NC0028037_Fact Sheet_20200813

FACT SHEET FOR EXPEDITED PERMIT RENEWALS
This form must be completed by Permit Writers for all expedited permits which do not require
full Fact Sheets. Expedited permits are generally simple 100% domestics (e.g., schools, mobile
home parks, etc) that can be administratively renewed with minor changes, but can include
facilities with more complex issues (Special Conditions, 303(d) listed water, toxicity testing,
instream monitoring, compliance concerns).
Basic Information for Expedited Permit Renewals
Permit Writer / Date
Brianna Young 8/13/2020
Permit Number
NCO028037
Facility Name / Facility Class
Lexington WTP # 1 & #2 / PC-1
Basin Name / Sub -basin number
Yadkin Pee -Dee / 03-07-07
Receiving Stream / HUC
Abbotts Creek / 03040103020
Stream Classification/ Stream Segment
WS-III; CA / 12-119- 4.5
Does permit need Daily Maximum NH3
limits?
N/A
Does permit need TRC limits/language?
Already resent
Does permit have toxicity testing? IWC (%) if
so
Yes; IWC = 21 %
Does permit have Special Conditions?
Yes — High Rock Lake reo ener
Does permit have instream monitoring?
Yes — added upstream hardness for renewal
Is the stream impaired on 303 d list)?
No not at the point of discharge)
Any obvious compliance concerns?
None
Any permit mods since last ermit?
None
New expiration date
4/30/2024
Comments on Draft Permit?
Yes See Section 7 below
Section 1. Facility Overview:
The City of Lexington operates two conventional WTPs with one combined discharge.
The total designed potable flowrate is 9.3 MGD and a design wastewater discharge of
0.200 MGD. The facility generates backflow with an intermittent discharge. The
maximum monthly average flow between February 2017 and January 2020 was
approximately 0.439 MGD. The permittee confirmed (via email 4/22/2020) that there are
10 media filters and 8 drying beds.
The facility currently discharges the leachate from the sludge drying beds through the
effluent outfall. This leachate goes through a sand and gravel filter system below the beds
before entering the v-notch weir box with the pond decant water, and going to the outfall.
Per the previous factsheet: Thom-A-Lex Reservoir provides raw water for the potable
water plants. Potable water which has been chlorinated, fluorinated, and treated with a
zinc base corrosion inhibitor is used to backwash and rinse the filter beds on an
intermittent bases. The resulting wastewater (sedimentation and backwash) is combined
and directed to a splitter box where the flow is controlled to two settling lagoons. To
maintain a safe operating level in the lagoons or to dewater a lagoon, a gravity
telescoping siphon decant system is used to intermittently extract wastewater that

discharges to the gravity sewer. The accumulated sludge in the settling lagoons is
transferred by a pump to the drying beds. If needed polymer may be added to accelerate
sludge thickening in a lagoon. The drying bed drain system collects the filtered
wastewater and discharges to the gravity sewer. As needed solids are removed from the
drying beds and transported to a landfill. A storage pad is available to store solids. As the
combined wastewater flows through the gravity sewer it passes through the effluent meter
and is dechlorinated with calcium thiosulfate from a liquid chemical addition system.
Section 2. Compliance History:
• 1 NOD for manganese frequency violation
• Multiple TRC violations (all BPJ'd)
• 1 TSS violation (BPJ'd)
• Passed all toxicity tests since February 2016
Abbotts Creek is not impaired at the point of discharge, but an impairment does exist
close to the point of discharge for chlorophyll -a. Although the receiving stream is not
impaired for turbidity at the point of discharge, a turbidity limit will remain in the permit
per anti -degradation.
Section 3. RPA:
The maximum monthly average flow between February 2017 and January 2020 was
approximately 0.439 MGD.
• Copper — RP shown; monthly monitoring with limits applied
• Zinc - RP shown; monthly monitoring with limits applied
• Fluoride —per renewal application, has the potential to be discharged, but
monitoring was removed in the previous permit per the RPA
Section 4. NCG59 General Permit Eligibility:
• They use conventional treatment technology, therefore they are eligible
• They have passed last 12 tox tests, therefore they are eligible by tox standards
• They had limits added for copper and zinc, therefore they are not eligible
• Conclusion: They are not eligible for the NCG59
Section 5. Changes from previous permit to draft:
• Updated eDMR footnote inA(1) and language in A(5)
• Updated outfall map
• Added facility grade in A(1)

• Updated permit expiration date to match others in the subbasin; permit short -
cycled due to this
• Updated components list on the Supplement to Permit Cover Sheet
• Added receiving stream characteristics on the Supplement to Permit Cover Sheet
• Manganese monitoring reduced to quarterly in A(1) as there is no longer a water
quality standard, but monitoring retained per current water treatment plant
guidance
• Limits applied for copper and monitoring increased to monthly in A(1) per RPA
• Limits applied for copper and monitoring increased to monthly in A(1) per RPA
• Added total hardness monitoring and associated footnotes per current WTP
guidance
• Removed footnote #3 stating "Parameters shall be monitored in conjunction with
toxicity test." as this is no longer required per the 2012 WTP guidance
• Tox language updated in A(2)
• Added compliance schedule as A(3) for new copper and zinc limits
Section 6. Changes from draft to final:
• Updated eDMR language in A(5)
Section 7. Comments received on draft permit:
• Paul DiMatteo (WSRO; via email 7/30/20): Some of the footnotes look
mismatched in the limits page, e.g. nitrogen footnote should be 4 not 3, hardness
should be 5/6, and tox should be 7 not 6.
o DWR response: The footnotes will be reviewed and corrected as needed.

NPDES Implementation of Instream Dissolved Metals Standards — Freshwater
Standards
The NC 2007-2015 Water Quality Standard (WQS) Triennial Review was approved by
the NC Environmental Management Commission (EMC) on November 13, 2014. The
US EPA subsequently approved the WQS revisions on April 6, 2016, with some
exceptions. Therefore, metal limits in draft permits out to public notice after April 6,
2016 must be calculated to protect the new standards - as approved.
Table 1. NC Dissolved Metals Water Quality Standards/Aquatic Life Protection
Parameter
Acute FW, µg/1
(Dissolved)
Chronic FW,
µg/1
(Dissolved)
Acute SW, µg/1
(Dissolved)
Chronic SW,
µg/1
(Dissolved)
Arsenic
340
150
69
36
Beryllium
65
6.5
---
---
Cadmium
Calculation
Calculation
40
8.8
Chromium III
Calculation
Calculation
---
---
Chromium VI
16
11
1100
50
Copper
Calculation
Calculation
4.8
3.1
Lead
Calculation
Calculation
210
8.1
Nickel
Calculation
Calculation
74
8.2
Silver
Calculation
0.06
1.9
0.1
Zinc
Calculation
Calculation
90
81
Table 1 Notes:
1. FW= Freshwater, SW= Saltwater
2. Calculation = Hardness dependent standard
3. Only the aquatic life standards listed above are expressed in dissolved form.
Aquatic life standards for Mercury and selenium are still expressed as Total
Recoverable Metals due to bioaccumulative concerns (as are all human health
standards for all metals). It is still necessary to evaluate total recoverable aquatic
life and human health standards listed in 15A NCAC 213.0200 (e.g., arsenic at 10
µg/l for human health protection; cyanide at 5 µg/L and fluoride at 1.8 mg/L for
aquatic life protection).
Table 2. Dissolved Freshwater Standards for Hardness -Dependent Metals
The Water Effects Ratio (WER) is equal to one unless determined otherwise
under 15A NCAC 02B .0211 Subparagraph (11)(d)
Metal
NC Dissolved Standard, µg/1
Cadmium,Acute
WER*{1.136672-[lnhardness](0.041838)] e^{0.9151 [ln hardness]-3.1485}
Cadmium, Acute Trout waters
WER* {1.136672-[ln hardness](0.041838)] e^{0.9151 [ln hardness]-3.6236}
Cadmium,Chronic
WER* {1.101672-[ln hardness](0.041838)] e^{0.7998[ln hardness]-4.4451 }
Chromium III, Acute
WER*0.316 e^{0.8190[lnhardness]+3.7256}
Chromium III, Chronic
WER*0.860 e^{o.8190[lnhardness]+0.6848}

Copper, Acute
WER*0.960 e^10.9422[ln hardness]-1.7001
Copper, Chronic
WER*0.960 e^10.8545[ln hardness]-1.7021
Lead, Acute
WER* 11.46203-[ln hardness](0.145712)) • e^11.273 [In hardness]-1.4601
Lead, Chronic
WER*11.46203-[ln hardness](0.145712)) • e^11.273[In hardness]-4.705}
Nickel, Acute
WER*0.998 • e^10.8460[ln hardness]+2.2551
Nickel, Chronic
WER*0.997 • e^10.8460[ln hardness]+0.05841
Silver, Acute
WER*0.85 • e^11.72[ln hardness]-6.591
Silver, Chronic
Not applicable
Zinc, Acute
WER*0.978 e^10.8473[ln hardness]+0.8841
Zinc, Chronic
WER*0.986 e^10.8473[ln hardness]+0.8841
General Information on the Reasonable Potential Analysis (RPA)
The RPA process itself did not change as the result of the new metals standards.
However, application of the dissolved and hardness -dependent standards requires
additional consideration in order to establish the numeric standard for each metal of
concern of each individual discharge.
The hardness -based standards require some knowledge of the effluent and instream
(upstream) hardness and so must be calculated case -by -case for each discharge.
Metals limits must be expressed as `total recoverable' metals in accordance with 40 CFR
122.45(c). The discharge -specific standards must be converted to the equivalent total
values for use in the RPA calculations. We will generally rely on default translator values
developed for each metal (more on that below), but it is also possible to consider case -
specific translators developed in accordance with established methodology.
RPA Permitting Guidance/WQBELs for Hardness -Dependent Metals - Freshwater
The RPA is designed to predict the maximum likely effluent concentrations for each
metal of concern, based on recent effluent data, and calculate the allowable effluent
concentrations, based on applicable standards and the critical low -flow values for the
receiving stream.
If the maximum predicted value is greater than the maximum allowed value (chronic or
acute), the discharge has reasonable potential to exceed the standard, which warrants a
permit limit in most cases. If monitoring for a particular pollutant indicates that the
pollutant is not present (i.e. consistently below detection level), then the Division may
remove the monitoring requirement in the reissued permit.
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 IQ 10 using the formula IQ 10 = 0.843
(s7Q 10, CfS) 0.993
• Effluent hardness and upstream hardness, site -specific data is preferred
• Permitted flow
• Receiving stream classification
2. In order to establish the numeric standard for each hardness -dependent metal of
concern and for each individual discharge, the Permit Writer must first determine
what effluent and instream (upstream) hardness values to use in the equations.
The permit writer reviews DMR's, Effluent Pollutant Scans, and Toxicity Test
results for any hardness data and contacts the Permittee to see if any additional
data is available for instream hardness values, upstream of the discharge.
If no hardness data is available, the permit writer may choose to do an initial
evaluation using a default hardness of 25 mg/L (CaCO3 or (Ca + Mg)).
Minimum and maximum limits on the hardness value used for water quality
calculations are 25 mg/L and 400 mg/L, respectively.
If the use of a default hardness value results in a hardness -dependent metal
showing reasonable potential, the permit writer contacts the Permittee and
requests 5 site -specific effluent and upstream hardness samples over a period of
one week. The RPA is rerun using the new data.
The overall hardness value used in the water quality calculations is calculated as
follows:
Combined Hardness (chronic)
_ (Permitted Flow, cfs *Avg. Effluent Hardness, mg/L) x (s7Q 10, cfs *Avg. Upstream
Hardness, mjg/L)
(Permitted Flow, cfs + s7Q 10, cfs)
The Combined Hardness for acute is the same but the calculation uses the IQ 10
flow.
3. The permit writer converts the numeric standard for each metal of concern to a
total recoverable metal, using the EPA Default Partition Coefficients (DPCs) or
site -specific translators, if any have been developed using federally approved
methodology.

