NC0081931_Permit (Issuance)_20180928

NPDES DOCUMENT SCANNING 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:
September 28, 2018
Thus document its printed on reuse paper - ignore any
content an the reYerse side

ROY COOPER
coverhor
MICHAEL S. RECAN
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
September 28, 2018
Subject: Issuance of Permit Modification
NPDES Permit 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).
Issuance.-- Changes from the Permit Draft — Per your request we have modified this permit to
include your proposed discharge from a new Outfall 005. As discussed with your representatives
on 27Sep2018, we have identified this complex wastestream as a "low volume waste" [40 CFR
423.11] and have therefore permitted this outfall in accord with 40 CFR 423.15 (c), New source
performance standards (NSPS). It follows that Outfall 005 requires monitoring and limits for the
additional parameters Total Suspended solids (TSS) and Oil & Grease [see section A. (4.)].
Lastly, please note that we have edited the permit outline for clarity.
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, now included in section A. (2.)].
CrI)
North Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 11617 Mail Service Center I Raleigh, North Carolina 27699-1617 — 919.707.9000

Mark Gross, OPS
Cube Yadkin Generation LLC
Permit MOD Issuance, Page 2
September 26, 2018
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.
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, Inte
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]]
ctor

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 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 October 1, 2018.
This permit and authorization to discharge shall expire at midnight on January 31, 2019.
Signed this day September 28, 2018.
L. Culpepper, Interim Dir for
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 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 construct and begin operating facilities classified as low -volume wastes including an oil/water
separator and treated conveyance system, and
4. discharge cooling water from said treatment works via Outfalls 001, 002 and 003; discharge
stormwater via Outfall 004; and discharge low -volume wastes including an oil/water separator
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 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 from Outfalls 001, 002 and 003. Such
discharges shall be limited, and monitored and reported 1 by the Permittee as specified below:
DISCHARGE
LIMITATIONS.
Monthly
Average
Measurement
Frequency
ample
Type
Sample
Location2
Flow (MGD)
00500
Annual
Estimate
Effluent
Temperature 3 (C°)
00010
Annual
Grab
Effluent
pH
(standard units)
00400
Not <6.Oor>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 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 from Outfall 004. Such discharges shall be limited and
monitored by the Pennittee as specified below:
i r °
Y
PARAMETER..
-' r r 1 > Jr
�. L l lsT ONS 1
+, r1 J ;1i a
-
MONJ 4 .
,;- J r:44' ,.c t..:.se ..:... )} is r. i• :..•
. RE�Qi ., . +BENTS
11�Ioht`hly`
Y '
Average
— Dail ` f
":
Maximum
,1-6 iir
Mefisurm�`t
Frequenncy
a7`' 3 `,_'
Sampxe�`
Type
�r
Sample
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
P.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
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 low -volume waste [including an oil/water separator] via Outfall 005. Such
discharges shall be limited, monitored, and reported 1 by the Permittee as specified below:
MONITORING:
REQUIREMENTS
LIMITATIONS
EFFLEUENT
CHARACTERISTIC
(PARAMETER CODE)
Monthly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample
Location 2
Flow (MGD)
50050
Annual
Estimate
Effluent
Total Suspended
Solids
C0530
30.0 mg/L
100.0 mg/L
Annual
Grab
Effluent
Oil & Grease 3
[EPA 1664 sGT HEM]
00552
15.0 mg/L
20.0 mg/L
Annual
Grab
Effluent
pH4
[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 300 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.
3. Limits and monitoring defined as low volume wastes [40 CFR 423.11] in accord with 40
CFR 423.15 (c), New source performance standards (NSPS).
4. Effluent pH shall not fall below 6.0 nor exceed 9.0 standard units, unless documented
ambient river conditions prevent compliance.
Page 5 of 8

. Permit NC0081931
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 II of this permit
(Standard Conditions for NPDES Permits):
• Section B. (11.)
• Section D. (2.)
• Section D. (6.)
• Section E. (5.)
Signatory Requirements
Reporting
Records Retention
Monitoring Reports
1. Reportinff Requirements (Supersedes Section D. (2.) and Section E. (5.) (a)j
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 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 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 maybe 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).
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.
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
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 jy, 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. 1 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 8 of 8

Cube Yadkin Generating LLC
High Rock Powerhouse
Latitude: 35°36'03" Sub -Basin: 03-07-08
Longitude: 80°14'03" Receiving Stream: Yadkin River
Quad #: EI8SW Stream Class: WS-IV & B
Stream Segment: 12-(136.3) HUC: 03040103
Facility
Location
(not to scale)
North
ARP
NPDES Permit NC0081931
Davidson County

