NC0036269_Draft_20210810

ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
S. DANIEL SMITH
Director
NORTH CAROLINA
Environmental Quality
August 9, 2021
Mr. Mark Fowler, Facilities Director
Water and Sewer Authority of Cabarrus County
232 Davidson Highway
Concord, North Carolina 28025
Subject:
Dear Mr. Fowler:
2nd Draft NPDES Permit Renewal with
Adding an Intermediate Flow Tier of 30 MGD
Permit NC0036269
Rocky River Regional WWTP
Cabarrus County
Grade IV Biological WPCS
SIC Code 4952
Enclosed with this letter is a copy of the 2nd Draft NPDES permit renewal with adding an intermediate
flow tier of 30 MGD for your facility. Please review this draft carefully to ensure thorough
understanding of the requirements and conditions it contains.
The following changes were made to the first draft permit sent to you on March 23, 2020:
• The permittee submitted a request for an intermediate flow tier of 30 MGD on June 3, 2021.
The effluent limitations page for 30 MGD has been added to the permit [See Section A. (2)].
• The permittee submitted a request to USGS for updated low -flow characteristics for the Rocky
River at the discharge location on March 3, 2020. The updated low -flow characteristics
including 7Q10 have been used to calculate effluent limitations for all the three flow tiers (26.5,
30, and 34 MGD).
• The effluent limit of Total Residual Chlorine at 26.5 MGD has been updated from a daily
maximum of 27 ug/L to 26 ug/L using updated 7Q10 [See Section A. (1)].
• Limits for Ammonia -Nitrogen (NH3-N) have been adjusted for both the 26.5 MGD and the 34
MGD flow tiers. This is based on EPA's 2013 freshwater ammonia criteria and site -specific
effluent and instream characteristics. See Sections A. (1) and A. (3) for updated site -specific
limits. The site -specific ammonia limits have also been applied to the 30 MGD flow tier.
• To provide an opportunity for the permittee to make necessary plant modification in order to
come in compliance with the ammonia limits at 26.5 MGD, a 4-year schedule of compliance
has been added to the permit [See Section A. (7)]. The dates listed in the schedule are projected
completion dates, which may be adjusted per the final effective date of this permit.
• The years for performing the Effluent Pollutant Scans have been updated to 2023, 2024, and
2025 [See Section A. (5)].
• A notation was made concerning the Electronic Reporting Rule — NPDES Electronic
Reporting Rule — Phase 2 Extension. EPA extended the Phase 2 deadline to December 21,
2025. The current compliance date, effective January 4, 2021, was extended as a final
regulation change published in the November 2, 2020 Federal Register [See Section A. (8)].
D_E
NORTH GAF LIMA
prtmentor F,wImemetl quaI>
North Carolina Department of Environmental Quality 1 Division of Water Resources
512 North Salisbury Street 11617 Mail Service Center f Raleigh, North Carolina 27699-1617
919.707.9000

This second draft permit maintains the following significant changes identified in the letter sent
on March 23, 2020:
• Since the previous permit cycle, the facility has triggered the 26.5 MGD permit tier with one
maximum monthly average flow > 21.6 MGD (90% of 24 MGD). The permittee requested the
Division to evaluate the trigger. The Division staff analyzed the most recent 3 -year flow data
from January 2017 to December 2019. The results indicated that the daily average 3-year flow
rate was 19.03 MGD and there were 7 months with a monthly average flow larger than 21.6
MGD during the period. Given that the monthly average flow exceeded 21.6 MGD on several
occasions for the past 3 years, the Division has deleted the 24 MGD effluent sheet from this
permit.
• The limit for TRC has been corrected from Daily Average to Daily Maximum. The TRC limit
changed from 25 µg/L to 24 µg/L at the 34 MGD flow tier based on the updated 7Q10
[See Sections A. (3)].
• The facility reported Arsenic, Cadmium, Lead, Selenium and Silver at less than detection, with
detection levels < 2.5 µg/L, < 2.5 µg/L, < 2.5 µg/L, < 5 µg/L, and < 2.5 µg/L, respectively.
DWR's laboratory identifies the target Practical Quantification Limits (PQLs) for Arsenic as
2.0 µg/L, Cadmium as 0.5 µg/L, Lead as 2.0 µg/L, Selenium as 1.0 µg/L, and Silver as 1 µg/L.
