies
Permit No.: NCO023736
#
Question
(Ifyes, place a "Y" in box; if no, place an "N" in box. If question cannot be
answered in yes/no format, then place answer in "Comments" section.)
Study 1
Study 2
Study 3
Comments
1994
Guidance
page #, part
Selecting Primary and Secondary Tests
8.
Species used for primary toxicity test? Ceriodaphnia dubia
C dubia
C dubia
C dubia
45-47, C
9.
Species used for secondary toxicity test? Pimephales promelas
PproinelaS
___ ___
45-47, C
Acquiring and Acclimating Test Organisms
10.
Organism culture, hold, acclimation, feed, and handling protocols
summarized?
r(
47-48,
D(1-2)
1 1 .
Were the organisms acclimated to site water prior to initiating the test?
I(
47, D(l)
12.
Were randomization procedures utilized?
r(
47, D(1)
53, G(9)
Collecting and Handling Upstream Water and Effluent
Mr
13.
Was rainfall data or stream flow data included and was upstream water
unaffected by recent runoff events? Rainfall data should be included.
iI
fI
Provided by POTW
All WERs 1
48, E(1)
14.
Is the effluent sample representative of normal operations?
48, E(2)
15.
Was the plant operating at "normal levels"? Flow data should be included.
49, E(5)
16.
Were samples stored at 0-4°C?
48, E(4)
17.
Are chains -of -custody for samples included, accurate, and filled out
completely?
49, E(6)
18.
Were toxicity tests initiated w/in a maximum of 36 hours from the time of
sample collection? Test initiation and termination times should be included.
49, E(7)
62, J(1)
19.
If predators in the site water are a concern, was the site water filtered
through a 37-60 µm sieve or screen?
V
IV
fI
No predators in site
water
49, E(8)
Page 2

Permittee: City of Lenoir Gunpowder Creek Permit No.: NC0023736
#
Question
(If yes, place a "Y" in box; if no, place an "N" in box. If question cannot be
answered in yes/no format, then place answer in "Comments" section.)
Study 1
Study 2
Study 3
Comments
1994
Guidance
page #, part
Laboratory Dilution Water
20.
Did the lab water have TOC and TSS <5 mg/L as required?
50, F(2)
21.*
Was the hardness of the lab water between the required 40 and 220 mg/L?I(
50, F(3)
22.*
Was the lab water hardness (w/in the above range) close to the site water?
From 1997 Guidance, page 3, next to lastparagraph
I(r
i
<<1997
Guidance
23.
Are the lab water pH and alkalinity appropriate for the hardness used?
50, F(4)
Conducting Tests
24.
Was the spiking stock solution made from an appropriate reagent?
50-51,
G(4)(a-b)
25.
Was the same stock solution used for lab water and site water tests?
�I
�(i
51, G(4)(c)
26.
Was a static test run?
51, G(5)
27.
If the test ran longer than 48 h, was it a renewal test?
48 hr test
51, G(5)
28.
If it was a renewal test, were side -by -side tests renewed at the same time
and were proper procedures for renewal followed?
i�ri
not a renewal test
51, G(5)
29.
Was a range finder test conducted?
II
51, G(7)
30.
Was the dilution factor used in the definitive tests of 0.65 or greater?
��I
�I
ICI
0.7 dilution factor
53, G(8)
31.
Was an unspiked dilution water control for each test used?
53, G(9)
32.
Were at least 20 test organisms per treatment used?
j l
V
fI
53, G(9)
33.
Were two or more replicates used per treatment?
53, G(9)
Page 3

