NC0043583_Fact Sheet_20230421

FACT SHEET
EXPEDITED - PERMIT RENEWAL for WTP
Basic Information
Permit Writer/Date Joe R. Corporon P.G. /O1Mar2023
Permit Number NCO043583
County of Pasquotank
PO Box 2245,Elizabeth City,NC 27909
Permittee/Consultant Sparty Hammett, County Manager
David Smithson,Utilities Director,252-335-2240
smithsondgco.pasquotank.nc.us
Rodney Tart [r.tart reenen in.com]
Weeksville Water Purification Facility
Water Treatment Plant(WTP),WPCS Class PC-1
Facility 1466 Weeksville Road,Elizabeth City 27909
Potable Water Production at 2.4 MGD
Wastewater average discharge—0.065 MGD
Eligible for General Permit NCG59? NO. WET-test failure; Total Copper limited
Regional Office/Contact WaRO/Robert Tankard, Supervisor,Robbie Bullock
last inspection 14Ju12021 / Staff Report not required]
Basin Name/Hydrological Unit Pasquotank/03-01-50
Receiving Stream/Verified New Begun Creek[segment 30-3-16-(1)] /Yes.
Stream Classification in Permit/Verified? C-Swam /NOT verified;USGS suspects"Tidal."
Does permit need Daily Max NH3 limits? No
Does permit need TRC limits/language? Has limit/footnote: limit 17 µg/L
Yes—Chronic [TGP3B] monitoring for conventional
treatment(WTP). DWR assumes zero-flow conditions
Does permit have toxicity testing? (IWC incalculable). USGS (J. Curtis Weaver 2015)
described flow as likely"Tidal"(see Permittee,Addressing
Deficiencies to Renewal Application,2018).
Does permit have Special Conditions? Yes - Compliance Period for new Total Copper limits [see
A. (1)]. eDMR explanatory text [see A. (4.)].
Does permit have instream monitoring? Yes—Total Hardness upstream
Is the stream impaired [303(d)listed]? No
Any obvious compliance concerns? Despite stream class C; Sw, despite no flows in BIMS.
Any pen-nit mods since lastpermit? No.
Current expiration date December 31,2022
New expiration date December 31,2027
Comments received on Draft Permit?
Facility Description
Weeksville Water Purification Facility(Weeksville WTP)The facility purpose is to provide
drinking water to approximately 4500 connection(estimated population 11,250 people) in the
southern half of Pasquotank County. Distribution map is attached to this section. The plants
primary water source is raw ground water that is pumped to the plant front 30 individual wells
with an average depth of approx. 100- 125 ft.
Chemicals Used: This facility is a conventional iron removal plant that incorporates aeration,
sedimentation, rapid sand pressure filtration plant and post disinfection. Post filtration water is
polished with the addition of hexametaphosphate for corrosion, fluoride for dental decay,
caustic soda for pH control and chlorine disinfection.
Page 1 of 8

BIMS Downloads and Review
For renewal:
• No treatment system changes since last renewal; DWR updated permit format; updated facility map
and description; no other changes recommended, except as note below.
• Permitted Flow Monitoring. This WTP produces potable water @ 2.4 MGD. Effluent wastewater
discharges average 0.065 MGD over a three (3)year period; MAX= 0.182 MGD consistent with the
application [flow database: DMRs Jan2020-Jan2O23, count= 1,061]. Wastewater flow reported daily
consistent w/permit.
• Compliance Record is generally good—one NOV(25Aug2022)for two violations of TSS limits.
TRC reported< 50 ug/L; verified compliance to Chronic WET testing. Other effluent data within the
bounds of the permit. No assessment for Total Copper inconsistently reported units of measure.
• Reasonable Potential Anal (RPA)—See attached:
1. Total Copper(Cu) -RP=Yes
a. allowable=acute 10.47 µg/L
b. allowable chronic= 7.88 µg/L
c. max predicted= 850 µg/L
Pal RPA
Use"PASTE
SPECIAL-Values"
Copper then"COPY".
Maximum data
points=58
Date Data BDL=1/2DL Results
1 2020 < 1000 500 Std Dev. 227.8135
2 2020 < 1000 500 Mean 367.0000
3 2020 < 1000 500 C.V. 0.6207
4 2020 12 12 n 11
5 2021 < 1000 500
6 2021 < 1000 500 Mult Factor 1.70
7 2021 20 20 Max. Value 500.00 ug/L
2021 10 Max. Pred
8 < 5 Cw 850.00 ug/L
9 2022 < 1000 500
10 2022 < 1000 500
11 2022 < 1000 500
Note:
reporting error
- inconsistent
units of
measure
15
Page 2 of 8