EPA default partition coefficients or the "Fraction Dissolved" converts the
value for dissolved metal at laboratory conditions to total recoverable metal
at in -stream ambient conditions. This factor is calculated using the linear
partition coefficients found in The Metals Translator: Guidance for
Calculating a Total Recoverable Permit Limit from a Dissolved Criterion
(EPA 823-B-96-007, June 1996) and the equation:
Cdiss = 1
Ctotal 1 + { [Kpo] [SS(l+a)] [10-6] }
Where:
ss = in -stream suspended solids concentration [mg/1], minimum of 10 mg/L
used, and
Kpo and a = constants that express the equilibrium relationship between
dissolved and adsorbed forms of metals. A list of constants used for each
hardness -dependent metal can also be found in the RPA program under a
4. The numeric standard for each metal of concern is divided by the default partition
coefficient (or site -specific translator) to obtain a Total Recoverable Metal at
ambient conditions.
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) (Cb)
Qw
Where: Ca = allowable effluent concentration (µg/L or mg/L)
Cwqs = NC Water Quality Standard or federal criteria (µg/L or mg/L)
Cb = background concentration: assume zero for all toxicants except NH3*
(µg/L or mg/L)
Qw = permitted effluent flow (cfs, match s7Q 10)
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 s7Q 10 may be incorporated as applicable:
IQ 10 = used in the equation to protect aquatic life from acute toxicity

QA = used in the equation to protect human health through the
consumption of water, fish, and shellfish from carcinogens
30Q2 = used in the equation to protect aesthetic quality
6. The permit writer enters the most recent 2-3 years of effluent data for each
pollutant of concern. Data entered must have been taken within four and one-half
years prior to the date of the permit application (40 CFR 122.21). The RPA
spreadsheet estimates the 95th percentile upper concentration of each pollutant.
The Predicted Max concentrations are compared to the Total allowable
concentrations to determine if a permit limit is necessary. If the predicted max
exceeds the acute or chronic Total allowable concentrations, the discharge is
considered to show reasonable potential to violate the water quality standard, and
a permit limit (Total allowable concentration) is included in the permit in
accordance with the U.S. EPA Technical Support Document for Water Quality -
Based Toxics Control published in 1991.
7. When appropriate, permit writers develop facility specific compliance schedules
in accordance with the EPA Headquarters Memo dated May 10, 2007 from James
Hanlon to Alexis Strauss on 40 CFR 122.47 Compliance Schedule Requirements.
8. The Total Chromium NC WQS was removed and replaced with trivalent
chromium and hexavalent chromium Water Quality Standards. As a cost savings
measure, total chromium data results may be used as a conservative surrogate in
cases where there are no analytical results based on chromium III or VI. In these
cases, the projected maximum concentration (95th %) for total chromium will be
compared against water quality standards for chromium III and chromium VI.
9. Effluent hardness sampling and instream hardness sampling, upstream of the
discharge, are inserted into all permits with facilities monitoring for hardness -
dependent metals to ensure the accuracy of the permit limits and to build a more
robust hardness dataset.
10. Hardness and flow values used in the Reasonable Potential Analysis for this
permit included:
Parameter
Value
Comments (Data Source)
Average Effluent Hardness
Default value used (no
(mg/L)
25 mg/L
monitoring data available)
[Total as, CaCO3 or (Ca+Mg)]
Average Upstream Hardness
Default value used (no
(mg/L)
25 mg/L
monitoring data available)
[Total as, CaCO3 or (Ca+Mg)]
7Q 10 summer (cfs)
2.90 cfs
BIMS
1 Q 10 (cfs)
2.43 cfs
BIMS
Permitted Flow (MGD)
Maximum, monthly avg in
0.439
previous 36 months at time of
renewal

42008346
J000663808
AFFIDAVIT OF PUBLICATION
STATE OF NORTH CAROLINA LEXINGTON, NC July 9, 2020
DAVIDSON COUNTY
I, Lynn Bowers OF THE DISPATCH, A NEWSPAPER PUBLISHED IN THE CITY OF LEXINGTON, COUNTY AND STATE
AFORESAID, BEING DULY SWORN, SAYS THE FOREGOING LEGAL OF WHICH THE ATTACHED IS A TRUE COPY,
WAS PUBLISHED IN SAID NEWSPAPER ONCE, BEGINNING THE 9th DAY OF July, 2020.
PUBLICATION FEE: $ 103.23
�o�tuiuuurn
C W0�F
Y1 (SEAL)
\ hJSPN
,
Notary Public
Rowan County
+\
My C�m isms- n Expires=
SWORN TO AND SUBSCRIBED BEFORE ME, THIS 16 DAY OF
%120CY
WV ISO M W c��
C Aap, ,.
MY COMMISSION EXPIRES a
Ad Copy:
The North Carolina
Environmental Management
Commission proposes to issue
a NPDES wastewater
discharge permit to the
person(s) listed below. Written
comments regarding the
proposed permit will be
accepted until 30 days after the
publish date of this notice. The
Director of the INC Division of
Water Resources (DWR) may
hold a public hearing should
there be a significant degree of
public interest. Please mail
comments and/or information
requests to DWR at the above
address. Interested persons
may visit the DWR at 512 N.
Salisbury Street, Raleigh, NC
to review information on file.
Additional information on
NPDES permits and this notice
may be found on our website:
http://dea. nc. oov/about/d ivision
s/water-resources/water-
resources-perm its/wastewater-
bmnch/npdes-
wastewater/public-notices, or
by calling [phone]. City
of Lexington has requested
renewal of NPDES permit
NCO028037 for the Lexington
WTP #1 and #2 in Davidson
County. This permitted
discharge is for treated
backwash wastewater to
Abbotts Creek, Yadkin -Pee
Dee River Basin. This
discharge may affect future
allocations in this portion of the
Yadkin -Pee Dee River Basin.
July 9, 2020

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
Director
MEMORANDUM
NORTH CAROI...INA
Environmental Quality
July 8, 2020
To: Jeff Bryan
NC DEQ / DWR / Public Water Supply
Winston-Salem Regional Office
From: Brianna Young
Compliance and Expedited Permitting Unit
Subject: Review of Draft NPDES Permit NCO028037
Lexington WTP #1 & #2
Davidson County
Please indicate below your agency's position or viewpoint on the draft permit and return this form by
August 7, 2020. If you have any questions on the draft permit, please contact me at 919-707-3619 or
via e-mail [[e-mail]].
§§§§§§§§§§§§§§§§§§§§§§§§§§§§§§§§
RESPONSE: (Check one)
ConcurE with the issuance of this permit provided the facility is operated and maintained properly,
the stated effluent limits are met prior to discharge, and the discharge does not contravene the
designated water quality standards.
1-1 Concurs with issuance of the above permit, provided the following conditions are met:
1-1 Opposes the issuance of the above permit, based on reasons stated below, or attached:
Signed:
�-� P-y AY� I P W s S
Date: it. I 1_0 "Lt
North Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 1 1617 Mail Service Center I Raleigh, North Carolina 27699-1617
919.707.9000