SalisburyPost Publisher's Affidavit Of Publication
STATE OF NORTH CAROLINA
ROWAN COUNTY
Before the undersigned, a Notary Public of said county and
state, duly commissioned, qualified, and authorized by law
to administer oaths, personally appeared WINFRED MEN-
TION, who being first duly sworn, deposes and says that
he is ADVERTISING OPERATIONS MANAGER of the SALIS-
BURY POST, published, issued and entered as second class
mail in the city of Salisbury, in Rowan County, North Caro-
lina, that he is authorized to make this affidavit and sworn
statement, that the notice or other legal advertisement, a
true copy of which was attached hereto, was published in
the SALISBURY POST, on the following dates:
E07/12/18
and that the said newspaper in which such notice, paper
document or legal advertisement was published at the time
of each and every such publication, a newspaper meeting
all the requirements and qualifications of Section 1-597 of
the General Statutes of North Carolina, and was a qualified
newspaper within the meaning of Section 1-597 of the Gen-
eral Statutes of North Carolina,
At a cost of
Account #:
Tagline:
Purchase Order #:
S112.98
23483
No. 557908 PUBLIC NO
(signature of person making affidavit)
Sworn and subscribed before me on 07/12/18.
Notary Public
My commission expires 05/02/2021
No. 557908
PUBLIC NOTICE
STATE OF NORTH CAROLINA
ENVIRONMENTAL MANAGEMENT
COMMISSION
1617 MAIL SERVICE CENTER
RALEIGH, NORTH CAROLINA
27699-1617
NOTIFICATION OF
CONSIDERATION TO ISSUE
A NPDES Wastewater Permit
The North Carolina Environmen-
tal Management Commission
proposes to issue a NPDES
wastewater discharge permit
to the person(s) listed below.
Written comments regarding the
proposed permit will be accepted
until 30 days atter the publish
date of this notice. The Direc-
tor of the NC Division of Water
Resources (DWR) may hold a
public hearing should there be a
significant degree of public inter-
est. Please mail comments and/
or information requests to DWR
at the above address. Interested
persons may visit the DWR at
512 N. Salisbury Street, Raleigh,
NC to review information on file.
Additional information on NPDES
permits and this notice may be
found on our website: htto://dea.
nc,gov/about/divisions/water-re-
sources/wate r-resources-permits/
wastewater-b ranch/nodes-waste-
water/public-notices,or by calling
[phone]. The Alcoa Power
Generating, Inc requested re-
newal of permit NC0081931 for
High Rock Powerhouse in Rowan
County; this facility discharge
is once -through cooling water
and stormwater to Yadkin River,
Yadkin River Basin. Publish Date:
07/12

Corporon, Joe
From:
Sent:
To:
Cc:
Subject:
Keith McCullock <[e-mail]>
Thursday, June 07, 2018 3:28 PM
Corporon, Joe
Matthew Wike
FW: [External] Status of NPDES Permit Application - High Rock Powerhouse Application
No. NC0081931
CAUTION: External email. Do not click links or open attachments unless verified. Send all suspicious email as an attachment to
Joe:
Per Mr. Hennessy's email, you were assigned the referenced application.
Cube Hydro received an invoice in the amount of $1,030 (which they have paid). Based on NCDEQ's website, the $1,030
fee is for a major modification of a major individual NPDES Permit.
The High Rock Powerhouse operates under a Minor Individual NPDES Permit. The NCDEQ website and a previous email
(4/30/18) from Mr. Sergei Chernikov indicates that the fee should have been $260.
Can you address why an invoice was issued for the higher fee?
Thanks for your help.
Keith
Keith D. McCullock, P.E.
Director/Principal
GEL
Engineering of NC INC
2700 Sumner Boulevard, Suite 106, Raleigh, NC 27616
Office: 919.323.8830 I Cell: 919.323.9398
Environmental I Engineering I Surveying
gelengineering.com
Follow GEL Engineering of NC on Linkedln
From: Hennessy, John <[e-mail]>
Sent: Friday, June 1, 2018 3:03 PM
To: Keith McCullock <[e-mail]>
Cc: Corporon, Joe <[e-mail]>
Subject: RE: [External] Status of NPDES Permit Application - High Rock Powerhouse Application No. NC0081931
Keith,
1