Copper Data Submitted-Note: Reporting Error—Inadequate/Inconsistent Units of Measure
2020 01042 - Copper,Total(as Cu) mg/1 10
2020 01042 - Copper, Total(as Cu) mg/l 10
2020 01042 - Copper, Total(as Cu) mg/1 10
2020 01042 - Copper, Total(as Cu) mg/1 12
2021 01042 - Copper, Total(as Cu) mg/1 10
2021 01042 - Copper, Total(as Cu) ug/l 10
2021 01042 - Copper, Total(as Cu) ug/l 20
2021 01042 - Copper,Total(as Cu) ug/l 10
2022 01042 - Copper, Total(as Cu) mg/1 10
2022 01042 - Copper, Total(as Cu) mg/l 10
2022 01042 - Copper, Total(as Cu) mg/l 10
Therefore,Total Copper monitoring is increased from Quarterly to Monthly [see A. (1.)] with
permit limits added as RPA allowable concentrations(see above). It follows that renewal includes a
Schedule of Compliance for Total Copper,limits to become effective on April 15,2027,
approximately four(4)years from the permit effective date. [see A. (3.)].
• Total Hardness—decreased monitoring from Monthly to Quarterl , in accord with current permitting
guidance.
• Whole Effluent Toxicity(WET)—Changes to Previous Permit: DWR verified that, despite
receiving stream Class C;Swamp,the USGS (J. Curtis Weaver,2015)described stream flow near
the outfall as"likely Tidal"(see Permittee,Addressing Deficiencies to Renewal Application,
2018). DWR therefore assumes that the instream waste concentration (IWC) is incalculable, and
therefore recommends discontinuing Chronic TGP313 monitoring and replacing it for renewal
with Acute 24-hour Pass/Fail testing at 90% effluent concentration [see A. (1.)],per ATB
permitting Guidance, 300ct2012.
• Eligibility for NCG59
• Because effluent monitoring is limited for Total Copper, NOT eligible
for NCG59.
• FAILED WET test in Jun 2022,therefore NOT eligible for General
Permit NCG59.
• Deficiencies in Monitoring Reports
The Permittee inconsistently reported analytical data for Total Copper in milligrams per
liter(mg/L) instead of the required micrograms per liter(ug/L). This is a reporting
violation. A note will be added to the permit cover letter admonishing the Permittee to apply
the proper analytical sensitivity considering each analyte's applicable surface water quality
standard.
• Sludge-Management Plan (from the APP to Renew received 06Jan2023)
Residuals Permit: WQ0008008
Class A Residuals
"The Weeksville Water plant generates iron oxide sludge in the aeration and settling process.
Sludge is developed by aeriation of the raw ground water with potassium permanganate as an
additional oxidant. These settable solids are transferred from the settling basins and stored in a
1 MG earthen lagoon on site.
Page 3 of 8

Permit issued August 9, 2022, changed the land application of Class B residuals to a
Distribution of Class A residuals. Current Permit approved dry annual tonnage has been
increased from 116 dry tons DT/yr)to 318 DT/yr.
Residuals are collected continuously in the settling basins and discharge to the holding lagoon
weekly and monthly. One time per year a contract hauler dredges the sludge from the holding
lagoon and land applied as a liquid solid.
The current permit does not require farmland to be permitted for the residual application since
they are not biologically produced. Records are maintained for each application event which
occurs once per year but usually no more than twice per year."
Proposed Schedule of Issuance
Draft Permit to Public Notice: 14Mar2023 (est.)
Permit Scheduled to Issue: 21Apr2023 (est.)
Effective Date 01 Jun2023 (est.)
NPDES Division Contact
If you have questions about any of the above information, or on the attached permit,please
email Joe R. Co ron, P.G. [e-mail]].
NAME: DATE: O 1 MAR2023
l
NPDES Implementation of Instream Dissolved Metals Standards — Freshwater
Standards
The NC 2007-2015 Water Quality Standard(WQS)Triennial Review was approved by the NC
Environmental Management Commission(EMC)on November 13,2014. The US EPA subsequently
approved the WQS revisions on April 6,2016,with some exceptions. Therefore,metal limits in draft
permits out to public notice after April 6,2016 must be calculated to protect the new standards -as
approved.
Page 4 of 8

Table 2.NC Dissolved Metals Water ualit Standards/Aquatic Life Protection
Parameter Acute FW, µg/l Chronic FW, µg/l Acute SW, µg/1 Chronic SW, µg/1
(Dissolved) (Dissolved) (Dissolved) (Dissolved)
Arsenic 340 150 69 36
Beryllium 65 6.5 --- ---
Cadmium Calculation Calculation 40 8.8
Chromium III Calculation Calculation --- ---
Chromium VI 16 11 1100 50
Copper Calculation Calculation 4.8 3.1
Lead Calculation Calculation 210 8.1
Nickel Calculation Calculation 74 8.2
Silver Calculation 0.06 1.9 0.1
Zinc Calculation Calculation 90 81
Table 2 Notes:
1. FW=Freshwater, SW= Saltwater
2. Calculatio"I=Hardness dependent standard
3. Only the aquatic life standards listed above are expressed in dissolved form. Aquatic life
standards for Mercury and selenium are still expressed as Total Recoverable Metals due to
bioaccumulative concerns(as are all human health standards for all metals). It is still necessary
to evaluate total recoverable aquatic life and human health standards listed in 15A NCAC
213.0200(e.g., arsenic at 10 µg/1 for human health protection; cyanide at 5 µg/L and fluoride at
1.8 mg/L for aquatic life protection).
Table 3.Dissolved Freshwater Standards for Hardness-Dependent Metals
The Water Effects Ratio (WER)is equal to one unless determined otherwise under 15A
NCAC 02B .0211 Subparagraph(11)(d)
Metal NC Dissolved Standard, /1
Cadmium,Acute WER*{1.136672-[ln hardness](0.0418 3 8)) e"10.9151 [In hardness]-
3.1485}
Cadmium, Acute Trout WER*{1.136672-[ln hardness](0.041838)} e^{0.9151[ln hardness]-
waters 3.62361
Cadmium,Chronic WER*{1.101672-[In hardness](0.041838)} e^{0.7998[ln hardness]-
4.4451}
Chromium 111,Acute WER*0.316 e^{0.8190[ln hardness]+3.7256}
Chromium III, Chronic WER*0.860 e^{0.8190[ln hardness]+0.6848{
Copper,Acute WER*0.960 e"{0.9422[ln hardness]-1.700}
Copper, Chronic WER*0.960 e^{0.8545[ln hardness]-1.702}
Lead,Acute WER*{1.46203-[ln hardness](0.145712)} e^{1.273[ln hardness]-
1.460}
Lead, Chronic WER*{1.46203-[ln hardness](0.145712){ e^{1.273[ln hardness]-
4.705{
Page 5 of 8