AC73753 North Carolina Division of Water Resources Water Sciences Section Laboratory Results
Loc. Descr.:
LEXINGTON WTP EFFLUENT
County:
Davidson Collector:
P DIMATTEO
VisitlD
Region:
Winston-Salem Report To
WSRO
Location ID:
WSRO NLC
River Basin
YAD Collect Date:
04/15/2020
Priority
ROUTINE
Emergency
Collect Time:
11_09
Sample Matrix:
SURFACEWATER
COC Yes/No
Sample Depth
Loc. Type:
Effluent
Final Report
If this report is labeled preliminary report, the results have not been validated. Do not use for Regulatory purposes.
Result/ Method Analysis
CAS # AnalVte Name PQL Qualifier Units Reference Date Validated by
LAB
Sample temperature at receipt by lab 2.4 °C 4/16/20 TASCENZ01
Turbidity
1.0
MIC
1.8
NTU
SM 2130 B-2001
4/16/20
ESTAFFORD1
7664-41-7
NH3 as N in liquid
0.02
NUT
0.05
mg/Las N
EPA350.1 REV 2
4/17/20
MIBRAHIM1
14797-55-8
NO2+NO3 as N in liquid
0.02
0.32
mg/Las N
EPA353.2 REV 2
4/17/20
MIBRAHIM1
7723-14-0
Phosphorus_ total as P in liquid
0.02
0.06
mg/L as P
EPA365.1 REV 2
4/22/20
MIBRAHIM1
7727-37-9
Total Kjeldahl N as N In liquid
0.2
0.31
mg/L as N
EPA 351.2 REV 2
4/21/20
MIBRAHIM1
Residue_Suspended in liquid
6.7
WET
6.7 U
mg/L
SM 2540 D-1997
4/20/20
AWILLIAMS
Total Dissolved Solids in liquid
12
60
mg/L
SM 2540 C-1997
4/20/20
AWILLIAMS
7440-22-4
Ag by ICPMS
1.0
MET
1.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7429-90-5
Al by ICP
50
350
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-36-0
Antimony by ICPMS
10
10 U
ug/L
EPA200.8 Rev5.4
5/5/20
ESTAFFORD1
7440-38-2
As by ICPMS
2.0
2.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7440-38-3
Ba by ICP
10
28
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-41-7
Be by ICP
5.0
5.0 U
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-70-2
Ca by ICP
0.10
8.3
mg/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-43-9
Cd by ICPMS
0.50
0.50 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7440-48-4
Cobalt by ICP
50
50 U
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-47-3
Cr by ICPMS
5.0
5.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7440-50-8
Cu by ICPMS
2.0
2.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7439-89-6
Fe by ICP
50
66
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7439-97-6
Hg 245.1
0.2
0.20 U
ug/L
EPA245.1 Rev3
5/4/20
ESTAFFORD1
7440-09-7
K by ICP
0.10
2.5
mg/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7439-93-2
Li ICP
25
25 U
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7439-95-4
Mg by ICP
0.10
3.0
mg/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7439-96-5
Mn by ICP
10
680
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7439-98-7
Mo by ICPMS
10
10 U
ug/L
EPA200.8 Rev5.4
5/5/20
ESTAFFORD1
7440-23-5
Na by ICP
0.10
11
mg/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-02-0
Ni by ICPMS
2.0
2.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7439-92-1
Pb by ICPMS
2.0
2.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7782-49-2
Se by ICPMS
1.0
1.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
WSS Chemistry Laboratory>> 1623 Mail Service Center, Raleigh, NC 27699-1623 [phone]
"Not Detected" or " U" does not indicate the sample is analyte free but that the analyte is not detected at or above the PQL
Page 1 of 2

NCDWX Laboratory Section 12esutts/Sampte Comments/QuarifierDefinitions
Sample ID: AC73753
u Result/ Method Analysis
V/lV TT (1"a YLG IVQIIIG
7440-31-5 Sri by ICPMS
�" Qualifier Units Reference Date Validated by
10 10 U ug/L EPA200.8 Rev5.4 5/5/20 ESTAFFORD1
7440-24-6
Sr by ICPMS
10
100
ug/L
EPA200.8 Rev5.4
5/5/20
ESTAFFORD1
7440-28-0
Thallium (TI) ICPMS
2.0
2.0 U
ug/L
EPA200.8 Rev5.4
5/5/20
ESTAFFORD1
7440-32-6
Ti (Titanium) by ICP
10
10 U
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-62-2
V by ICP
10
10 U
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-66-6
Zn by ICPMS
10
10 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
WSS Chemistry Laboratory>> 1623 Mail Service Center, Raleigh, NC 27699-1623 [phone]
"Not Detected" or " Ll" does not indicate the sample is analyte free but that the analyte is not detected at or above the PQL.
Page 2 of 2

AC73754 North Carolina Division of Water Resources Water Sciences Section Laboratory Results
Loc. Descr.:
LEXINGTON WTP DOWNSTREAM
County:
Davidson Collector:
P DIMATTEO
VisitlD
Region:
Winston-Salem Report To
WSRO
Location ID:
WSRO NLC
River Basin
YAD Collect Date:
04/15/2020
Priority
ROUTINE
Emergency
Collect Time:
11_20
Sample Matrix:
SURFACEWATER
COC Yes/No
Sample Depth
Loc. Type:
River/Stream
Final Report
If this report is labeled preliminary report, the results have not been validated. Do not use for Regulatory purposes.
Result/ Method Analysis
CAS # AnalVte Name PQL Qualifier Units Reference Date Validated by
LAB
Sample temperature at receipt by lab 2.4 °C 4/16/20 TASCENZ01
Turbidity
1.0
MIC
9.0
NTU
SM 2130 B-2001
4/16/20
ESTAFFORD1
7664-41-7
NH3 as N in liquid
0.02
NUT
0.02 U
mg/Las N
EPA350.1 REV 2
4/17/20
MIBRAHIM1
14797-55-8
NO2+NO3 as N in liquid
0.02
0.12
mg/Las N
EPA353.2 REV 2
4/17/20
MIBRAHIM1
7723-14-0
Phosphorus_ total as P in liquid
0.02
0.04
mg/L as P
EPA365.1 REV 2
4/22/20
MIBRAHIM1
7727-37-9
Total Kjeldahl N as N In liquid
0.2
0.48
mg/L as N
EPA 351.2 REV 2
4/21/20
MIBRAHIM1
Residue_Suspended in liquid
12
WET
12 U
mg/L
SM 2540 D-1997
4/20/20
AWILLIAMS
Total Dissolved Solids in liquid
12
48
mg/L
SM 2540 C-1997
4/20/20
AWILLIAMS
7440-22-4
Ag by ICPMS
1.0
MET
1.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7429-90-5
Al by ICP
50
510
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-36-0
Antimony by ICPMS
10
10 U
ug/L
EPA200.8 Rev5.4
5/5/20
ESTAFFORD1
7440-38-2
As by ICPMS
2.0
2.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7440-38-3
Ba by ICP
10
33
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-41-7
Be by ICP
5.0
5.0 U
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-70-2
Ca by ICP
0.10
8.4
mg/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-43-9
Cd by ICPMS
0.50
0.50 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7440-48-4
Cobalt by ICP
50
50 U
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-47-3
Cr by ICPMS
5.0
5.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7440-50-8
Cu by ICPMS
2.0
2.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7439-89-6
Fe by ICP
50
520
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7439-97-6
Hg 245.1
0.2
0.20 U
ug/L
EPA245.1 Rev3
5/4/20
ESTAFFORD1
7440-09-7
K by ICP
0.10
2.3
mg/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7439-93-2
Li ICP
25
25 U
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7439-95-4
Mg by ICP
0.10
3.1
mg/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7439-96-5
Mn by ICP
10
96
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7439-98-7
Mo by ICPMS
10
10 U
ug/L
EPA200.8 Rev5.4
5/5/20
ESTAFFORD1
7440-23-5
Na by ICP
0.10
5.6
mg/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-02-0
Ni by ICPMS
2.0
2.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7439-92-1
Pb by ICPMS
2.0
2.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7782-49-2
Se by ICPMS
1.0
1.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
WSS Chemistry Laboratory>> 1623 Mail Service Center, Raleigh, NC 27699-1623 [phone]
"Not Detected" or " U" does not indicate the sample is analyte free but that the analyte is not detected at or above the PQL
Page 1 of 2

NCDWX Laboratory Section 12esutts/Sampte Comments/QuarifierDefinitions
Sample ID: AC73754
u Result/ Method Analysis
V/lV TT (1"a YLG IVQIIIG
7440-31-5 Sri by ICPMS
�" Qualifier Units Reference Date Validated by
10 10 U ug/L EPA200.8 Rev5.4 5/5/20 ESTAFFORD1
7440-24-6
Sr by ICPMS
10
110
ug/L
EPA200.8 Rev5.4
5/5/20
ESTAFFORD1
7440-28-0
Thallium (TI) ICPMS
2.0
2.0 U
ug/L
EPA200.8 Rev5.4
5/5/20
ESTAFFORD1
7440-32-6
Ti (Titanium) by ICP
10
11
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-62-2
V by ICP
10
10 U
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-66-6
Zn by ICPMS
10
10 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
WSS Chemistry Laboratory>> 1623 Mail Service Center, Raleigh, NC 27699-1623 [phone]
"Not Detected" or " Ll" does not indicate the sample is analyte free but that the analyte is not detected at or above the PQL.
Page 2 of 2

AC73755 North Carolina Division of Water Resources Water Sciences Section Laboratory Results
Loc. Descr.:
LEXINGTON WTP UPSTREAM
County:
Davidson Collector:
P DIMATTEO
VisitlD
Region:
Winston-Salem Report To
WSRO
Location ID:
WSRO NLC
River Basin
YAD Collect Date:
04/15/2020
Priority
ROUTINE
Emergency
Collect Time:
11_33
Sample Matrix:
SURFACEWATER
COC Yes/No
Sample Depth
Loc. Type:
River/Stream
Final Report
If this report is labeled preliminary report, the results have not been validated. Do not use for Regulatory purposes.
Result/ Method Analysis
CAS # AnalVte Name PQL Qualifier Units Reference Date Validated by
LAB
Sample temperature at receipt by lab 2.4 °C 4/16/20 TASCENZ01
Turbidity
1.0
MIC
9.0
NTU
SM 2130 B-2001
4/16/20
ESTAFFORD1
7664-41-7
NH3 as N in liquid
0.02
NUT
0.02
mg/Las N
EPA350.1 REV 2
4/17/20
MIBRAHIM1
14797-55-8
NO2+NO3 as N in liquid
0.02
0.12
mg/Las N
EPA353.2 REV 2
4/17/20
MIBRAHIM1
7723-14-0
Phosphorus_ total as P in liquid
0.02
0.04
mg/L as P
EPA365.1 REV 2
4/22/20
MIBRAHIM1
7727-37-9
Total Kjeldahl N as N In liquid
0.2
0.53
mg/L as N
EPA 351.2 REV 2
4/21/20
MIBRAHIM1
Residue_Suspended in liquid
6.2
WET
10
mg/L
SM 2540 D-1997
4/20/20
AWILLIAMS
Total Dissolved Solids in liquid
12
56
mg/L
SM 2540 C-1997
4/20/20
AWILLIAMS
7440-22-4
Ag by ICPMS
1.0
MET
1.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7429-90-5
Al by ICP
50
480
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-36-0
Antimony by ICPMS
10
10 U
ug/L
EPA200.8 Rev5.4
5/5/20
ESTAFFORD1
7440-38-2
As by ICPMS
2.0
2.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7440-38-3
Ba by ICP
10
34
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-41-7
Be by ICP
5.0
5.0 U
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-70-2
Ca by ICP
0.10
8.6
mg/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-43-9
Cd by ICPMS
0.50
0.50 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7440-48-4
Cobalt by ICP
50
50 U
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-47-3
Cr by ICPMS
5.0
5.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7440-50-8
Cu by ICPMS
2.0
2.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7439-89-6
Fe by ICP
50
540
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7439-97-6
Hg 245.1
0.2
0.20 U
ug/L
EPA245.1 Rev3
5/4/20
ESTAFFORD1
7440-09-7
K by ICP
0.10
2.4
mg/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7439-93-2
Li ICP
25
25 U
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7439-95-4
Mg by ICP
0.10
3.2
mg/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7439-96-5
Mn by ICP
10
100
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7439-98-7
Mo by ICPMS
10
10 U
ug/L
EPA200.8 Rev5.4
5/5/20
ESTAFFORD1
7440-23-5
Na by ICP
0.10
5.6
mg/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-02-0
Ni by ICPMS
2.0
2.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7439-92-1
Pb by ICPMS
2.0
2.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
7782-49-2
Se by ICPMS
1.0
1.0 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
WSS Chemistry Laboratory>> 1623 Mail Service Center, Raleigh, NC 27699-1623 [phone]
"Not Detected" or " U" does not indicate the sample is analyte free but that the analyte is not detected at or above the PQL
Page 1 of 2