Permittee: City of Lenoir Gunpowder Creek
Permit N(Perm it No.: NCO023736
#
Question
Study 1
Study 2
Study 3
Comments
1994
(If yes, place a "Y" in box; if no, place an "N" in box. If question cannot be
Guidance
answered yes/no format, then place answer in "Comments " section.)
MMEL
=
page #, part
34.
Were the laboratory hard water and the site water prepared in accordance
53, G(10)
with appropriate guidelines?
54, G(11)
35.
Were the test organisms (already acclimated), added to the test chambers for
54, G(12)
the side -by -side tests at the same time?
Chemical and Other Measurements
36.
Were hardness (or salinity for marine water), pH, alkalinity, TSS, and TOCii
55, H(2)
measured at test initiation for both site water and lab water?
37.
If "yes" to the above question, did the dissolved oxygen level remain
�,
55, H(3)
acceptable throughout the entire test?
38.
Were dissolved oxygen, pH, and temperature measured for each treatment at
55, H(3)
the appropriate times during the test?
39.
Were both total recoverable and dissolved metal measured for all samples?
54, H(4)
40.
Were the metal concentrations measured at the appropriate frequency?
54, H(4)(d)
41.
Were QA/QC requirements summarized?
57,
H(4)(d)(5)
Calculating and Interpreting the Results
42.
To prevent roundoff error in subsequent calculations, were at least four
57,1(1)
significant digits retained in all endpoints and WERs?
43.
Were greater than 10% of control organisms adversely affected (for acute
57, I(2)(b)
tests)?
44.
The percent of organisms that were adversely affected must have been less
57,
than 50%, and should have been less than 37%, in at least one treatment
I(2)(c)(1)
other than the control. Did this occur?
Page 4

Permittee: City of Lenoir - Gunpowder Creek
------------------------
Permit No.: NCO023736
#
Question
Study 1
Study 2
Study 3
Comments
1994
(If yes, place a "Y" in box; if no, place an "N" in box. If question cannot be
Guidance
answered in yes/no format, then place answer in "Comments " section.) _
MMML
page #, part
45.
For lab water, at least one treatment showed at least 50% of the organisms
57,
to be adversely affected?
I(2)(c)(2)
46.
For site water, at least one treatment showed at least 63% of the organisms
ij�iiI
57,
to be adversely affected?
I(2)(c)(2)
47.
Did a lower concentration kill a higher % of organisms than a higher
57,
concentration?
1(2)(c)(3)
48.
If so, did this occur for more than two concentrations affecting between 20-
57,
80% of the organisms?
1(2)(c)(3)
49.
If a static test was run, did the dissolved metal concentration at the end of 48
58, I(2)(e)
hours decrease by more than 50% from test initiation?
50.
Did it increase by more than 10% from test initiation?I
�I
—
51.
Did each individual test meet all acceptability requirements, as specified in
57,1(2)
#43-49 above?
52.
Were the LC50 (or EC50) values calculated appropriately and with similar
{I
�I
58, I(4 & 6)
statistics?
53.*
Was the hardness of the laboratory dilution water normalized (to obtain an
I
�(i
�I
39-43
adjusted LC50) according to the guidance document?
54.
Do the results from the laboratory dilution water compare with results that
We do not have access to
data from other labs.
59,1(5)
were obtained using a comparable laboratory dilution water in one or more
Results were comparable to
other laboratories?
results of the many previous
WERs we have done.
55.
Is the WER larger than 5? If so, investigate results further as specified in the
61,
1994 Interim Guidance on page 61.
1(7)(c)(3)
56.
Were summary tables provided containing metal concentrations and
y�l
9
yV
64, J(3)
organism response for each concentration?
Page 5

Permittee: City of Lenoir - Gunpowder Creek Permit No.: NCO023736
Final Report
#
Question
Final Report
Comments
1994
(Ifyes, place a "Y" in box; if no, place an "N" in box. If question cannot
Guidance
be answered in yes/no format, then place answer in "Comments " section.)
page #, part
57.
Were toxicity tests conducted at least three weeks apart?
(
48, E(3)
58.
Three WERs for primary test developed?
y�l(
45, C(1)
59.
At least one WER for secondary test developed?
yl�
45, C(1)
60.
Are the WERs obtained with the primary and secondary tests w/in a factor
61, I(7)(b)(1)
of 3? If yes, then results are further confirmed.
61.
Does the test with the higher endpoint give the higher WER? If yes, then
61, 1(7)(b)(2)
results are further confirmed.
62.
Were both total recoverable and dissolved WERs calculated?
60,1(6)
63.
Was the final WER calculated as the geometric mean of the three individual
Because all were Type I WERs, the lowest
WER was used. It was 6.0449.
37-38
test WERs? Provide the final WER in the comments section.
64.
Were acute and chronic criteria calculated? If yes, provide the results in the
Y
Acute (maximum) limit: 98.5 ug/L
—
comments section.
Chronic (average) limit: 75.3 ug/L
65.
Were any individual studies eliminated from consideration in the final
—
WER calculation? If yes, provide an explanation.
66.
Was an explanation of "unusual' observations and/or any procedural
—
deviations provided if necessary?
* As an alternative to conducting testing with laboratory water with a hardness between 40 and 220 mg/1 total hardness and then mathematically adjusting the LC50 of the
laboratory water to the segment regulatory hardness, testing can be conducted using laboratory water with the total hardness chemically adjusted to be the same as the
segment regulatory hardness. If the laboratory water is adjusted, then no mathematical adjustment should be necessary.
Additional Comments:
Page 6