Nickel,Acute WER*0.998 e^{0.8460[ln hardness]+2.255}
Nickel, Chronic WER*0.997 e^{0.8460[ln hardness]+0.0584}
Silver,Acute WER*0.85 • e^{1.72[ln hardness]-6.59}
Silver, Chronic Not applicable
Zinc,Acute WER*0.978 e^{0.8473[ln hardness]+0.884}
Zinc, Chronic WER*0.986 eA10.8473[ln hardness]+0.884}
General Information on the Reasonable Potential Analysis(RPA)
The RPA process itself did not change as the result of the new metals standards. However, application of
the dissolved and hardness-dependent standards requires additional consideration in order to establish
the numeric standard for each metal of concern of each individual discharge.
The hardness-based standards require some knowledge of the effluent and instream(upstream)hardness
and so must be calculated case-by-case for each discharge.
Metals limits must be expressed as `total recoverable' metals in accordance with 40 CFR 122.45(c). The
discharge-specific standards must be converted to the equivalent total values for use in the RPA
calculations.We will generally rely on default translator values developed for each metal(more on that
below),but it is also possible to consider case-specific translators developed in accordance with
established methodology.
RPA Permitting Guidance/WOBELs for Hardness-Dependent Metals-Freshwater
The RPA is designed to predict the maximum likely effluent concentrations for each metal of concern,
based on recent effluent data, and calculate the allowable effluent concentrations,based on applicable
standards and the critical low-flow values for the receiving stream.
If the maximum predicted value is greater than the maximum allowed value (chronic or acute),the
discharge has reasonable potential to exceed the standard,which warrants a permit limit in most cases. If
monitoring for a particular pollutant indicates that the pollutant is not present(i.e. consistently below
detection level),then the Division may remove the monitoring requirement in the reissued permit.
1. To perform a RPA on the Freshwater hardness-dependent metals the Permit Writer compiles the
following information:
• Critical low flow of the receiving stream, 7Q 10(the spreadsheet automatically
calculates the 1 Q 10 using the formula 1 Q 10=0.843 (s7Q 10, cfs) 0.993
• Effluent hardness and upstream hardness, site-specific data is preferred
• Permitted flow
• Receiving stream classification
2. In order to establish the numeric standard for each hardness-dependent metal of concern and for
each individual discharge,the Permit Writer must first determine what effluent and instream
(upstream)hardness values to use in the equations.
The permit writer reviews DMR's,Effluent Pollutant Scans, and Toxicity Test results for any
hardness data and contacts the Permittee to see if any additional data is available for instream
hardness values,upstream of the discharge.
Page 6 of 8

If no hardness data is available,the permit writer may choose to do an initial evaluation using a
default hardness of 25 mg/L(CaCO3 or(Ca+Mg)). Minimum and maximum limits on the
hardness value used for water quality calculations are 25 mg/L and 400 mg/L,respectively.
If the use of a default hardness value results in a hardness-dependent metal showing reasonable
potential,the permit writer contacts the Permittee and requests 5 site-specific effluent and
upstream hardness samples over a period of one week. The RPA is rerun using the new data.
The overall hardness value used in the water quality calculations is calculated as follows:
Combined Hardness(chronic)
_(Permitted Flow, cfs *Avg. Effluent Hardness,mg/L)x(s7Q10, cfs *Avg.Upstream Hardness,mg/L)
(Permitted Flow, cfs+s7Q10, cfs)
The Combined Hardness for acute is the same but the calculation uses the 1 Q 10 flow.
3. The permit writer converts the numeric standard for each metal of concern to a total
recoverable metal,using the EPA Default Partition Coefficients (DPCs) or site-specific
translators, if any have been developed using federally approved methodology.
EPA default partition coefficients or the "Fraction Dissolved" converts the
value for dissolved metal at laboratory conditions to total recoverable metal
at in-stream ambient conditions. This factor is calculated using the linear
partition coefficients found in The Metals Translator: Guidance for
Calculating a Total Recoverable Permit Limit from a Dissolved Criterion
(EPA 823-B-96-007, June 1996) and the equation:
Cdiss = I
Ctotal I + 1 [KPo] [Ss(I+a)] [1 6] J
Where:
ss= in-stream suspended solids concentration [mg/1], minimum of 10 mg/L
11"Prl and
4. The numeric standard for each metal of concern is divided by the default partition
coefficient(or site-specific translator)to obtain a Total Recoverable Metal at ambient
conditions.
a. In some cases,where an EPA default partition coefficient translator does not
exist (ie. silver),the dissolved numeric standard for each metal of concern is
divided by the EPA conversion factor to obtain a Total Recoverable Metal at
ambient conditions. This method presumes that the metal is dissolved to the
same extent as it was during EPA's criteria development for metals. For
more information on conversion factors see the June, 1996 EPA Translator
Guidance Document.
5. The RPA spreadsheet uses a mass balance equation to determine the total allowable
concentration(permit limits) for each pollutant using the following equation:
Ca= (s7Q 10 + Qw) Cwgs)-s7Q 10) (CW
Qw
Page 7 of 8