My unit just got this application. I have just assigned it to Joe Corporon on my staff. I have asked him to make it a
priority.
John Hennessy
Supervisor, Compliance and Expedited Permitting Unit
Division of Water Resources
Department of Environmental Quality
919-807-6377 office
lohn.hennessy a(�ncdenr.gov
1617 Mail Service Center
Raleigh, NC 27669-1617
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.
From: Keith McCullock[mailto:[e-mail]]
Sent: Tuesday, May 29, 2018 3:36 PM
To: Hennessy, John <[e-mail]>
Subject: [External] Status of NPDES Permit Application - High Rock Powerhouse Application No. NC0O81931
CAUTION: External email. Do not click links or open attachments unless verified. Send all suspicious email as an attachment to
Mr. Hennessy:
Cube Yadkin Generation LLC (Cube) submitted a NPDES permit application to NCDEQ in January 2018 to add an outfall
associated a proposed oil/water separator at their High Rock Powerhouse.
Cube has indicated they would like to install the proposed oil/water separator in July or August 2018.
Based on a May 23, 2018 email from Sergei Chernikov, I understand that the permit modification was reassigned to a
permit engineer in your unit.
Could you provide an update on the processing of the referenced application?
Thanks
Keith
Keith D. McCullock, P.E.
Director/Principal
GEL
Engineering of NC INC
2700 Sumner Boulevard, Suite 106, Raleigh, NC 27616
Office: 919.323.8830 I Cell: 919.323.9398
Environmental I Engineering I Surveying
gelengineering.com
2

Grzyb, Julie
From: Thedford, Wren
Sent: Wednesday, May 23, 2018 12:30 PM
To: [e-mail]
Subject: NC0081931 Major Modification Fee
Mr. Hopson,
Per our phone conversation, please mail the Major Modification Fee of $1030 to:
NCDEQ/DWR/NPDES
Water Quality Permitting Section
Attn: Ms. Wren Thedford
1617 Mail Service Center
Raleigh, NC 27699-1617
If you would like to overnight the payment use the following address:
NCDEQ/DWR/NPDES
Water Quality Permitting Section
Attn: Ms. Wren Thedford
512 N. Salisbury Street-RM 942B
Raleigh, NC 27604
https://deq.nc.gov/about/divisions/water-resources/water-resources-permits/wastewater-branch/npdes-
wastewater/fees
Wren Thedford-t\clmiuisttativc Specialist II
NCDEQ-DWR-N PDES
\\'atcr Quality Permitting Section
1617 Mail Service Center Raleigh, NC 27699-1617
Phone: [phone]
Fax: [phone]
1

CUBE HYDRO'
CAROLINAS
December 18, 2017
Mr. Sergei Chernikov, Ph.D.
North Carolina Department of Environmental Quality
Division of Water Resources
WQ Permitting Section
1617 Mail Service Center
Raleigh, NC 27699-1617
RE: NPDES Permit Application — Minor Industrial
Cube Yadkin Generation LLC
High Rock Powerhouse - NC0081931
Dear Mr. Chernikov:
Cube Hydro Carolinas LLC
Highway 740
PO Box 575
Baden, NC 28009-0575
RECEIVED%gatitil
DEC 21.2017
Water Resources
Permitting Section
Cube Yadkin Generation LLC (Cube) is submitting the enclosed National Pollutant
Discharge Elimination System (NPDES) — Minor Industrial Permit Application for a new
Outfall 005 which will include discharge to the Yadkin River from the station separation
tank / skimmer located on the turbine floor at Unit 3.
As you discussed with GEL Engineering of NC, Inc. (GEL) on a conference call on October
11, 2017, no engineering alternatives analysis is required for this project. Additionally,
as noted in North Carolina Session Law 2011-394, an Authorization to Construct (ATC)
permit is no longer required for construction work at power generation facilities with an
NPDES permit. Since Cube's High Rock Powerhouse is a power generation operation, no
ATC permit is needed.
If you have any questions regarding this submittal, please don't hesitate to contact Keith
McCullock of GEL at [phone] or Paul Tran with Cube at [phone].
Very Truly Yours
M. toss
OP ` ► anger
Attachments

GEL
Enc
heehnc
of \C IN
an affiliate of The GEL Group INC
NPDES PERMIT No. NC0081931 MODIFICATION
ADDITION OF OUTFALL 005 -
UNIT Nos. 1-3 SUMP DISCHARGE
High Rock Powerhouse
Cube Yadkin Generation LLC
Davidson County, North Carolina
Prepared by:
GEL Engineering of NC, Inc.
2700 Sumner Boulevard, Suite 106
Raleigh, North Carolina 27616
NC Corporate Engineering License No. C-1938
DECEMBER 2017