15A NCAC 2B .0505 (e) (4) requires that 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. If no
approved methods are determined capable of achieving detection and reporting levels below
permit discharge requirements, then the approved method with the lowest detection and
reporting level must be used. The facility must use sufficiently sensitive test methods for all
pollutants, including when performing Effluent Pollutant Scans.
• Silver effluent reporting showed all samples at < 2.5 ug/L; however, the allowable discharge
concentration for this facility is 0.097 ug/L. Therefore, a quarterly monitoring requirement
has been added for Silver at all the flow tiers and it is requested that the Permittee use
sufficiently sensitive test methods with a target PQL of 1 ug/L [See Sections A. (1), A. (2),
and A. (3)].
• Based on the reasonable potential analysis (RPA) showing no reasonable potential to violate
state water quality standards, the monitoring requirements for Copper, Zinc and Selenium have
been removed for 26.5 MGD and 34 MGD flow tiers.
• Based on the Mercury TMDL evaluation, no Mercury limit or monitoring requirement is
added to the permit. Because the facility is greater than 2 MGD and discharges quantifiable
levels of mercury (> 1 ng/L), the Mercury Minimization Plan (MMP) requirement shall be
maintained and implement during this permit cycle [See Special Condition A. (6)]. Please
note the results shall be summarized and submitted with the next permit renewal.
• The NC 2007-2014 Water Quality Standard (WQS) Triennial Review was approved by the
NC Environmental Management Committee (EMC) on November 13, 2014. The US EPA
subsequently approved the WQS revisions on April 6, 2016 with some exceptions. The NC
Division of Water Resources NPDES Permitting Unit is required to implement the new
dissolved metal standards in all permits public noticed after April 6, 2016. The new standards
for most metals include acute standards. Further, the freshwater standards for several metals
are expressed as the dissolved form of the metals, and seven metals have hardness -dependent
equations. As a result, the NPDES Permitting Unit will need site -specific effluent hardness
data and instream hardness data, upstream of the discharge, for each facility monitoring these
metals in order to calculate permit limitations. Effluent hardness and instream hardness
sampling, upstream of the discharge, have been added to the permit at a monitoring
frequency of quarterly [See Sections A. (1), A. (2), and A. (3)].
Page 2 of 3

• Some of the wording has changed and an email address for electronic submittal of toxicity
testing results has been added in Special Condition A. (4), Chronic Toxicity Permit Limit.
Please review each paragraph carefully.
• Special Condition A. (5) has been modified to include the specific three years in which the
Effluent Pollutant Scan shall be performed (2023, 2024, 2025), and to allow for electronic
submittal. 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.
• Federal regulations require electronic submittal of all discharge monitoring reports (DMRs)
and program reports. The requirement to continue 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)].
• Parameter codes have been added to the Effluent Limitations and Monitoring Requirements
[See A. (1), A. (2), and A. (3)] and the Effluent Pollutant Scan [See A. (5)].
• Regulatory citations have been added to the permit.
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 I). 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 Cabarrus 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.
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,
by:
M
`— B0B410C9F6204F7...
Min Xiao, PE
NPDES Industrial Permitting Unit
Hardcopy: NPDES Files
Ecopy: US EPA Region 4
DWR/Ecosystems Branch/Mark Vander Borgh
DWR/Aquatic Toxicology Branch/Zachary Thomas, Cindy Moore
DWR/Operator Certification Program/Maureen Kinney
DWR/Mooresville Regional Office/Water Quality/Corey Basinger, Wes Bell
DWR/NPDES Permitting/Municipal Permitting Unit/Keyes McGee
Cabarrus County/Rocky River Regional WWTP/James Sims, Beverly Metcalf
Page 3 of 3

Permit NC0036269
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 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,
Water and Sewer Authority of Cabarrus County
is hereby authorized to discharge wastewater from a facility located at the
Rocky River Regional Wastewater Treatment Plant
6400 Breezy Lane
Concord, NC
Cabarrus County
to receiving waters designated as Rocky River in the Yadkin -Pee Dee River Basin in accordance with effluent
limitations, monitoring requirements, and other conditions set forth in Parts I, II, III and IV hereof.
This permit shall become effective Month XX, 2021.
This permit and authorization to discharge shall expire at midnight on Month XX, 202X.
Signed this day Month XX, 2021.
Draft
S. Daniel Smith, Director
Division of Water Resources
By Authority of the Environmental Management Commission

Permit NC0036269
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby revoked, and as
of this issuance, any previously issued permit bearing this number is no longer effective. Therefore, the exclusive
authority to operate and discharge from this facility arises under the permit conditions, requirements, terms, and
provisions included herein.
