NC0036196_Draft_20240612

ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
RICHARD E. ROGERS, JR.
Director
Mr. Eric Jones
WWTP Superintendent
City of Newton
P.O. Box 550
Newton, North Carolina 28658
Dear Mr. Jones:
NORTH CAROLINA
Environmental Quality
June 11, 2024
Subject: Draft NPDES Permit Modification
Permit NC0036196
Clark Creek WWTP
Catawba County
Grade IV Biological WPCS
SIC Code 4952
The Division of Water Resources staff has reviewed your May 20, 2024 request for modification of the
Clark Creek WWTP's NPDES permit to reevaluate the City's Total Aluminum limitations, as they are
believed to be calculated in error. Review of the existing total aluminum limitations found that an outdated
EPA Nationally Recommended Water Quality Criterion (NRWQC) was used for assessment of need for
total aluminum limitations. As the EPA revised their NRWQC in 2018, the outdated value should not have
been used. The use of the outdated value is considered a "technical mistakes or mistaken interpretations of
law" and is an exception to the antibacksliding rule per 40 CFR 122.44(1)(2)(i)(13)(2). As such, the limits
in the permit have been removed.
To evaluate total aluminum in accordance with the 2018 EPA NRWQC, quarterly monitoring for upstream
pH and DOC has been added to the permit. Total aluminum monitoring is required in the permit at a
quarterly frequency. Monitoring for upstream hardness, pH and DOC and effluent total aluminum shall be
conducted in conjunction with quarterly chronic toxicity testing.
Enclosed with this letter is a copy of the Draft NPDES permit modification for your facility, with revisions
to Section A.(1.) Effluent Limitations and Monitoring Requirements [5.0 MGD] (Pages 3-4) and Section
A.(2.) Effluent Limitations and Monitoring Requirements [7.5 MGD] (Pages 5-6), and an updated cover
page (Page 1). Please review this draft modification carefully to ensure thorough understanding of the
requirements and conditions it contains.
The NPDES standard conditions (Parts II, III, and IV) that are a part of the permit are not included in this
draft document (cover, map, and Part 1). The conditions are the same as in your current permit except that
agency and division names have been updated. The latest version is available at https://bit.ly/3k5NFaL and
can be viewed online or downloaded as a PDF file.
Concurrent with this notification the Division is publishing a notice in a newspaper having circulation in
the general Wake County area, soliciting public comments on this draft permit. Please provide any written
comments you may have to the following: NCDEQ/DWR, NPDES Permitting Branch, 1617 Mail Service
Center, Raleigh, NC 27699-1617 no later than 30 days after receipt of this draft permit.
D E Q�� North Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 1 1611 Mail Service Center I Raleigh, North Carolina 27699-1611
NORTH CAROLINA 919.707.9000
neper .mo F.o. wnual�

Following the 30-day public comment period, the Division will review all pertinent comments and take
appropriate action prior to issuing a final permit. If you have questions concerning this draft permit,
please call me at [phone] or by email at [e-mail].
Sincerely,
DocuSigned by:
7900A4FBFCA14FD...
Nick Coco, PE
NPDES Municipal Permitting Unit
Hardcopy: NPDES Files
Ecopy: US EPA Region 4
DWR/Mooresville Regional Office/Water Quality/Andrew Pitner & Wes Bell
D E Q�� North Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 1 1611 Mail Service Center I Raleigh, North Carolina 27699-1611
NORTH CAROLINA 919.707.90�0
nape .mo EnWronmanW quay

Permit NCO036196
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF WATER RESOURCES
PFR 1ViTT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
In compliance with the provisions of North Carolina General Statute 143-215.1, other lawful standards
and regulations promulgated and adopted by the North Carolina Environmental Management
Commission, and the Federal Water Pollution Control Act, as amended, the
City of Newton
is hereby authorized to discharge wastewater from a facility located at the
Clark Creek Wastewater Treatment Plant
1407 McKay Road
Newton
Catawba County
to receiving waters designated as Clark Creek in the Catawba River Basin
in accordance with the effluent limitations, monitoring requirements, and other applicable conditions
set forth in Parts I, II, III, and IV hereof.
This permit shall become effective..............................................................................................August 1, 2021.
This permit and authorization to discharge shall expire at midnight on ..................................July 31, 2026.
Signed this day ..................... June 4, 2021.
Michael J. Montebello, NPDES Permitting Branch Chief
Division of Water Resources
Page 1 of 13
Modification Effective Date: Month xx, 2024