Where: Ca= allowable effluent concentration (µg/L or mg/L)
Cwqs=NC Water Quality Standard or federal criteria(µg/L or mg/L)
Cb =background concentration: assume zero for all toxicants except NH3* (µg/L
or mg/L)
Qw=permitted effluent flow(cfs, match s7Q10)
s7Q 10 = summer low flow used to protect aquatic life from chronic toxicity and
human health through the consumption of water, fish, and shellfish from
noncarcinogens (cfs)
* Discussions are on-going with EPA on how best to address background
concentrations
Flows other than s7Q10 may be incorporated as applicable:
1 Q 10=used in the equation to protect aquatic life from acute toxicity
QA=used in the equation to protect human health through the consumption of
water, fish, and shellfish from carcinogens
30Q2 =used in the equation to protect aesthetic quality
6. The permit writer enters the most recent 2-3 years of effluent data for each pollutant of
concern. Data entered must have been taken within four and one-half years prior to the
date of the permit application(40 CFR 122.21). The RPA spreadsheet estimates the
95th percentile upper concentration of each pollutant. The Predicted Max
concentrations are compared to the Total allowable concentrations to determine if a
permit limit is necessary. If the predicted max exceeds the acute or chronic Total
allowable concentrations, the discharge is considered to show reasonable potential to
violate the water quality standard, and a permit limit (Total allowable concentration) is
included in the permit in accordance with the U.S. EPA Technical Support Document
for Water Quality-Based Toxics Control published in 1991.
7. When appropriate, permit writers develop facility specific compliance schedules in
accordance with the EPA Headquarters Memo dated May 10, 2007 from James Hanlon
to Alexis Strauss on 40 CFR 122.47 Compliance Schedule Requirements.
8. The Total Chromium NC WQS was removed and replaced with trivalent chromium and
hexavalent chromium Water Quality Standards. As a cost savings measure, total
chromium data results may be used as a conservative surrogate in cases where there are
no analytical results based on chromium III or VI. In these cases, the projected
maximum concentration (95th%) for total chromium will be compared against water
quality standards for chromium III and chromium VI.
9. Effluent hardness sampling and instream hardness sampling,upstream of the discharge,
are inserted into all permits with facilities monitoring for hardness-dependent metals to
ensure the accuracy of the permit limits and to build a more robust hardness dataset.
10. Hardness and flow values used in the Reasonable Potential Analysis for this permit
included:
Table 4
Parameter Value Comments(Data Source)
Average Effluent Hardness(mg/L) TBD No data available.
[Total as,CaCO3 or(Ca+M ]
Average Upstream Hardness(mg/L) TBD No data available.
[Total as,CaCO3 or(Ca+Mg)]
7Q10 summer(cfs),7Q10 Winter(cfs) 0 USGS reports stream-flow conditions
Average(cfs) 0' likely"Tidal'
Permitted Flow(MGD) N/A Not limited,per WTP Guidance
Page 8 of 8

Freshwater RPA- 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
REQUIRED DATA ENTRY CHECK WQS
Table 1. Project Information Table 2. Parameters of Concern
❑CHECK IF HQW OR ORW WQS Name WQS Type Chronic Modifier Acute PQL Units
Facility Name County of Pasquotank Par01
WWTP/WTP Class Par02
NPDES Permit NCO043583 Par03
Outfal I 001 Par04
Flow,Qw(MGD) 0.199 Par05
Receiving Stream UT to New Begun Creek Par06
HUC Number Par07
Stream Class Par08
❑ C;Sw Apply WS Hardness WQC Par09
7Q10s(cfs) 0.00 Par10
7Q10w(cfs) 0.00 Par11 Copper Aquatic Life NC #REF! FW #REF! 2.0 ug/L
30Q2(cfs) 0.00 Par12
QA(cfs) Par13
1Q10s(cfs) Par14
Effluent Hardness 25 mg/L(Avg) Par15
Upstream Hardness 25 mg/L(Avg) Par16
Combined Hardness Chronic DATA INCOMPLETE Par17
------------- --------------------
Combined Hardness Acute DATA INCOMPLETE Par18
Data Source(s) Par19
❑CHECK TO APPLY MODEL BIMS Database Jan2018-Jan2023 No receiving- Par20
stream flow available at discharge;assumed Par21
zero-flow conditions(0.0 cfs.) Par22
Par23
Par24
43583 Pasquotank WTP RPA dissolved-edited pages for PDF 21Apr2023 , input
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43583 Pasquotank WTP RPA dissolved-edited pages for PDF 21Apr2023, input
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REASONABLE POTENTIAL ANALYSIS
H1 H2 Use"PASTE SPECIAL Use"PASTE SPECIAL
Effluent Hardness Values"then"COPY" Upstream Hardness Values"then"COPY"
.Maximum data .Maximum data
points=58 points=58
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results
1 25 25 Std Dev. N/A 1 25 25 Std Dev. N/A
2 Mean 25.0000 2 Mean 25.0000
3 C.V. 0.0000 3 C.V. 0.0000
4 n 1 4 n 1
5 10th Per value 25.00 mg/L 5 10th Per value 25.00 mg/L
6 Average Value 25.00 mg/L 6 Average Value 25.00 mg/L
7 Max.Value 25.00 mg/L 7 Max.Value 25.00 mg/L
8 8
9 9
10 10
11 11
12 12
13 13
14 14
15 15
16 16
17 17
18 18
19 19
20 20
21 21
22 22
23 23
24 24
25 25
26 26
27 27
28 28
29 29
30 30
31 31
32 32
33 33
34 34
35 35
36 36
37 37
38 38
39 39
40 40
41 41
42 42
43 43
44 44
45 45
46 46
47 47
48 48
49 49
50 50
51 51
52 52
53 53
54 54
55 55
56 56
57 57
58 58
43583 Pasquotank WTP RPA dissolved-edited pages for PDF 21Apr2023,data
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REASONABLE POTENTIAL ANALYSIS
Pall
Use"PASTE SPECIAL
Copper Values"then"COPY"
.Maximum data
points=58
Date Data BDL=1/2DL Results
1 2020 < 1000 500 Std Dev. 227.8135
2 2020 < 1000 500 Mean 367.0000
3 2020 < 1000 500 C.V. 0.6207
4 2020 12 12 n 11
5 2021 < 1000 500
6 2021 < 1000 500 Mult Factor= N/A
7 2021 20 20 Max.Value N/A ug/L
8 2021 < 10 5 Max.Pred Cw N/A ug/L
9 2022 < 1000 500
10 2022 < 1000 500
11 2022 < 1000 500
Note:reporting
error-
inconsistant
units of
measure
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
43583 Pasquotank WTP RPA dissolved-edited pages for PDF 21Apr2023,data
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County of Pasquotank - Outfall 001
NCO043583 Freshwater RPA- 95% Probability/95% Confidence Using Metal Translators Qw = 0.199 MGD
MAXIMUM DATA POINTS = 58
Qw(MGD)= 0.20 WWTP/WTP Class: COMBINED HARDNESS(me/L)
1Q10S(cfs)= 0.00 1WC% @ 1Q10S = 100 NO DATA
7Q10S(cfs)= 0.00 1WC% @ 7Q10S= 100 NO DATA
7Q10W(cfs)= 0.00 IWC%@ 7QIOW= 100
30Q2(cfs)= 0.00 1WC%@ 30Q2= 100
Avg.Stream Flow,QA(cfs)= NO QA DATA IW%C @ QA= N/A
Receiving Stream: NO HUC NUMBER Stream Class: C;Sw
NC STANDARDS OR EPA CRITERIA REASONABLE POTENTIAL RESULTS
PARAMETER � � RECOMMENDED ACTION
TYPE Chronic Applied Acute o_ n #Det. Max Pred Cw Allowable Cw
Standa
Copper NC #REF! FW #REF! 2 ug/L 11 2 N/A
Acute: #REF! RP shown-apply Monthly Monitoring with Limit
__ _ _---- _ _
-- ---------------------------
Chronic: -#REF! RP shown-apply Monthly Monitoring with Limit
#REF!
43583 Pasquotank WTP RPA dissolved-edited pages for PDF 21Apr2023,rpa
Page 5 of 12 4/21/2023