The Water and Sewer Authority of Cabarrus County is hereby authorized to:
1. Continue to operate a 26.5 MGD wastewater treatment facility consisting of the following components:
• influent bar screens;
• influent pump station;
• four (4) primary clarifiers;
• grit removal system;
• first stage aeration (pure oxygen);
• four (4) intermediate clarifiers;
• second stage aeration (pure oxygen);
• four (4) final clarifiers;
• chlorine disinfection (sodium hypochlorite);
• pure oxygen generator;
• sludge disposal by pumping to two gravity -flow sludge thickeners;
• sludge conditioning (polymer addition);
• two (2) centrifuges;
• sludge incinerator;
• two (2) sludge -ash settling basins;
• alkalinity addition;
• imported bisolids handling facility
• odor control system;
• RAS automative flow controls;
• plant automation control system;
• one (1) standby power generator;
This facility is located at Rocky River Regional Wastewater Treatment Plant, 6400 Breezy Lane, Concord,
Cabarrus County. Rocky River Regional WWTP is currently rated a Class IV facility.
2. After receiving an Authorization to Construct from the Division to further expand flow, construct the
wastewater treatment facility to 30 MGD; and after submitting to the Division an Engineer's Certification
form documenting that upgrades were completed in accord with this permit and the Authorization to
Construct, then (4).
3. After receiving an Authorization to Construct from the Division to further expand flow, construct the
wastewater treatment facility to 34 MGD; and after submitting to the Division an Engineer's Certification
form documenting that upgrades were completed in accord with this permit and the Authorization to
Construct, then (4).
4. Discharge from said treatment works at the location specified on the attached map into the Rocky River,
which is classified C water in the Yadkin -Pee Dee River Basin.
Page 2of15

Permit NC0036269
Part I
A. (1) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (26.5 MGD)
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.'
Grade IV Biological Water Pollution Control System [15A NCAC 08G .0302]
Beginning on the effective date of this permit and lasting until expiration or expansion to 30 MGD, the Permittee
is authorized to discharge up to 26.5 MGD treated wastewater through Outfall 001. Such discharges shall be
limited and monitored' by the Permittee as specified below:
Effluent Characteristics
Parameter Code
Discharge Limitations
Monitoring Requirements
Monthly
Average
Weekly
Average
Daily
Maximum
Measuremen
t Frequency
Sample
Type
Sample
Location'
Flow 50050
26.5 MGD
Continuous
Recording
I or E
CBOD5 (20°C)3 [Summer]
(April 1 —October 31) 80082
15.4 mg/L
23.1 mg/L
Daily
Composite
I and E
CBOD5 (20°C)3 [Winter]
(November 1 — March 31) 80082
22.6 mg/L
33.9 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 [Summer] 4
(April 1 —October 31) C0610
1.7 mg/L
4.2 mg/L
Daily
Composite
E
NH3 as N [Winter] 4
(April 1 —October 31) C0610
3.9 mg/L
9.8 mg/L
Daily
Composite
E
Dissolved Oxygen 00300
Daily Average not less than 6.0 mg/L
Daily
Grab
E
Fecal Coliform
(geometric mean) 31616
200/100m1
400/100m1
Daily
Grab
E
Total Residual Chlorines 50060
26 µg/L
Daily
Grab
E
Total Nitrogen6 C0600
Monthly
Composite
E
Total Phosphorus C0665
Monthly
Composite
E
Chronic Toxicity' TGP3B
Quarterly
Composite
E
Temperature (°C) 00010
Daily
Grab
E
pH 00400
Between 6 0 and 9.0 standard units
Daily
Grab
E
Total Silver 01077
Quarterly
Composite
E
Effluent Pollutant Scan NC01
Monitor and report
Footnote 8
E
Dissolved Oxygen (mg/L) 00300
Variable'
Grab
U and D
Temperature (°C) 00010
Variable'
Grab
U and D
Conductivity (µmhos/cm) 00094
Variable'
Grab
U and D
Fecal Coliform
(geometric mean) 31616
Variable'
Grab
U and D
Total Hardness [as CaCO3] 00900
(mg/L)9
Quarterly
Composite
E
(Totgal )la�rdness [as CaCO3] 00900
Quarterly
Grab
U
Influent Pump Station Flow"
Footnote 11
I
See footnotes on next page
Page 3 of 15

Permit NC0036269
Footnotes:
1. The permittee shall submit discharge monitoring reports electronically using the NC DWR's eDMR application
system [see A. (8)].