Permit NCO036196
A.(1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS [5.0 MGD]
[15A NCAC 02B .0400 et seq.,15A NCACO2B .0500 et seq.] Grade IV
Biological Water Pollution Control System [15A NCAC 08G .0302]
a. During the period beginning on the effective date of the permit and lasting until expansion above
5.0 MGD or permit expiration, whichever comes first, the permittee is authorized to discharge
treated wastewater from Outfall 001. Such discharges shall be limited and monitored' by the
permittee as specified below:
PARAMETER
Parameter Code
EFFLUENT LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Weekly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample
LocationZ
Flow 50050
5.0 MGD
Continuous
Recording
I or E
BOD, 5 day, 20°C3 C0310
(April 1- October 31)
15.0 mg/L
22.5 mg/L
Daily
Composite
I and E
BOD, 5 day, 20°C3 C0310
(November 1- March 31)
30.0 mg/L
45.0 mg/L
Daily
Composite
I and E
Total Suspended Solids3 C0530
30.0 mg/L
45.0 mg/L
Daily
Composite
I and E
NH3 as N
(April 1- October 31) C0610
1.6 mg/L
4.8 mg/L
Daily
Composite
E
NH3 as N C0610
(November 1- March 31)
3.8 mg/L
11.4 mg/L
Daily
Composite
E
Fecal Coliform 31616
(geometric mean)
200/100 mL
400/100 mL
Daily
Grab
E
Dissolved Oxygen 00300
Daily Average >_ 5.0 mg/L
Daily
Grab
E
pH 00400
Between 6.0 and 9.0 Standard Units
Daily
Grab
E
Total Residual Chlorine 50060
1 1 28 pg/L
Daily
Grab
E
Temperature, °C 00010
Monitor and Report
Daily
Grab
E
Conductivity, pmhos/cm 00094
Monitor and Report
Daily
Grab
E
Total Nitrogen, mg/L C0600
Monitor and Report
Monthly
Composite
E
Total Phosphorous, mg/L C0665
Monitor and Report
Monthly
Composite
E
Total Aluminum, pg/L5 01105
Monitor and Report
Quarterly
Composite
E
Total Copper 01042
46.0 pg/L
67.1 lag/L
Monthly
Composite
E
Total Hardness [as CaC031, mg/L6 00900
Monitor and Report
Quarterly
Grab
E
Chronic Toxicity? TGP3B
Monitor and Report
Quarterly
Composite
E
Effluent Pollutant Scan8 NC01
Monitor and Report
Footnote 8
Footnote 8
E
Dissolved Oxygen (mg/L) 00300
Monitor and Report
Variablez
Grab
U and D
Temperature °C 00010
Monitor and Report
Variablez
Grab
U and D
Conductivity, pmhos/cm 00094
Monitor and Report
Variablez
Grab
U and D
Fecal Coliform, #/100ml- 31616
Monitor and Report
Variablez
Grab
U and D
pH, s.u.s 00400
Monitor and Report
Quarterly
Grab
U
Dissolved Organic Carbon, mg/L5 00681
Monitor and Report
Quarterly
Grab
U
Total Hardness [as CaC031, mg/L5,9 00900
Monitor and Report
Quarterly
Grab
U
Footnotes:
1. The permittee shall submit Discharge Monitoring Reports electronically using NC DWR's eDMR application system. See Special
Condition A. (6.).
2. Sample locations I -Influent, E-Effluent, U-Upstream at NCSR 2014, D-Downstream at NCSR 2007. Upstream and downstream
samples shall be grab samples collected 3/week during June, July, August, and September and 1/week during the remainder of
the year.
3. The monthly average effluent BOD5 and Total Suspended Solids concentrations shall not exceed 15% of the respective influent
value (85% removal).
(Footnotes continued on next page.)
Page 3 of 13
Michael Montebello, NPDES Branch Chief
Modification Effective Date: Month xx, 2024

Permit NCO036196
Footnotes (continued)_
4. The Division shall consider all effluent total residual chlorine 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 North Carolina certified laboratory
(including field certified), even if these values fall below 50 µg/L.
5. Effluent Total Aluminum and Upstream pH, Dissolved Organic Carbon and Hardness sampling shall be conducted in
conjunction with chronic toxicity testing.
6. Effluent hardness sampling should be performed in conjunction with testing for hardness dependent metals (cadmium, copper,
lead, nickel, silver, and zinc).
7. Chronic Toxicity (Ceriodaphnia dubia) P/F at 56% with testing in March, June, September and December. See Special Condition
A. (3.).
8. The permittee shall perform three effluent pollution scans during the term of this permit. See Special Condition A. (4.).
9. The Permittee shall sample instream hardness, upstream of the facility's discharge. The sample shall be representative of the
hardness in the receiving stream.
b. There shall be no discharge of floating solids or visible foam in other than trace amounts.
Page 4 of 13
Michael Montebello, NPDES Branch Chief
Modification Effective Date: Month xx, 2024