Dissolved Metals & H
I. How to Determine Hardness for use
HARDNESS- Use 25 mg/L,expressed as C
OR
To determine a Hardness value for permit
Hardness - (Hardness instream(a), rr
(mass balance)
(a) Use the median instream Hardness ve
(b) For the purpose of this estimation, use the
II. To Develop Dissolved Metal cor
Table A: Dissolved Freshwater Standards for Hat
Metal
Cadmium,Acute
Cadmium,Acute(Trout Waters)
Cadmium, Chronic
Chromium III, Acute
Chromium III, Chronic
Copper,Acute
Copper, Chronic
Lead,Acute
Lead, Chronic
Nickel, Acute
Nickel, Chronic
Silver, Acute
Silver, Chronic
Zinc,Acute
Zinc, Chronic
Complete information on all the proposed S
US EPA Translators
using Default Partition I
Translator equation using Default Partition Coeff
Kpo and cc are constants that express the equili
A default value of 10 mg/L Total Suspended S
Table A contains the Default Partition Coef
Table B contains the calculated translators
TABLE A. Default Partition Coefficients
Metal(1)
Cu
Zn
Pb
Cr(III) (2)

Cd
Ni
(1) Delos,C.G.,et al.Technical Guidance for Perfor
(2) Linear partition coefficients shall not apply to th,
TABLE B. US EPA Translators
PARAMETER
Cadmium
Chromium III
Chromium VI
Chromium,Total
Copper
Lead
Nickel
Silver
Zinc

ardness Determination
v. 5/27/2010
with Dissolved Freshwater Standards for Permitting Purposes
aCO3 or Ca+Mg,as the default Hardness
limit development, use the following equation:
is/L * 7Q10, MGD)+(Hardness effluent(b), mg/L* Plant flow, MGD)
(7Q10, MGD + Plant flow, MGD)
flue of the ambient 8-digit HUC data collected by the Division of Water Quality. To find the 8-digit HUC h:
facility's median effluent Hardness value, if available. The Division will request the permittee to sample effluent har,
Icentrations for permitting purposes use the Freshwater Standards for Hardness De
-dness Dependent Metals
Ng/L
{1.136672-[In hardness](0.041838)} • eA{0.9151 [In hardness]-3.1485}
{1.136672-[In hardness](0.041838)} • eA{0.9151[ln hardness]-3.62361
{1.101672-[In hardness](0.041838)} • e^{0.7998[ln hardness]-4.44511
0.316 - e^{0.8190[ln hardness]+3.7256}
0.860 • e^{0.8190[ln hardness]+0.6848}
0.960 - e^{0.9422[ln hardness]-1.700}
0.960 • e^{0.8545[ln hardness]-1.702}
{1.46203-[In hardness](0.145712)} • eA{1.273[ln hardness]-1.4601
{1.46203-[In hardness](0.145712)} • eA{1.273[ln hardness]-4.705}
0.998 - e^{0.8460[ln hardness]+2.255}
0.997 • e^{0.8460[ln hardness]+0.0584}
0.85 - eA{1.72[ln hardness]-6.59}
Not applicable
0.978 - e^{0.8473[ln hardness]+0.884}
0.986 • e^{0.8473[ln hardness]+0.884}
urface Water Quality Standards can be viewed at: http://h2o.enr.state.nc.us/csu/trirev SW.html.
Coefficients (DPQ
v. 6/2/2010
Icients = 1
[1 + (Kpo * TSS (1+a) * 10-6)]
brium relationship between dissolved and adsorbed forms of metals.
olids(TSS) will be used.
ficients for the equation.
using the default partition coefficients for streams.
STREAMS
Kpo a
1.04E+06 -0.7436
1.25E+06 -0.7038
2.80E+06 -0.8
3.36E+06 -0.09304

4.00E+06 -1.1307
4.90E+05 -0.5719
ming Waste Load Allocations. Book II: Streams and Rivers. Chapter 3: Toxic Substances, For the U.S. EPA. (EPA-440/4-84-022)
e Chromium VI numerical criterion.The approved analytical method for Chromium VI measures only the dissolved form.Therefore
US EPA Translators
Using stream Default Partition Coefficients
T55=10 mg/L
0.252
0.202
1
N/A
0.348
0.184
0.432
1
0.288

dness once/month and submit one to two years of data with the permit renewal application. If no effluent hardness data is subr

Example for Cadmium(streams)
Given:
TSS= 10 mg/L
Kpo=4.00E+06
a =-1.1307
Translator = 1
[1 + (Kpo*TSS 10-6)]
— 1
[1 + (4.00X106* 101-1.1307)* 10-6)]
— 1
[1+2.960465]
= 0.252

nitted, a default of 25 mg/L will be applied.

Public Notice Blurb
31Jan2023
"Pasquotank County WTP of Elizabeth City applied to renew permit NCO043583 to discharge
potable water filter backwash into a UT to New Begun Creek, Pasquotank River Basin.
Currently, Total Residual Chlorine (TRC) and Total Copper are water-quality limited. This
discharge may affect future wasteload allocations to the receiving stream."