2. Sample locations: I — Influent; E — Effluent; U — Upstream at NCSR 1132; Di — Downstream at U.S. Highway 601;
D2 - Downstream at NCSR 1006. Instream samples shall be grab samples collected 3/Week during the months of
June, July, August, and September and Weekly during the months of April, May, and October only. Instream
monitoring for DO, temperature, conductivity, and fecal coliform is provisionally waived in light of the permittee's
participation in the Yadkin -Pee Dee River Basin Association. Instream monitoring will be immediately reinstated
and the Division shall be notified immediately should the permittee end its participation in the Association.
3. The monthly average effluent CBOD5 and Total Suspended Solids concentrations shall not exceed 15% of the
respective influent value (85% removal).
4. An 4-year schedule of compliance has been added to the permit [See A. (7) Schedule of Compliance for Ammonia -
Nitrogen at 26.5 MGD].
5. The limit and monitoring requirements only apply when the effluent is chlorinated. 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 North Carolina certified laboratory (including field certified),
even if these values fall below 50 µg/L.
6. TN = TKN + NO3-N + NO2-N where TN is Total Nitrogen, TKN is Total Kjeldahl Nitrogen, and NO3-N + NO2-N
are Nitrate and Nitrite Nitrogen, respectively.
7. Chronic Toxicity (Ceriodaphnia) at 66.5% with testing in February, May, August, and November [see A. (4)].
8. The permittee shall perform three effluent pollutant scans during the term of this permit [See A. (5)].
9. Effluent hardness sampling should be performed in conjunction with testing for hardness dependent metals
(cadmium, copper, lead, nickel, silver, and zinc).
10. The Permittee shall sample instream hardness, upstream of the facility's discharge. The sample shall be
representative of the hardness in the receiving stream. The Permittee is responsible for submitting instream hardness
test results with its permit renewal application package.
11. Additional Influent Pump Station/Flow Monitoring Requirements at 26.5 MGD:
a. Flow monitoring for the two influent pump stations (Lower Rocky River and Main) including peak hourly
flow, and daily flow. Monitoring shall also include pump run times, both for individual pumps and pumps
running in combination, in order to establish the number of pumps required to run for peak flow events.
Records shall be maintained for 10 years and made available to the Division upon request.
b. Annual reporting for each influent pump station outlining all wet weather events where all pumps were
required to run to handle peak flows. This annual report shall be submitted to the Mooresville Regional
Office along with rainfall amounts specific to the wet weather flow event. This report does not supersede
any other reporting requirements. The report shall also indicate whether any reportable overflows occurred
at either pump station.
c. Flow monitoring of individual jurisdictional bulk customers (i.e., local government units) that are tributary
to the WSACC system. Records shall be maintained for 10 years and made available to the Division upon
request. Basins with the highest peak flows compared to average daily flow shall be discussed with the
local government unit and the WSACC Board with respect to targeted sewer rehabilitation in those specific
individual drainage basins.
There shall be no discharge of floating solids or visible foam in other than trace amounts.
Page 4 of 15

Permit NC0036269
A. (2) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (30.0 MGD)
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
Grade IV Biological Water Pollution Control System [15A NCAC 08G .0302]
Beginning on the effective date of this permit and lasting until expiration or expansion to 34 MGD, the Permittee
is authorized to discharge up to 30 MGD treated wastewater through Outfall 001. Such discharges shall be
limited and monitored' by the Permittee as specified below:
Effluent Characteristics
Parameter Code
Discharge Limitations
Monitoring Requirements
Monthly
Average
Weekly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample
Location2
Flow 50050
30.0 MGD
Continuous
Recording
I or E
CBOD5 (20°C)3 [Summer]
(April 1 —October 31) 80082
10.0 mg/L
25.0 mg/L
Daily
Composite
I and E
CBOD5 (20°C)3 [Winter]
(November 1 — March 31) 80082
20.0 mg/L
35.0 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 [Summer]
1.6 mg/L
4.1 mg/L
Daily
Composite
E
(April 1 —October 31) C0610
NH3 as N [Winter]
(April 1 —October 31) C0610
3.7 mg/L
9.3 mg/L
Daily
Composite
E
Dissolved Oxygen 00300
Daily Average not less than 6.0 mg/L
Daily
Grab
E
Fecal Coliform
(geometric mean) 31616
200/100m1
400/100m1
Daily
Grab
E
Total Residual Chlorine' 50060
25 µg/L
Daily
Grab
E
Total Nitrogen5 C0600
Monthly
Composite
E
Total Phosphorus C0665
Monthly
Composite
E
Chronic Toxicity6 TGP3B
Quarterly
Composite
E
Temperature (°C) 00010
Daily
Grab
E
pH 00400
Between 6 0 and 9.0 standard units
Daily
Grab
E
Total Silver 01077
Quarterly
Composite
E
Effluent Pollutant Scan NC01
Monitor and report
Footnote 7
E
Dissolved Oxygen (mg/L) 00300
Variable2
Grab
U and D
Temperature (°C) 00010
Variable2
Grab
U and D
Conductivity (µmhos/cm) 00094
Variable2
Grab
U and D
Fecal Coliform
(geometric mean) 31616
Variable2
Grab
U and D
Total Hardness [as CaCO3] 00900
(mg/L)8
Quarterly
Composite
E
T(rotgal )a Hardness [as CaCO3] 00900
Quarterly
Grab
U
Influent Pump Station Flow10
Footnote 10
I
See footnotes on next page
Page 5 of 15

Permit NC0036269
Footnotes:
1. The permittee shall submit discharge monitoring reports electronically using the NC DWR's eDMR application
system [see A. (8)].
