NC0081931_Draft Permit_20180711

ROY COOPER
Governor
N
I:Y
MICHAEL S. RAGAN
Secretary
'" LINDA CULPEPPER
Water Resources Interim Duector
ENVIRONMENTAL QUALITY
July 11, 2018
Mark Gross, OPS
Cube Yadkin Generation LLC
Highway 740
PO Box 575
Badin,North Carolina 28009-0575
Subject: NPDES Permit Modification-DRAFT Review
Permit NC0081931
High Rock Powerhouse, Class PC-1
3344 Bringle Ferry Road, Denton
' Davidson County
Dear Mr. Gross:
Based on your request to modify the subject permit,the Division of Water Resources (DWR)
hereby transmits this draft for your review and comment. Please review it carefully to ensure
your understanding of the limits and monitoring conditions, and to correct errors, if any.
Concurrent with this notification, the Division will solicit public comment on this draft by
publishing a notice in newspapers having circulation in the general Davidson County area, as
required by the NPDES Program. Please provide your written comments, if any, to DENR/
DWR/NPDES Program no later July 31,2018 (approximately 30 days after receiving this
document).
Modification for Proposed Outfall 005—We have updated your facility description(see
Supplement to the Permit Cover Sheet). Per your request, we have added Outfall 005 for
discharge from an oil/water separator. However, we note that your application does not specify
the processes upstream of this device, nor doe's it document discharge parameters of concern
(POCs) that may require monitoring at this outfall. Please provide. This draft proposes limits and
monitoring conditions consistent only with similar facilities statewide.
Concerning Stormwater-Future Permitting for Outfall 004—DWR is currently transferring
stormwater permitting statewide, to be newly regulated by the Division of Energy, Minerals and
Land Resources (DEMLR). Please note that Cube Yadkin Generation LLC shall apply to
DEMLR for stormwater coverage at Outfall 004 within 90 days of the effective date of this
Permit. If there are other wastes in addition to stormwater known to drain to this outfall, it shall
remain in this permit,redefined and monitored as a complex waste-stream.
For the interim, this DWR permit will cover Outfall 004's stormwater, subject to existing permit
conditions until an individual stormwater permit is issued by DEMLR, at which time all DWR
monitoring and compliance will expire. We have retained stormwater monitoring best
management practices (BMPs)reflecting current requirements [see section A. (3.)].

Mark Gross, OPS
Cube Yadkin Generation LLC
Permit MOD, Page 2
Division records show that you have successfully registered with the eDMR Program. Please be
reminded that until the state's eDMR application is approved compliant with EPA's Cross-
Media Electronic Reporting Regulation (CROMERR), all permittees must continue to submit
hardcopy of DMRs as backup to eDMR reporting [see permit section A. (6.)].
Following the mandatory 45-day public comment period, the Division will review all pertinent
comments, if any, and take appropriate action prior to issuing an NPDES permit final. If you
have questions concerning this draft,please e-mail me [[e-mail]], or call my
direct line(919) 807-6394.
Respect
of
to!, -4. ' X---(..
J,- R. Corporo , L.G.
Compliance a d Expedited Permitting Unit
Enclosure: NPDES Permit NC0081931 [modification(MOD) draft]
hc: NPDES Program Files [DRAFT permit modification]
ec: DWR/W-SRO,Sherri Knight, Supervisor[DRAFT permit modification]
OCU,Maureen Kinney[DRAFT permit modification]

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
(NPDES)
In compliance with the provision of North Carolina General Statute 1 -2' 15�;other lawful standards and
regulations promulgated and adopted by the North Carolina Envlro ental Management Commission,
_ and the Federal Water Pollution Control Act, as amended,
Cube Yadkin Gener .LLC
is herebyauthorized to discharge wastewater fro affacilit locat-d at the
g \p\ IIT
YHigh--Rock �F ;ouse
3344eff\ ngle Fe Rc enton
"DayAidsonCount
. (---, \ ."-----,_.J
to receiving waters designated as the Ya, in Rf jerr in the Yadkin-Pee Dee River Basin in accordance
with effluent limitations,monrtoring requirements, and other applicable conditions set forth in Parts I, II,
III and IV hereof.
V
This permit shall become effectve , 2018.
This permit and authorization to discharge shall expire at midnight on January 31, 2019.
Signed this day , 2018.
Linda Culpepper, Interim Director
Division of Water Resources
By Authority of the Environmental Management Commission
Page 1 of 8