[External] Permit Modification Request
Triplett, Lisa R. <[e-mail]>
Mon 11/6/2023 11:39 AM
To:Perlmutter, Gary <[e-mail]>
CAUTION: External email. Do not click links or open attachments unless verified. Report suspicious emails with the Report
Message button located on your Outlook menu bar on the Home tab.
Good afternoon Gary,
I am requesting a permit modification for the City of Lenoir Gunpowder Creek Wastewater
Treatment Plant NCO023736 reflecting the recent WER study results done by ETT Environment
lab for a possible less stringent permit limit on Copper. If you need further information or
data please feel free to let me know. Thank you.
Seaga R, 2w*&,
7.Uaatecu4ten %aeatM"e ;V&Wr soeze ateotde�ct
1828J 757-4462
LENOIRA
PUBLIC UTILITIES W

NCO023736 jW5.00'Gity of Lenoir - Gunpowder Creek WWTP
Caldwell'�AshevilleT 001 �'F2021-1111
NCO023736
F 5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
5
11
2021
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
6
8
2021
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
7
13
2021
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
8
10
2021
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
9
7
2021
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
10
14
2021
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
11
16
2021
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
12
� j 2021_
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
1
27
2022
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
2
_
15
2022
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
3
8
2022
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
4
5
2022
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
4
6
2022
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
4
7
2022
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
5
17
2022
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
6
7
2022
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
7
12
2022
NCO023736
5.00 City of Lenoir_ Gunpowder Creek WWTP
Caldwell
-Asheville
001 1
8
M9
2022_
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP_
Caldwell
Asheville
001
9
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2022
NCO023736
5.00 City of Lenoir[ Gunpowder Creek WWTP
Caldwell
_
Asheville
001
10
_
11
2022
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
11
15
2022
NCO023736
5.00 City of Lenoir[ Gunpowder Creek WWTP
Caldwell
Asheville
001
12
6
2022
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
1
9
2023
NCO023736
5.00 City of Lenoir[ Gunpowder Creek WWTP
Caldwell
Asheville
001
2
14
2023
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
3
14
2023
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
4
11
2023
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
5
16
2023
NCO023736
5.00 City of Lenoir_ Gunpowder Creek WWTP
Caldwell
Asheville
001
6
13
2023.
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
7
25
2023
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
00�E
8
8
2023
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
001
9
12
2023
NCO023736
5.00 City of Lenoir - Gunpowder Creek WWTP
Caldwell
Asheville
OQ m
10
17
2023
4/22/2021 IID1042 - Copper, Total (as Cu) r'Metal
5/11/2021 01042 - Copper, Total (as Cu)
Metal
6/8/2021 01042 - Copper, Total (as Cu)
Metal
7/13/2021 01042 - Copper, Total (as Cu)
Metal
8/10/2021 01042 - Copper, Total (as Cu)
Metal
9/7/2021 01042 - Copper, Total (as Cu)
Metal
10/14/2021 01042 - Copper, Total (as Cu)
Metal
11/16/2021 01042 - Copper, Total (as Cu)
Metal
_12/7/2021 01042 - Copper, Total (as Cu)
Metal
1/27/2022 01042 - Copper, Total (as Cu)
Metal
_
2/15/2022 01042 - Copper, Total (as Cu)
Metal
3/8/2022 01042 - Copper, Total (as Cu)
Metal
4/5/2022 01042 - Copper, Total (as Cu)
Metal
4/6/2022 01042 - Copper, Total (as Cu)
Metal
4/7/2022 01042 - Copper, Total (as Cu)
Metal
5/17/2022 01042 - Copper, Total (as Cu)
Metal
6/7/2022 01042 - Copper, Total (as Cu)
Metal
7/12/2022 01042 - Copper, Total (as Cu)
Metal
_ 8/9/2022 01042 - Copper, Total (as Cu) _
Metal
9/6/2022 01042 - Copper, Total (as Cu)
Metal
_
10/11/2022 01042 - Copper, Total (as Cu)
Metal
11/15/2022 01042 - Copper, Total (as Cu)
Metal
12/6/2022 01042 - Copper, Total (as Cu)
Metal
1/9/2023 01042 - Copper, Total (as Cu)
Metal
2/14/2023 01042 - Copper, Total (as Cu)
Metal
3/14/2023 01042 - Copper, Total (as Cu)
Metal
4/11/2023 01042 - Copper, Total (as Cu)
Metal
5/16/2023 01042 - Copper, Total (as Cu)
Metal
6/13/2023, 01042 - Copper, Total (as Cu)
Metal
7/25/2023 01042 - Copper, Total (as Cu)
Metal
8/8/2023 01042 - Copper, Total (as Cu)
Metal
9/12/2023 01042 - Copper, Total (as Cu)
Metal
10/17/2023 01042 - Copper, Total (as Cu)
Metal
Composite'15g/I 1�.
-Fffluent -W
Composite ug/I 1
22.5
Effluent
Composite ug/I W23.9
Effluent
Composite ug/I
16.2
Effluent
Composite ug/I
8
Effluent
Composite ug/I
30
Effluent
Composite ug/I
21
Effluent
Composite ug/I
9.9
Effluent
Composite /I
10
,
f-ffluent
Composite ug/I
23
Effluent
Composite ug/I
_
16
�tffluent
Composite ug/I
17
Effluent
Composite ug/I IL
12
Effluent
Composite ug/I
16
Effluent
Composite uMJ�=M
12
Effluent
Composite ug/I
13
Effluent
Composite -M
12
Effluent
Composite ug/I
9
Effluent
Composite--NNNL6....F-ffluent
Composite ug/I
12
Effluent
Composite ug/I
14'rffluent
Composite ug/I
21
Effluent
Composite ug/I
10
Effluent
Composite ug/I
13
Effluent
Composite
go
Effluent
Composite ug/I
23
Effluent
Composite -j
14
Effluent
Composite ug/I
12
Effluent
Composite -M
11
�gffluent
Composite ug/I
13
Effluent
Composite ug/I W
11
-effluent
Composite ug/I
7
Effluent
Composite ug/I
6
Effluent

Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
REQUIRED DATA ENTRY
Table 1. Project Information
❑ CHECK IF HQW OR ORW WQS
Facility Name Gunpowder Creek WWTP Par01
WWTP/WTP Class IV Par02
NPDES Permit
NCO023736
Par03
Outfal I
001
Par04
Flow, Qw (MGD)
Par05
2.000
Receiving Stream
Gunpowder Creek
Par06■
HUC Number
03050101
Par07
Stream Class
WS-IV
2.90
Par08
Par09
Par10
0 Apply WS Hardness WQC
7Q10s (cfs)
7Q10w (cfs)
Par11
4.00
30Q2 (cfs)
Par12
5.80
QA (cfs)
Par13
17.40
1 Q10s (cfs)
Par14
Par15
2.43
Effluent Hardness
20.86 mg/L (Avg)
-------------
Upstream Hardness
----------------------
20.86 mg/L (Avg)
Par16
-------------
Combined Hardness Chronic
----------------------
$20.86
Par17
-------------
Combined Hardness Acute
----------------------
$20.86
Par18
Par19
Data Source(s)
----------------------
Copper data are from DMRs. Total Copper Chronic
and Acute criteria modified by multiplying the lowest
WER of four rounds.
Parzo
❑ CHECK TO APPLY MODEL
Par21
Par22
Par23
Par24
Table 2. Parameters of Concern
Name wQs Type Chronic Modifier Acute PQL Units
Arsenic
Aquactic Life
C
150
FW
340
ug/L
Arsenic
Human Health
Water Supply
C
10
HH/WS
N/A
ug/L
Beryllium
Aquatic Life
NC
6.5
FW
65
ug/L
Cadmium
Aquatic Life
NC
0.5899
FW
3.2396
ug/L
Chlorides
Aquatic Life
NC
230
FW
mg/L
Chlorinated Phenolic Compounds
Water Supply
NC
1
A
ug/L
Total Phenolic Compounds
Aquatic Life
NC
300
A
ug/L
Chromium III
Aquatic Life
NC
117.7325
FW
905.0818
ug/L
Chromium VI
Aquatic Life
NC
11
FW
16
pg/L
Chromium, Total
Aquatic Life
NC
N/A
FW
N/A
pg/L
Copper
Aquatic Life
NC
47.6377
FW
63.3022
ug/L
Cyanide
Aquatic Life
NC
5
FW
22
10
ug/L
Fluoride
Aquatic Life
NC
1,800
FW
ug/L
Lead
Aquatic Life
NC
2.9416
FW
75.4871
ug/L
Mercury
Aquatic Life
NC
12
FW
0.5
ng/L
Molybdenum
Human Health
NC
2000
HH
ug/L
Nickel
Aquatic Life
NC
37.2313
FW
335.2087
pg/L
Nickel
Water Supply
NC
25.0000
WS
N/A
pg/L
Selenium
Aquatic Life
NC
5
FW
56
ug/L
Silver
Aquatic Life
NC
0.06
FW
0.2964
ug/L