2. Sample locations: I — Influent; E — Effluent; U — Upstream at NCSR 1132; Di — Downstream at U.S. Highway 601;
D2 - Downstream at NCSR 1006. Instream samples shall be grab samples collected 3/Week during the months of
June, July, August, and September and Weekly during the months of April, May, and October only. Instream
monitoring for DO, temperature, conductivity, and fecal coliform is provisionally waived in light of the permittee's
participation in the Yadkin -Pee Dee River Basin Association. Instream monitoring will be immediately reinstated
and the Division shall be notified immediately should the permittee end its participation in the Association.
3. The monthly average effluent CBOD5 and Total Suspended Solids concentrations shall not exceed 15% of the
respective influent value (85% removal).
4. The limit and monitoring requirements only apply when the effluent is chlorinated. 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 North Carolina certified laboratory (including field certified),
even if these values fall below 50 µg/L.
5. TN = TKN + NO3-N + NO2-N where TN is Total Nitrogen, TKN is Total Kjeldahl Nitrogen, and NO3-N + NO2-N
are Nitrate and Nitrite Nitrogen, respectively.
6. Chronic Toxicity (Ceriodaphnia) at 69% with testing in February, May, August, and November [see A. (4)].
7. The permittee shall perform three effluent pollutant scans during the term of this permit [See A. (5)].
8. Effluent hardness sampling should be performed in conjunction with testing for hardness dependent metals
(cadmium, copper, lead, nickel, silver, and zinc).
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. The Permittee is responsible for submitting instream hardness
test results with its permit renewal application package.
10. Additional Influent Pump Station/Flow Monitoring Requirements at 30 MGD:
d. Flow monitoring for the two influent pump stations (Lower Rocky River and Main) including peak hourly
flow, and daily flow. Monitoring shall also include pump run times, both for individual pumps and pumps
running in combination, in order to establish the number of pumps required to run for peak flow events.
Records shall be maintained for 10 years and made available to the Division upon request.
e. Annual reporting for each influent pump station outlining all wet weather events where all pumps were
required to run to handle peak flows. This annual report shall be submitted to the Mooresville Regional
Office along with rainfall amounts specific to the wet weather flow event. This report does not supersede
any other reporting requirements. The report shall also indicate whether any reportable overflows occurred
at either pump station.
f. Flow monitoring of individual jurisdictional bulk customers (i.e., local government units) that are tributary
to the WSACC system. Records shall be maintained for 10 years and made available to the Division upon
request. Basins with the highest peak flows compared to average daily flow shall be discussed with the
local government unit and the WSACC Board with respect to targeted sewer rehabilitation in those specific
individual drainage basins.
There shall be no discharge of floating solids or visible foam in other than trace amounts.