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-tower system servicing eldctric power
generation facilities, and
2. continue to operate a Stormwater Discharge System for treatment and\periodie
conveyance in support of secondary containment surrounding electric transformers, and
3. construct and operate a new oil/water separator servicing --n ed o.*- q
]\
these facilities located at the High Rock Powerhouse, 3344 Bringle Ferry Road, Denton, Davidson
County, and
--"N :1"------...---,_ '
4. discharge from sai l'tr`atment`works v Outfalls 00. , 002 and 003 (cooling water); via
Outfall 004 (perio'di tormwat )),id vaa�Outfal1005 (oil/water separator), at a location
specified on the attached map, into\the Yadkin River [stream Segment 12-136.3)], a waterbody
currently classified WS-T , B with ju_basin 03-07-08 [HUC: 03040103] of the Yadkin-Pee
Dee River Basin. `�/y
Page 2 of 8

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 via Outfalls 001, 002 and 003. Such discharges
shall be limited,monitored, and reported 1 by the Permittee as specified below:
DISCHARGE MONITORING
EFFLUENT LIMITATIONS REQUIREMENTS
CHARACTERISTIC Monthly Daily Measurement Sample Sample
[PARAMETER CODE] Frequency Type Average Maximum Fre
g q Y YP Location 2
Flow(MGD) 00500 �uall�\ Estimate Effluent
Temperature 3 00010 A\Athally \'Grab Effluent
pH [Standard Units] 00400 Not<6.0 or>\9.s.u. � n ua 1y Grab Effluent
FOOTNOTES:
1. The permittee shall submit discharge.m nitorin •�epo s electronically using the Division's
Electronic Discharge Monitore kieprt�(eDMR) stemt ee Section A. (6.)].
2. Collect a representati .e-effluent s\p el -prior to mixing at the outfall, or at a sample point
downstream closes easibly tot e o
3. Effluent temperature accurateeprese tl e discharge and shall not increase the receiving-
stream temperature by•more than 2.�' °C?,In no case shall effluent increase receiving-stream
temperature above 32 °C.
CONDITIONS:
• Samples obtained for monitoring purposes may be collected anytime during the calendar
year. Results shall be recorded and reported on the annual DMR/eDMR forms,postmarked
no later than January 30th following the completed reporting period.
• The Permittee shall discharge no floating solids or foam visible in other than trace amounts
unless ambient river conditions prevent compliance.
Page 3 of 8

Permit NC0081931
A. (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 via Outfall 004. Such discharges shall be limited,monitored, and
reported by the Permittee as specified below:
DISCHARGE Monitoring
EFFLUENT LIMITATIONS Re uirements
CHARACTERISTICS Monthly Daily Measurement Sample Sample
Average Maximum Frequency Type Location
BMPs[sEE A. (3)].
A. (3.) BEST MANAGEMENT PRACTICES (B Ps)FOR PERIODIC
STORMWATER DISCHARGE [GS 14V45.66l
The permittee is authorized by the Division to use WestM anagemen Practices for the stormwater
discharge from the secondary containment around tlie'transformers\un e the following conditions:
a. Sumps shall be designed with'underflow weirs/de icestorp event discharge of oily stormwater.
b. Weekly inspections of the transformers shall be prformed to detect leaks/drips of oil.
c. Routine preventivemaintenance procedures shall be conducted to address any leaks/drips of oil.
d. Inspection of theump for the p ce\�f oil a indicated by a visible sheen shall be conducted
prior to the discharge �g
e. The Permittee shall mainta n logs o1r each discharge event to include Time, Date, Flow Rate and
calculated Volume of stormwateridischarged.
f. All stormwater discharge events shall be reported together with the annual Discharge Monitoring
Report(DMR).
g. The Permittee shall discharge no floating solids or foam visible in other than trace amounts
unless ambient river conditions prevent compliance.
Page 4 of 8

