NC0081931_Technical Correction_20181023

NPDES DOCUMENT :MCANNIN` COVER SHEET
NPDES Permit:
NC0081931
High Rock Powerhouse
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Technical Correction
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
October 23, 2018
This document is printed on reuse paper - ignore any
content an the re Terse side

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
LINDA CULPEPPER
Interim Director
Mark Gross, OPS
Cube Yadkin Generation LLC
Highway 740
PO Box 575
Badin, North Carolina 28009-0575
NORTH CAROLINA
Environmental Quality
October 23, 2018
Subject: Permit Correction - NPDES NC0081931
High Rock Powerhouse, Class PC-1
3344 Bringle Ferry Road, Denton
Davidson County
Dear Mr. Gross:
The Division of Water Resources (DWR of the Division) has approved your application to renew
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
the Memorandum of Agreement between North Carolina and the U.S. Environmental Protection
Agency dated October 15, 2007 (or as subsequently amended).
Permit Correction: After further review, the Division concludes that influent reservoir stream -
water seepage via structural concrete does not constitute a wastewater generated by the facility.
Therefore, the recently imposed Total Suspended Solids (TSS) monitoring requirement is hereby
discontinued [see revised section A. (4.)].
Concerning Stormwater from Outfall 004 — DWR has decided to retain outfall 004 in this permit,
Per conversations with your consultant and John Hennessy (NPDES)on October 17, 2018.
Therefore, there is no longer need to apply to DEMLR for stormwater coverage for Outfall 004.
Outfall 004's stormwater monitoring continues subject to existing permit conditions. We have
retained stormwater monitoring best management practices (BMPs) reflecting current
requirements, now included in section A. (2.)].
If any parts, measurement frequencies or sampling requirements contained in this permit are
unacceptable, you have the right to an adjudicatory hearing upon written request within thirty
(30) days following receipt of this letter. This request must take 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.
ECC
North Carolina Department of Environmental Quality Division of Water Resources
512 North Salisbury Street 11617 Mail Service Center 1 Raleigh, North Carolina 27699-1617 — 919.707.9000

Mark Gross, OPS
Cube Yadkin Generation LLC
Permit Correction, Page 2
October 23, 2018
Please note that this permit is not transferable except after notice to the Division. The Division
may modify or revoke and reissue this permit. This permit does not affect your legal
requirements to obtain other permits required by the Division of Water Resources, the Division
of Land Resources, the Coastal Area Management Act or any other federal or local government.
If you have questions concerning this permit modification, please contact Joe R. Corporon P.G.
[[e-mail]] or call his new direct line [phone].
Linda Culpepper, Interim b'rector
Division of Water Resources
Enclosure: NPDES Permit Modification NC0081931 (issuance final)
hc: NPDES Program Files
Central Files
ec: DWR/W-SRO, Sherri Knight, SWPS Supervisor
OCU, Maureen Kinney
Keith McCullock [[e-mail]]

Permit NC0081931
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF WATER RESOURCES
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
IDES)
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,
Cube Yadkin Generation LLC
is hereby authorized to discharge wastewater from a facility located at the
High Rock Powerhouse
3344 Bringle Ferry Road, Denton
Davidson County
to receiving waters designated as the Yadkin River in the Yadkin -Pee Dee River Basin in accordance
with effluent limitations, monitoring requirements, and other applicable conditions set forth in Parts I, II,
III and IV hereof.
This permit shall become effective November 1, 2018.
This permit and authorization to discharge shall expire at midnight on January 31, 2019.
Signed this day October 23, 2018.
410 plelf IV/
LA,. .. Culpepper, Interim Direc or
Division of Water Resources
By Authority of the Environmental Management Commission
Page 1 of 7

Permit NC0081931
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.
Cube Yadkin Generation LLC
is hereby authorized to:
1. continue to operate a once -through cooling water servicing High Rock Powerhouse, 3344
Bringle Ferry Road, Denton in Davidson County, and
2. to continue to operate a Stormwater Discharge System, including a stormwater conveyance
system servicing secondary containment for electric transformers, and
3. to operate an oil/water separator installed to treat wastes pumped from a turbine sump generating
lost lubricants [petroleum hydrocarbons] and influent stream -water seepage via structural
concrete walls, and
4. discharge cooling water from said treatment works via Outfalls 001, 002 and 003; discharge
stormwater via Outfall 004; and discharge oil/water-separator wastes via Outfall 005, at locations
specified on the attached map, into the Yadkin River [stream segment 12-(136.3)], a waterbody
currently classified WS-IV; B within subbasin 03-07-08 [HUC: 03040103] of the Yadkin River
Basin.
Page 2 of 7

Permit NC0081931
Part I
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[15A NCAC 02B.0400 et seq., 15A NCAC 02B.0500 et seq.]
During the period beginning on the effective date of the permit and lasting until expiration, the Permittee
is authorized to discharge once -through cooling water from Outfalls 001, 002 and 003. Such
discharges shall be limited, and monitored and reported i by the Permittee as specified below:
DISCHARGE
:LIMITATIONS
Monitoring Requirements
LFFJ UENT
CHARACTE ISTIC
(P METER CODE]
Montll y
i• Average
Dail
Maxunum
Measurement .
Frequency
Sample
Type
Sample
Location -.
Flow (MGD)
00500
Annual
Estimate
Effluent
Temperature 3 (C°)
00010
Annual
Grab
Effluent
pH
(standard units)
00400
Not < 6.0 or > 9.0
Annual
Grab
Effluent
Footnotes:
1. The permittee shall submit discharge monitoring reports (DMRs) electronically using the Division's eDMR
reporting system [see section A. (5.)]. Monitoring results obtained during the calendar year shall be recorded
and reported on the annual Discharge Monitoring Report (DMR) form, and postmarked no later than January
30th following the completed reporting period. Samples obtained for monitoring purposes may be collected
anytime during the calendar year.
2. The Permittee shall sample effluent, prior to mixing with other waters, at a point feasibly closest to
discharge where a representative sample can be obtained.
3. Effluent temperature shall not increase receiving -stream temperature by more than 2.8 °C above natural
ambient conditions. In no case shall facility operations cause the receiving stream temperature to
exceed 32 °C. A representative effluent temperature shall be sampled anywhere downstream of the heat
exchanger.
Conditions:
• The Permittee shall discharge no floating solids or foam visible in other than trace amounts unless
documented ambient river conditions prevent compliance.
• See Biocide Condition A. (3.).
Page 3 of 7

