NC0055786_Permit (Issuance)_20160107

NPDES DOCIJHENT !;CANNING COVER SHEET
NPDES Permit:
NC0055786
Lexington Regional WWTP
Document Type: (Permit
Issuance
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Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Owner Name Change
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
January 7, 2016
This document is printed on reuse paper - ignore any
content on the reirerse side

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Water Resources
ENVIRONMENTAL QUALITY
January 7, 2016
Ms. Gisele Comer, Interim Water Resources Superintendent
City of Lexington
28 West Center Street
Lexington, North Carolina 27292
Dear Ms. Comer:
PAT MCCRORY
Governor
DONALD R. VAN DER VAART
ScCIYYG,v
S. JAY ZIMMERMAN
Direcwr
Subject: Issuance of NPDES Permit Renewal
Permit No. NC0055786
Lexington Regional WWTP
Davidson County
Facility Class IV
Division personnel have reviewed and approved your application for renewal of the subject permit.
Accordingly, we are forwarding the attached NPDES discharge permit. This permit is issued pursuant to
the requirements of North Carolina General Statute 143-215.1 and Memorandum of Agreement between
North Carolina and the U.S. Environmental Protection Agency dated October 15, 2007 (or as
subsequently amended).
Please note that the receiving stream is listed as impaired for chlorophyll -a and PCB fish tissue on the
North Carolina 2014 303(d) Impaired Waters List. Addressing impaired waters is a high priority with the
Division, and instream data will continue to be evaluated. If there is noncompliance with permitted
effluent limits and stream impairment can be attributed to your facility, then mitigative measures may be
required.
No changes were made to the draft permit sent to you on November 4, 2015. The final permit
authorizes City of Lexington to discharge wastewater from the Lexington Regional WWTP to Abbotts
Creek, a class WS-V; B water in the Yadkin -Pee Dee River Basin. The permit includes discharge
limitations and/or monitoring for flow, BOD5, ammonia nitrogen, total suspended solids (TSS), dissolved
oxygen, pH, temperature, conductivity, total residual chlorine, fecal colifolm, total nitrogen, total
phosphorus, total copper, total zinc, total silver, and bromodichloromethane.
As identified previously, the renewal permit contains the following significant changes from
your current permit:
• The requirement to begin reporting discharge monitoring data electronically using the NC DWR's
Electronic Discharge Monitoring Report (eDMR) internet application has been added to your NPDES
permit. [See Special Condition A.(8.)]
For information on eDMR, registering for eDMR and obtaining an eDMR user account, please visit the
following web page: http://portal.ncdenr.org/web/wq/admin/bog/ipu/edmr.
State of North Carolina Environmental Quality I Water Resources
1617 Mail service Center I Raleigh, North Carolina 27699-1617
919 707 9000

For information on EPA's proposed NPDES Electronic Reporting Rule, please visit the following web
site: http://www2.epa.gov/compliance/proposed-npdes-electronic-reporting-rule.
The Division recognizes that the City is currently submitting eDMRs. This requirement is being
inserted into all NPDES permits and should be considered a formality.
• Effluent sampling data for cadmium, total phenolic compounds, chromium, lead, nickel, and selenium
showed concentrations less than detection levels. The limitation and monitoring requirements for these
parameters have been removed from the permit. Monitoring for cadmium, chromium, lead, nickel, and
selenium will continue with the City's Pretreatment LTMP. Monitoring for total phenolic compounds
will continue as part of the effluent pollutant scans. In accordance with NC Administrative Code
Section 15A NCAC 02B .0500, all test procedures must produce detection and reporting levels that are
below the permit discharge requirements and all data generated must be reported to the approved
detection level or lower reporting level of the procedure. Please note that DWR's Water Sciences
Section has determined that the Practical Quantitation Limit (PQL) for cadmium is 0.50 ug/L, for total
chromium is 5 ug/L, for nickel is 2 ug/L, and for lead is 2 ug/L (PQLs list updated 12/1/2015).
• Effluent sampling data for cyanide showed no reasonable potential to exceed NC Water Quality
Standards (WQSs); however, the maximum predicted concentration was greater than 50% of the
allowable allocation (permit limit). No limitations for cyanide were put in the permit renewal. Cyanide
monitoring will continue as part of the City's Pretreatment LTMP.
• Effluent sampling data for copper, silver, and zinc showed reasonable potentials to exceed' both the
chronic and acute allowable concentrations. Copper, silver, and zinc are action level standards and are
reviewed in conjunction with toxicity testing results. The facility has passed all toxicity tests since
January 2010; therefore, no limitations for copper, silver, and zinc were put in the permit renewal but
monitoring requirements were maintained at a reduced frequency of quarterly to coincide with toxicity
testing.
• Limited effluent sampling data for bromodichloromethane showed reasonable potential to exceed
chronic allowable concentrations. Since the analysis was based on a limited sample set (< 8 samples),
no limit was required but quarterly monitoring for bromodichloromethane was added to the permit.
• Nutrients instream monitoring requirements have been removed from the permit since DWR
Modeling and the Assessment Branch concurred that the High Rock Lake model has been completed.
Instream monitoring for DO, temperature, conductivity, and fecal coliform have been maintained in
the permit. As a member of Yadkin -Pee Dee River Basin Association, the requirement to perform
instream monitoring is waived.
• Some of the wording has changed in Special Condition A. (3.), Chronic Toxicity Permit Limit, please
review each paragraph carefully.
• Special Condition A.(5.), Effluent Pollutant Scan, has been modified to include the specific three
years in which the Effluent Pollutant Scans shall be performed (2016, 2017, and 2018). Please note
that samples should be collected with one quarterly toxicity test each year as mentioned above, and
must represent seasonal variation [i.e., do not sample in the same quarter every year]. In addition, at
the end of the Special Condition, 2nd species Toxicity Testing Requirements for municipal permit
renewals per Federal Regulations [40 CFR 122.21(j)(5)] have been added.
• Special Condition A. (6.), Nutrient Reopener for High Rock Lake, has been added in this permit
renewal.
• Effluent mercury data was reviewed from January 2012 to July 2015. In accordance with the 2012
Mercury TMDL NPDES Guidance the permittee needs to show annual mean effluent concentrations
below both the Water Quality Based Effluent Limitation (WQBEL) of 20 ng/L and the Technology
Based Effluent Limitation (TBEL) of 47 ng/L. A review of the data showed that the annual averages

were below both the WQBEL and the TBEL, therefore, no mercury limitation is required. The
2/month monitoring of mercury has been removed from the permit and the permittee is required to
sample mercury, at a frequency of quarterly, due to the requirements of its pretreatment program.
In accordance with the NPDES implementation of the 2012 Statewide Mercury TMDL, facilities
reporting mercury concentrations in quantifiable levels (greater than 1 ng/L) during the past five years
shall develop and implement MMPs. The effluent mercury samples, reported 18 instances over 1 ng/L
in 2012, 23 instances over 1 ng/L in 2013, 21 instances over 1 ng/L in 2014, and 8 instances over 1
ng/L in 2015. As a result, a Mercury Minimization Plan (MMP) requirement has been added to this
permit renewal. See section A.(7.). Please note that the Permittee shall develop and implement a
MMP during this permit term. The MMP shall be developed within 180 days of the NPDES Permit
Effective Date, and shall be available for inspection on -site. A sample MMP was developed through
a stakeholder review process and has been placed on the Division website for guidance
(http://portal.ncdenr.org/web/wq/swp/ps/npdes, under Model Mercury Minimization Plan).
If any parts, measurement frequencies or sampling requirements contained in this permit are unacceptable
to you, you have the right to an adjudicatory hearing upon written request within thirty (30) days
following receipt of this letter. This request must be in the form of a written petition, conforming to
Chapter 150B of the North Carolina General Statutes, and filed with the Office of Administrative
Hearings (6714 Mail Service Center, Raleigh, North Carolina 27699-6714). Unless such demand is made,
this decision shall be final and binding.
Please note that this permit is not transferable except after notice to the Division. The Division may
require modification or revocation and reissuance of the permit. This permit does not affect the legal
requirements to obtain other permits which may be required by the Division of Water Resources or any
other Federal, State, or Local government permits that may be required.
If you have questions concerning this permit, please contact Yang Song by e-mail
([e-mail]) or phone at [phone].
Sincerely,
Jay Zimmerm
irector, Division of Water Resources
Enclosure: NPDES Permit NC0055786
cc: NPDES Unit
Central Files
Winston-Salem Regional Office / Water Quality Program
e-copy:
EPA Region IV
Susan Meadows, Aquatic Toxicity Branch
Gisele Comer, Interim Water Resources Superintendent, Lexington Regional WWTP
Carrie Ruhlman, Water Sciences Section
Winston-Salem Regional Office / Public Water Supply Section

Permit NC0055786
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL. QUALITY
DIVISION OF WATER RESOURCES
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
In compliance with the provision 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
City of Lexington
is hereby authorized to discharge wastewater from a facility located at the
Lexington WWTP
South of Lexington
Davidson County
to receiving waters designated as Abbotts Creek in the Yadkin -Pee Dee River Basin
in accordance with effluent (imitations, monitoring requirements, and other conditions set forth in Parts
I, II, III, and IV hereof.
The permit shall become effective February 1, 2016.
This permit and the authorization to discharge shall expire at midnight on April 30, 2019
Signed this day January 7, 2016.
e. ay Zimmerman;
rector, Division of Water Quality
By Authority of the Environmental Management Commission
Page 1 of 10

Permit NC0055786
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby revoked. As of
this permit 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 included herein.
The City of Lexington
is hereby authorized to:
1. Continue to operate the existing 6.5 MGD wastewater treatment facility consisting of the following
treatment components:
• Two influent pump stations
• Influent flow measurement and recording
• A fine bar screen
• Grit separator
• Two primary clarifiers (not in use)
• Biological nutrient removal (BNR) system
• Two final clarifiers
• Two polishing ponds
• Chlorine contact chamber
• Post aeration
• Anaerobic digesters
• Diffused air flotation (DAF) unit
This facility is located at the City of Lexington's Regional Wastewater Treatment Plant, 500 Glendale
Road, Lexington, Davidson County, and
2. Discharge treated wastewaters from said facility into Abbotts Creek, a Class WS-V and B water in
the Yadkin -Pee Dee River Basin, at the location specified on the attached map.
Page 2 of 10

Permit NC0055786
PART I
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
Beginning on the effective date of this permit and lasting through the expiration date, the Permittee is authorized
to discharge treated wastewater from Outfall 001 subject to the following effluent limitations and monitoring(')
requirements:
•} PARAMETER
EFFLUENT LIMITATIONS
MONITORING REQUIREMENTS
_ .
Monthly.Weekly
Average
Average
Daily
Maximum
Measurement
Frequency ':
Sample_,
'Type
Sample
Ligation (2)
Flow •
6.5 MGD
Continuous
Recording
I or E
BOD, 5-day, 20°C (3) (Apr 1 - Oct 31)
(Nov 1- Mar 31)
5.0 mg/L
10.0 mg/L
7.5 mg/L
15.0 mg/L
Daily
Composite
1, E
Total Suspended Solids (3)
30.0 mg/L
45.0 mg/L
Daily
Composite
1, E
NH3-N, mg/L (Apr 1 - Oct 31)
(Nov 1- Mar 31)
1.0 mg/L
2.0 mg/L
3.0 mg/L
6.0 mg/L
Daily
Composite
E
Fecal Coliform (geometric mean)
200/100 mL
400/100 mL
Daily
Grab
E
Dissolved Oxygen .
Daily average shall not be less than 6.0 mg/L
Daily
Grab
E
Dissolved Oxygen (mg/I.)
Variable (2)
Grab
U, D
•
pH
> 6.0 and < 9.0 standard units
Daily
Grab
E
Temperature (°C)
Daily
Grab
E
Temperature (°C)
Variable (2)
Grab
U, D
Conductivity (umhos/cm)
Daily
Grab
E
Conductivity (umhos/cm)
Variable (2)
Grab
U, D
Fecal Coliform (#/100m1)
(geometric mean)
Variable (2)
Grab
U, D
Total Residual Chlorine (4)
28 µg/L
Daily
Grab
E
Total Phosphorus (5) (Apr 1 - Oct 31)
(Nov 1- Mar 31)
Monitor (mg/L)
4,910 pounds seasonal total
Monitor (mg/L)
6,930 pounds seasonal total
Weekly
Seasonally
Weekly
Seasonally
Composite
Calculated
Composite
Calculated
E
E
Total Nitrogen (mg/L)
Monthly
Composite
E
Total Copper (µg/L)
Quarterly
Composite
E
Total Zinc (µg/L)
Quarterly
Composite
E
Total Silver (µg/L)
Quarterly
Composite
E
Bromodichloromethane (µg/L)
Quarterly
Grab
E
Chronic Toxicity
Ceriodaphnia, P/F @60% (6)
Quarterly
Composite
E
Effluent Pollutant Scan
Monitor & Report
Footnote 7
Footnote 7
E
All footnotes are listed on the following page.
Part I, Page 3 of 10