NPDES PERMIT No. NC0081931 MODIFICATION
ADDITION OF OUTFALL 005 - UNIT Nos. 1-3 SUMP DISCHARGE
HIGH ROCK POWERHOUSE
CUBE YADKIN GENERATION LLC
DAVIDSON COUNTY, SOUTH CAROLINA
Table of Contents
Section Subject Page
Summary
10 Overview of Permit Application 1
2.0 Project Description 1
NPDES Permit Application — Short Form C — Minor Industrial
Figures
1
2
Appendix
Site Location Map
Process Flow Diagram for High Rock Powerhouse
Manufacturer Information for Separation Tank / Skimmer

NPDES PERMIT No. NC0081931 MODIFICATION
ADDITION OF OUTFALL 005 - UNIT Nos. 1-3 SUMP DISCHARGE
HIGH ROCK POWERHOUSE
CUBE YADKIN GENERATION LLC
ROWAN COUNTY, SOUTH CAROLINA
1.0 OVERVIEW OF PERMIT APPLICATION
Cube Hydro Generation LLC (Cube Hydro) operates the High Rock Powerhouse located on
the Yadkin River in Davidson County, North Carolina. Cube Hydro currently operates
under NPDES Permit No. NC0081931 issued by the North Carolina Department of
Environmental Quality (NCDEQ) Division of Water Resources on February 22, 2017. The
High Rock Powerhouse currently has four permitted outfalls. Outfalls 001, 002 and 003
discharge once -through cooling water. Outfall 004 discharges stormwater (periodically)
from the secondary containment for transformers. Cube Hydro intends to add Outfall
005 which will discharge treated wastewater from the Unit Nos. 1-3 sumps. A project
description is included in Section 2.0.
The location of the Cube Hydro facility is shown on the site location map included as
Figure 1.
2.0 PROJECT DESCRIPTION
For this proposed project, Cube Hydro plans to install a cooling water rotary strainer and
two turbine guide bearing filtration packages. Back flush from the cooling water rotary
strainer and two turbine guide bearing filtration packages will be discharged to the
Yadkin River. As noted in Title 15A of the North Carolina Administrative Code 2H .0106
(f), filter backwash from raw water intake screening devices do not require a NPDES
permit. Therefore, the backflush discharges from the cooling water rotary strainer and
two turbine guide bearing filtration packages do not need to be included in the High Rock
Powerhouse's NPDES's permit.
Cube Hydro plans to install Outfall 005 which will include discharge to the Yadkin River
from the station separation tank / skimmer located on the turbine floor at Unit 3. The
separation tank will have a total capacity of 350 gallons. The separation tank will have a
rope skimmer, oil baffle and discharge oil monitor which can shut down the system if oil
is detected in the discharge. Total separator discharge flow is dependent on unit
leakage. Two new 25 gallon per minute (gpm) sump pumps will be installed in each
wheelpit for a total unit discharge capacity of 50 gpm. Since the unit head cover sump
flows are variable dependent upon unit seal wear the station sump tank / skimmer
system will be designed for a constant flow of 50 gpm for all three units. However, daily
flow will not exceed 10,000 gallons per day. All equipment will be located on the turbine
floor inside the powerhouse. Outfall 005 will be core drilled through the floor into the
existing trash chute. A sample connection tap will be provided.
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6541 Me4aon UAW. Sub 101
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919.544.1100
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PROJECT: cube00217
CUBE YADKIN GENERATION LLC
HIGH ROCK POWERHOUSE
BRINGLE FERRY ROAD
ROWAN COUNTY. NC
SITE LOCATION
MAP
FIGURE
1
DATE: November 21. 2017
DRAWN BY:TJP IAPPRV. BY:KDM

FLOW DIAGRAM FOR HIGH ROCK POWERHOUSE
NPDES PERMIT NO. NC0081931
High Rock
Unit One
Scroll Case
Yadkin River
High Rock
Unit Two
Scroll Case
High Rock
Unit Three
Scroll Case
Unit One
Thrust Bearing
Cooling Water
Outfall 001
Into Yadkin River
(17,280 gal/day)
Unit Two
Thrust Bearing
Cooling Water
Outfall 002
Into Yadkin River
(17,280 gal/day)
Unit Three
Thrust Bearing
Cooling Water
Outfall 003
Into Yadkin River
(17,280 gal/day)
Stormwater
Secondary
Containment for
Transformers
Outfall 004
Into Yadkin River
(Flow Varies)
Unit Nos. 1-3
Wheelpits
Discharges
Oil Separator
Tank &
Skimmer
Oil to Drum
Outfall 005
Into Yadkin River
(10,000 gal/day)