Page 6 of 15

Permit NC0036269
A. (3) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (34.0 MGD)
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
Grade IV Biological Water Pollution Control System [15A NCAC 08G .0302]
Beginning with the receipt of an Engineer's Certification of Completion for expansion to 34 MGD, and lasting
until permit expiration, the Permittee is authorized to discharge from Outfall 001. Such discharges shall be
limited and monitored' by the Permittee as specified below:
Effluent Characteristics
Parameter Code
Discharge Limitations
Monitoring Requirements
Monthly
Average
Weekly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample
Location'
Flow 50050
34.0 MGD
Continuous
Recording
I or E
CBOD5 (20°C)3 [Summer]
(April 1 —October 31) 80082
10.0 mg/L
25.0 mg/L
Daily
Composite
I and E
CBOD5 (20°C)3 [Winter]
(November 1 — March 31) 80082
20.0 mg/L
35.0 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 [Summer]
1.6 mg/L
4.0 mg/L
Daily
Composite
E
(April 1 —October 31) C0610
NH3 as N [Winter]
(April 1 —October 31) C0610
3.5 mg/L
8.8 mg/L
Daily
Composite
E
Dissolved Oxygen 00300
Daily Average not less than 6.0 mg/L
Daily
Grab
E
Fecal Coliform
(geometric mean) 31616
200/100m1
400/100m1
Daily
Grab
E
Total Residual Chlorine' 50060
24 µg/L
Daily
Grab
E
Total Nitrogen5 C0600
Monthly
Composite
E
Total Phosphorus C0665
Monthly
Composite
E
Chronic Toxicity6 TGP3B
Quarterly
Composite
E
Temperature (°C) 00010
Daily
Grab
E
pH 00400
Between 6 0 and 9.0 standard units
Daily
Grab
E
Total Silver 01077
Quarterly
Composite
E
Effluent Pollutant Scan NC01
Monitor and report
Footnote 7
E
Dissolved Oxygen (mg/L) 00300
Variable2
Grab
U and D
Temperature (°C) 00010
Variable2
Grab
U and D
Conductivity (µmhos/cm) 00094
Variable2
Grab
U and D
Fecal Coliform
(geometric mean) 31616
Variable2
Grab
U and D
Total Hardness [as CaCO3] 00900
(mg/L)8
Quarterly
Composite
E
T(Totgal )a Hardness [as CaCO3] 00900
Quarterly
Grab
U
See footnotes on next page
Page 7 of 15

Permit NC0036269
Footnotes:
1. The permittee shall submit discharge monitoring reports electronically using the NC DWR's eDMR application
system [see A. (8)].
2. Sample locations: I — Influent; E — Effluent; U — Upstream at NCSR 1132; Di — Downstream at U.S. Highway 601;
D2 - Downstream at NCSR 1006. Instream samples shall be grab samples collected 3/Week during the months of
June, July, August, and September and Weekly during the months of April, May, and October only. Instream
monitoring for DO, temperature, conductivity, and fecal coliform is provisionally waived in light of the permittee's
participation in the Yadkin -Pee Dee River Basin Association. Instream monitoring will be immediately reinstated
and the Division shall be notified immediately should the permittee end its participation in the Association.
3. The monthly average effluent CBOD5 and Total Suspended Solids concentrations shall not exceed 15% of the
respective influent value (85% removal).
4. The limit and monitoring requirements only apply when the effluent is chlorinated. 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 North Carolina certified laboratory (including field certified),
even if these values fall below 50 µg/L.
5. TN = TKN + NO3-N + NO2-N where TN is Total Nitrogen, TKN is Total Kjeldahl Nitrogen, and NO3-N + NO2-N
are Nitrate and Nitrite Nitrogen, respectively.
6. Chronic Toxicity (Ceriodaphnia) at 71.8% with testing in February, May, August, and November [see A. (4)].
7. The permittee shall perform three effluent pollutant scans during the term of this permit [See A. (5)].
8. Effluent hardness sampling should be performed in conjunction with testing for hardness dependent metals
(cadmium, copper, lead, nickel, silver, and zinc).
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. The Permittee is responsible for submitting instream hardness
test results with its permit renewal application package.
There shall be no discharge of floating solids or visible foam in other than trace amounts.
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Permit NC0036269
A. (4) 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 66.5% at 26.5 MGD, 69% at 30.0 MGD, and 71.8% at 34.0
MGD.
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:
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, [e-mail].
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 there be no discharge of flow from the facility during a month in which toxicity monitoring is required, the
permittee will complete the information located at the top of the aquatic toxicity (AT) test form indicating the
facility name, permit number, pipe number, county, and the month/year of the report with the notation of "No
Flow" in the comment area of the form. The report shall be submitted to the Water Sciences Section at the address
cited above.
Should the permittee fail to monitor during a month in which toxicity monitoring is required, 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.