Permit NC0055786
Footnotes:
(1) No later than 270 days from the effective date of this permit, begin submitting discharge monitoring reports
electronically using NC DWR's eDMR application system. See Special Condition A.(8.).
(2) Sample locations: I - Influent, E — Effluent, U - Upstream at I-85, D — Downstream at Highway 47. Instream
samples shall be, grab samples collected 3/Week during the months of June, July, August, and September and
Weekly during the remainder of the year. Instream monitoring requirements are waived as long as
Permittee maintains membership in the Yadkin -Pee Dee River Basin Association. If Permittee ceases
membership, then all instream monitoring requirements specified in this permit are immediately
reinstated.
(3) The monthly average effluent BOD5 and Total Suspended Solids concentrations shall not exceed 15% of the
respective influent values.
(4) The Division shall consider all effluent TRC values reported below 50 µg/L to be in compliance with the
permit. However, the permittee shall continue to record and submit all values reported by a NC certified
laboratory (including field certified), even if these values fall below 50 µg/L.
(5) Monitoring and effluent limitations for Total Phosphorus shall be conducted and calculated as prescribed
above and in Condition A. (2.) of this permit.
(6) Chronic Toxicity (Ceriodaphnia, P/F @60%), February, May, August, and November; see A. (4.). Toxicity
monitoring shall coincide with metals monitoring.
(7) See Condition A. (5.) of this permit.
There shall be no discharge of floating solids or visible foam in other than trace amounts.
Part I, Page 4 of 10

Permit NC0055786
A. (2.) TOTAL PHOSPHORUS MONITORING
[G.S. 143-215.1(b)]
The Permittee shall calculate the seasonal mass loading of total phosphorus as the sum of monthly
loadings, according to the following equations: •
(a) Monthly Mass Loading (pounds/month) = TP x Q x 8.34
where: TP = the average total phosphorus concentration (mg/L) of the
composite samples collected during the month at each
outfall
Q = the total volume of wastewater discharged during the month at
each outfall (MG/month)
8.34 = conversion factor, from (mg/L x MG) to pounds
(b) Seasonal Mass Loading (pounds/season) = E (Monthly Mass Loadings) for the season
The Permittee shall report the total phosphorus concentration for each sample and the monthly mass
loading in the appropriate self -monitoring report and the seasonal mass loading of total phosphorus ill
the final self -monitoring report for the season.
A. (3.) CHRONIC TOXICITY PERMIT LIMIT (QUARTERLY)
[15A NCAC 02B .0500 et seq.]
The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant
mortality to Ceriodaphnia dubia at an effluent concentration of 60 %.
The permit holder shall perform at a minimum, quarterly monitoring using test procedures outlined in
the "North Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," Revised December 2010, or
subsequent versions or "North Carolina Phase II Chronic Whole Effluent Toxicity Test Procedure"
(Revised- December 2010) or subsequent versions. The tests will be performed during the months of
February, May, August and November. 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.
If the test procedure performed as the first test of any single quarter results in a failure or ChV
below the permit limit, then multiple -concentration testing shall be performed at a minimum, in
each of the two following months as described in "North Carolina Phase II Chronic Whole
Effluent Toxicity Test Procedure" (Revised -December 2010) or subsequent versions.
All toxicity testing results required as part of this permit condition will be entered on the Effluent
Discharge Monitoring Form (MR-1) for the months in which tests were performed, using the parameter
code TGP3B for the pass/fail results and THP3B for the Chronic Value. Additionally, DWR Form AT-
3 (original) is to be sent to the following address:
Attention: North Carolina Division of Water Resources
Water Sciences Section/Aquatic Toxicology Branch
1623 Mail Service Center
Raleigh, NC 27699-1623
Part I, Page 5 of 10

Permit NC0055786
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, accurate, include all supporting chemical/physical measurements and all
concentration/response data, and be certified by laboratory supervisor and ORC or approved designate
signature. Total residual chlorine of the effluent toxicity sample must be measured and reported if
chlorine is employed for disinfection of the waste stream.
Should therebe 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, monitoring
will be required during the following month. Assessment of toxicity compliance is based on the toxicity
testing quarter, which is the three month time interval that begins on the first day of the month in which
toxicity testing is required by this permit and continues until the final day of the third month.
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.
A. (4.) NON -DETECTION REPORTING AND DETERMINATION OF COMPLIANCE
[G.S. 143-215.1 (b)]
When pursuant to this permit a pollutant analysis is conducted using an approved analytical protocol
with the appropriate minimum detection level and a result of "non -detectable" or "below quantitation
limit" is obtained, the Permittee shall record that result as reported. For the purpose of determining
compliance with a permit limit for the pollutant, the numerical value of that individual analytical result
shall be zero.
Part I, Page 6 of 10

Permit NC0055786
A. (5.) EFFLUENT POLLUTANT SCAN
[G.S. 143-215.1(b)]
The Permittee shall perform a total of three (3) Effluent Pollutant Scans for all parameters listed below.
One scan must be performed in each of the following years: 2016, 2017, and 2018. Analytical methods
shall be in accordance with 40 CFR Part 136 and shall be sufficiently sensitive to determine whether
parameters are present in concentrations greater than applicable standards and criteria. Samples should be
collected with one quarterly toxicity test each year, and must represent seasonal variation [i.e., do not
sample in the same quarter every year].. Unless otherwise indicated, metals shall be analyzed as "total
recoverable."
Ammonia (as N)
Chlorine (total residual, TRC)
Dissolved oxygen
Nitrate/Nitrite
Kjeldahl nitrogen
Oil and grease
Phosphorus
Total dissolved solids
Hardness
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury (EPA Method 163 1E)
Nickel
Selenium
Silver
Thallium
Zinc
Cyanide
Total phenolic compounds
Volatile organic compounds:
Acrolein
Acrylonitrile
Benzene
Bromoform
Carbon tetrachloride
Chlorobenzene
Chlorodibromomethane
Chloroethane
2-chloroethylvinyl ether
Chloroform
Dichlorobromomethane
1,1-dichloroethane
1,2-dichloroethane
Trans-1,2-dichloroethylene
1,1-dichloroethylene
1,2-dichloropropane
1,3-dichloropropylene
Ethylbenzene
Methyl bromide
Methyl chloride
Methylene chloride
1,1,2,2-tetrachloroethane
Tetrachloroethylene .
Toluene
1,1, 1 -trichloro ethane
1,1,2-trichloroethane
Trichloroethylene
Vinyl chloride
Acid -extractable compounds:
P-chloro-m-cresol
2-chlorophenol
2,4-dichlorophenol
2,4-dimethylphenol
4,6-dinitro-o-cresol
2,4-dinitrophenol
2-nitrophenol
4-nitrophenol
Pentachlorophenol
Phenol
2,4,6-trichlorophenol
Base -neutral compounds:
Acenaphthene
Acenaphthylene
Anthracene
Benzidine
Benzo(a)anthracene
Benzo(a)pyrene
3,4 benzofluoranthene
Benzo(ghi)perylene
Benzo(k)fluoranthene
Bis (2-chloroethoxy) methane
Bis (2-chloroethyl) ether
Bis (2-chloroisopropyl) ether
Bis (2-ethylhexyl) phthalate
4-bromophenyl phenyl ether
Butyl benzyl phthalate
2-chloronaphthalene
4-chlorophenyl phenyl ether
Chrysene
Di-n-butyl phthalate
Di-n-octyl phthalate
Dibenzo(a,h)anthracene
1,2-dichlorobenzene
1,3-dichlorobenzene
1,4-dichlorobenzene
3,3-dichlorobenzidine
Diethyl phthalate
Dimethyl .phthalate
2,4-dinitrotoluene
2,6-dinitrotoluene
1,2-diphenylhydrazine
Fluoranthene
Fluorene
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclo-pentadiene
Hexachloroethane
Indeno(1,2,3-cd)pyrene
Isophorone
Naphthalene
Nitrobenzene
N-nitrosodi-n-propylamine.
N-nitrosodimethylamine
N-nitrosodiphenylamine
Phenanthrene
Pyrene
1,2,4-trichlorobenzene
Reporting. Test results shall be reported on DWQ Form -A MR PPA1 (or in a form approved by the Director) by
December 31st of each designated sampling year. The report shall be submitted to the following address: NC
DEQ / DWR / Central Files, 1617 Mail Service Center, Raleigh, North Carolina 27699-1617.
Part I, Page 7 of 10

Permit NC0055786
Additional Toxicity Testing Requirements for Municipal Permit Renewal. Please note that
Municipal facilities that are subject to the Effluent Pollutant Scan requirements listed above are also
subject to additional toxicity testing requirements specified in Federal Regulation 40 CFR 122.21(j)(5).
The US EPA requires four (4) toxicity tests for a test organism other than the test species currently
required in this permit. The multiple species tests should be conducted either quarterly for a 12-month
period prior to submittal of the permit renewal application, or four tests performed at least annually in
the four and one half year period prior to the application. These tests shall be performed for acute or
chronic toxicity, whichever is specified in this permit. The multiple species toxicity test results shall be
filed with the Aquatic Toxicology Branch at the following address:
North Carolina Division of Water Resources
Water Sciences Section/Aquatic Toxicology Branch
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
Contact the Division's Aquatic Toxicology Branch at 919-743-8401 for guidance on conducting the
additional toxicity tests and reporting requirements. Results should also be summarized in Part E
(Toxicity Testing Data) of EPA Municipal Application Form 2A, when submitting the permit renewal
application to the NPDES Permitting Unit.
A. (6.) NUTRIENT REOPENER FOR HIGH ROCK LAKE
[G.S. 143-215.1(b)]
This permit may be reopened and modified to implement nutrient requirements in accordance with any
future TMDL and/or nutrient management strategy for High Rock Lake.
A. (7.) MERCURY MINIMIZATION PLAN (MMP)
[G.S. 143-215.1(b)]
The Permittee shall develop and implement a mercury minimization plan during this permit term. The
MMP shall be developed within 180 days of the NPDES Permit Effective Date, and shall be available
for inspection on -site. A sample MMP was developed through a stakeholder review process and has
been placed on the Division website for guidance (http://portal.ncdennor web/wq/swp//psin p des, under
Model Mercury Minimization Plan). The MMP should place emphasis on identification of mercury
contributors and goals for reduction. Results of MMP implementation shall be summarized and
submitted with the next permit renewal. Performance of the Mercury Minimization Plan will meet the
requirements of the TMDL (Total Maximum Daily Load) for mercury approved by USEPA on October
12, 2012, unless and until a Waste Load Allocation specific to this facility is developed and this
NPDES permit is amended to require further actions to address the Waste Load Allocation.
A. (8.) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS
[G.S. 143-215.1(b)]
Proposed federal regulations require electronic submittal of all discharge monitoring reports (DMRs)
and specify that, if a state does not establish a system to receive such submittals, then permittees must
submit DMRs electronically to the Environmental Protection Agency (EPA). The Division anticipates
that these regulations will be adopted and is beginning implementation in late 2013.
Part I, Page 8 of 10

a
Permit NC0055786
NOTE: This special condition supplements or supersedes the following sections within Part II of this
permit (Standard Conditions for NPDES Permits):
• Section B. (11.)
• Section D. (2.)
• Section D. (6.)
• Section E. (5.)
Signatory Requirements
Reporting
Records Retention
Monitoring Reports
1. Reporting [Supersedes Section D. (2.) and Section E. (5.) (a)1
Beginning no later than 270 days from the effective date of this permit, the permittee shall begin
reporting 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 / DWR / Information Processing Unit
ATTENTION: Central Files / eDMR
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.
Requests for temporary waivers from the NPDES electronic reporting requirements 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 using eDMR. Temporary waivers shall be. valid
for twelve (12) months and shall thereupon expire. At such time, DMRs shall be submitted
electronically to the Division unless the permittee re -applies for and is granted a new temporary
waiver by the Division.
Information on eDMR and application for a temporary waiver from the NPDES electronic reporting
requirements is found on the following web page:
http://portal.ncdenr.org/web/wq/admin/bog/ipu/edmr
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.
Part I, Page 9 of 10