ROY COOPER
Governor
MICHAEL S. RAGAN
Secretary
" LINDA CULPEPPER
Water Resources
Interim Director
ENVIRONMENTAL QUALITY
March 5, 2018
Rodney Bunch, County Manager
County of Pasquotank
P.O. Box 2245
Elizabeth City,North Carolina 27909
Subject: Issuance NPDES Permit NCO043583
Pasquotank County Water System—Class 1
1466 Weeksville Road, Elizabeth City
Pasquotank County
Dear Mr. Bunch:
The Division of Water Quality(the Division)issues this permit pursuant to the requirements of
North Carolina General Statute 143-215.1 and the Memorandum of Agreement between North
Carolina and the U.S. Environmental Protection Agency dated October 15, 2007, or as
subsequently amended.
Thank you for addressing deficiencies in your renewal application. Based on your response of
January 30,2018, you supplied:
1. a revised flow schematic,
2. an outfall location,
3. flow at the outfall [7Q10/34Q2], and
4. Sludge Management Plan.
This renewal assumed zero-flow receiving stream conditions at Outfall 001 [7Q10/30Q2 = 0.0
cfs] because we have no flow data for New Begun Creek.
Changes to Your Previous Permit. We note that you have made no significant alterations to your
wastewater treatment facilities or treatment processes since last renewal. Therefore, the Division
has considered your monitoring data, your renewal application, and current permitting guidance
for potable-water treatment plants (WTPs)utilizing conventional treatment technology,
consistent with similar permits statewide. Note that you no longer need to sample parameters
concurrently with Whole Effluent Toxicity(WET)unless you suspect a cause for failed WET
testing.
Because this failed its Whole Effluent Toxicity(WET)test within the last year, and because this permit
includes a limited parameter for Total Aluminum[87 ug/L,DM&MA],this facility is not currently
eligible for General Permit NCG590000.

Changes for Renewal Recommended br Reasonable Potential Analyses(RPA):
1. Total Iron and Total Manganese—discontinued monitoring per conventional treatment policy;
2. Total Copper-RP=no,>50%allowable;therefore,continue monitoring only, Quarterly,no
limit
3. Total Zinc-not detected: Max predicted<50%allowable; discontinue monitoring
4. Total Aluminum—max predicted(3,577 ug/L), 14 values exceed acute/chronic standards;
increase monitoring to Monthly w/limit.
5. Total Fluoride—max predicted<50%allowable,therefore discontinue monitoring.
Division records show that you have successfully registered with the eDMR Program. Please
be reminded that until the state's eDMR application is approved compliant with EPA's Cross-
Media Electronic Reporting Regulation (CROMERR), all permittees must continue to submit
hardcopy of DMRs as backup to eDMR reporting [see permit section A. (3.)].
If any parts, measurement frequencies, or sampling requirements contained in this permit are
unacceptable, you have the right to an adjudicatory hearing,upon written request submitted
within thirty(30)days after receiving this letter. Your request must take the form of a written
petition conforming to Chapter 150B of the North Carolina General Statutes,and you must file it
with the office of Administrative Hearings, 6714 Mail Service Center,Raleigh,North Carolina
27699-6714. Unless such a demand is made,this permit shall be final and binding.
This permit is not transferable except after notifying the Division of Water Resources. The
Division may require permit modification, or revocation and re-issuance. Please note that this
permit does not affect your legal obligation to obtain other permits required by the Division of
Water Resources, the Division of Land Resources, the Coastal Area Management Act, or other
federal or local governments.
If you have questions, or if we can further assist you, please contact Joe Corporon at
[ioe.corporonna,ncdenr.gov] or call(919) 807-6394.
p ctfully,
c
Linda Culpepper,Acting Di�eor
Enclosure: NPDES Permit NCO043583 (issuance final)
hc: Central Files
NPDES Program Files
ec: WaRO/SWPS:Robert Tankard
ATU: Susan Meadows
OCU:Maureen Kinney

Permit NCO043583
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF WATER RESOURCES
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
(NPDES)
In compliance with the provisions of North Carolina General Statute 143-215.1, other lawful standards
and regulations promulgated and adopted by the North Carolina Environmental Management
Commission, and the Federal Water Pollution Control Act, as amended, the
County of Pasquotank
is hereby authorized to discharge wastewater from a facility located at the
Pasquotank County Water System (WTP)
1466 Weeksville Road
Pasquotank County
to receiving waters designated as an unnamed tributary of New Begun Creek within the Pasquotank
River Basin in accordance with effluent limitations, monitoring requirements, and other conditions set
forth in Parts I, II, III and IV hereof.
This permit shall become effective April 1, 2018.
This permit and authorization to discharge shall expire at midnight on December 31, 2022.
Signed this day March 5, 2018.
da Culpepper, Interim irec or
ivision of Water Resources
By Authority of the Environmental Management Commission
Page 1 of 7

Permit NCO043583
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby
revoked, and as of this issuance, any previously issued permit bearing this number is no longer effective.
Therefore, the exclusive authority to operate and discharge from this facility arises under the permit
conditions, requirements, terms, and provisions described herein.
County of Pasquotank
is hereby authorized to:
1. continue to operate an existing 2.4 MGD potable-water treatment plant(WTP) applying
conventional treatment technology to a well-water source, generating filter-backwash wastewater
(0.075 MGD)utilizing:
• anthracite sand filters
• chlorine [sodium hypochlorite]
• ammonia [19% concentration]
• potassium permanganate(KMn04)
• hydrofluosilic acid(HFS)
• polymer [ammonium chloride Superfloc-300]
• sodium hydroxide(NaOH)
• phosphate: calcium/magnesium [Aqua Mag Blended Phosphate].
• holding lagoon
these facilities located at the Pasquotank County Water System(WTP), 1466 Weeksville Road,
Elizabeth City,Pasquotank County, and
2. discharge from said treatment works via Outfall 001, at the location specified on the attached map,
into an unnamed tributary of New Begun Creek [stream segment 30-3-16-(1)] a waterbody currently
classified C-Sw within subbasin 03-01-50 [HUC: 03010205] of the Pasquotank River basin.
Page 2 of 7