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
and monitored by the Permittee as specified below:
LIMITS . MONITORING'
EFFLUENT REQUIREMENTS
CHARACTERISTICS
[Parameter Codes] Monthly Daily Measurement Sample Sample
. Average Maximum Frequency Type . Location
Flow 2 00500 Episodo'c'\ Effluent
Total Suspended Solids C0530 45.0 mg/L ,Each�is`'a�rge Grab Effluent
Volatile Organic Compounds 76029 Monitor and Report/i" Eac`h�Dischaige\ Grab Effluent
[via EPA 624] `'x\ \ . ,\\`
Oil&Grease 00556 30.0 mg/L\ Each��scharge \ `G, ab Effluent
[EPA Method 1664[SGT-HEM] � \\,/ -. )/
pH(Standard Units) 34030 Not<6.0\k9-7(c Eac Discharge Grab Effluent
A. (5.) BIOCIDE CONDITION
[G.S. 143-21;(43-215.1]
The Permittee shall add no cmium, zinc or copper to the treatment system except as pre-approved
additives to biocidal compounds.
The permittee shall obtain approvalifro the Division's Aquatic Toxicology Unit prior to the use of any
biocide(not previously approved byahe Division) for the effluent discharged under this permit.
Approval for use of any biocide not previously approved should be requested at least 90 days in advance
of any planned usage.
Contact the Aquatic Toxicology Unit for detailed instructions on requesting approval of biocides:
NC DENR/DWR/Aquatic Toxicology Unit
1621 Mail Service Center
Raleigh,North Carolina 27699-1621
Page 5 of 8

Permit NC0081931
A. (6.) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS
[GS 143-215.1 (b)]
Federal regulations require electronic submittal of all discharge monitoring reports(DMRs)and program reports.
The fmal 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 to NC DWR's Electronic
Discharge Monitoring Report(eDMR)internet application. KX
Monitoring results obtained during the previous month(s) s lbe mmarized reach month and submitted
electronically using eDMR. The eDMR system allows pe t e• faci s to enteer\ oring data and
submit DMRs electronically using the internet. Until such time`�t�h tthe-site's eDM application is
compliant with EPA's Cross-Media Electronic Rep rting Regulation<CROMERR),permittees will be
required to submit all discharge monitoring data to t estate electron'cai1y using eDMR and will be required
to complete the eDMR submission by printing, signing and submittmg.one signed original and a copy of the
computer printed eDMR to the followi g address: \\/>,/,,,,,,,, )//'
NC DENR/Division of Water Rehr IWar QualitYa g
Section
ATTENTION: Central Files ..\\:\)
1617 Mail Service Cen
Raleigh,North Carolina 27699-161
If a permittee is unable to u the eDMR 4tem ue to a demonstrated hardship or due to the facility being
physically located in an area rker,e less tha10 percent of the households have broadband access,then a
temporary waiver from the NPDKS\elecy9kc reporting requirements may be granted and discharge
monitoring data may be submitted ,n p tier DMR forms(MR 1, 1.1, 2,3) or alternative forms approved by
the Director. Duplicate signed copiesall 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).
Page 6 of 8

Permit NC0081931
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. 7'C�
Electronic submissions must start by the dates listed in the"Reporting equ rements"section above.
3. How to Request a Waiver from Electronic Reporting K/
The permittee may seek a temporary electronic reporting waiver from the'II ivision. To obtain an electronic
reporting waiver, a permittee must first submit an electronic reportin " aiver request to the Division.
Requests for temporary electronic reporting waivers rq. st e,submittec(in writing to the Division for written
approval at least sixty(60)days prior t j he date the fac ityyoul@ e reegiI ed under this permit to begin
submitting monitoring data and reportr-T�ee duration o\,tempibrg\ry waiver shall not exceed 5 years and
shall thereupon expire. At such time,moniito4;ing data and eports 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 elect ori?- ec rr porting\aiv ers are not transferrable. Only permittees with an approved
reporting waiver request'nfay submit m nit ng d`ata;a eports on paper to the Division for the period that
the approved reporting waiWer requests effective.
Information on eDMR and pplicatio for a temporary electronic reporting waiver are found on the
following web page: \\
http://deq.nc.gov/about/divisions/water-resources/edmr
(--
4.
4. Signatory Requirements [Supplements Section B. (11.) (b)and Supersedes Section B.(11.) (d)l
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
Page 7 of 8

Permit NC0081931
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 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].
<IIS"
(—\)
Page 8 of 8

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Cube Hydro Carolinas LLC Facility
*
High Rock Powerhouse Location
Latitude: 35°36'03" Sub-Basin: 03-07-08 91 (not to scale)
Longitude: 80°14'03" Receiving Stream: Yadkin River
Quad#: El8SW Stream Class: WS-IV&B NPDES Permit NC0081931
Stream Segment: 12-(136.3) HUC: 03040103 North Davidson County