Permit NC0055786
2. Signatory Requirements [Supplements Section B. (11.) (b) and supersedes Section B. (11.) (d)1
All eDMRs submitted to the permit issuing authority shall be signed by a person described in Part II,
Section B. (11.)(a) or by a duly authorized representative of that person as described in Part II,
Section B. (11.)(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://portal.ncdenr.org/web/wq/admin/bog/ipu/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:
"I 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 offines and imprisonment for knowing violations."
3. Records Retention [Supplements Section D. (6.)1
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].
Part I, Page 10 of 10

Discharge Location
8-Digit HUC: 03040103
Latitude: 35°46'06"
Longitude: 80°14'14"
Stream Class: WS-V & B
Subbasin: 030707
Receiving Stream: Abbotts Creek
NC0055786
Lexington Regional WWTP
,(ional'Geograplc Socie94cu1ed
1 4 1 ,1 I;
Facility
Location '°k
NOT TO SCALE

DEQ/DWR
FACT SHEET FOR NPDES PERMIT DEVELOPMENT
NPDES Permit No. NC0055786
Facility Information
Applicant/Facility Name:
City of Lexington/ Lexington Regional WWTP
Applicant Address:
28 West Center Street Lexington, North Carolina 27292
Facility Address:
500 Glendale Road Lexington, North Carolina 27292
Permitted Flow
6.5 MGD
Type of Waste:
Domestic and Industrial; long term monitoring pretreatment program
Facility/Permit Status:
Class IV /Active; Renewal
County:
Davidson County
Miscellaneous
Receiving Stream:
Abbotts Creek
Regional Office:
Winston-Salem (WSRO)
Stream Classification:
WS-V, B
8-digit HUC:
03040103
303(d) Listed?
Yes
Permit Writer:
Yang Song
Subbasin/ Stream Index:
03-07-07/ 12-118.5
Date:
December 30, 2015
Drainage Area (mi2):
182
411141141P
Lat. 35° 46' 06" N Long. 80° 14' 14" W
Summer 7Q10 (cfs):
6.7
Winter 7Q10 (cfs):
IS
30Q2 (cfs):
18
Average Flow (cfs):
167
IWC (%):
60
Background
The Lexington Regional WWTP (Class IV) has a permitted flow of 6.5 MGD and serves
approximately 30,000 people in the City of Lexington. The City of Lexington currently has six
(6) significant industrial users (SIUs) and a full pretreatment program through the Division of
Water Resource's PERCS Unit. Five (5) out of the 6 SIUs are categorized as metal finishing
industry. The application for renewal (Form 2A) of the permit was received on November 4,
2013. The permit expired on April 30, 2014 and is administratively continued until the permit
renewal is issued. The Permittee did not request any modifications to the current permit.
The Lexington Regional WWTP utilizes an activated sludge process to treat municipal
wastewater. The wastewater treatment plant was expanded and upgraded in 2005, which consists
of an influent pump station, a fine bar screen, grit separator, flow measurement and recording, a
second stage lift station, two primary clarifiers (not in use), biological nutrient removal (BNR)
system, two final clarifiers, two polishing ponds, chlorine contact chamber, and post -aeration.
The treated wastewater is discharged into Abbotts Creek. All sludge is wasted from BNR system
into a diffused air flotation (DAF) unit. Concentrated sludge from this unit is pumped into four
old anaerobic digesters for storage and dewatering. The further concentrated sludge is then
applied on the plant's compost facility under Permit WQ0001318. The City is reusing a portion
of its treated wastewater under Non -discharge permit WQ0016165. The City also operates a
conjunctive golf course wastewater treatment and reclaimed water utilization system under
permit WQ0023213.
This facility discharges to Abbotts Creek in the Yadkin -Pee Dee River Basin. Abbotts Creek is
classified as WS-V and B waters at the point of discharge. This portion of Abbotts Creek is listed
on the 2014 303(d) list as impairment for chlorophyll a and PCB fish tissue. Abbotts Creek
discharges to High Rock Lake which is also impaired for chlorophyll a and PCB fish tissue.
Fact Sheet
NPDES NC0055786 Renewal
Page 1

Waste Load Allocation (WLA)
The Division prepared the last NPDES WLA in 1994. The effluent limits for BOD5 (5 mg/L in
the summer period and 10 mg/L in the winter period) were based on this WLA. The effluent
limits for NH3-N (1.0 mg/L in the summer period and 2.0 mg/L in the winter period) were
required as part of the approved expansion to 6.5 MGD in 2004 permit renewal. These limits
were derived using EPA NH3-N criteria of 1 mg/L summer, and 1.8 mg/L winter. There have
been no modifications of the existing plant or requests for expansion of flow since 2005.
Current Effluent Characteristics
The Lexington Regional WWTP's average flow was 2.26 MGD from Aug. 2014 through July
2015, which represents 35% of permitted flow. During the same period, the monthly average
flows ranged from 1.45 MGD to 3.32 MGD.
Table 1. Lists average and maximum effluent data collected from 1/2012 through 07/2015.
Parameter
Flow
BODS
Total Suspended
Solids
Ammonia
Nitrogen
Total
Nitrogen
Total Phosphorus
(MGD)
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(lb/season)
average
2.75
2.27 S/ 2.35 W
2.56
0.37 S/ 0.39 W
4.29
3707 S/ 1071 W
maximum
13.43
8.07 S/ 7.92 W
9.2
5.62 S/ 15.0 W
11.2
4311 S/ 1786 W
Limit (MA)
6.5
5.0 S/ 10.0 W
30.0
1.0 S/ 2.0 W
4,910 S/ 6,930 W
(ST)
Table 1 (continued
Parameter
Total
Cadmium
Total Lead
Phenols
Selenium
Fecal Coliform
DO
(µg/L)
(µg/L)
(µg/L)
(µg/L)
(#/100m1)
(mg/L)
Average
< 2
< 18.56
< 2.03
< 5.03
3.02
8.25
maximum
< 2
< 23
< 5
< 10
164
6.1 (minimum)
Limit (MA)
3.0 (WA)
34.0 (DM)
8.0 (WA)
200/100 ml
Note: MA -Monthly Average; ST-Seasonal Total; WA -Weekly Average; DM -Daily Maximum.
Evaluation of Compliance Data
Discharge Monitoring Reports (DMRs) have been reviewed for the period of August 2009
through July 2015. During that period, two permit limit violations were reported: one ammonia -
nitrogen weekly average limit violation (07/20/2013), and one ammonia -nitrogen monthly
average violation (07/31/2013). Corresponding NOVs were issued for these violations.
WSRO conducted six (6) routine compliance inspections with six (6) pretreatment audits since
the existing permit was issued on July 10, 2009. Except for one compliance inspection in
February 2014 which gave a Facility Evaluation Rating of marginal, all other inspections found
the facility to be very reliable. The 2014 staff report indicated trash was seen discharging from
the effluent pipe into the surface water during the inspection. The last routine inspection was
conducted on July 21, 2015 and the facility was found to be in compliance. The inspector, Jenifer
Carter of WSRO, stated that the Permittee had installed a new fine screen at the influent, which
eliminated the issue of effluent trash. In addition, Jenifer noted that the trickling filter was
dismantled, primary clarifiers were not in use, and anaerobic digester #1 served as sludge
holding tank only.
Toxicity Testing. Since January 2010 the facility has passed 22 of 22 chronic toxicity tests and 4
of 4 fathead minnow second species tests.
Fact Sheet
NPDES NC0055786 Renewal
Page 2

Evaluation of Instream Data
The City of Lexington is a member of the Yadkin -Pee Dee River Basin Association (YPDRBA)
and the requirement to perform instream monitoring listed in this permit is waived as long as the
City maintains its membership. The YPDRBA monitors upstream and downstream sites on
Abbotts Creek [Q5940000, upstream at Abbotts Creek at I85 near Lexington; Q5970000,
downstream at Abbotts Creek at NC47 near Cotton Grove].
Monitoring data, obtained through EPA STORET database, from January 2010 through July
2013 was reviewed. It showed no violations for pH, DO and conductivity. For temperature, there
were 9 instances where the temperature increase from upstream to downstream exceeded 2.8
degrees C during the period of 2010-2012. No exceedances were reported in 2013. The
corresponding effluent data showed effluent temperatures were lower than the downstream
samples temperature that showed temperature differences exceeding 2.8 degrees C. It is difficult
to conclude that the WWTP effluent had an impact on downstream temperature increase. For
fecal coliform, upstream samples reported 8 instances over 400/100 ml and downstream fecal
coliform samples reported 2 over 400/100 ml. Those 2 downstream samples coincide with the 2
upstream high fecal coliform samples. In addition, the facility had no violations of fecal coliform
from 2010 through 2013 in the effluent; it is not likely that the effluent caused the downstream
high fecal coliform instances.
Downstream monitoring included data on total hardness and chlorophyll -a while upstream
monitoring did not include testing for these two parameters. Downstream total hardness did not
exceed the WS Standard of 100mg/L (CaCO3). However, there were 11 downstream samples
that showed chlorophyll -a concentrations over 40 ug/L, which is the WQS maximum limitation
for lakes, reservoirs, and other waters subject to growths of macroscopic or microscopic
vegetation not designed as trout waters.
NPDES was notified by the DWR Ecosystems Branch that upstream monitoring station
Q5940000 was discontinued in August 2013. There is another monitoring station on Abbotts
Creek (Q5930000), which is about 3.3 miles upstream from the discharge point.
PERMIT LIMIT DEVELOPMENT
Reasonable Potential (RP) Analysis
The Division conducted EPA -recommended analyses to determine the reasonable potential for
toxicants to be discharged by this facility, based on DMR data from January 2012 through July
2015. Effluent samples for arsenic, cadmium, total phenolic compounds, chromium, lead, nickel,
and selenium showed parameters were less than detection levels during this period. As a result,
monitoring and limitations for these parameters (except arsenic which is not in permit) have been
removed from the permit. Monitoring for arsenic, cadmium, chromium, lead, nickel, and
selenium will continue as part of the City's Pretreatment LTMP. Total phenolic compounds
monitoring will continue as part of the effluent pollutant scans.
In addition, the Permittee will be notified that in accordance with NC Administrative Code
Section 15A NCAC 02B .0500, all test procedures must produce detection and reporting levels
that are below the permit discharge requirements and all data generated must be reported to the
approved detection level or lower reporting level of the procedure. DWR's Water Sciences
Section has determined that the Practical Quantitation Limit for cadmium is 0.50 ug/L, for total
chromium is 5 ug/L, for nickel is 2 ug/L, and for lead is 2 ug/L.
Fact Sheet
NPDES NC0055786 Renewal
Page 3