Permit NCO043583
PART I
A. (L) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[15A NCAC 02B .0400 et seq.,02B .0500 et seq.]
During the period beginning on the effective date of the permit and lasting until expiration,the Permittee is
authorized to discharge from Outfall 001. Such discharges shall be limited,monitored and reported 1
by the Permittee as specified below:
EFFLUENT LIMITS MONITORING REQUIREMENTS
CHARACTERISTICS Monthly Daily Measurement Sample Sample
[Parameter Codes] Average Maximum Frequency Type Location
Flow 50050 Continuous Recording Effluent
Total suspended Solids(TSS) 00530 30.0 mg/L 45.0 mg/L 2/Month Grab Effluent
pH 00400 Not<6.0 or>9.0 s.u. 2/Month Grab Effluent
Total Residual Chlorine 50060 17 µg/L,2 2/Month Grab Effluent
Turbidity 2/Month Grab Effluent
.Ammonia Nitrogen 00610 Quarterly Grab Effluent
(NH3 as N)
Total Copper 01042 Quarterly Grab Effluent
Total Nitrogen(TN) 00600 Quarterly Grab Effluent
Total Phosphorus(TP) 00665 Quarterly Grab Effluent
Whole Effluent Toxicity
(WET)Testing
3 TGP3B Quarterly Grab Effluent
Footnotes:
1. Beginning on the permit effective date,the Permittee shall submit discharge monitoring reports
electronically using the NC DWR's Electronic Discharge Monitoring Report(eDMR)program [See
Special Condition A.(3.)]
2. Total Residual Chlorine(TRC)—The Division shall consider compliant all effluent TRC values reported
below 50µg/L.However,the Permittee shall continue to record and submit all values reported by North
Carolina-certified test methods(including field certified), even if these values fall below 50 µg/L.
3. Chronic Effluent Toxicity(WET)Testing, Quarterly P/F(Ceriodaphnia @ 90%),March,June,
September and December,see Section A. (2.).
Condition: The Permittee shall discharge no floating solids or foam visible in other than trace amounts.
Page 3 of 7

Permit NCO043583
A. (2.) CHRONIC TOXICITY MONITORING (QUARTERLY)
[15A NCAC 02B .0500 et seq.]
The permittee shall conduct quarterly chronic toxicity tests using test procedures outlined in the"North
Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure,"Revised December 2010, or subsequent
versions.
The effluent concentration defined as treatment two in the procedure document is 90 %. The testing
shall be performed as a Ceriodaphnia dubia 7-day pass/fail test. The tests will be performed during the
months of March,June, September and December.These months signify the first month of each three-
month toxicity testing quarter assigned to the facility. Effluent sampling for this testing must be
obtained during representative effluent discharge and shall be performed at the NPDES permitted final
effluent discharge below all treatment processes.
All toxicity testing results required as part of this permit condition will be entered on the Effluent
Discharge Monitoring Form(MR-1) for the month in which it was performed,using the parameter code
TGP3B. Additionally, DWR Form AT-1 (original)is to be sent to the following address:
Attention: North Carolina Division of Water Resources
Water Sciences Section/Aquatic Toxicology Branch
1621 Mail Service Cdnter
Raleigh,NC 27699-1621
Completed Aquatic Toxicity Test Forms shall be filed with the Water Sciences Section no later than 30
days after the end of the reporting period for which the report is made.
Test data shall be complete and accurate and include all supporting chemical/physical measurements
performed in association with the toxicity tests, as well as all dose/response data. Total residual chlorine
of the effluent toxicity sample must be measured and reported if chlorine is employed for disinfection of
the waste stream.
Should there be no discharge of flow from the facility during a month in which toxicity monitoring is
required, the permittee will complete the information located at the top of the aquatic toxicity(AT)test
form indicating the facility name,permit number,pipe number, county, and the month/year of the report
with the notation of"No Flow"in the comment area of the form. The report shall be submitted to the
Water Sciences Section at the address cited above.
Should the permittee fail to monitor during a month in which toxicity monitoring is required, then
monthly monitoring will begin immediately. Upon submission of a valid test, this monthly test
requirement will revert to quarterly in the months specified above.
Should any test data from this monitoring requirement or tests performed by the North Carolina Division
of Water Resources indicate potential impacts to the receiving stream, this permit may be re-opened and
modified to include alternate monitoring requirements or limits.
NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum control
organism survival,minimum control organism reproduction, and appropriate environmental controls,
shall constitute an invalid test and will require immediate follow-up testing to be completed no later
than the last day of the month following the month of the initial monitoring.
Page 4 of 7