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Permit NC0036269
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: 2023, 2024, and 2025. 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 (Method 1631E)
Nickel
Selenium
Silver
Thallium
Zinc
Cyanide
Total phenolic compounds
Volatile organic compounds:
Acrolein
Acrylonitrile
Benzene
Bromoform
Carbon tetrachloride
Chlorobenzene
Chlorodibromomethane
Chloroethane
2-chloroethyl vinyl ether
Chloroform
Dichlorobromomethane
1,1-dichloroethane
1,2-dichloroethane
C0610
50060
00300
00630
00625
00556
C0665
70295
00900
01097
01002
01012
01027
C0034
01042
01051
COMER
01067
01147
01077
01059
01092
00720
32730
34210
34215
34030
32104
32102
34301
34306
85811
34576
32106
32101
34496
32103
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-trichloroethane
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
34546
34501
C0541
77163
34371
34413
34418
34423
81549
34475
34010
34506
34511
39180
39175
34452
34586
34601
34606
34657
34616
34591
34646
39032
34694
34621
34205
34200
CO220
39120
C0526
34247
34230
34521
34242
34278
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-tichlorobenzene
34273
34283
C0100
34636
34292
34581
34641
34320
39110
34596
34556
34536
34566
34571
34631
34336
34341
34611
C0626
34346
C0376
34381
C0700
C0702
34386
34396
34403
34408
34696
34447
34428
34438
34433
34461
34469
C0551
Reporting. Test results shall be reported electronically using the Division's eDMR system or on DWR Form
DMR-PPA-1(or on a form approved by the Director) by December 31" of each designated sampling year. The
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Permit NC0036269
Permittee must at least report completion of the test in the eDMR system by entering "1" or "Y" for parameter code
NC01 - Annual Pollutant Scan. If utilizing the DWR Form submit to the following address:
NC DEQ / DWR / NPDES Files, 1617 Mail Service Center, Raleigh, North Carolina 27699-1617.
Or the form may be uploaded at: https://edocs.deq.nc.gov/Forms/NPDES_WW-EDMR-Supplemental-Form
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
Or, results can be sent to the email: [e-mail].
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) MERCURY MINIMIZATION PLAN
[G.S. 143-215.1(b)]
The Permittee shall maintain and implement a Mercury Minimization Plan (MMP) during this permit term. The
MMP shall be available for inspection on -site. Results 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. (7) SCHEDULE OF COMPLIANCE FOR AMMONIA -NITROGEN AT 26.5 MGD
[G.S. 143-215.1(b)]
1. By October 31, 2021, the Permittee shall complete pilot study of Nitrification Enhanced Facility,
30% design, and have selected the design -builder for these improvements. A report summarizing
the results of the pilot study and a Preliminary Engineering Report shall be submitted for review.
2. By May 31, 2022, the Permittee shall complete 90% design and submit a progress report for
review.
3. By August 31, 2022, the Permittee shall complete 100% design and submit a progress report and an
application for Authorization to Construct for plant modification.
4. By December 31, 2022, the Permittee shall send out Notice to Proceed and commence construction.
A progress report shall be submitted for review.
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Permit NC0036269
5. By December 31, 2023, and December 31, 2024, the Permittee shall submit annual progress reports
summarizing the status of the construction and identify the percentage of construction completed.
6. By October 31, 2025, achieve compliance with ammonia limits specified in Section A. (1).
A. (8) ELECTRONIC REPORTING OF MONITORING REPORTS
[G.S. 143-215.1(b)]
Federal regulations require electronic submittal of all discharge monitoring reports (DMRs) and program reports.
The final NPDES Electronic Reporting Rule was adopted and became effective on December 21, 2015.
NOTE: This special condition supplements or supersedes the following sections within Part II of this permit
(Standard Conditions for NPDES Permits):
• Section B. (11.) Signatory Requirements
• Section D. (2.) Reporting
• Section D. (6.) Records Retention
• Section E. (5.) Monitoring Reports
1. Reporting Requirements [Supersedes Section D. (2.) and Section E. (5.) (a)1
The permittee shall report discharge monitoring data electronically using the NC DWR's Electronic Discharge
Monitoring Report (eDMR) internet application.