Reasonable potential analyses were conducted for copper, cyanide, molybdenum, silver, zinc,
chloroform, and bromodichloromethane. See attached RPA results.
• Copper, Silver, and Zinc — the maximum predicted values for copper, silver, and zinc
demonstrated reasonable potentials to exceed both the chronic and acute allowable
concentrations. Copper, silver, and zinc are action level standards and are reviewed in
conjunction with toxicity testing results. The facility has passed all toxicity tests since
January 2010; therefore, no limitations for copper, silver, and zinc were put in the permit
renewal but monitoring requirements were maintained in the permit at reduced
monitoring frequency of quarterly to coincide with toxicity testing.
• Cyanide — effluent data showed no reasonable potential to exceed state water quality
standards; however, the maximum predicted concentration was greater than 50% of the
allowable allocation (permit limit). No limitations for cyanide were put in the permit
renewal. Cyanide monitoring will continue as part of the City's Pretreatment LTMP.
• Molybdenum — effluent data showed no reasonable potential to exceed state water
quality standards and the maximum predicted concentration was less than 50% of the
allowable allocation. No limitations for molybdenum were put in the permit renewal.
Quarterly monitoring for arsenic, cadmium, chromium, copper, cyanide, lead, mercury,
molybdenum, nickel, silver, selenium, and zinc will continue as part of the City's Pretreatment
LTMP.
Effluent Pollutant Scans
Effluent pollutant scans were performed in the 1 St quarter of 2011, the 1 St quarter of 2013, and the
1st quarter of 2015. Data from these annual effluent pollutant scans was evaluated and
chloroform and bromodichloromethane were detected in addition to zinc. However, the detected
zinc concentrations were not greater than the ones analyzed in the RPA discussed above.
• Chloroform — a reasonable potential analysis was performed on the limited data for
chloroform and it showed no reasonable potential to exceed state water quality standards
and the maximum predicted concentration was less than 50% of the allowable allocation.
Chloroform monitoring will continue as part of the effluent pollutant scan tests.
• Bromodichloromethane — a reasonable potential analysis was performed on the limited
date for bromodichloromethane and the maximum predicted value demonstrated a
reasonable potential to exceed chronic allowable concentrations. Since the analysis was
based on a limited sample set (< 8 samples), no limit was required but quarterly
monitoring for bromodichloromethane was added to the permit.
Nutrients Instream Monitoring
The current permit contains a special instream monitoring condition which requires the permittee
to monitor nutrients upstream and downstream. As a member of Yadkin -Pee Dee River Basin
Association, the requirement to perform instream monitoring is waived. The nutrient instream
monitoring requirements were initialized in 1989 as a part of the Abbots Creek Basin Monitoring
Plan. Two other permits (Thomasville WWTP - NC0024112 and High Point Westside WWTP —
NC0024228) also have similar requirements. See memo from Steve Tedder dated 9/23/1997.
DWR Modeling and the Assessment Branch concurred that there is no need to keep the instream
nutrients monitoring requirements in this permit since the High Rock Lake model has been
completed. As a consequence, the nutrients instream monitoring requirements have be removed
from the permit renewal. A stakeholder group has been formed to determine a Nutrient
Management Strategy for High Rock Lake which will impact this discharge.
Fact Sheet
NPDES NC0055786 Renewal
Page 4

Mercury TMDL Evaluation
Effluent mercury data was reviewed from January 2012 to July 2015. In accordance with the
2012 Mercury TMDL NPDES Guidance the permittee needs to show annual mean effluent
concentrations below both the Water Quality Based Effluent Limitation (WQBEL) of 20 ng/L
and the Technology Based Effluent Limitation (TBEL) of 47 ng/L. A review of the data showed
that the annual averages were below both the WQBEL and the TBEL, therefore, no mercury
limitation is required. The 2/month monitoring of mercury was removed from the permit. The
permittee will continue to sample mercury, at a frequency of quarterly, as part of its pretreatment
LTMP.
In accordance with the NPDES implementation of the 2012 Statewide Mercury TMDL, facilities
reporting mercury concentrations in quantifiable levels (greater than 1 ng/L) during the past five
years shall develop and implement MMPs. The effluent mercury samples, reported 18 instances
over 1 ng/L in 2012, 23 instances over 1 ng/L in 2013, 21 instances over 1 ng/L in 2014, and 8
instances over 1 ng/L in 2015. As a result, a Mercury Minimization Plan (MMP) requirement has
been added to this permit renewal. See section A.(8.). Please note that the Permittee shall
develop and implement a MMP during this permit term. The MMP shall be developed within
180 days of the NPDES Permit Effective Date, and shall be available for inspection on -site. A
sample MMP was developed through a stakeholder review process and has been placed on the
Division website for guidance(http://portal.ncrWweb/wq/swp/ps/npdes, under Model Mercury
Minimization Plan).
Table 2. Tabor City WWTP Mercury Effluent Concentrations 2010-2015
Lexington Regional WWTP/ NC0055786
Mercury Data Statistics (Method 1631 E)
2012
2013
2014
2015
# of Samples
24
24
24
14
Annual Average, ng/L
2.2
3.7
2.0
1.5
Maximum Value, ng/L
6.80
6.70
6.10
2.70
TBEL, ng/L
47
WQBEL, ng/L
20.0
Basis for Permit Effluent Limits
PARAMETER
EFFLUENT LIMITATIONS
RATIONALE FOR LIMITATION
Monthly
Average
Weekly
Average
Daily
Maximum
Flow
6.5 MGD
I5A NCAC 02B .0400 et seq., 02B .0500 et seq.
BOD, 5-day, 20°C (Apr 1 - Oct 31)
(Nov 1- Mar 31)
5.0 mg/L
10.0 mg/L
7.5 mg/L
15.0 mg/L
WLA Model in 1994
Total Suspended Solids
30.0 mg/L
45.0 mg/L
Administrative Code 15A NCAC 02B .0406 for
Municipal Wastewaters
NH3-N, mg/L (Apr 1 - Oct 31)
(Nov I- Mar 31)
1.0 mg/L
2.0 mg/L
3.0 mg/L
6.0 mg/L,
WLA Calculation in 2005
Fecal Coliform (geometric mean)
200/100 mL
400/100 ► il,
Administrative Code 15A NCAC 02B .0211;
Administrative Code 15A NCAC 02B .0500
Dissolved Oxygen
Daily average shall not be less than 6.0 mg/L
Administrative Code 15A NCAC 02B .0211
ICI I
> 6.0 and < 9.0 standard units
Administrative Code 15A NCAC 02B .0211
Fact Sheet
NPDES NC0055786 Renewal
Page 5

Temperature (°C)
Administrative Code 15A NCAC 02B .0500
Conductivity (umhos/cm)
Administrative Code 15A NCAC 02B .0500
Total Residual Chlorine
28 µg/L
Administrative Code 15A NCAC 02B .0211
Total Phosphorus (Apr 1 - Oct 31)
(Nov 1- Mar 31)
Monitor (mg/L)
4,910 pounds seasonal total
Monitor (mgfL)
6,930 pounds seasonal total
Administrative Code 15A NCAC 02B .0500;
Memorandum of Nutrient Limits for Major
Dischargers to Abbotts Creek Arm of High Rock
Lake
Total Nitrogen (mglL)
15A NCAC 02B .0500 et seq
Total Copper {µg/L)
Administrative Code 15A NCAC 02B .0211;
RPA
Total Zinc (µg/L)
Administrative Code 15A NCAC 02B .0211;
RPA
Total Silver (µg/1,)
Administrative Code 15A NCAC 02B .0211;
RPA
Bromodichloromethane (µg/L)
EPA NR Water Quality Criteria; RPA
lnstream monitoring of DO,
temperature, and conductivity
Administrative Code 15A NCAC 02B .0500
Chronic Toxicity
Ceriodaphnia, P/F @60%
15A NCAC 02B .0200 et seq.
Effluent Pollutant Scan
Monitor & Report
G.S. 143-215.1(b)
Summary of Proposed Changes
The following permit changes are proposed for this permit renewal:
1. Addition of electronic DMR requirement.
2. Removal of cadmium, lead, mercury, nickel, phenols, selenium, chromium effluent limitations
and monitoring requirements.
3. Addition of quarterly monitoring of bromodichloromethane.
4. Reduced monitoring frequency requirements for copper and zinc to quarterly.
5. Removal of nutrients instream monitoring requirements.
6. Addition of revised Effluent Pollutant scan specifying three years of sampling and 2nd species
testing requirements.
7. Addition of revised Toxicity testing language.
8. Addition of Special Condition A. (6.) Nutrient Reopener for High Rock Lake.
9. Addition of Special Condition A. (7.) Mercury Minimization Plan.
Proposed Schedule for Permit Issuance
Draft Permit to Public Notice: November 4, 2015 (estimate)
Permit Scheduled to Issue: December 28, 2015 (estimate)
NPDES Division Contact
If you have questions regarding any of the above information or on the attached permit, please contact
Yang Song at [phone] or [e-mail].
N ,�o� S,
NAME:
DATE:
Comments
No comments were received from Region IV EPA or the Winston-Salem Regional Office —
Surface Water Protection. The Winston-Salem Regional Office - Public Water Supply Section
concurred with the issuance of this NPDES permit.
Fact Sheet
NPDES NC0055786 Renewal
Page 6

North Carolina Department of Environmental Quality
Pat McCrory
Governor
MEMORANDUM
To:
Front
Subject:
November 4, 2015
NC DEQ / DWR / Regional Engineer
Winston-Salem Regional Office
Yang Song
919-807-6479
NPDES Unit
Review of Draft NPDES Permit NC0055786
Lexington Regional WWTP
Davidson County
Donald R. van der Vaart
Secretary
Please indicate below your agency's position or viewpoint on the draft permit and return this form by December 11,
2015. If you have any questions on the draft permit, please feel free to contact me at the telephone number shown
above.
RESPONSE: (Check one)
Concur 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.
Concurs with issuance of the above permit, provided the following conditions are met:
Opposes the issuance of the above permit, based on reasons stated below, or attached:
Signed --L
t"- A
Date:
//�-z c%�- U/ 5
1601 Mail Service Center, Raleigh, North Carolina 27699-1601
Phone: [phone] Internet: www.ncdenr.gov
An Equal Opportunity \Affirmative Action Employer - Made in part by recycled paper

42008346
J000531588
MY COMMISSION EXPIRES
Ad Copy:
PUBLIC NOTICE
North Carolina Environmental
Management
Commission/NPDES Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
Notice of Intent to Issue a
NPDES Wastewater Permit
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 NC 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.://portal. ncdenr. org/web/wq/
swp/ps/npdes/calendar, or by
calling [phone].
AFFIDAVIT OF PUBLICATION
STATE OF NORTH CAROLINA
DAVIDSON COUNTY
LEXINGTON, NC NOVEMBER 5, 2015
I, JENNIFER NICHOLSON 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 5th DAY OF NOVEMBER, 2015.
PUBLICATION FEE: $ 88.60
TO AND SUB yED BEFORE ME, THIS 5
filAPA
2-!Grab16
The City of Lexington
requested renewal of permit
NC0055786 for Lexington
Regional WWTP in Davidson
County; this permitted
discharge is treated municipal
wastewater to Abbotts Creek,
Yadkin -Pee Dee River Basin.
November 5, 2015
DAY OF
nWanhaJt, 9,t/5
Notary
Public
Davidson County
JMy Commission Expires=

NPDES/Aquifer Protection Permitting Unit Pretreatment Information Request Form
PERMIT WRITER COMPLETES THIS PART:
PERMIT WRITERS - AFTER you get this form back
Check that
f
from PERCS:
all apply
Notify PERCS if LTMP/STMP data be
Date of Request
9/9/2015
municipal renewal
v
we said should
on DMRs is not really there, so we can get it for you
Requestor
Yang Song
new industries
(or NOV POTW).
Facility Name
Lexington Regional WWTP
WWTP expansion
- Notify PERCS if you want us to keep a specific POC
Permit Number
NC0055786
Speculative limits
in LTMP/STMP so you will have data for next permit
Region
Winston-Salem
stream reclass.
renewal.
- Email PERCS draft permit, fact sheet, RPA.
Basin
YAD
outfall relocation
- Send PERCS paper copy of permit (w/o NPDES
7Q10 change
boilerplate), cover letter, final fact sheet. Email RPA if
other
changes.
other
check
applicable PERCS staff:
Other Comments to PERCS:
BRD, CPF, CTB, FRB, TAR - Sarah Morrison (807-6310)
'/
CHO, HIW, LUM, LTN, NES, NEW, ROA, YAD - Monti
Hassan (807-6314)
It seems like this facility has 1 non -categorical SIUs and 5 ClUs.
PERCS
Status
PRETREATMENT STAFF COMPLETES THIS PART:
of Pretreatment Program (check all that apply)
1) facility has no SIU's, does have Division approved Pretreatment Program that is INACTIVE
2) facility has no SIUs, does not have Division approved Pretreatment Program
3) facility has SIUs and DWQ approved Pretreatment Program (list "DEV" if program still under development)
V
3a) Full Program with LTMP
3b) Modified Program with STMP
4) additional conditions regarding Pretreatment attached or listed below
Flow, MGD
Permitted
Actual
Time period for Actual
STMP time frame:
Industrial
0 . 13
0, 0 U-
2p I ,;
Most recent:
Uncontrollable
n/a
Next Cycle:
POC in LTMPI
STMP
Parameter of
Concern (POC)
Check List
POC due to
NPDES/ Non-
Disch Permit
Limit
Required by
EPA"
Required
by 503
Sludge**
POC due
to SIU"*"
POTW POC
(Explain
below)****
STMP
Effluent
Freq
LTMP
Effluent
Freq
./
BOD
V
✓
4
Q M
✓
TSS
V
4
Q M
Q = Quarterly
r
NH3
V/
4
Q M
— NrUnIn y
✓
Arsenic
t/
4
Q M
4
Cadmium
V
4
✓
✓
4
Q M
4
Chromium
-4
V
4
Q M
4
Copper
q
✓
✓
4
Q M
✓
Cyanide
✓
4
Q M
Is all data on DMRs?
4
Lead
1/
1I
�
+�
4
Q M
YES
✓
v
Mercury
I.V.
✓
4
Q M
NO (attach data)
v
Molybdenum
✓
4
Q M
4
Nickel
q
I.
✓
4
Q M
U
Silver
✓
4
Q M
N.,..,
Selenium
4
Q M
4
Zinc
d
1/
f
4
Q M
Is data in spreadsheet?
Total Nitrogen
4
Q M
YES (email to writer)
r
Phosphorus��
4
Q M
NO
v
Pk(No, S
✓
4
Q M
4
Q M
4
Q M
4
Q M
*Always in the LTMP/STMP
** Only in LTMP/STMP if sludge and app or composte (dif POCs for incinerators)
**" Only in LTMP/STMP while SIU still discharges to POTW "*** Only in LTMP/STMP when pollutant is still of concern to POTW
Comments to Permit Writer (ex., explanation of any POCs; info you have on IU related investigations into NPDES problems):
Copy of NPDES Pretreatment request form-Lexington.xlsx
Revised. July 24, 2007