Permit NC0081931
.= (2.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[15A NCAC 02B.0400 et seq., 15A NCAC 02B.0500 et seq.]
During the period beginning on the effective date of the permit and lasting until expiration, the Permittee
is authorized to discharge stormwater from Outfall 004. Such discharges shall be limited and
monitored by the Permittee as specified below:
easux�nnen�
r d;
H
reque icy
SamXe:
Type
�S�ainple
Location
BMPs
Best Management Practices (BMPs) -- The Division authorizes the Permittee to use Best
Management Practices for stormwater discharge from secondary containment around transformers
under the following conditions:
1. Sumps shall be designed with underflow weirs/devices to prevent discharge of oily stormwater.
2. The Permittee shall perform at minimum weekly transformer inspections as routine maintenance
procedures to preventive and detect oil leaks and drips.
3. Inspection of the sump for the presence of oil, as indicated by a visible sheen, shall be
conducted prior to any discharge.
4. For each discharge event, the Permittee shall maintain logs documenting time, date, and volume
of stormwater discharge.
5. All stormwater discharge events shall be reported/included with the annual Discharge
Monitoring Report (DMR).
6. The Permittee shall discharge no floating solids or foam visible in other than trace amounts
unless ambient river conditions prevent compliance.
A. (3.) BIOCIDE CONDITION
[G.S.143-215,143-215.1]
The Permittee shall add no chromium, zinc or copper to the treatment system except as a
DWR pre -approved additive to biocidal compounds.
The permittee shall obtain approval from the Division's Aquatic Toxicology Unit prior to the use of any
biocide (not previously approved by the Division) in the effluent discharged under this permit. The
Permittee shall apply for approval and use of any biocide not previously approved at minimum 90 days
in advance of any planned usage.
For detailed instructions on requesting approval of biocides, contact the Aquatic Toxicology Unit:
NC DENR / DWR / Aquatic Toxicology Unit
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
Page4of7

Permit NC0081931
A. (4.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[15A NCAC 02B.0400 et seq., 15A NCAC 02B.0500 et seq.]
During the period beginning on the effective date of the permit and lasting until expiration, the Permittee
is authorized to discharge from an oil/water separator via Outfall 005. Such discharges shall be limited,
monitored, and reported 1 by the Permittee as specified below:
•�
� L-IIVIITATIONS'
.-
REQUIREMENTS
n
EFFLEUENT
CHARACTERISTIC
(FAR4MKETER CODE)
Monthly
Average
Daily'
Maximum
Measurement-.
Frequency
Sample,
Type._ ,,
,
Sample
Locat oji 2:
Annual
Estimate
Effluent
Flow (MGD)
00500
Oil & Grease
[EPA 1664 SGT HEM]
00010
15.0 mg/L
20.0 mg/L
Annual
Grab
Effluent
pH
[standard units]
00400
Not < 6.0 or > 9.0
Annual
Grab
Effluent
1. The permittee shall submit discharge monitoring reports (DMRs) electronically using the Division's
eDMR reporting system [see section A. (5.)]. Monitoring results obtained during the calendar year shall
be recorded and reported on the annual Discharge Monitoring Report (DMR) form and postmarked no
later than January 30th following the completed reporting period. Samples obtained for monitoring
purposes may be collected anytime during the calendar year.
2. The Permittee shall sample effluent at the point closest to discharge where a representative
sample can feasibly be obtained.
A. (5.) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS
[NCGS 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 11 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
Page 5 of 7

Permit NC0081931
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
electronically using eDMR. The eDMR system allows permitted facilities to enter monitoring data and
submit DMRs electronically using the intemet. 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 DENR / 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, 2020, the permittee must electronically report the following compliance
monitoring data' and reports, when applicable:
• Sewer Overflow/Bypass Event Reports;
• Pretreatment Program Annual Reports; and
• Clean Water Act (CWA) Section 316(b) Annual Reports.
The permittee may seek an electronic reporting waiver from the Division (see "How to Request a Waiver
from Electronic Reporting" section below).
2. Electronic Submissions
In accordance with 40 CFR 122.41(1)(9), the permittee must identify the initial recipient at the time of each
electronic submission. The permittee should use the EPA's website resources to identify the initial recipient
for the electronic submission.
Initial recipient of electronic NPDES information from NPDES-regulated facilities means the entity (EPA or
the state authorized by EPA to implement the NPDES program) that is the designated entity for receiving
electronic NPDES data [see 40 CFR 127.2(b)].
EPA plans to establish a website that will also link to the appropriate electronic reporting tool for each type of
electronic submission and for each state. Instructions on how to access and use the appropriate electronic
reporting tool will be available as well. Information on EPA's NPDES Electronic Reporting Rule is found at:
http://www2.epa.gov/compliance/final-national-pollutant-discharge-elimination-system-npdes-electronic-
reporting-rule.
Page 6 of 7

Permit NC0081931
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:
"I certiAl, 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].
Page 7 of 7