Permit NCO043583
A. (3.) ELECTRONIC REPORTING - DISCHARGE MONITORING REPORTS
[G.S. 143-215.1(b)]
Federal regulations require electronic submittal of all discharge monitoring reports(DMRs) and program
reports. The final NPDES Electronic Reporting Rule was adopted and became effective on December
21, 2015.
NOTE: This special condition supplements or supersedes the following sections within Part II of this
permit(Standard Conditions for NPDES Permits):
• Section B. (11.) Signatory Requirements
• Section D. (2.) Reporting
• Section D. (6.) Records Retention
• Section E. (5.) Monitoring Reports
1. Reporting Requirements [Supersedes Section D. (2.) and Section E. (5.) (a)I
The permittee shall report discharge monitoring data electronically using the NC DWR's Electronic
Discharge Monitoring Report(eDMR) internet application.
Monitoring results obtained during the previous month(s) shall be summarized for each month and
submitted electronically using eDMR. The eDMR system allows permitted facilities to enter
monitoring data and submit DMRs electronically using the internet. Until such time that the state's
eDMR application is compliant with EPA's Cross-Media Electronic Reporting Regulation
(CROMERR),permittees will be required to submit all discharge monitoring data to the state
electronically using eDMR and will be required to complete the eDMR submission by printing,
signing, and submitting one signed original and a copy of the computer printed eDMR to the
following address:
NC DEQ/Division of Water Resources/Water Quality Permitting Section
ATTENTION: Central Files
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
If a permittee is unable to use the eDMR system due to a demonstrated hardship or due to the facility
being physically located in an area where less than 10 percent of the households have broadband
access, then a temporary waiver from the NPDES electronic reporting requirements may be granted
and discharge monitoring data may be submitted on paper DMR forms (MR 1, 1.1, 2, 3) or
alternative forms approved by the Director. Duplicate signed copies shall be submitted to the
mailing address above. See"How to Request a Waiver from Electronic Reporting" section below.
Regardless of the submission method, the first DMR is due on the last day of the month following
the issuance of the permit or in the case of a new facility, on the last day of the month following the
commencement of discharge.
Page 5 of 7

Permit NC0043583
Starting on the issuance date,the permittee must electronically report the following compliance
monitoring data and reports, when applicable:
• Sewer Overflow/Bypass Event Reports;
• Pretreatment Program Annual Reports; and
• Clean Water Act(CWA) Section 316(b)Annual Reports.
The permittee may seek an electronic reporting waiver from the Division(see"How to Request a
Waiver from Electronic Reporting" section below).
2. Electronic Submissions
In accordance with 40 CFR 122.41(1)(9),the permittee must identify the initial recipient at the time
of each electronic submission. The permittee should use the EPA's website resources to identify the
initial recipient for the electronic submission.
Initial recipient of electronic NPDES information from NPDES-regulated facilities means the entity
(EPA or the state authorized by EPA to implement the NPDES program)that is the designated entity
for receiving electronic NPDES data [see 40 CFR 127.2(b)].
EPA plans to establish a website that will also link to the appropriate electronic reporting tool for
each type of electronic submission and for each state. Instructions on how to access and use the
appropriate electronic reporting tool will be available as well. Information on EPA's NPDES
Electronic Reporting Rule is found at: http://www2.epa.gov/compliance/final-national-pollutant-
dischart;e-elimination-system-npdes-electronic-reporting=rule.
Electronic submissions must start by the dates listed in the"Reporting Requirements"section above.
How to Request a Waiver from Electronic Reporting
The permittee may seek a temporary electronic reporting waiver from the Division. To obtain an
electronic reporting waiver, a permittee must first submit an electronic reporting waiver request to
the Division. Requests for temporary electronic reporting waivers must be submitted in writing to
the Division for written approval at least sixty(60) days prior to the date the facility would be
required under this permit to begin submitting monitoring data and reports. The duration of a
temporary waiver shall not exceed 5 years and shall thereupon expire. At such time,monitoring data
and reports shall be submitted electronically to the Division unless the permittee re-applies for and is
granted a new temporary electronic reporting waiver by the Division. Approved electronic reporting
waivers are not transferrable. Only permittees with an approved reporting waiver request may
submit monitoring data and reports on paper to the Division for the period that the approved
reporting waiver request is effective.
Information on eDMR and the application for a temporary electronic reporting waiver are found on
the following web page: http://deq.nc.gov/about/divisions/water-resources/edmr
Page 6of7

Permit NC0043583
3. Signatory Requirements ISupplements Section B. (11 ) (b) and Supersedes Section B (11 ) (d)l
All eDMRs submitted to the permit issuing authority shall be signed by a person described in Part II,
Section B. (I 1.)(a) or by a duly authorized representative of that person as described in Part II,
Section B. (I 1.)(b). A person, and not a position,must be delegated signatory authority for eDMR
reporting purposes.
For eDMR submissions,the person signing and submitting the DMR must obtain an eDMR user
account and login credentials to access the eDMR system. For more information on North
Carolina's eDMR system,registering for eDMR and obtaining an eDMR user account,please visit
the following web page:
http://dpq.nc.gov/about/divisions/water-resources/edmr
Certification. Any person submitting an electronic DMR using the state's eDMR system shall make
the following certification [40 CFR 122.22]. NO OTHER STATEMENTS OF CERTIFICATION
WILL BE ACCEPTED:
7 certify, under penalty of law, that this document and all attachments were prepared under my
direction or supervision in accordance with a system designed to assure that qualified personnel
properly gather and evaluate the information submitted. Based on my inquiry of the person or
persons who manage the system, or those persons directly responsible for gathering the information,
the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I
am aware that there are significant penalties for submitting false information, including the
possibility of fines and imprisonment for knowing violations."
4. Records Retention ISupplements Section D. (6.)I
The permittee shall retain records of all Discharge Monitoring Reports, including eDMR
submissions. These records or copies shall be maintained for a period of at least 3 years from the
date of the report. This period may be extended by request of the Director at any time [40 CFR
122.41].
Page 7of7

UT to New Begun Creek
-----'� X.
(flows southwest)
t• -r Outfall/001 -
,+. (flows north)
�� t .� �.�\ .�• ��t 1, '� �ri � `;� /�_, � .:• � yif -
� Pasquotank
} J L �- iJ o
River
- fir'
NC Hwy 334 1' , r
am
4.
Jilt
New Begun Creek
�. : _ L - 'K• I (flows south then east)
W '
�^ rIt
.-
,j t ,
4
County of Pasquotank Facility
Pasquotank County Water System (WTP) Location
Receivinc-, Stream: UT to New Be Creek Se not to scale
_ gun [Segment 30-3-16-(1)]
Drainace Basin: Pasquotank River Basin Stream Class: C;Sw
Latitude: 360 14'28" Longitude: 761 10' 18" NPDES Permit NC043583
State Grid/Quad: C34NW/Weeksville Sub-Basin: 3-01-50 North Pasquotank County