2014 AU Number:
AU Name:
AU Length Area:
Yadkin -Pee Dee River Basin
AU Units:
Classification:
_IAU Description:
12-(114)a YADKIN RIVER (including lower portion of High Roc
478.1 FW Acres WS-IV,B
From a line across High Rock lake from the downstream side of mouth of Crane Creek to Second Creek Arm of High
Rock Lake
IRCategory: ACS: Parameter Of Interest:
5 EC Chlorophyll a (40 µg/I, AL, NC)
5 EC pH (9.0, AL, FW)
5 EC Turbidity (25 NTU, AL, FW acres & SW)
5 EC PCB Fish Tissue Advisory (Advisory, FC, NC)
Collection Year: 303(d) yr:
2012 2008
2012 2008
2012 2010
2012 2014
12-(114)bl YADKIN RIVER (including lower portion of High Roc
From Second Creek Arm of High Rock Lake to above the dam
2,627.0 FW Acres WS-IV,B
IRCategory: ACS: Parameter Of Interest: Collection Year: 303(d) yr:
5 EC Chlorophyll a (40 µg/I, AL, NC) 2012 2008
5 EC pH (9.0, AL, FW) 2012 2008
5 EC PCB Fish Tissue Advisory (Advisory, FC, NC) 2012 2014
12-(114)b3 YADKIN RIVER (including lower portion of High Roc
Lower Flat Swamp Creek Arm above railroad bridge
861.0 FW Acres WS-IV,B
IRCategory: ACS: Parameter Of Interest: Collection Year: 303(d) yr:
5 EC Chlorophyll a (40 µg/I, AL, NC) 2012 2008
5 EC PCB Fish Tissue Advisory (Advisory, FC, NC) 2012 2014
12-(114)b2 YADKIN RIVER (including lower portion of High Roc
Lower Abbots Creek Arm Above NC 8
859.0 FW Acres WS-IV,B
IRCategory: ACS: Parameter Of Interest: Collection Year: 303(d) yr:
5 EC Chlorophyll a (40 µg/I, AL, NC) 2012 2008
5 EC PCB Fish Tissue Advisory (Advisory, FC, NC) 2012 2014
12-(124.5)a YADKIN RIVER (including lower portion of High Roc 10.8 FW Acres
From a point 0.6 mile upstream of dam of High Rock Lake to High Rock Dam
WS-IV,B;CA
IRCategory: ACS: Parameter Of Interest:
5
5
EC Chlorophyll a (40 µg/I, AL, NC)
EC PCB Fish Tissue Advisory (Advisory, FC, NC)
Collection Year: 303(d) yr:
2012 2008
2012 2014
12-(124.5)d YADKIN RIVER (including Tuckertown Lake, Badin L
Badin Lake
6,847.0 FW Acres WS-IV,B;CA
IRCategory: ACS: Parameter Of Interest: Collection Year: 303(d) yr:
5 EC PCB Fish Tissue Advisory (Advisory, FC, NC) 2012 2010
2014 NC 303(d) List -Category 5 Final December 19, 2014
Page 146 of 149

IWC Calculations
Facility: Lexington Regional WWTP
NC0055786
Prepared By: Yang Song
Enter Design Flow (MGD):
Enter s7Q10 (cfs):
Enter w7Q10 (cfs):
6.5
6.7
15
Total Residual Chlorine (TRC)
Daily Maximum Limit (ug/I)
s7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (UG/L)
Upstream Bkgd (ug/I)
IWC (%)
Allowable Conc. (ugll)
Fecal Coliform
Monthly Average Limit:
(If DF >331; Monitor)
(If DF<331; Limit)
Dilution Factor (DF)
6.7
6.5
10.075
17.0
0
60.06
28
Ammonia (Summer)
Monthly Average Limit (mg NH3-N/I)
s7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
Upstream Bkgd (mg/I)
IWC (%)
Allowable Conc. (mg/I)
Ammonia (Winter)
Monthly Average Limit (mg NH3-N/I)
w7Q10 (CFS)
2001100ml DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
1.67 Upstream Bkgd (mg/I)
IWC (%)
Allowable Conc. (mg/I)
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/I, Monitor Only
2. Monthly Avg limit x 3 = Weekly Avg limit (Municipals); capped at 35 mg/I
3. Monthly Avg limit x 5 = Daily Max limit (Non-Munis); capped at 35 mg/l
4. BAT for Minor Domestics: 2 mg/I (summer) and 4 mg/I (winter)
5. BAT for Major Municipals: 1 mg/I (year-round)
6.7
6.5
10.075
1.0
0.22
60.06
1.5
15
6.5
10.075
1.8
0.22
40.18
4.2
Fecal Coliform
1. Monthly Avg limit x 2 = 400/100 ml = Weekly Avg limit (Municipals) = Daily Max limit (Non -Muni)
NPDES Server/Current Versions/WLA; TB 1/16/2009

10/7/15 WQS = 12 ng/L
Facility Name Lexington Regional WWTP/ NC0055786
/Permit No. :
MERCURY WQBEL/TBEL EVALUATION V:2013-6
Total Mercury 1631E PQL = 0.5 ng/L 7Q10s =
Date Modifier Data Entry Value Permitted Flow =
1/4/2012
1/18/2012
2/8/2012
2/21/2012
3/7/2012
3/21/2012
4/4/2012
4/18/2012
5/2/2012
5/16/2012
6/5/2012
6/20/2012
7/11/2012
7/25/2012
8/8/2012
8/22/2012
9/4/2012
9/19/2012
10/3/2012
10/17/2012
11/7/2012
11/21/2012
12/5/2012
12/18/2012
1/9/2013
1/23/2013
2/6/2013
<
1
1.7
1.2
1.1
1.2
1
1.6
1
6
1.7
1.1
1
4.1
1.4
1.3
1
1.2
1.1
1.2
1.1
4.2
6.8
5
6.3
3.6
3,7
3.4
No Limit Required
MMP Required
0.5
1.7
1.2
1.1
1.2
0.5
1.6
0.5
6
1.7
1.1
1
4.1
1.4
1.3
0.5
1.2
1.1
1.2
1.1
4.2
6.8
5
6.3
3.6
3.7
3.4
6.700
6.500
cfs
WQBEL =
19.98 ng/L
47 ng/L
2.2 ng/L - Annual Average for 2012

2/20/2013
3/6/2013
3/19/2013
4/3/2013
4/16/2013
5/15/2013
5/29/2013
6/4/2013
6/19/2013
7/2/2013
7/23/2013
8/6/2013
8/20/2013
9/3/2013
9/17/2013
10/1/2013
10/15/2013
11/5/2013
11/20/2013
12/3/2013
12/18/2013
1/7/2014
1/21/2014
2/4/2014
2/18/2014
3/4/2014
3/18/2014
4/8/2014
4/22/2014
5/6/2014
5/20/2014
6/4/2014
6/18/2014
7/9/2014
2.9
3.9
4.5
4.4
5.6
5.3
4.2
6.1
4.1
3.5
1.8
1.4
5.9
3.2
3.3
2.5
3.8
2
1
1.2
6.7
4.4
1.8
1.8
2
1.2
1.7
3.9
1.6
1.1
1.3
6.1
2.6
1
2.9
3.9
4.5
4.4
5.6
5.3
4.2
6.1
4.1
3.5
1.8
1.4
5.9
3.2
3.3
2.5
3.8
2
1
1.2
6.7
4.4
1.8
1.8
2
1.2
1.7
3.9
1.6
1.1
1.3
6.1
2.6
0.5
3.7 ng/L - Annual Average for 2013

7/15/2014
8/5/2014
8/19/2014
9/2/2014
9/16/2014
10/7/2014
10/21/2014
11/4/2014
11/25/2014
12/2/2014
12/16/2014
1/6/2015
1/20/2015
2/3/2015
2/24/2015
3/3/2015
3/17/2015
4/7/2015
4/21/2015
5/6/2015
5/19/2015
6/2/2015
6/23/2015
7/7/2015
7/21/2015
1.5
1.2
3.4
1.6
1.6
2.3
1.3
2
1
1
1
1
1
1.3
1.6
1.8
1
1
2.6
1.4
2.2
1
1
2.29
2.7
1.5
1.2
3.4
1.6
1.6
2.3
1.3
2
1
0.5
0.5
1
1
1.3
1.6
1.8
0.5
0.5
2.6
1.4
2.2
0.5
1
2.29
2.7
2.0 ng/L - Annual Average for 2014
1.5 ng/L - Annual Average for 2015

Lexington Regional WWTP
NC0055786
Qw (MGD) = 6.50
IQ10S(cfs)= 5.57
7QIOS (cfs) = 6.70
7QIOW (cfs) = 15.00
30Q2 (cfs) = 18.00
Avg. Stream Flow, QA (cfs) = 167.00
Receiving Stream: Abbotts Creek
2014 Freshwater RPA - 95% Probability/95% Confidence
MAXIMUM DATA POINTS = 58
WWTP/WTP Class: Class IV
IWC K[ 1Q1OS = 64.397571%
IWC ©7Q1OS = 60.059613%
IWC Qa 7Q IOW = 40.179462%
IWC Q 30Q2 = 35.886020%
IWC @ QA = 5.689680%
Stream Class: WS-V; B
Outfall 001
Qw = 6.5 MGD
PARAMETER
TYPE
(1)
STANDARDS & CRITERIA (2)co
PQL
f-
z
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
NC WQS /
Chronic
Applied
Standard
'/2 FAV /
Acute
ri
Max Pred
# Det. Cw Allowable Cw
Arsenic
Arsenic
C
C
50
10
FW(7QI0s)
HH/WS(Qavg)
ug/L
a JI,
24
24
0
0
5.0
5.0
Acute: NO WQS
_ _ _---- _--
Chronic-- 83.3
N_ o value_> Allowable___C_w _
Chronic: 175.8
No value > Allowable Cw
----------------------------
_ _ _ _ _ _ _ _ _ _ _ _ _ _
All data was less than 10 ug/L.
Cadmium
NC
2
FW(7Q10s)
15
ug/L
58
0
1.0
Acute: 23.3
_ _ _______ ____
Chronic: 3.3
No value > Allowable Cw
_ _ _ _ _ _ _ __ ___________
All data was less than 2 ug/L.
Total Phenolic Compounds
NC
300
A(30Q2)
ua/I.
58
0
2.5
Acute: NO WQS
_ _ _____ _ ___
Chronic: 836.0
No value > Allocable Cw
_ _ _ _ _ _ ______________
All data was less than 5 ug/L.
Chromium
NC
50
FW(7Q10s)
1022
ug/L
32
0
12.0
Acute: 1,587.0
_ _ _____ ____
Chronic: 83.3
No value > Allowable Cw
_ _ _ _ _ _ _ _ ___________
All data was less than 20 ug/L.
Copper(AL)
NC
7
FW(7Q10s)
7.3
ug/L
43
26
135.9
Acute: 11.3
_ _____ ____
Chronic: 11.7
8 value(s) > Allowable CwMonitoring
_ _ _ _ _ _ _ _ _ _ _ _____
RP for AL(Cu,Zn,Ag,Fe,CI) apply Quarterly
in conjunction with TOX Test
Cyanide
NC
5
FW(7Q10s)
22
10
ug/L
26
4
5.0
Acute: 34.2
_ _____ ____
Chronic: 8.3
No value > Allowable Cw
_ _ _ _ _ _ _ _ _ _ _ _ ____
No RP , Predicted Max a 50% of Allowable Cw -
defer to LTMP
Lead
NC
25
FW(7Q10s)
33.8
u0JL
5S
0
11.5
Acute: 52.5
_ _ ----_ _ ---------------------------
Chronic: 41.6
No value > Allowable Cw
-- -
All data was less than 20 ug/L.
Molybdenum
NC
160
WS(7Q10s)
ug/L
24
3
16.6
Acute: NO WQS
Chronic: 266.4
No value > Allowable Cw
No RP, Predicted Max < 50% of Allowable Cw - No
Monitoring required.
Page 1 of 2
9595 FRESHWATER RPA2014 31, rpa
10/28/2015