NCDWX Laboratory Section 12esutts/Sampte Comments/QuarifierDefinitions
Sample ID: AC73755
u Result/ Method Analysis
V/lV TT (1"a YLG IVQIIIG
7440-31-5 Sri by ICPMS
�" Qualifier Units Reference Date Validated by
10 10 U ug/L EPA200.8 Rev5.4 5/5/20 ESTAFFORD1
7440-24-6
Sr by ICPMS
10
120
ug/L
EPA200.8 Rev5.4
5/5/20
ESTAFFORD1
7440-28-0
Thallium (TI) ICPMS
2.0
2.0 U
ug/L
EPA200.8 Rev5.4
5/5/20
ESTAFFORD1
7440-32-6
Ti (Titanium) by ICP
10
10 U
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-62-2
V by ICP
10
10 U
ug/L
EPA200.7 Rev4.4
5/12/20
ESTAFFORD1
7440-66-6
Zn by ICPMS
10
10 U
ug/L
EPA200.8 Rev5.4
5/4/20
ESTAFFORD1
WSS Chemistry Laboratory>> 1623 Mail Service Center, Raleigh, NC 27699-1623 [phone]
"Not Detected" or " Ll" does not indicate the sample is analyte free but that the analyte is not detected at or above the PQL.
Page 2 of 2

Young, Brianna A
From:
DiMatteo, Paul
Sent:
Friday, January 24, 2020 3:43 PM
To:
Young, Brianna A
Cc:
Graznak, Jenny
Subject:
Lexington WTP - NC0028037
Attachments:
I M G_20200114_094941.j pg
Hi Brianna,
According to the NPDES Application Tracker you're reviewing this renewal. Sorry if you aren't! Let me know who to
direct this to if that's the case.
I did an inspection at the facility noted above recently and thought it was strange that their sludge drying bed leachate
was discharged to their effluent without further treatment. At the very least it doesn't look pretty coming out of the
pipe, as seen in the attached picture.
This is as described in the most recent fact sheet. "The drying bed drain system collects the filtered wastewater and
discharges to the gravity sewer.... As the combined wastewater flows through the gravity sewer it passes through the
effluent meter... discharged to Abbotts Creek."
This seemed a bit odd to us over here. I don't think we've seen a drying bed which has leachate tied directly to the
outfall. Should we worry about the leachate containing concentrated amounts of chemicals used in the treatment
process? Is this a common practice?
Given the visual state of the effluent when I was there, I might take some unannounced samples to verify some of their
conditions. Other than Turbidity and TSS are there other parameters you I should look at?
Thank you,
Paul DiMatteo
Environmental Specialist
Division of Water Resources
Department of Environmental Quality
Winston-Salem Regional Office
450 W. Hanes Mill Road, Suite 300
Winston-Salem, NC 27105
[phone] office
[phone] mobile
[e-mail]
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.

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Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
rREQUIRED DATA ENTRY
Table 1. Project Information
Facility Name
WWTP/WTP Class
NPDES Permit
Outfal I
Flow, Qw (MGD)
Receiving Stream
HUC Number
Stream Class
❑ CHECK IF HQW OR ORW WQS
Lexington WTP #1 & #2
PC-1
NCO028037
001
0.439
Abbots Creek
03040103020
WS-III; CA
Z Apply WS Hardness WQC
7Q10s (cfs)
7Q10w (cfs)
30Q2 (cfs)
CIA (cfs)
1Q10s (cfs)
2.90
14.00
17.00
158.00
2.43
Effluent Hardness
----
Upstream Hardness
Combined Hardness Chronic
Combined Hardness Acute
25 mg/L (Avg)
------------
25 mg/L (Avg)
25 m /L
25 m /L
Data Source(s)
I —I CHECK TO APPLY MODEL
Par01
Par02
Par03
Par04
Par05
Par06E
Par07
Par08
Par09
Par10
Par11
Par12
Par13
Par14
Par15
Par16
Par17
Par18
Par19
Par20
Par21
Par22
Par23
Par24
Table 2. Parameters of Concern
Name wos 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.
11, 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
Ng/L
Chromium, Total
Aquatic Life
NC
N/A
FW
N/A
Ng/L
Copper
Aquatic Life
NC
7.8806
FW
10.4720
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
NCO028037 RPA - Freshwater, input
8/13/2020

H1
Date Data
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
REASONABLE POTENTIAL ANALYSIS
H2
Use"PASTE SPECIAL
Effluent Hardness Values" then "COPY• Upstream Hardness
. Maximum data
points = 58
Use"PASTE SPECIAL
Values" then "COPY'
. Maximum data
points = 58
BDL=1/2DL Results
Date
Data BDL=1/2DL Results
25 25 Std Dev. N/A
1
25 25 Std Dev. N/A
Mean
25.0000
2
Mean
25.0000
C.V.
0.0000
3
C.V.
0.0000
n
1
4
n
1
10th Per value
25.00 mg/L
5
10th Per value
25.00 mg/L
Average Value
25.00 mg/L
6
Average Value
25.00 mg/L
Max. Value
25.00 mg/L
7
Max. Value
25.00 mg/L
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
NCO028037 RPA - Freshwater, data
-2- 8/13/2020

REASONABLE POTENTIAL ANALYSIS
Pal
Copper
Date
Data
BDL=1/2DL
Results
1
8/4/2015
30
30
Std Dev.
2
12/1/2015
50
50
Mean
3
3/1/2016
40
40
C.V.
4
5/3/2016
< 20
10
n
5
8/9/2016
57.9
57.9
6
11/8/2016
< 20
10
Mult Factor =
7
2/7/2017
< 20
10
Max. Value
8
5/2/2017
9
9
Max. Pred Cw
9
8/8/2017
2.45
2.45
10
11 /7/2017
3.21
3.21
11
2/6/2018
1.59
1.59
12
5/8/2018
1.6
1.6
13
8/7/2018
1.59
1.59
14
11/6/2018
1.59
1.59
15
2/5/2019
1.59
1.59
16
5/7/2019
3.48
3.48
17
8/6/2019
1.6
1.6
18
11/5/2019
1.6
1.6
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
Par13
Use"PASTE SPECIAL Use"PASTE SPECIAL
Values" then "COPY" Fluoride Maximum
then "COPY"
. Maximum data . Maximum data
points = 58 points = 58
13.1778
1.3839
18
1.90
57.90 ug/L
110.01 ug/L
Date
Data
BDL=1/2DL
Results
1
6/7/2011
150
150
Std Dev.
41.8850
2
7/7/2011
100
100
Mean
151.0811
3
8/2/2011
170
170
C.V.
0.2772
4
9/8/2011
190
190
n
37
5
10/4/2011
170
170
6
11/8/2011
220
220
Mult Factor =
1.06
7
12/20/2011
150
150
Max. Value
220.0 ug/L
8
1/4/2012
100
100
Max. Pred Cw
233.2 ug/L
9
2/7/2012
100
100
10
3/7/2012
100
100
11
4/3/2012
140
140
12
5/8/2012
210
210
13
6/6/2012
150
150
14
7/10/2012
170
170
15
8/7/2012
190
190
16
9/6/2012
190
190
17
18
11/6/2012
200
200
19
12/6/2012
160
160
20
1 /9/2013
160
160
21
2/5/2013
100
100
22
3/6/2013
120
120
23
4/3/2013
130
130
24
5/14/2013
170
170
25
6/6/2013
210
210
26
7/9/2013
220
220
27
8/6/2013
220
220
28
9/10/2013
170
170
29
10/9/2013
100
100
30
11/5/2013
200
200
31
12/4/2013
150
150
32
1 /7/2014
100
100
33
2/5/2014
100
100
34
3/4/2014
100
100
35
4/9/2014
100
100
36
5/6/2014
150
150
37
6/3/2014
130
130
38
7/8/2014
100
100
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
NCO028037 RPA - Freshwater, data
-3- 8/13/2020

REASONABLE POTENTIAL ANALYSIS
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
Use "PASTE SPECIAL
Zinc
Values" then "COPY"
. Maximum data
points = 58
Date
Data
BDL=1/2DL
Results
8/4/2015
940
940
Std Dev.
272.0108
12/1/2015
630
630
Mean
164.6539
3/1/2016
270
270
C.V.
1.6520
5/3/2016
462
462
n
18
8/9/2016
134.7
134.7
11/8/2016
390
390
Mult Factor =
2.04
2/7/2017
92.4
92.4
Max. Value
940.0 ug/L
5/2/2017
0.14
0.14
Max. Pred Cw
1917.6 ug/L
8/8/2017
4.4
4.4
11 /7/2017
4.39
4.39
2/6/2018
4.39
4.39
5/8/2018
4.4
4.4
8/7/2018
4.39
4.39
11 /6/2018
4.98
4.98
2/5/2019
4.39
4.39
5/7/2019
4.39
4.39
8/6/2019
4.4
4.4
11 /5/2019
4.4
4.4
-4-
NCO028037 RPA - Freshwater, data
8/13/2020