Permit NCO036196
A.(2.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS [7.5 MGD]
[15A NCAC 02B .0400 et seq.,15A NCACO2B .0500 et seq.] Grade IV
Biological Water Pollution Control System [15A NCAC 08G .0302]
a. Beginning upon receipt of the Engineer's Certification for completion of the expansion to 7.5
MGD and lasting until permit expiration, the Permittee is authorized to discharge treated
wastewater from Outfall 001. Such discharges shall be limited and monitored' by the Permittee as
specified below:
PARAMETER
Parameter Code
EFFLUENT LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Weekly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample
LocationZ
Flow 50050
7.5 MGD
Continuous
Recording
I or E
BOD, 5 day, 20°C3 C0310
(March 1- October 31)
15.0 mg/L
22.5 mg/L
Daily
Composite
I and E
BOD, 5 day, 20°C3 C0310
(November 1- February 28/29)
30.0 mg/L
45.0 mg/L
Daily
Composite
I and E
Total Suspended Solids3 C0530
30.0 mg/L
45.0 mg/L
Daily
Composite
I and E
NH3 as N C0610
(March 1- October 31)
1.4 mg/L
4.2 mg/L
Daily
Composite
E
NH3 as N
(November 1- February 28/29) C0610
3.2 mg/L
9.6 mg/L
Daily
Composite
E
Fecal Coliform 31616
(geometric mean)
200/100 mL
400/100 mL
Daily
Grab
E
Dissolved Oxygen 00300
Daily Average >_ 5.0 mg/L
Daily
Grab
E
pH 00400
Between 6.0 and 9.0 Standard Units
Daily
Grab
E
Total Residual Chlorine 50060
1 1 26 lag/L
Daily
Grab
E
Temperature, °C 00010
Monitor and Report
Daily
Grab
E
Conductivity, pmhos/cm 00094
Monitor and Report
Daily
Grab
E
Total Nitrogen, mg/L C0600
Monitor and Report
Monthly
Composite
E
Total Phosphorous, mg/L C0665
Monitor and Report
Monthly
Composite
E
Total Aluminum, lag/L5 01105
Monitor and Report
Quarterly
Composite
E
Total Copper 01042
42.9 lag/L 1 1 63.1 lag/L
Monthly
Composite
E
Total Hardness [as CaC031, mg/L6 00900
Monitor and Report
Quarterly
Grab
E
Chronic Toxicity? TGP38
Monitor and Report
Quarterly
Composite
E
Effluent Pollutant Scan$ NC01
Monitor and Report
Footnote 7
Footnote 7
E
Dissolved Oxygen (mg/L) 00300
Monitor and Report
Variable
Grab
U and D
Temperature °C 00010
Monitor and Report
Variable
Grab
U and D
Conductivity, pmhos/cm 00094
Monitor and Report
Variable
Grab
U and D
Fecal Coliform, #/100mL 31616
Monitor and Report
Variablez
Grab
U and D
pH, s.u.s 00400
Monitor and Report
Quarterly
Grab
U
Dissolved Organic Carbon, mg/L5 00681
Monitor and Report
Quarterly
Grab
U
Total Hardness [as CaC031, mg/L5.9 00900
Monitor and Report
Quarterly
Grab
U
Footnotes:
1. The permittee shall submit Discharge Monitoring Reports electronically using NC DWWs eDMR application system. See Special
Condition A. (6.).
2. Sample locations I -Influent, E-Effluent, U-Upstream at NCSR 2014, D-Downstream at NCSR 2007. Upstream and downstream
samples shall be grab samples collected 3/week during June, July, August, and September and 1/week during the remainder of
the year.
3. The monthly average effluent BOD5 and Total Suspended Solids concentrations shall not exceed 15% of the respective influent
value (85% removal).
(Footnotes continued on next page.)
Page 5 of 13
Michael Montebello, NPDES Branch Chief
Modification Effective Date: Month xx, 2024

Permit NCO036196
Footnotes (continued)_
4. The Division shall consider all effluent total residual chlorine 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 North Carolina certified laboratory
(including field certified), even if these values fall below 50 µg/L.
5. Effluent Total Aluminum and Upstream pH, Dissolved Organic Carbon and Hardness sampling shall be conducted in
conjunction with chronic toxicity testing.
6. Effluent hardness sampling should be performed in conjunction with testing for hardness dependent metals (cadmium, copper,
lead, nickel, silver, and zinc).
7. Chronic Toxicity (Ceriodaphnia dubia) P/F at 66% with testing in March, June, September and December. See Special Condition
A. (3.).
8. The permittee shall perform three effluent pollution scans during the term of this permit. See Special Condition A. (4.).
9. The Permittee shall sample instream hardness, upstream of the facility's discharge. The sample shall be representative of the
hardness in the receiving stream.
b. There shall be no discharge of floating solids or visible foam in other than trace amounts.
A.(3.) CHRONIC TOXICITY PERMIT LIMIT (QUARTERLY)
[15A NCAC 02B.0200]
The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant
mortality to Ceriodaphnia dubia at an effluent concentration of 56% at 5.0 MGD flow and 66% at 7.5
MGD flow.
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
March, June, September and December. These months signify the first month of each three-month
toxicity testing quarter assigned to the facility. Effluent sampling for this testing must be obtained
during representative effluent discharge and shall be performed at the NPDES permitted final effluent
discharge below all treatment processes.
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 electronically using
the Divisions eDMR system for the month 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
1621 Mail Service Center
Raleigh, NC 27699-1621
Or, results can be sent to the email, ATForms.ATB@ncdenr. ov.
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
Page 6 of 13
Michael Montebello, NPDES Branch Chief
Modification Effective Date: Month xx, 2024