Lexington Regional WWTP
NC0055786
2014 Freshwater RPA - 95% Probability/95% Confidence
Outfall 001
Qw = 6.5 MGD
Nickel
NC
25 WS(7Q10s) 261
uJL
58 58
In
Acute: 405.3
Chronic:41.6
No value > Allowable Cw
All data was less than 20 ug/L.
Selenium
NC
5 FW(7Q10s) 56
uojl,
58 0
5.0
Acute: 87.0
Chronic: 8.3
No value > Allowable Cw
Except one sample was less than 10 ug/L, all other
samples were less than 5 ug/L.
Silver(AL)
NC
0.06 FW(7QIOs) 1.23
uajl.
28 I
6.820
Acute: 1.910
Chronic: 0.100
28 value(s) > Allowable CwMonitoring
RP for AL(Cu,Zn,Ag,Fe,CI) - apply Quarterly
in conjunction with TOX Test
Zinc (AL)
NC
50 FW(7Q10s) 67
u_ I.
43 43
110.3
Acute: 104.0
Chronic: 83.3
3 value(s) > Allowable Cw
-
RP for AL(Cu,Zn,Ag,Fe,CI)apply Quarterly
Monitoring in conjunction with TOX Test
Chloroform
C
5.6 WS(Qavg)
ug/L
3 2
Note: n < 9
Limited data set
17.40000.
Default C.V.
Acute: NO WQS
_ _ ___ _ _ __
Chronic: 98.42382
No value> Allowable Cw
____________________________
No RP, Predicted Max < 50% of Allowable Cw - No
Monitoring required
Dichlorobromomethane
C
0.55 WS(Qavg)
ug/L
3 3
Note: n < 9
Limited data set
18.00000
Default C.V.
Acute: NO WQS
_ ______ _ __
Chronic: 9.66663
No value> Allowable Cw
_ _ _ _ _ _ _ _ _ _ _ _____
RP for Limited Dataset (n<8 samples) - apply
Quarterly Monitoring
Page 2of2
9595 FRESHWATER RPA2014_31, rpa
10/28/2015

REASONABLE POTENTIAL ANALYSIS
9
Copper (AL)
Date Data BDL=I/2DL Results
1 1/3/2012 12.1 12.1 Std Dev.
2 2/7/2012 < 20 10 Mean
3 3/6/2012 < 20 10 C.V.
4 4/3/2012 < 20 10 n
5 5/1/2012 < 20 10
6 6/5/2012 4.2 4.2 Mult Factor =
7 7/10/2012 8.14 8.14 Max. Value
8 8/7/2012 < 20 10 Max. Pred Cw
9 9/4/2012 < 20 10
10 10/2/2012 5.65 5.65
11 11/6/2012 < 20 10
12 12/4/2012 30.3 30.3
13 1/8/2013 2.86 2.86
14 2/19/2013 4.63 4.63
15 3/5/2013 4.07 4.07
16 4/2/2013 4.9 4.9
17 5/7/2013 5.5 5.5
18 6/4/2013 9.72 9.72
19 7/2/2013 16.6 16.6
20 8/6/2013 20 20
21 9/3/2013 4.3 4.3
22 10/1/2013 16.1 16.1
23 11/5/2013 7 7
24 12/3/2013 4.3 4.3
25 1/7/2014 4.94 4.94
26 2/4/2014 < 20 10
27 3/4/2014 < 20 10
28 4/8/2014 12.2 12.2
29 5/6/2014 5.5 5.5
30 6/3/2014 115.2 115.2
31 7/1/2014 < 20 10
32 8/5/2014 2.42 2.42
33 9/2/2014 47.7 47.7
34 10/7/2014 < 20 10
35 11/4/2014 < 2 1
36 12/2/2014 2.1 2.1
37 1/6/2015 4.3 4.3
38 2/2/2015 < 10 5
39 3/3/2015 < 20 10
40 4/7/2015 < 2 1
41 5/5/2015 < 20 10
42 6/2/2015 < 20 10
43 7/7/2015 3.54 3.54
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Use"PASTE SPECIAL
Values" then "COPY"
. Maximum data
points = 58
10
Cyanide
18.0455
11.7505
1.5357
43
1.18
115.2 ug/L
135.9 ug/L
Date Data BDL=112DL Results
1 Std Dev.
2 2/8/2012 < 5 5 Mean
3 6/5/2012 < 5 5 C.V.
4 7/11/2012 5 5 n
5 10/3/2012 < 5 5
6 1/9/2013 < 5 5 Mult Factor =
7 2/20/2013 < 5 5 Max. Value
8 3/6/2013 < 5 5 Max. Pred Cw
9 4/3/2013 < 5 5
10 5/8/2013 < 5 5
11 6/4/2013 5 5
12 7/3/2013 < 5 5
13 8/6/2013 5 5
14 9/3/2013 < 5 5
15 10/1/2013 < 5 5
16 11/6/2013 < 5 5
17 12/3/2013 5 5
18 1/7/2014 < 5 5
19 8/5/2014 < 5 5
20 11/4/2014 < 5 5
21 1/6/2015 < 5 5
22 1/6/2015 < 5 5
23 2/3/2015 < 5 5
24 4/7/2015 < 5 5
25 4/7/2015 < 5 5
26 7/7/2015 < 5 5
27 7/7/2015 < 5 5
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
Values" then "COPY"
. Maximum data
points = 58
0.0000
5.00
0.0000
26
1.00
5.0 ug/L
5.0 ug/L
9595 FRESHWATER RPA2014_31, data
- 2 - 10/28/2015

REASONABLE POTENTIAL ANALYSIS
14
Molybdenum
Date Data BDL=1/2DL Results
1 1/3/2012 < 10 5 Std Dev.
2 6/5/2012 12 12 Mean
3 7/10/2012 < 10 5 C.V.
4 10/2/2012 < 10 5 n
5 1/8/2013 < 10 5
6 2/19/2013 < 10 5 Mult Factor =
7 3/5/2013 < 10 5 Max. Value
8 4/2/2013 < 10 5 Max. Pred Cw
9 5/7/2013 < 10 5
10 6/4/2013 < 10 5
11 7/2/2013 < 10 5
12 8/6/2013 13.7 13.7
13 9/3/2013 < 10 5
14 10/1/2013 < 10 5
15 11/5/2013 12.9 12.9
16 12/3/2013 < 10 5
17 1/7/2014 < 10 5
18 5/6/2014 < 10 5
19 8/5/2014 < 10 5
20 11/4/2014 < 10 5
21 12/2/2014 < 10 5
22 1/6/2015 < 10 5
23 4/7/2015 < 10 5
24 7/7/2015 < 10 5
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
Values" then "COPY"
. Maximum data
points = 58
17
Silver (AL)
Date Data BDL=1/2DL Results
2.6094 1 1/3/2012 < 5 2.5 Std Dev.
5.9833 2 6/5/2012 < 5 2.5 Mean
0.4461 3 6/12/2012 < 5 2.5 C.V.
24 4 6/19/2012 < 5 2.5 n
5 6/26/2012 < 5 2.5
1.21 6 7/10/2012 6.2 6.2 MuIt Factor =
13.7 ug/L 7 10/2/2012 < 5 2.5 Max. Value
16.6 ug/L 8 1/8/2013 < 5 2.5 Max. Pred Cw
9 2/19/2013 < 5 2.5
10 3/5/2013 < 5 2.5
11 4/2/2013 < 5 2.5
12 5/7/2013 < 5 2.5
13 6/4/2013 < 5 2.5
14 7/2/2013 < 5 2.5
15 8/6/2013 < 5 2.5
16 9/3/2013 < 5 2.5
17 10/1/2013 < 5 2.5
18 11/5/2013 < 5 2.5
19 12/3/2013 < 5 2.5
20 1/7/2014 < 5 2.5
21 5/6/2014 < 5 2.5
22 8/5/2014 < 5 2.5
23 11/4/2014 < 5 2.5
24 12/2/2014 < 5 2.5
25 1/6/2015 < 5 2.5
26 2/2/2015 < 5 2.5
27 4/7/2015 < 5 2.5
28 7/7/2015 < 5 2.5
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
Values' then "COPY"
. Maximum data
points = 68
0.6992
2.6321
0.2657
28
1.10
6.200 uglL
6.820 ug/L
9595 FRESHWATER RPA2014_31, data
- 3 - 10/28/2015

REASONABLE POTENTIAL ANALYSIS
18
Zinc (AL)
Date
Data
1/3/2012
2/7/2012
3/6/2012
4/3/2012
5/1/2012
6/5/2012
7/10/2012
8/7/2012
9/4/2012
10/2/2012
11/6/2012
12/4/2012
1/8/2013
2/19/2013
3/5/2013
4/2/2013
5/7/2013
6/4/2013
7/2/2013
8/6/2013
9/3/2013
10/1/2013
11/5/2013
12/3/2013
1/7/2014
2/4/2014
3/4/2014
4/8/2014
5/6/2014
6/10/2014
7/1/2014
8/5/2014
9/2/2014
10/7/2014
11/4/2014
12/2/2014
1/6/2015
2/2/2015
3/3/2015
4/7/2015
5/5/2015
6/2/2015
7/7/2015
33.4
49.4
26.9
22.7
63.8
55.05
61.59
53.9
49
45.9
48.9
89.7
72.8
80.6
44.8
42.9
37
98.3
80.5
64.6
54
65.5
77.8
58.3
37
66.7
41.7
37
60
45.5
75.4
37.6
59.3
105
57.5
53.9
48.1
48
46.2
40.5
68.4
45.3
30.7
BDL=1/2DL
33.4
49,4
26.9
22.7
63.8
55.05
61.59
53.9
49
45.9
48.9
89.7
72.8
80.6
44.8
42.9
37
98.3
80.5
64.6
54
65.5
77.8
58.3
37
66.7
41.7
37
60
45.5
75.4
37.6
59.3
105
57.5
53.9
48.1
48
46.2
40.5
68.4
45.3
30.7
Results
Std Dev.
Mean
C.V.
n
Mutt Factor =
Max. Value
Max. Pred Cw
Use "PASTE SPECIAL
Values" then "COPY-
. Maximum data
points = 58
19
Chloroform
18.3765
55.3753
0.3319
43
1.05
105.0 ug/L
110.3 ug/L
Date Data
2/8/2011
2/6/2013
2/3/2015 <
5.4
5.8
5
BDL=1/2DL
5.4
5.8
2.5
Results
Std Dev.
Mean
C.V. (default)
n
Use "PASTE SPECIAL
Values" then "COPY"
. Maximum data
points = 58
1.8009
4.5667
0.6000
3
Mult Factor = 3.00
Max. Value 5.800000 ug/L
Max. Pred Cw 17.400000 ug/L
-4-
9595 FRESHWATER RPA2014_31, data
10/28/2015

REASONABLE POTENTIAL ANALYSIS
20
Dichlorobromomethane
Date Data
2/8/2011 6
2/6/2013 5.6
2/3/2015 5.2
BDL=1/2DL Results
6 Std Dev.
5.6 Mean
5.2 C.V. (default)
n
Use "PASTE SPECIAL
Values.' then "COPY"
. Maximum data
points = 58
0.4000
5.6000
0.6000
3
Mull Factor = 3.00
Max. Value 6.000000 ug/L
Max. Pred Cw 18.000000 ug/L
9595 FRESHWATER RPA2014_31, data
- 5 - 10/28/2015