Zinc
Aquatic Life
NC
126.7335
FW
125.7052
ug/L
23736 RPA 2023, input
5/21 /2024

REASONABLE POTENTIAL ANALYSIS
Pal
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Date Data
4/22/2021
5/11 /2021
6/8/2021
7/13/2021
8/10/2021
9/7/2021
10/14/2021
11 /16/2021
12/7/2021
1 /27/2022
2/15/2022
3/8/2022
4/5/2022
4/6/2022
4/7/2022
5/17/2022
6/7/2022
7/12/2022
8/9/2022
9/6/2022
10/11 /2022
11 /15/2022
12/6/2022
1 /9/2023
2/14/2023
3/14/2023
4/11 /2023
5/16/2023
6/13/2023
7/25/2023
8/8/2023
9/12/2023
10/17/2023
Copper
BDL=1/2DL
17.8
17.8
22.5
22.5
23.9
23.9
16.2
16.2
8
8
30
30
21
21
9.9
9.9
10
10
23
23
16
16
17
17
12
12
16
16
12
12
13
13
12
12
9
9
16
16
12
12
14
14
21
21
10
10
13
13
29
29
23
23
14
14
12
12
11
11
13
13
11
11
7
7
6
6
Results
Std Dev
Mean
C.V.
n
Mult Factor =
Max. Value
Max. Pred Cw
Use "PASTE SPECIAL
Values" then "COPY"
Maximum data
points = 58
6.0429
15.1909
0.3978
33
1.11
30.00 ug/L
33.30 ug/L
-4-
23736 RPA 2023, data
5/21 /2024

Gunpowder Creek WWTP
NCO023736
Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
Qw (MGD) =
2.0000
1Ql0S (cfs) =
2.43
7Q10S (cfs) =
2.90
7Q10W (cfs) =
4.00
30Q2 (cfs) =
5.80
Avg. Stream Flow, QA (cfs) =
17.40
Receiving Stream: Gunpowder Creek HUC 03050101
WWTP/WTP Class: IV
IWC% @ 1Q10S = 56.05786618
IWC% @ 7Q10S = 51.66666667
IWC% @ 7Q10W = 43.66197183
IWC% @ 30Q2 = 34.83146067
IW%C @ QA = 15.12195122
Stream Class: WS-IV
Outfall 001
Qw = 2 MGD
COMBINED HARDNESS (mi!/Ll
Acute = 25 mg/L
Chronic = 25 mg/L
YOU HAVE DESIGNATED THIS RECEIVING
STREAM AS WATER SUPPLY
Effluent Hard: 0 value > 100 mg/L
20.86 mg/L (Avg)
PARAMETER
TYPE
NC STANDARDS OR EPA CRITERIA
J
CO
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
Applied
Chronic Acute0.
D
n # Det. Max Pred Cw Allowable Cw
Standard
Acute: 112.92
Copper
NC
47.6377 FW(7Q10s) 63.3022
ug/L
33 33
33.30
Chronic: 92.20
No RP, Predicted Max < 50% of Allowable Cw - No
No value > Allowable Cw
Monitoring required
23736 RPA 2023, rpa
Page 5 of 5 5/21/2024