Lexington WTP #1 & #2 -
NC0028037 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM
Qw (MGD) =
0.4393
1Q10S (cfs) =
2.43
7Q10S (cfs) =
2.90
7Q10W (cfs) =
14.00
30Q2 (cfs) =
17.00
Avg. Stream Flow, QA (cfs) =
158.00
Receiving Stream: Abbots Creek HUC 03040103020
DATA POINTS = 58
WWTP/WTP Class: PC-1
IWC% @ 1Q10S = 21.88598729
IWC% @ 7Q10S = 19.0133593
IWC% @ 7Q10W = 4.637593053
IWC% @ 30Q2 = 3.850708429
rW%C @ QA = 0.429060944
Stream Class: WS-III; CA
Outfall 001
Qw = 0.43925 MGD
COMBINED HARDNESS (mg/L)
Acute = 25 mg/L
Chronic = 25 mg/L
YOU HAVE DESIGNATED THIS RECEIVING
STREAM AS WATER SUPPLY
Effluent Hard: 0 value > 100 mg/L
Effluent Hard Avg = 25 mg/L
PARAMETER
NC STANDARDS OR EPA CRITERIA
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
TYPE
J
a
D
Applied
Chronic Acute
n # Det. Max Pred Cw Allowable Cw
d
StandCopper
Acute: 47.85
RP shown - apply Monthly Monitoring with Limit
NC
7.8806 FW(7Q 10s) 10.4720
ttg L
18 15
110.01
_ _ -----------------------------------------
Chronic: 41.45
RP shown - apply Monthly Monitoring with Limit
2 value(s) > Allowable Cw
Acute: NO WQS
Fluoride
NC
1800 FW(7Q10s)
ug/L
37 37
233.2
Chronic: 9,467.0
No RP, Predicted Max < 50% of Allowable Cw - No
No value > Allowable Cw
Monitoring required
Acute: 574.4
RP shown - apply Monthly Monitoring with Limit
Zinc
NC
126.7335 FW(7Q10s) 125.7052
ug/L
18 18 1,917.E
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Chronic: 666.5
RP shown - apply Monthly Monitoring with Limit
1 values > Allowable Cw
NCO028037 RPA - Freshwater, rpa
Page 5 of 50 8/13/2020

NH3/TRC WLA Calculations
Facility: Lexington WTP #1 & #2
PermitNo. NCO028037
Prepared By: Brianna Young
Enter Design Flow (MGD): 0.43925
Enter s7Q10 (cfs): 2.9
Enter w7Q10 (cfs): 14
Total Residual Chlorine (TRC)
Daily Maximum Limit (ug/1)
Ammonia (Summer)
Monthly Average Limit (mg NH3-N/1)
s7Q10 (CFS)
2.9
s7Q10 (CFS)
2.9
DESIGN FLOW (MGD)
0.43925
DESIGN FLOW (MGD)
0.43925
DESIGN FLOW (CFS)
0.680838
DESIGN FLOW (CFS)
0.68084
STREAM STD (UG/L)
17.0
STREAM STD (MG/L)
1.0
Upstream Bkgd (ug/1)
0
Upstream Bkgd (mg/1)
0.22
IWC (%)
19.01
IWC (%)
19.01
Allowable Conc. (ug/1)
89
Allowable Conc. (mg/1)
4.3
Ammonia (Winter)
Monthly Average Limit (mg NH3-N/1)
Fecal Coliform
w7Q10 (CFS)
14
Monthly Average Limit:
200/100ml DESIGN FLOW (MGD)
0.43925
(If DF >331; Monitor)
DESIGN FLOW (CFS)
0.68084
(If DF<331; Limit)
STREAM STD (MG/L)
1.8
Dilution Factor (DF)
5.26 Upstream Bkgd (mg/1)
0.22
IWC (%)
4.64
Allowable Conc. (mg/1)
34.3
Total Residual Chlorine
1. Cap Daily Max limit at 28 ug/I to protect for acute toxicity
Ammonia (as NH3-N)
1. If Allowable Conc > 35 mg/l, Monitor Only
2. Monthly Avg limit x 3 = Weekly Avg limit (Municipals)
3. Monthly Avg limit x 5 = Daily Max limit (Non-Munis)
If the allowable ammonia concentration is > 35 mg/L, no limit shall be imposed
Fecal Coliform
1. Monthly Avg limit x 2 = 400/100 ml = Weekly Avg limit (Municipals) = Daily Max limit (Non -Muni)

Whole Effluent Toxicity Testing and Self Monitoring Summary
Lenoir- Gunpowder Creek WWTP
NCO023736/001
County:
Caldwell
Region:
ARO
Basin:
CTB32
Mar Jun Sep Dec
Ceri7dPF
Begin:
2/1/2012
chr lim: 52%
NonComp:
Single
7Q10: 3.0
PF: 2.0
IWC:
52.0 Freq: Q
J
F
M
A
M
J
J
A
S O
2016
-
-
Pass
-
-
Pass
-
-
Pass -
2017
-
-
Pass
-
-
Pass
-
-
Pass -
2018
-
-
Pass
Pass >100(P)
>100
Pass >100(P)
>100(P)
-
Pass -
2019
-
-
Pass
-
-
Pass
-
-
Pass -
Lenoir- Lower Creek WWTP
NCO023981/001
County:
Caldwell
Region:
ARO
Basin:
CTB31
Feb May Aug Nov
Ceri7dPF
Begin:
1/1/2017
chr lim: 44%
NonComp:
Single
7Q10: 11.75
PF: 6.0
IWC:
44 Freq: Q
J
F
M
A
M
J
J
A
S O
2016
-
Pass
-
-
Pass
-
-
Pass
- -
2017
-
Pass
-
-
Pass
-
-
Pass
- -
2018
-
Pass
-
-
Pass 62.2(P)
-
-
Pass >100(P)
- -
2019
-
Pass
>100(P)
-
-
Pass
-
-
Pass
- -
2020
-
Pass
-
-
-
-
-
-
- -
Lenoir -Lake Rhodhiss WTP
NCO044164/001
County:
Caldwell
Region:
ARO
Basin:
CTB32
Jan Apr Jul Oct
Ceri7dPF
Begin:
6/1/2011
ChrMonit:
90%-Ann
NonComp:
7Q10:
PF:
IWC:
Freq: A
J
F
M
A
M
J
J
A
S O
2016
Fail
-
-
Pass
-
-
-
-
- -
2017
-
-
-
-
Pass
-
-
-
- -
2018
-
-
-
-
Pass
-
-
-
- -
Lexington Regional WWTP
NCO055786/001
County:
Davidson
Region:
WSRO
Basin:
YAD07
Feb May Aug Nov
Ceri7dPF
Begin:
2/1/2016
Chr lim: 60%
NonComp:
SINGLE
7Q10: 6.7
PF: 6.5
IWC:
60.06 Freq: Q
J
F
M
A
M
J
J
A
S O
2016
-
Pass
-
-
Pass
-
-
Pass
- -
2017
-
Pass
-
-
Pass
-
-
Pass
- -
2018
-
Pass
-
-
Pass
-
-
H
- -
2019
-
Pass
-
-
Pass
-
-
Pass
- -
Lexington WTP #1 & #2
NCO028037
County:
Davidson
Region:
WSRO
Basin:
YAD07
Feb May Aug Nov
Ceri7dPF
Begin:
4/1/2015
Chr Monit:
21%
NonComp:
70.10: 2.9
PF: 0.467 IWC:
20 Freq: Q
J
F
M
A
M
J
J
A
S O
2016
-
Pass
-
-
Pass
-
-
Pass
- -
2017
-
Pass
-
-
Pass
-
-
Pass
- -
2018
-
Pass
-
-
Pass
-
-
Pass
- -
2019
-
Pass
-
-
Pass
-
-
Pass
- -
Lincoln County WTP
NCO084573/001
County:
Lincoln
Region:
MRO
Basin:
CTB32
Mar Jun Sep Dec
Fthd24PF
Begin:
4/1/2017
Acu Fthd 24PF Monit:
NonComp:
7Q10:
PF:
IWC:
Freq: Q
J
F
M
A
M
J
J
A
S O
2016
-
-
Fail
-
-
Fail
-
-
Fail -
2017
-
-
Fail
-
-
Pass
-
-
Pass -
2018
-
-
Pass
-
-
Pass
-
-
Pass -
2019
-
-
Pass
-
-
Fail
-
-
Pass -
Leeend: P= Fathead
minnow
(Pimohales
Dromelas). H=No Flow (facility
is active). s =
Split test between
Certified
Labs
Page 64 of 117
SOC JOC
N
D
Pass
Pass
Pass
Pass
SOC JOC:
N
Pass
Pass
Pass >100(P)
Pass
SOC JOC:
N
SOC JOC
N
Pass
Pass
Pass
Pass
SOC JOC:
N
Pass
Pass
Pass
Pass
SOC JOC:
N
G
C
C
r
D
Fail
Pass
Pass
Pass

2018 NC Category 5 Assessments "303(d) List" Final
Yadkin -Pee Dee River Basin
Subbasin
ff
Ln.arl'I W; nin 14119LA;y�
12-119-(4.5)b Abbotts Creek (including Lexington -Thomasville Water Supply Reservoir at normal reservoir elevation, Tom-A-Lex Lake)
13-17-6-(1.5)b
From Yokely Road to Dam
Classification I WS-III;CA Length or Area
\ssessment Criteria Status Reason for Rating
Exceeding Criteria > 10% and >90 conf
220 Units FW Acres
Parameter of Interest
i Previous AU Number) 12-119-(4.5)
Chlorophyll a (40 µg/I, AL, NC)
Category
5
Coddle Creek, including water supply reservoir for Concord)
Water supply for Concord excluding Coddle Creek Arm
Classification WS-II;HQW,CA ::11-ength or Area L 1,027 Units FW Acres Previous AU Number 13-17-6-(1.5)
assessment Crit Reason for Rating Paji tegory
Exceeding Criteria > 10% and >90 conf
13-45-(2)a4 Marks Creek (Boyds Lake, City Lake, Everetts Lake)
pH (9.0, AL, FW)
5
South half of City Lake
Classification C Length or Area 19 Units FW Acres (Previous AU Number 13-45-(2)a
\ssessment Criteria Status Reason for Rating Parameter of Interest
Exceeding Criteria Dissolved Oxygen (4 mg/I, AL, FW)
13-45-(2)a5 Marks Creek (Boyds Lake, City Lake, Everetts Lake)
From City Lake to NC 177
Classification Length or Area 4 Units FW Miles Previous AU Number 13-45-(2)a
Asses R Paramet
Exceeding Criteria > 10% and >90 conf Dissolved Oxygen (4 mg/I, AL, FW)
13-(1)a PEE DEE RIVER (including Lake Tillery below normal operating levels)
From mouth of Uwharrie River to a line across the reservoir at Richland Creek and Bunny Creek
Classification WS-IV,B;CA Length or Area
3,441 (Units FW Acres
Previous AU Number 13-(1)
kssessment Criteria Status Reason for Rating Parameter of Interest Category
Exceeding Criteria Fish Consumption Advisory PCB Fish Tissue Advisory (Advisory, FC, NC) 5
6/3/2019 2018 NC Category 5 Assessments "303(d) List" Approved by EPA May 22,2019 Page 235 of 262