Song, Yang
From: Grzyb, Julie
Sent: Wednesday, October 07, 2015 5:34 PM
To: Behm, Pamela; Ruhlman, Carrie; Templeton, Mike; Song, Yang
Cc: Belnick, Tom
Subject: Re: High Rock Lake WWTPs Instream Monitoring Historical Change
Yes - this concern is much bigger then these three permits. Mike and I have been discussing some sort of
reopener clause as Pam suggests and we'll be pursuing the discussion with upper management (Tom,
Jeff, ...). Certainly, based on the coalition meeting and Jay Z's follow-up letter to the coalitions this is a topic
that needs to be considered.
Yang's original question toMike was just trying to assess if there was any technical or modelling reason to
maintain instream TN and TP sampling in the permit I believe the answer was no. The NCAC 2B 0.0500
rules only address instream monitoring for fecal coliform, DO, conductivity, pH, and temperature for
WWTPs. Guidance signed off through the years allows NPDES to remove fecal coliform if the stream is not
impaired for that parameter and conductivity can be removed if the discharge is 100% domestic
wastewater. The reason TN and TP instream sampling was put in these permits was not documented and I am
not sure if the data was ever used or even reviewed.
I think the reopener clause will be a good first step but what parameters (metals, nutrients, etc.) we actually
add to permits if they leave the coalition is going to have to be clearly spelled out with a justified rationale
and signed off by upper management. Your suggestions and corresponding rationales in this area are
welcome because a uniform justified approach would be best. Mike and I will start by discussing the addition
of the reopener clause with Tom on Monday.
Thanks for the feedback.
Julie
From: Behm, Pamela
Sent: Wednesday, October 7, 2015 4:29 PM
To: Ruhlman, Carrie; Templeton, Mike; Song, Yang
Cc: Grzyb, Julie
Subject: RE: High Rock Lake WWTPs Instream Monitoring Historical Change
Carrie raises a good point. It's not necessarily the monitoring requirements currently written into their permit that we
are concerned with, but the potential to lose the monitoring the coalition is covering. This concern is bigger than just
these permits, this is a concern for all permittees in the coalitions. Usually, the coalitions are monitoring for a lot more
than would be written into permits for u/d monitoring. Might need to develop some blanket language for all coalition
permits that have waived u/d requirements. Something like, "if you leave the coalition, your permit may be reopened
and u/d monitoring requirements may be modified."
From: Ruhlman, Carrie
Sent: Tuesday, October 06, 2015 1:56 PM
To: Behm, Pamela <[e-mail]>; Templeton, Mike <[e-mail]>; Song, Yang
1

<[e-mail]>
Cc: Grzyb, Julie <[e-mail]>
Subject: RE: High Rock Lake WWTPs Instream Monitoring Historical Change
If they drop out of the coalition, and the YPDRBA decides to drop monitoring at the sites ups/dns of their outfalls, would
we be upset about losing that data? This has happened before.
If the answer is no, then I have no issues with dropping those requirements. If the answer is yes, I'd suggest keeping
them in the permit b/c they can easily discontinue their membership with the coalition at any time.
Carrie Ruhlman
NC Division of Water Resources
Phone: [phone]
Carrie.ruhlmanoncdenr.gov
http: / /portal. ncdenr.grg/web/wq / ess/ eco/coalition
Email correspondence to and from this address may be subject to the North Carolina Public Records Law and may be
disclosed to third parties.
Please consider the environment before printing this e-mail.
From: Behm, Pamela
Sent: Tuesday, October 06, 2015 12:18 PM
To: Templeton, Mike <[e-mail]>; Song, Yang <yang.songPncdenr.gov>
Cc: Grzyb, Julie <[e-mail]>; Ruhlman, Carrie <carrie.ruhlman(ancdenr.gov>
Subject: RE: High Rock Lake WWTPs Instream Monitoring Historical Change
With these 3 belonging to the coalition, instream monitoring requirements are waived anyway, correct? I can
understand why the requirements were put in place back in the day, there were some issues with some pretty severe
algae blooms in Abbotts Creek, but all 3 also have phosphorus limits now and we aren't seeing the severity of algae
blooms in this arm. I wonder when is the last time they actually had to collect the data as they've been a member of the
coalition for a while now. Bottom line, the modeling and assessment branch sees no reason to include these
requirements in these permits.
Thanks,
Pam
From: Templeton, Mike
Sent: Tuesday, October 06, 2015 12:02 PM
To: Song, Yang <yang.song(a)ncdenr.gov>
Cc: Grzyb, Julie <[e-mail]>; Ruhlman, Carrie <[e-mail]>; Behm, Pamela
<[e-mail]>
Subject: RE: High Rock Lake WWTPs Instream Monitoring Historical Change
(Carrie and Pam — Please see question below my note to Yang.)
Hi, Yang —
That Abbots Creek monitoring plan is over 25 years old now, so it's no wonder that inconsistencies have crept into the
U/D requirements in these three permits. Still, that's a fairly minor issue. The larger question is whether we still think
the instream data are necessary. This would be a good time to consider that and to update the permits accordingly.
Let's see what Carrie and Pam think about it (see note to them, below), then you and Julie can decide how to proceed.
(I'll be out the rest of the week but will be glad to talk with you next week, if needed.)
If we decide to keep the requirements, then we can improve consistency in the permits. The facilities are members of
the monitoring coalition. The monitoring schedule in the coalition's MOA shows what is currently monitored and how
2

often, and we can align the requirements in the permit with those, if we think it makes sense. (Check with Carrie if you
have questions about the MOA.) Pam can also tell us if she needs specific monitoring to support of the High Rock Lake
nutrient modeling efforts (unlikely at this point) or to gauge the success of the nutrient strategy now under
development.
Good luck. I'll catch up with you next week.
— Mike T
Carrie and Pam — These are the only permits I've seen with instream monitoring requirements for nutrients. The
requirements go *way* back, and we don't know if they are still needed. Given the history of nutrient issues in the lake,
our current efforts and data needs, and the relatively recent formation of the coalition, is there any particular reason to
keep the U/D monitoring in these permits, when we aren't doing the same anywhere else? Thanks for your
thoughts. — MT
From: Song, Yang
Sent: Tuesday, October 06, 2015 10:44 AM
To: Templeton, Mike <[e-mail]>
Cc: Grzyb, Julie <[e-mail]>
Subject: High Rock Lake WWTPs Instream Monitoring Historical Change
Hello Mike,
Upon our discussion on the nutrients instream monitoring requirements for three high rock lake WWTPs (Lexington-
55786; Thomasville-24112; High Point-24228), I reviewed the files for those three permittees and summarized a table
for their instream monitoring requirements historical change. They are all currently involved in Yadkin -Pee Dee River
Basin Association and the instream monitoring is waived.
To answer the question "Why they have special monitoring of nutrients?" — In 1989, the Division established an Abbots
Creek Basin Monitoring Plan for these three facilities.
Another question for Lexington "Why they do depth integrated monitoring for nutrients?" - I am not so sure for this
one...
Just curious, do you prefer me change anything for their nutrients instream monitoring requirements? Is there any
necessary to keep all three permit as consistent?
Thank you so much for your help!
Best regards,
Yang Song
Engineer, NPDES Complex Permitting Unit
NCDWR/Water Quality Programs
919-807-6479
E-mail correspondence to and from this address may be subject to the
North Carolina Public Records Law and may be disclosed to third parties
3

J
MEMORANDUM •
TO: Preston Howard
FROM: Steve Tedder
'Pel(44401- /14:14 Act Ucto
�KlS'�l� GiVlevli bekvis
DIVISION OF WATER QUALITY
September 23,1997
40z,1zz$-1191001,4 Ocshslie
� _ LAIC; -Eon
NC ops578� L .q
,4C OV z 1 I J ?L Th or��soi 11e.
SUBJECT: Nutrient Limits for Major Dischargers to Abbotts Creek Arm of High Rock Lake
As you are aware, the Water Quality Section has been evaluating conditions on High Rock Lake during
development of the management plan for the Yadkin basin. We have determined that conditions on the
Abbotts Creek arm of the lake are unacceptable and that a reduction in phosphorus loading is necessary.
Below is a description of the permitting strategy the section is planning to implement on Abbotts Creek and
a discussion of the reasons for that strategy.
Numerous studies conducted over the past 20 years, as well as ongoing monitoring efforts, have
documentedthe high nutrient loading to High Rock Lake, as well as high levels of in -lake nutrients and
. algal growth. The Abbotts Creek arm of the lake in particular is subject to very high nutrient
concentrations and nuisance algal blooms. It is clear from ambient conditions that the nutrient assimilative
capacity of the Abbotts Creek arm has-been exceeded and that the high nutrient loading is threatening its
. designated uses. The Winston Salem Regional Office has received numerous complaints about this arm of
the lake. Conditions on Abbotts Creek tend to be worse during dry periods, although an extremely dry year
has not occurred since 1988. inuring that year the Abbotts Creek arm experienced persistent bloom
conditions from May through October and numerous chlorophyll a violations, including levels as high as
280 µg/i. Similar conditions occurred in 1996, vvhen chlorophyll levels exceeded 150 }tg/l foir three months
at the Highway 47 ambient station: At the monitoring site near Southmont, chlorophyll a exceeded 65 µg/1
during four months in 1996, reaching a high of 95 µg/1 in August. Violations of the chlorophyll a standard
on, Abbotts Creek occurred as early as March and as late as November.
A significant reduction in the phosphorus load is necessary to minimize the frequency, duration and extent
of nuisance conditions. There are three major wastewater discharges in the watershed: High Point
Westside (6.2 mgd), Lexington (5.5 mgd), Thomasville (4 mgd). Even during high flow periods, when the
nonpoint source nutrient loading hould be greatest, these facilities contribute about 65% of the phosphorus
load to the Abbotts Creek watershed Substantial reductions in the loading from these three facilities is •.
required if we are to improve water quality in this arm of High Rock Lake.
We propose that, beginning with the 2003 permit cycle, each of these three dischargers receive summer
mass TP limits (April -October, 2,Waysj based upon its current permitted flow capacity and a TP
con i ation of 0.5 rig l [mass TP limit in kg = permitted flow in mgd x 0.5 mg/I x unit' conversion factor
ber of days in the summer period]. Eacli faciiity should receive winter limits (November-
c 1 days) based upon its current permitted flow capacity and a TP concentration of 1.0 mg/1. An
increase in permitted wasteflows would be allowable as long as the facilities.can remain under the specified
mass IP limits, although dissolved oxygen concerns and other potential impacts on receiving waters must
also be addressed before any expansion in permitted flow can occur. The specific proposed limits are as
follows:
•

Summer Mass Limits (kg) Winter Mass Limits (kg)
High Point Westside 2568 3624
Lexington ' z 2 9 � " (�11) 3O9; ► 43. ((c )
Thomasville 1712 2416
4'9 10 (�b) 6lic, .
/0 /.
In order to reduce P loading in the shorter term, each of these permittees should be required to conduct an
operation and maintenance assessment in order to identify methods of optimizing phosphorus removal with
existing facilities. Within one year after the beginning of the 1998 permit cycle, each facility should submit
a report to the Division outlining the operational improvements recommended by the assessment and
documenting actions taken.
Additionally, we intend to struligly encourage local governments in the Abbotts Creek watershed to
implement programs to reduce nonpoint source phosphorus loading and to develop strategies for managing
shoreline development. Higher phosphorus allocations to the major dischargers in this' watershed will be
considered only if reductions in nonpoint source nutrient loads are documented and if sufficient water
quality improvements occur.
If you have any questions or concerns please advise.
cc: Harlan Britt
Greg Thorpe
Jim Blose
Don Safrit
Dave Goodrich
Larry Coble
A-C

City of Lexington, NC
Department of Water Resources
October 28, 2013
Mr. Charles Weaver
NCDENR/DWR/Point Source Branch
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject:
NPDES Permit - C0055786
Lexington 'onal WWTP
--Da ' son County
Application for Permit Renewal
Dear Mr. Weaver:
RECEIVED
�, r,.,,;1 r.r EN'R
OCT 3 0 2013
Regional Office
By this letter and attachments, I am requesting renewal of the NPDES permit for the City
of Lexington's Regional WWTP — NC0055786.
Attached are the following: EPA Form 2A — with attachments
Sludge Management Plan: The City disposes of the sludge generated at this facility
through its Compost Facility — WQ0001318.
Please forward comments and questions to my attention at 336-248-3970 or to
RASpachalexingtonnc.gov.
Sincerely
Roger Spach,
Water Resources Superintendent
CC: Rick Comer
Joe Shaffer
Jennifer Carter