Monitoring results obtained during the previous month(s) shall be summarized for each month and submitted
monthly electronically using eDMR. The eDMR system allows permitted facilities to enter monitoring data
and submit DMRs electronically using the internet. Until such time that the state's eDMR application is
compliant with EPA's Cross -Media Electronic Reporting Regulation (CROMERR), permittees will be required
to submit all discharge monitoring data to the state electronically using eDMR and will be required to complete
the eDMR submission by printing, signing, and submitting one signed original and a copy of the computer
printed eDMR to the following address:
NC DEQ / Division of Water Resources / Water Quality Permitting Section
ATTENTION: Central Files
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
If a permittee is unable to use the eDMR system due to a demonstrated hardship or due to the facility being
physically located in an area where less than 10 percent of the households have broadband access, then a
temporary waiver from the NPDES electronic reporting requirements may be granted and discharge monitoring
data may be submitted on paper DMR forms (MR 1, 1.1, 2, 3) or alternative forms approved by the Director.
Duplicate signed copies shall be submitted to the mailing address above. See "How to Request a Waiver from
Electronic Reporting" section below.
Regardless of the submission method, the first DMR is due on the last day of the month following the issuance
of the permit or in the case of a new facility, on the last day of the month following the commencement of
discharge.
Starting on December 21, 2025, the permittee must electronically report the following compliance monitoring
data and reports, when applicable:
• Sewer Overflow/Bypass Event Reports;
• Pretreatment Program Annual Reports; and
• Clean Water Act (CWA) Section 316(b) Annual Reports.
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Permit NC0036269
The permittee may seek an electronic reporting waiver from the Division (see "How to Request a Waiver from
Electronic Reporting" section below).
2. Electronic Submissions
In accordance with 40 CFR 122.41(1)(9), the permittee must identify the initial recipient at the time of each
electronic submission. The permittee should use the EPA's website resources to identify the initial recipient for
the electronic submission.
Initial recipient of electronic NPDES information from NPDES-regulated facilities means the entity (EPA or
the state authorized by EPA to implement the NPDES program) that is the designated entity for receiving
electronic NPDES data [see 40 CFR 127.2(b)].
EPA plans to establish a website that will also link to the appropriate electronic reporting tool for each type of
electronic submission and for each state. Instructions on how to access and use the appropriate electronic
reporting tool will be available as well. Information on EPA's NPDES Electronic Reporting Rule is found at:
https: //www. federalregi ster. gov/documents/2015/ 10/22/2015-24954/national-pollutant-di scharge-elimination-
system-npdes-electronic-reporting-rule.
Electronic submissions must start by the dates listed in the "Reporting Requirements" section above.
3. How to Request a Waiver from Electronic Reporting
The permittee may seek a temporary electronic reporting waiver from the Division. To obtain an electronic
reporting waiver, a permittee must first submit an electronic reporting waiver request to the Division. Requests
for temporary electronic reporting waivers must be submitted in writing to the Division for written approval at
least sixty (60) days prior to the date the facility would be required under this permit to begin submitting
monitoring data and reports. The duration of a temporary waiver shall not exceed 5 years and shall thereupon
expire. At such time, monitoring data and reports shall be submitted electronically to the Division unless the
permittee re -applies for and is granted a new temporary electronic reporting waiver by the Division. Approved
electronic reporting waivers are not transferrable. Only permittees with an approved reporting waiver request
may submit monitoring data and reports on paper to the Division for the period that the approved reporting
waiver request is effective.
Information on eDMR and the application for a temporary electronic reporting waiver are found on the
following web page:
http://deq.nc.gov/about/divisions/water-resources/edmr
4. 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://deq.nc.gov/about/divisions/water-resources/edmr
Certification. Any person submitting an electronic DMR using the state's eDMR system shall make the
following certification [40 CFR 122.22]. NO OTHER STATEMENTS OF CERTIFICATION WILL BE
ACCEPTED:
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Permit NC0036269
"1 cert, under penalty of law, that this document and all attachments were prepared under my direction or
supervision in accordance with a system designed to assure that qualified personnel properly gather and
evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or
those persons directly responsible for gathering the information, the information submitted is, to the best of my
knowledge and belief true, accurate, and complete. I am aware that there are significant penalties for
submitting false information, including the possibility of fines and imprisonment for knowing violations."
5. 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].
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Permit NC0036269
Downstream (1)
Monitoring Point
Rocky River Regional WWTP — NC0036269
Water and Sewer Authority of Cabarrus County
Receiving Stream: Rocky River Stream Class: C
Drainage Basin: Yadkin -Pee Dee River Basin Sub -Basin: 03-07-12
Permitted Flow: 26.5, 30 and 34 MGD HUC: 03040105
State Grid/USGS Quad: F16SE / Concord SE, N.C.
Facility Location (Not to scale)
N
x
Latitude 35° 19' 35" N Longitude: 80° 32' 12" W
Page 15of15