MONITORING REPORT(MR) VIOLATIONS for:
Report Date:
04/06/2C Page
1 of 3
Permit:
nc0028037
MRS Betweei 4
- 2015 and 4 - 2020
Region:
%
Violation Category:%
Program Category:
Facility Name: %
Param Nam(%
County:
%
Subbasin: %
Violation Action: %
Major Minor:
%
PERMIT: NCO028037
FACILITY: City of Lexington - Lexington WTP #1 & 2
COUNTY: Davidson
REGION: Winston-Salem
Limit Violation
MONITORING
VIOLATION
UNIT OF
CALCULATED
%
REPORT
OUTFALL
LOCATION
PARAMETER
DATE
FREQUENCY
MEASURE
LIMIT
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
11 -2016
001
Effluent
Chlorine, Total Residual
11/21/16
2 X month
ug/I
28
34
21.4
Daily Maximum
No Action, BPJ
Exceeded
04-2017
001
Effluent
Chlorine, Total Residual
04/04/17
2 X month
ug/I
28
42
50
Daily Maximum
No Action, BPJ
Exceeded
05-2017
001
Effluent
Chlorine, Total Residual
05/02/17
2 X month
ug/I
28
44
57.1
Daily Maximum
No Action, BPJ
Exceeded
06-2017
001
Effluent
Chlorine, Total Residual
06/07/17
2 X month
ug/I
28
36
28.6
Daily Maximum
No Action, BPJ
Exceeded
06-2017
001
Effluent
Chlorine, Total Residual
06/21/17
2 X month
ug/I
28
44
57.1
Daily Maximum
No Action, BPJ
Exceeded
08-2017
001
Effluent
Chlorine, Total Residual
08/08/17
2 X month
ug/I
28
43
53.6
Daily Maximum
No Action, BPJ
Exceeded
08-2017
001
Effluent
Chlorine, Total Residual
08/22/17
2 X month
ug/I
28
48
71.4
Daily Maximum
No Action, BPJ
Exceeded
09-2017
001
Effluent
Chlorine, Total Residual
09/12/17
2 X month
ug/I
28
37
32.1
Daily Maximum
No Action, BPJ
Exceeded
09-2017
001
Effluent
Chlorine, Total Residual
09/26/17
2 X month
ug/I
28
46
64.3
Daily Maximum
No Action, BPJ
Exceeded
10-2017
001
Effluent
Chlorine, Total Residual
10/10/17
2 X month
ug/I
28
43
53.6
Daily Maximum
No Action, BPJ
Exceeded
11 -2017
001
Effluent
Chlorine, Total Residual
11/21/17
2 X month
ug/I
28
44
57.1
Daily Maximum
No Action, BPJ
Exceeded
12-2017
001
Effluent
Chlorine, Total Residual
12/05/17
2 X month
ug/I
28
36
28.6
Daily Maximum
No Action, BPJ
Exceeded
12-2017
001
Effluent
Chlorine, Total Residual
12/19/17
2 X month
ug/I
28
33
17.9
Daily Maximum
No Action, BPJ
Exceeded
03-2018
001
Effluent
Chlorine, Total Residual
03/20/18
2 X month
ug/I
28
35
25
Daily Maximum
No Action, BPJ
Exceeded
04-2018
001
Effluent
Chlorine, Total Residual
04/17/18
2 X month
ug/I
28
45
60.7
Daily Maximum
No Action, BPJ
Exceeded
06-2018
001
Effluent
Chlorine, Total Residual
06/05/18
2 X month
ug/I
28
38
35.7
Daily Maximum
No Action, BPJ
Exceeded

MONITORING REPORT(MR) VIOLATIONS for:
Report Date:
04/06/2C Page
2 of 3
Permit:
nc0028037
MRS Betweel 4
- 2015 and 4 - 2020
Region:
%
Violation Category:%
Program Category: %
Facility Name: %
Param Nam(%
County:
%
Subbasin: %
Violation Action: %
Major Minor:
%
PERMIT: NCO028037
FACILITY: City of Lexington - Lexington WTP #1 & 2
COUNTY: Davidson
REGION: Winston-Salem
Limit Violation
MONITORING
VIOLATION
UNIT OF
CALCULATED
%
REPORT
OUTFALL
LOCATION
PARAMETER
DATE
FREQUENCY
MEASURE
LIMIT
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
07-2018
001
Effluent
Chlorine, Total Residual
07/03/18
2 X month
ug/I
28
38
35.7
Daily Maximum
No Action, BPJ
Exceeded
08-2018
001
Effluent
Chlorine, Total Residual
08/07/18
2 X month
ug/I
28
38
35.7
Daily Maximum
No Action, BPJ
Exceeded
10-2018
001
Effluent
Chlorine, Total Residual
10/25/18
2 X month
ug/I
28
36
28.6
Daily Maximum
No Action, BPJ
Exceeded
01 -2019
001
Effluent
Chlorine, Total Residual
01/08/19
2 X month
ug/I
28
32
14.3
Daily Maximum
No Action, BPJ
Exceeded
01 -2019
001
Effluent
Chlorine, Total Residual
01/22/19
2 X month
ug/I
28
32
14.3
Daily Maximum
No Action, BPJ
Exceeded
02-2019
001
Effluent
Chlorine, Total Residual
02/21/19
2 X month
ug/I
28
46
64.3
Daily Maximum
No Action, BPJ
Exceeded
03-2019
001
Effluent
Chlorine, Total Residual
03/19/19
2 X month
ug/I
28
32
14.3
Daily Maximum
No Action, BPJ
Exceeded
04-2019
001
Effluent
Chlorine, Total Residual
04/02/19
2 X month
ug/I
28
37
32.1
Daily Maximum
No Action, BPJ
Exceeded
04-2019
001
Effluent
Chlorine, Total Residual
04/16/19
2 X month
ug/I
28
38
35.7
Daily Maximum
No Action, BPJ
Exceeded
05-2019
001
Effluent
Chlorine, Total Residual
05/07/19
2 X month
ug/I
28
47
67.9
Daily Maximum
No Action, BPJ
Exceeded
05-2019
001
Effluent
Chlorine, Total Residual
05/21/19
2 X month
ug/I
28
36
28.6
Daily Maximum
No Action, BPJ
Exceeded
06-2019
001
Effluent
Chlorine, Total Residual
06/11/19
2 X month
ug/I
28
43
53.6
Daily Maximum
No Action, BPJ
Exceeded
07-2019
001
Effluent
Chlorine, Total Residual
07/09/19
2 X month
ug/I
28
40
42.9
Daily Maximum
No Action, BPJ
Exceeded
07-2019
001
Effluent
Chlorine, Total Residual
07/23/19
2 X month
ug/I
28
46
64.3
Daily Maximum
No Action, BPJ
Exceeded
08-2019
001
Effluent
Chlorine, Total Residual
08/20/19
2 X month
ug/I
28
40
42.9
Daily Maximum
No Action, BPJ
Exceeded
09-2019
001
Effluent
Chlorine, Total Residual
09/10/19
2 X month
ug/I
28
45
60.7
Daily Maximum
No Action, BPJ
Exceeded

MONITORING REPORT(MR) VIOLATIONS for:
Report Date: 04/06/2C Page 3 of 3
Permit: nc0028037
MRS Betweel 4 - 2015 and 4 - 2020
Region: %
Violation Category:% Program Category: %
Facility Name: %
Param Nam(%
County: %
Subbasin: % Violation Action: %
Major Minor: %
PERMIT: NCO028037
FACILITY: City of Lexington - Lexington WTP #1 & 2
COUNTY: Davidson REGION: Winston-Salem
Limit Violation
MONITORING
VIOLATION
UNIT OF CALCULATED %
REPORT OUTFALL
LOCATION PARAMETER
DATE FREQUENCY
MEASURE LIMIT VALUE Over VIOLATION TYPE VIOLATION ACTION
10-2019
001
Effluent
Chlorine, Total Residual
10/08/19
2 X month
ug/I
28
44
57.1
Daily Maximum
No Action, BPJ
Exceeded
10-2019
001
Effluent
Chlorine, Total Residual
10/22/19
2 X month
ug/I
28
44
57.1
Daily Maximum
No Action, BPJ
Exceeded
11 -2019
001
Effluent
Chlorine, Total Residual
11/19/19
2 X month
ug/I
28
36
28.6
Daily Maximum
No Action, BPJ
Exceeded
01 -2020
001
Effluent
Chlorine, Total Residual
01/21/20
2 X month
ug/I
28
35
25
Daily Maximum
No Action, BPJ
Exceeded
05 -2019
001
Effluent
Solids, Total Suspended -
05/07/19
2 X month
mg/I
45
47
4.4
Daily Maximum
No Action, BPJ
Concentration
Exceeded
Monitoring Violation
MONITORING
VIOLATION
UNIT OF
CALCULATED
%
REPORT
OUTFALL
LOCATION
PARAMETER
DATE
FREQUENCY
MEASURE
LIMIT
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
09-2019
001
Effluent
Manganese, Total (as Mn)
09/30/19
Monthly
ug/I
Frequency Violation
Proceed to NOD