FACILITY NAME AND PERMIT NUMBER:
Lexington Regional WWTP, NC0055786
PERMIT ACTION REQUESTED:
renewal
RIVER BASIN:
Yadkin Pee -Dee
SUPPLEMENTAL APPLICATION INFORMATION
PART F.INDUSTRIAL USER DISCHARGES AND RCRAICERCLA WASTES
All treatment works receiving discharges from significant industrial users or which receive RCRA,CERCLA,
complete part F.
GENERAL INFORMATION:
F.1. Pretreatment program. Does the treatment works have, or is subject ot, an approved pretreatment program?
EI Yes ❑ No
F.2. Number of Significant Industrial Users (SIUs) and Categorical Industrial Users (ClUs). Provide the number
industrial users that discharge to the treatment works.
a. Number of non -categorical Sills. 1
or other remedial wastes must
of each of the following types of
questions F.3 through F.8 and
b. Number of Gills. 5
SIGNIFICANT INDUSTRIAL USER INFORMATION:
Supply the following information for each SIU. If more than one SIU discharges to the treatment works, copy
provide the Information requested for each SIU.
EPA Form 3510-2A (Rev. 1-99). Replaces EPA forms 7550-6 & 7550-22. Page 19 of 22

F.3. Significant Industrial User Information. Provide the name and address of each SIU discharging to the treatment works. Submit additional pages
as necessary.
Name: Cardinal Container Services
Mailing Address: P.O. Box 1866
Lexinaton.NC 27292
F.4. Industrial Processes. Describe all the industrial processes that affect or contribute to the SIU's discharge.
Cleans and conditions drums
F.S. Principal Product(s) and Raw Material(s). Describe all of the principal processes and raw materials that affect or contribute to the SIU's
discharge.
Principal product(s): Cleans and conditions drums
Raw material(s): drums and IBC's
F.6. Flow Rate.
a. Process wastewater flow rate. Indicate the average daily volume of process wastewater discharge into the collection system in
gallons per day (gpd) and whether the discharge is continuous or intermittent.
33,000 gpd (X continuous or intermittent)
b. Non -process wastewater flow rate. Indicate the average daily volume of non -process wastewater flow discharged into the collection
system in gallons per day (gpd) and whether the discharge is continuous or intermittent.
4000
gpd (x continuous or _ intermittent)
F.7. Pretreatment Standards. Indicate whether the SIU is subject to the following:
a. Local limits Yes No
b. Categorical pretreatment standards Yes No
If subject to categorical pretreatment standards, which category and subcategory?
F.T. Pretreatment Standards. Indicate whether the SIU is subject to the following:
a. Local limits Yes X No
b. Categorical pretreatment standards X Yes No
If subject to categorical pretreatment standards, which category and subcat— ory? 43
F.3. Significant Industrial User Information. Provide the name and address of each SIU discharging to the treatment works. Submit additional pages
as necessary. .
Name: Matcor Metal Fabrication
Mailing Address: P.O. Box 729
Welcome,NC 27274
F.4. Industrial Processes. Describe all the industrial processes that affect or contribute to the SIU's discharge.
OEM parts for off road heavy equipment
F.S. Principal Product(s) and Raw Material(s). Describe all of the principal processes and raw materials that affect or contribute to the SIU's
discharge.
Principal product(s):Heavy Construction Equipment Welded components and generator enclosures.
Raw material(s): Hot and cold rolled A36 Steel
F.6. Flow Rate.
EPA Form 350-2A (RevInceiiissRgainowareefitanag§511161110Megiverage daily volume of process wastewater discharge into the collection sysRatetao of 22
gallons per day (gpd) and whether the discharge is continuous or intermittent.

F.3. Significant Industrial User Information. Provide the name and address of each SIU discharging to the treatment works. Submit additional pages as
necessary.
Name: Diebold Southeast Manufacturing, Inc.
Mailing Address: 118 Lexington Parkway
Lexington,NC 27272
F.4. Industrial Processes. Describe all the industrial processes that affect or contribute to the SIU's discharge.
Assembles Atm's and products
F.S. Principal Product(s) and Raw Material(s). Describe all of the principal processes and raw materials that affect or contribute to the SIU's discharge.
Principal product(s):Atm's, Safe Deposit Sections, and Under counter cabinets
Raw materiai(s):Prepainted metal and plastic componets
F.6. Flow Rate.
a. Process wastewater flow rate. Indicate the average daily volume of process wastewater discharge into the collection system in gallons
per day (gpd) and whether the discharge is continuous or intermittent.
12,000
gpd (X continuous or intermittent)
b. Non -process wastewater flow rate. Indicate the average daily volume of non -process wastewater flow discharged into the collection
system in gallons per day (gpd) and whether the discharge is continuous or intermittent.
2500
gpd (x continuous or intermittent)
F.7. Pretreatment Standards. Indicate whether the SIU is subject to the following:
a. Local limits Yes X No
b. Categorical pretreatment standards X Yes No
If subject to categorical pretreatment standards, which category and subcategory? 433
F.3. Significant Industrial User Information. Provide the name and address of each SIU discharging to the treatment works. Submit additional pages as
necessary.
Name: Leggett & Platt, Inc. Plant #1
Mailing Address: 3040 Junior Order Horne road
Lexington, NC 27292
F.4. Industrial Processes. Describe all the industrial processes that affect or contribute to the SIU's discharge.
Punch ,shear ,assemble . angle, tubular steel into metal fumiture
F.S. Principal Product(s) and Raw Material(s). Describe all of the principal processes and raw materials that affect or contribute to the SIU's discharge.
Principal product(s): Bed frames.bed rails. rollaway beds
Raw material(s): roll metals, stainless
Flow Rate.
c. Process wastewater flow rate. Indicate the average daily volume of process wastewater discharge into the collection system in gallons
per day (gpd) and whether the discharge is continuous or intermittent.
15,000 gpd (X continuous or intermittent)
d. Non -process wastewater flow rate. Indicate the average daily volume of non -process wastewater flow discharged into the collection
system in gallons per day (gpd) and whether the discharge is continuous or intermittent.
3000
gpd (x continuous or _ intermittent)
F.7. Pretreatment Standards. Indicate whether the SIU is subject to the following:
a. Local limits Yes X No
EPA Form 3510-2A (Rev. 1-99). Replaces EPA forms 7550-6 & 7550-22. Page 21 of 22

b. Categorical pretreatment standards X Yes No // _
If subject to categorical pretreatment standards, which category and subcatego‘? 433
F.3. Significant Industrial User information. Provide the name and address of each SIU discharging to the treatment works. Submit additional pages
as necessary.
Name: Leggett & Platt, Inc. Plant #2
Mailing Address: 161 Proctor Lane
Lexington, NC 27292
F.4. Industrial Processes. Describe all the industrial processes that affect or contribute to the SIU's discharge.
Paint , punch. assemble, weld and pack wood and metal Pedestal beds
F.S. Principal Product(s) and Raw Materlal(s). Describe all of the principal processes and raw materials that affect or contribute to the SIU's
discharge.
Principal product(s): Pedestal beds
Raw material(s): roll metals, stainless and wood
Flow Rate.
e. Process wastewater flow rate. Indicate the average daily volume of process wastewater discharge into the collection system in
gallons per day (gpd) and whether the discharge is continuous or intermittent.
f.
8,000 gpd (X continuous or _ intermittent)
Non -process wastewater flow rate. Indicate the average daily volume of non -process wastewater flow discharged into the collection
system in gallons per day (gpd) and whether the discharge is continuous or intermittent.
300 gpd (x continuous or intermittent)
F.7. Pretreatment Standards. Indicate whether the SIU is subject to the following:
a. Local limits Yes X No
b. Categorical pretreatment standards X Yes No
If subject to categorical pretreatment standards, which category and subcatego
EPA Form 3510-2A (Rev. 1-99). Replaces EPA forms 7550-6 & 7550-22. Page 22 of 22

F.3. Significant Industrial User Information. Provide the name and address of each SIU discharging to the treatment works. Submit additional pages
as necessary.
Name: ASCO Power Technologies
Mailing Address: P.O. Box 689
Welcome,NC 27374
F.4. Industrial Processes. Describe all the industrial processes that affect or contribute to the SIU's discharge.
Manufacture of electrical transfer switches and enclosures
F.S. Principal Product(s) and Raw Material(s). Describe all of the principal processes and raw materials that affect or contribute to the SIU's
discharge.
Principal product(s): Automatic Electrical Transfer Switches and Enclosures
Raw material(s): Carbon Steel, Stainless Steel, Copper Bar, Insulated copper wires
Flow Rate.
9•
Process wastewater flow rate. Indicate the average daily volume of process wastewater discharge into the collection system in
gallons per day (gpd) and whether the discharge is continuous or intermittent.
8,000
gpd (X continuous or _ intermittent)
h. Non -process wastewater flow rate. indicate the average daily volume of non -process wastewater flow discharged into the collection
system in gallons per day (gpd) and whether the discharge is continuous or intermittent.
1000 gpd (x continuous or intermittent)
F.7. Pretreatment Standards. Indicate whether the SIU is subject to the following:
a. Local limits Yes X No
b. Categorical pretreatment standards X Yes No
If subject to categorical pretreatment standards, which category and subcatego
EPA Form 3510-2A (Rev. 1-99). Replaces EPA forms 7550-6 & 7550-22. Page 23 of 22

Compost
WQ0001318
Old digesters
— storage and
supernatent

Old digesters
— storage and
supernatent

Permit #NC0055786
Section B.3. Narrative:
Wastewater Treatment Process
Influent - An average of 2.8 MGD enters the Lexington Regional Wastewater Treatment Plant through a
single outfall that parallels Abbotts Creek.
Preliminary Treatment - Wastewater first goes through a bar screen, then it goes through the plant's
first stage lift station. The lift station consists of 4 submersible pumps and one screw pump. The lift
station presently discharges into a grit separator. A coarse bar screen was initially between the pump
discharge and the grit separator. This was removed when the plant was upgraded in 2005. Within the
next 12 months, plant staff will install a fine screen where the old coarse screen was. After the
wastewater exits the grit separator, it flows through a parshall flume and then flows by gravity to a
second stage lift station which is identical to the first stage.
BNR — Following the second stage lift station, wastewater flows by gravity to the plants BNR system,
This system is presently operated for phosphorous removal only. Nitrogen removal is incidental. Alum
is added as needed to enhance phosphorous removal. The BNR system consists to two identical units
with the influent flow split equally between them.
Final Clarifiers — Wastewater exiting the two final clarifiers is split between two final clarifiers. Return
activated sludge is recycled through the BNR system and a portion of it is wasted into a DAF unit. The
overflow from the DAF unit is returned to the head of the second stage lift station
Polishine - Following the clarifiers, the settled wastewater flows by gravity into two polishing lagoons.
Disinfection - Exiting the lagoons, wastewater enters a chlorine contact tank where it is disinfected with
a concentrated sodium hypochlorite solution. When the wastewater exits the contact tank a sodium
bisulfate solution is added for dechlorination.
Post -aeration — Following the chlorine contact tank the effluent flows through a rectangular weir where
flow is measured and then flows into a post -aeration tank where it is aerated as needed.
Effluent — The effluent is sampled upon leaving the post aeration tank and flows by gravity into Abbotts
Creek. A portion of the effluent is land applied onto 4 acres of trees on the plant site under permit
#WQ0016165.

Sludge Handling
All sludge is wasted from the BNR system into a diffused air flotation unit. Concentrated sludge from
this unit is pumped directly into four old anaerobic digesters. These digesters are presently used to
store and dewater (supernatant) the sludge before it is pumped to the compost facility. Supernatant
from these units is discharged directly to the head of the BNR System.
Concentrated sludge from these units is pumped directly to the plant's compost facility (WQ0001318).
All water removed from the sludge and from rainfall at this facility is contained and gravity flows directly
into the treatment plant's second stage lift station.
Sand is periodically removed from the BNR system and is used in the composting process.
The two polishing lagoons are periodically cleaned. The sludge from this is either pumped directly to the
compost facility or indirectly to the old digesters and then to the compost facility.
Sand (grit) from the plant's grit removal unit is hauled to the compost facility and is incorporated into
the compost process.