RE: [External] question on the permit modification for NCO023736
Triplett, Lisa R. <[e-mail]>
Fri 1/19/2024 10:46 AM
To:Perlmutter, Gary <[e-mail]>
CAUTION: External email. Do not click links or open attachments unless verified. Report suspicious entails with the Report Message button located on your Outlook menu bar on the Home tab
Thank you for checking on it for me. I think that chlorinated phenols is part of the PPA that we do once per year for 2023, 2024, and 2025
�Peaa ,� 7ukeetl.
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PUBLIC UTILITIES
From: Perlmutter, Gary <[e-mail]>
Sent: Friday, January 19, 202410:45 AM
To: Triplett, Lisa R. <[e-mail]>
Subject: Re: [External] question on the permit modification for NCO023736
Hi Lisa,
That is strange - I don't know why that is in there. I will make the correction
Thanks,
Gary
From: Triplett, Lisa R. <lrtriplettPCI.LENOIR.NC.US>
Sent: Friday, January 19, 202410:17 AM
To: Perlmutter, Gary <gary. [e-mail]>
Subject: [External] question on the permit modification for NCO023736
CAUTION: External email. Do not click links or open attachments unless verified. Report suspicious emails with the Report Message button located on your Outlook menu bar on the Home tab.
Good morning Gary,
As I was looking over the Draft Permit Modification letter I see that copper was dropped off which is good, but I also noticed that on the
effluent limits and monitoring requirements that Chlorinated Phenols was added for monitoring quarterly, which was not on the original permit
and I was wondering if that was something new that we will now be required to do, or if it was accidentally added on the list. Thank you for
clarifying the concern.
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(82Y) 757-4462
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Email correspondence to and from this address maybe subject to the North Carolina Public Records Law and maybe disclosed to third parties by an authorized state official.

CATAW BA
RIVERKEEPER®
February 61h, 2024
NCDEQ-DWR
Water Quality Permitting Section
1617 Mail Service Center
Raleigh, NC 27699-1617
Dear Water Quality Permitting Section,
The Catawba Riverkeeper Foundation is a member -funded environmental nonprofit that educates, advocates, and
protects the Catawba-Wateree River and all its tributaries. Our organization represents over 8,400 active members
who rely on the watershed for drinking water, recreation, and electricity. Gunpowder Creek is a WS-IV tributary to
the Catawba River and currently does not meet water quality criteria for benthos. The discharge is located within
the protected area for a water supply watershed and has two notices of violations in 2023 for Whole Effluent
Toxicity Failure and one NOD for monitoring requirements. We appreciate the opportunity to comment on the
Gunpowder WWTP NPDES permit (NC0023736). Additionally, we make the following recommendations:
• Monitor and report PFAS
Gunpowder Creek is designated as a WS-IV for the City of Hickory's drinking water intake on Lake
Hickory. Low, but detectable amounts of PFAS have been found in Lake Hickory. We recommend
adding language similar to Special Condition A.(8.) from the recently issued Sugar Creek WRRF
(NC0024937) permit. Hickory water users deserve the same level of protection as South Carolinians
downstream of the Sugar Creek facility.
• Monitor discharge E. coli in addition to fecal coliform.
For the last 38 years, the EPA has recommended using E. coli instead of fecal coliform as an indicator
of pathogens. The information would provide users with a better indicator of risk and water quality.
Access to the small reservoir downstream, Gunpowder Lake, was improved by NCWRC in 2020.
Despite its current class C classification, it has seen an increased number of users including
swimmers.
For the River,
r9J
Brandon Jones
Catawba Riverkeeper
A WATERKEEPER ALLIANCE° Member
115 Willow Drive McAdenville NC 28211
Phone: [phone] Fax: [phone]
www.catawbariverkeeper.org