Ploy COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
Director
Ronald S. Walser
City of Lexington
28 W. Center St
Lexington, NC 27292
NORTH CAROLINA
Environmental Quality
February 11, 2020
Subject: Compliance Evaluation Inspection Report
NPDES Permit NCO028037
Lexington WTP #1 & 2, Davidson County
Dear Mr. Walser:
On January 14, 2020, Paul DiMatteo of the Division of Water Resources (Division), Winston-
Salem Regional Office met with Ronald Walser, Operator in Responsible Charge (ORC), to
conduct a Compliance Evaluation Inspection of the above referenced wastewater treatment plant.
This inspection consists of (1) a review of the permit and accompanying documentation to
determine compliance with permit conditions, and (2) an on -site inspection of several collection
system components. The attached inspection form notes the areas that were evaluated for the
inspection, with any notable findings outlined as follows.
Item of Concern
Mr. Walser explained that leachate from the residuals drying beds is designed to combine with the
effluent rather than cycle back to the lagoons for settling and treatment. The Division is concerned
that this arrangement could impact water quality, as this set up is not a typical design seen at other
water treatment facilities. Therefore, the Division wishes to investigate this issue further via
sampling inspections and discussion with the Water Quality Permitting Section. If you wish, you
may provide any additional sampling results or other information related to the above for review.
If you have any questions concerning this report, please contact Paul DiMatteo at [phone]
or me at [phone].
Sincerely,
DocuSig ed by:
LOB, -T 5'at,
Lori 49 mde ;Regional Supervisor
Water Quality Regional Operations Section
Winston-Salem Regional Office
Division of Water Resources, NCDEQ
Enclosures — Inspection Report
CC: WSRO Laserfiche Files
R �� North Carolina Department of Environmental Quality I Division of Water Resources
Winston-Salem Regional Office { 450 West Hanes Mill Road, Suite 300 1 Winston-Salem, North Carolina 27105
NORTH CAROLImA
.......N f 336.776.9800

United States Environmental Protection Agency
Form Approved.
EPA Washington, D.C. 20460
OMB No. 2040-0057
Water Compliance Inspection Report
Approval expires 8-31-98
Section A: National Data System Coding (i.e., PCS)
Transaction Code NPDES yr/mo/day Inspection Type Inspector Fac Type
1 IN I 2 15 1 3 I NCO028037 111 12 I 20/01/14 I17 18 L d 19 L G j 201
21111111IIIIIIIIIIIIIIIIII1IIIIII IIIIIIIIIII f6
Inspection
Work Days Facility Self -Monitoring Evaluation Rating B1 QA ---------------------- Reserved -------------------
671
I 71 I n, I 72 I I 73I I I74 751 I I I I I I I80
70Iu ty �J l—L _!
Section B: Facility Data
Name and Location of Facility Inspected (For Industrial Users discharging to POTW, also include
Entry Time/Date
Permit Effective Date
POTW name and NPDES oermit Number)
09:30AM 20/01/14
15/04/01
Lexington WTP #1 & 2
2979 Old Greensboro St Extension
Exit Time/Date
Permit Expiration Date
Lexington INC 27292
10:45AM 20/01/14
20/02/29
Name(s) of Onsite Representative(s)/Titles(s)/Phone and Fax Number(s)
Other Facility Data
Ronald Stephen Walser/ORC/336-248-5820/
Name, Address of Responsible Official/Title/Phone and Fax Number
Contacted
Ronald S Walser,28 W Center St Lexington NC 27292/Utility Plant
Supervisor/336-248-3910/ No
Section C: Areas Evaluated During Inspection (Check only those areas evaluated)
Permit Flow Measurement Operations & Maintenance Records/Reports
Self -Monitoring Program Sludge Handling Disposal Facility Site Review Effluent/Receiving Waters
Laboratory
Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary)
(See attachment summary)
Name(s) and Signature(s) of Inspector(s) Agency/Office/Phone and Fax Numbers Date
Paul DiMatteo �DocuSigned by: DWR/WSRO WQ/336-776-9691/ 2/11/2020
41;M a=t-a
F10C7C2E5BB34D4...
Signature of Management Q A RevieLL-QdQ—'QQ—
EPA
Page#

NPDES yr/mo/day Inspection Type
NC0028037 I11 12, 20/01/14 117 18 JCJ
Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary)
During the inspection, the effluent looked rather turbid due to also carrying carbon dust. Carbon -rich
sludge is stored in the drying beds and leachate is sent to the effluent. Operators said this typically
happens during rain. He mentioned that they tested it some time ago and it wasn't over their turbidity
limits. I tried to observe the receiving stream downstream of the outfall but it already looked turbid due
to rain.
Page#

Permit: NCO028037 Owner - Facility: Lexington WTP #1 & 2
Inspection Date: 01/14/2020 Inspection Type: Compliance Evaluation
Operations & Maintenance Yes No NA NE
Is the plant generally clean with acceptable housekeeping? 0 ❑ ❑ ❑
Does the facility analyze process control parameters, for ex: MLSS, MCRT, Settleable 0 ❑ ❑ ❑
Solids, pH, DO, Sludge Judge, and other that are applicable?
Comment:
Permit
Yes No NA NE
(If the present permit expires in 6 months or less). Has the permittee submitted a new
0
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application?
Is the facility as described in the permit?
0
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# Are there any special conditions for the permit?
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0
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Is access to the plant site restricted to the general public?
0
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Is the inspector granted access to all areas for inspection?
0
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Comment: The permit expires on 2/29/2020. The renewal application was received on 1/14/2020.
Record Keeping
Are records kept and maintained as required by the permit?
Is all required information readily available, complete and current?
Are all records maintained for 3 years (lab. reg. required 5 years)?
Are analytical results consistent with data reported on DMRs?
Is the chain -of -custody complete?
Dates, times and location of sampling
Name of individual performing the sampling
Results of analysis and calibration
Dates of analysis
Name of person performing analyses
Transported COCs
Are DMRs complete: do they include all permit parameters?
Has the facility submitted its annual compliance report to users and DWQ?
(If the facility is = or > 5 MGD permitted flow) Do they operate 24/7 with a certified operator
on each shift?
Is the ORC visitation log available and current?
Is the ORC certified at grade equal to or higher than the facility classification?
Is the backup operator certified at one grade less or greater than the facility classification?
Is a copy of the current NPDES permit available on site?
Yes No NA NE
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Page# 3

Permit: NCO028037
Inspection Date: 01/14/2020
Record Keeping
Facility has copy of previous year's Annual Report on file for review?
Owner - Facility: Lexington WTP #1 & 2
Inspection Type: Compliance Evaluation
Yes No NA NE
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Comment: In response to the previous inspection, ORC began keeping a binder containing all relavent
visitation documents. Checked DMRs from 10/2018 and 8/2019.
Lagoons
Type of lagoons?
# Number of lagoons in operation at time of visit?
Are lagoons operated in?
# Is a re -circulation line present?
Is lagoon free of excessive floating materials?
# Are baffles between ponds or effluent baffles adjustable?
Are dike slopes clear of woody vegetation?
Are weeds controlled around the edge of the lagoon?
Are dikes free of seepage?
Are dikes free of erosion?
Are dikes free of burrowing animals?
# Has the sludge blanket in the lagoon (s) been measured periodically in multiple
locations?
# If excessive algae is present, has barley straw been used to help control the growth?
Is the lagoon surface free of weeds?
Is the lagoon free of short circuiting?
Yes No NA NE
Facultative
N
Parallel
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Comment: Operator said the liner was replaced in 1 lagoon in the past year, and the other is to be
replaced this year.
De -chlorination
Type of system ?
Is the feed ratio proportional to chlorine amount (1 to 1)?
Is storage appropriate for cylinders?
# Is de -chlorination substance stored away from chlorine containers?
Comment:
Are the tablets the proper size and type?
Are tablet de -chlorinators operational?
Number of tubes in use?
Yes No NA NE
Liquid
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Page# 4

Permit: NCO028037
Inspection Date: 01/14/2020
De -chlorination
Owner - Facility: Lexington WTP #1 & 2
Inspection Type: Compliance Evaluation
Yes No NA NE
Comment: Dechlor is only added when decanting from the lagoons, as operators said that leachate
from the drying beds is not chlorinated.
Flow Measurement - Effluent
Yes No NA NE
# Is flow meter used for reporting?
0
❑
❑
❑
Is flow meter calibrated annually?
0
❑
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❑
Is the flow meter operational?
0
❑
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❑
(If units are separated) Does the chart recorder match the flow meter?
❑
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0
❑
Comment:
Effluent Sampling
Yes No NA NE
Is composite sampling flow proportional?
❑
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0
❑
Is sample collected below all treatment units?
M
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Is proper volume collected?
M
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Is the tubing clean?
❑
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0
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# Is proper temperature set for sample storage (kept at less than or equal to 6.0 degrees
0
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❑
Celsius)?
Is the facility sampling performed as required by the permit (frequency, sampling type
0
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representative)?
Comment: DH. flow. chlorine. turbiditv and TSS run here. certification # 690: metals and toxicitv are
analyzed by Cameron Testing.
Effluent Pipe
Yes No NA NE
Is right of way to the outfall properly maintained?
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Are the receiving water free of foam other than trace amounts and other debris?
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If effluent (diffuser pipes are required) are they operating properly?
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Comment: Outfall was not viewed during the inspection due to area flooding/rain.
Drying Beds
Is there adequate drying bed space?
Is the sludge distribution on drying beds appropriate?
Are the drying beds free of vegetation?
# Is the site free of dry sludge remaining in beds?
Is the site free of stockpiled sludge?
Is the filtrate from sludge drying beds returned to the front of the plant?
Yes No NA NE
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Page# 5

Permit: NC0028037
Inspection Date: 01/14/2020
Drying Beds
# Is the sludge disposed of through county landfill?
# Is the sludge land applied?
(Vacuum filters) Is polymer mixing adequate?
Comment: Leachate from drying beds goes to the outfall.
Owner - Facility: Lexington WTP #1 & 2
Inspection Type: Compliance Evaluation
Yes No NA NE
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Page# 6

Lexington Water Treatment Plant
Zetag
(polymer)
Sedimentation
Basin w/Plate
Itor Settlers
Zetag
(polymer)
Sedimentation
Basin w/Plate
rtor Settlers
Drying Beds
Distribution
SvstPm
Abbotts Creek
Pumped to
system 2.937
MG average

ROY COOPER
Grn•rrnvr
MICHAEL S. REGAN
Serrrrar�
LINDA CULPEPPER
Mr4. 1w
City of Lexington
Attn: Tom Johnson, Dir. of Water Resources
28 W Center St
Lexington, NC 27292-3099
Subject: Permit Renewal
Application No. NCO028037
Lexington WTP # 1 & 2
Davidson County
Dear Applicant:
NUIi I N CAROL.INA
Environmental Quality
January 15, 2020
The Water Quality Permitting Section acknowledges the January 14, 2020 receipt of your permit renewal application and
supporting documentation. Your application will be assigned to a permit writer within the Section's NPDES WW permitting
branch. Per G.S. 150B-3 your current permit does not expire until permit decision on the application is made.
Continuation of the current permit is contingent on timely and sufficient application for renewal of the current permit. The
permit writer will contact you if additional information is required to complete your permit renewal. Please respond in a
timely manner to requests for additional information necessary to allow a complete review of the application and renewal
of the permit.
Information regarding the status of your renewal application can be found online using the Department of Environmental
Quality's Environmental Application Tracker at:
httPs://deq.nc.gov/permits-regulations/permit-guidance/environmental-application-tracker
If you have any additional questions about the permit, please contact the primary reviewer of the application using the
links available within the Application Tracker.
Sincerely
Wren Thedford
Administrative Assistant
Water Quality Permitting Section
cc: Central Files w/application
ec: WQPS Laserfiche File w/application
Nortt aro.rsDepertmertofEnvrormerts quat I Dv.sonofWsterFesouroos
D_E %*\. r-tortaerr Regora Off x 45�� West Hares h' Road•5ute 300 1 rstorSaiem, North Cerotrw 2%05
3.3s , 7 s-a800

mf-b--1
LEXINGTON
NORTH CAROLI NA
WATER RESOURCES
QI1ALITI' FIRST
January 71h, 2020
NCDENR/DWR/NPDES Unit
Attn: Wren Thedford
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: NPDES Permit — NCO028037
Lexington WTP
Davidson County
Application for Permit Renewal
Dear Sir/Madam:
RECEIVED
JAN 14 2020
NCDEQ/DWR/NPDES
By this letter and attachments, I am requesting renewal of the NPDES permit for the City of Lexington's
WTP #1 and #2 — NC0028037.
Attached are the following: NPDES Permit Application Short Form C WTP, Plant schematic, and narrative
of Sludge Management Plan(below).
Narrative of Sludge Management Plan:
Sludge at the two Lexington Water Plants is generated from filter back washing and cleaning of
sedimentation basins. Coagulation at the Water Plants is done with alum.
Backwash water and basin washing water are collected in two holding lagoons. Sludge is allowed to
settle out and water is decanted from the top of each basin. This decanted water constitutes the
permitted discharge.
Concentrated sludge from the holding lagoons has polymer added to accelerate dewatering and is
pumped to one of 6 sand drying beds for air -drying. When the sludge is dry enough, it is removed by a
front-end loader and hauled to the Davidson County Landfill (permit number 29-06) for final disposal.
Please forward comments and questions to my attention at 336-248-3930 ext. 3926 or email
[e-mail]
Sincerely,
28 We
Water Resources - Public Works - Engineering
st Center Street- Lexington, NC 27292 - 336.248-3930
\K��'lY'.LI�,YIN(�'1'ONNC.C�OV'

NPDES PERMIT APPLICATION - SHORT FORM C - WTP
For discharges associated with water treatment plants
Mail the complete application to:
NCDEQ / DWR / NPDES
1617 Mail Service Center, Raleigh, NC 27699-1617
NPDES Permit Number INCO028037- I
If you are completing this form in computer use the TAB key or the up - down arrows to move from one
field to the next. To check the boxes, click your mouse on top of the box. Otherwise, please print or type.
1. Contact Information:
Owner Name City Of Lexington
Facility Name City of Lexington WTP 1 & 2
Mailing Address 28 West Center Street
City Lexington
State / Zip Code NC 27292
Telephone Number [phone]
Fax Number ( )
e-mail Address [e-mail]
2. Location of facility producing discharge:
Check here if same as above ❑
Street Address or State Road 2979 Greensboro St Ext
City Lexington
State / Zip Code NC 27292
County Davidson
3. Operator Information:
Name of the firm, consultant or other entity that operates the facility. (Note that this is not referring to the
Operator in Responsible Charge or ORC)
Name City of Lexington
Mailing Address 28 West Center St
City Lexington
State / Zip Code NC 27292
Telephone Number [phone]
Fax Number [phone]
4. Ownership Status:
Federal ❑
State ❑
Private ❑
Page 1 of 3 Version 6/2017

NPDES PERMIT APPLICATION - SHORT FORM C - WTP
For discharges associated with water treatment plants
S. Type of treatment plant:
® Conventional (Includes coagulation, flocculation, and sedimentation, usually followed by
filtration and disinfection)
❑ Ion Exchange (Sodium Cycle Cationic ion exchange)
❑ Green Sand Filter (No sodium recharge)
❑ Membrane Technology (RO, nanofiltration)
Check here if the treatment process also uses a water softener ❑
6. Description of source water(s) (i.e. groundwater, surface water)
Surface Water
7. Describe the treatment process(es) for the raw water:
Source Water is treated with Potassium Permanganate, Aluminum Sulfate, Sodium
Hydroxide and a polymer goagulant aid. Chemicals are flash mixed with raw water before
entering the flocculation stage and then solids are allowed to settle out in sedimentation
basins. The settled water is then filtered thru dual media filters and Sodium Hypochlorite
is added as a disinfectant before the finished water is pumped to the distribution system.
8. Describe the wastewater and the treatment process(es) for wastewater generated by the
facility:
The sediment that is settled out in the sedimentation basins is periodically pumped out
and sent to the waste ponds as well as the waste water from the routine backwashing of
the filters. The ponds concentrate the solids which are periodically pumped to the sludge
drying beds and the pond decant is treated with calcium Thiosulfate for dechlorination
and the effluent discharges thru an outfall into Abbotts Creek.
9. Number of separate discharge points: 1 Outfall Identification number(s) 001
10. Frequency of discharge: Continuous ❑ Intermittent ❑
If intermittent:
Days per week discharge occurs: 1 Duration: 6 hours
11. Plant design potable flowrate 9.3 MGD
Backwash or reject flow .200 MGD
12. Name of receiving stream(s) (Provide a map showing the exact location of each outfall, including
latitude and longitude):
Abbotts Creek 35.8548 lat :-80.1977 long,
13. Please list all water treatment additives, including cleaning chemicals or disinfection
treatments, that have the potential to be discharged.
Alum / aluminum sulfate Yes x No
Page 2 of 3 Version 6/2017

NPDES PERMIT APPLICATION - SHORT FORM C - WTP
For discharges associated with water treatment plants
Iron sulfate / ferrous sulfate Yes No x
Fluoride Yes x No
Ammonia nitrogen / Chloramines Yes No x
Zinc -orthophosphate or sweetwater CP1236 Yes x No
List any other additives below:
Sodium Hydroxide
Calcium Thiosulfate
Sodium Hypochlorite
14. Is this facility located on Indian country? (check one)
Yes ❑ No
15. Additional Information:
Provide a schematic of flow through the facility, include flow volumes at all points in
the water treatment process. The plan should show the point[s] of addition for
chemicals and all discharges routed to an outfall [including stormwater].
Solids Handling Plan
16. NEW Applicants
Information needed in addition to items 1-15:
New applicants are strongly recommended to contact a permit coordinator with the
NCDENR Customer Service Center.
Was the Customer Service Center contacted? ❑ Yes ❑ No
Analyses of source water collected
Engineering Alternative Analysis
Discharges from Ion Exchange and Reverse Osmosis plants shall be evaluated using a
water quality model.
17. Applicant Certification
I certify that I am familiar with the information contained in the application and that to the
best of my knowledge and belief such information is true, complete, and accurate.
ow. Jo�hbe� WAitr :RCSooCcds 1". ;Cccicr
Printed name of Person Signing Title
Signature of
t- 4-
Date
North Carolina General Statute 143-215.6 (b)(2) provides that: Any person who knowingly makes any false statement representation, or certification in any application,
record, report, plan, or other document files or required to be maintained under Article 21 or regulations of the Environmental Management Commission implementing that
Article, or who falsifies, tampers with, or knowingly renders inaccurate any recording or monitoring device or method required to be operated or maintained under Article 21
or regulations of the Environmental Management Commission implementing that Article, shall be guilty of a misdemeanor punishable by a fine not to exceed $25,000, or by
imprisonment not to exceed six months, or by both. (18 U.S.C. Section 1001 provides a punishment by a fine of not more than $25,000 or imprisonment not more than 5
years, or both, for a similar offense.)
Page 3 of 3 Version 6/2017

'A

WTP Flow Process Flow Diagram
•
µye„
mentation
e'
Flash Mix
Sludge
/ removal
Finished Water Storage & Pumping
Back Wash
Waste
Decant Ponds

It
LEXINGTON
NORTH CAROL 1 N A
WATER RESOURCES
QUALITY F 1 RST
January 22, 2019
Division of Water Resources
Non -Discharge Permitting Unit
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
Subject: Signature Authority Designation
To Whom It May Concern:
As an appropriate signing official for the City of Lexington as designated by 15A NCAC
2T .0106, I hereby delegate authority to sign and certify all permit applications, reports or
other permit related documents to the following staff for the following permit types
sewer, spray, land a lication) and/or nermit numbers•
Position
Person
Currently in
Position
Permit Type or
Permit
Number
Water
Tom Johnson
NCO055786
Resources
NCO028037
Director
WQ0016165
WQ0023213
WQ0001318
W CS00042
If you have any questions, please contact me at the following:
Permittee/Applicant name (please print): Cih• of Lexinl,►ton / Newell Clark
Title: Mayor
Complete mailing address: 28 West Center Street
City: Lexington State: NC Zip: 27292
Telephone number: [phone]
Sincerely,
Newell �'fark, Mayor -�
500 Glendale Road - Lexington, NC 27292 - 336.357.7889
W W W.Ui)0NG3x)NNC.GOv