NCS000546_FINAL Permit Cover letter_20150515

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North Carolina Department of Environment and Natural Resources
Pat McCrory
Governor
Mr. Harry K. Sideris
Senior Vice President
Environmental, Health, & Safety
Duke Energy
526 South Church Street
Mail Code EC3XP
Charlotte, NC 28202
Dear Mr. Sideris:
Donald R. van der Vaart
Secretary
May 15, 2015
Subject: NPDES Stormwater Permit Application -
Allen Steam Station
Permit Number NCSOOO546
Gaston County
In response to your application for coverage under an NPDES stormwater permit, the Division of
Energy, Mineral, and Land Resources (Division or DEMLR) is forwarding herewith the subject state -
NPDES permit, NCS000546. This permit is issued pursuant to the requirements of both 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).
This final permit includes the following changes from the draft permit published on our
website on March 6,2015:
SWO02 was inadvertently left out of the draft permit and has been added to the final permit
along with the required monitoring.
The description of Outfall 13 was revised to "Outfall Group SWO13 (Drainage Area 13) includes
thirteen 10" stormwater discharge outfalls along approximately 12,400 linear feet of gravel
road and7501inear feet of rail lines."
Outfall SWO17 (Drainage Area 17) and Outfall SW021 (Drainage Area 21) were added in the
heading with Outfall SWO04 (Drainage Area 4), Outfall SWO06 (Drainage Area 6), and Outfall
SWO14 (Drainage Area 14).
Outfall SWO19 has been removed from the final permit.
Division of Energy, Mineral, and Land Resources
Energy Section • Geological Survey Section • Land Quality Section
1612 Mail Service Center, Raleigh, North Carolina 27699-1612.919-707-9200 / FAX: [phone]
512 North Salisbury Street, Raleigh, North Carolina 27604 • Internet: http://portal.ncdenr.org/web/Irl
An Equal Opportunity 1 Affirmative Action Employer- 50% Recycled 110% Post Consumer Paper

Mr. Harry Sideris
May 15, 2015
Page 2 of 4
Thank you for your comments submitted on May 5, 2015. Please see our responses below:
1. Duke Energy will be requesting Representative Outfall Status (ROS) as follows:
SW008 represents outfalls SW001, SW003, SW007, SW008, SW009, SW010 and Group
SW013
SW011 represents outfalls SW011 and SW012
SW015 represents outfalls SW015, SW016, SW018 and SW020
DEMLR handles ROS designation outside of the permit because ROS is subject to change if activities
or other circumstances change. This procedure allows designations of and any changes to ROS to
be handled more expeditiously, without reopening the permit for modification. Please coordinate
with the Mooresville Regional Office if you wish to pursue ROS designation for any stormwater
outfalls.
2. The permit application dated November 17, 2014, listed Outfall SW002 (Drainage Area 2). Neither
the permit nor the fact sheet references SW002. Duke Energy requests a review to determine if
any monitoring is required.
SW002 was inadvertently left out of the draft permit and has been added to the final permit along
with the required monitoring.
3. Duke Energy requests the description for outfall SW013 in the permit and fact sheet be revised to
match the description in the permit. The outfall is a group of outfalls that drain the rail lines and
the eastern vegetated slopes of the ash landfill. One of the outfalls within the group is accessible
and recommended for sampling.
The description of outfall 13 in the permit and fact sheet was revised to "Outfall Group SW013
(Drainage Area 13) includes thirteen 10" stormwater discharge outfalls along approximately
12,400 linear feet of gravel road and 750 linear feet of rail lines." The sample point or points for
Outfall Group SW013 will be handled outside the permit by the Regional Office.
4. For clarification, Duke Energy requests Outfall SW017 (Drainage Area 17) and Outfall SW021
(Drainage Area 21) be included in the heading with Outfall SW004 (Drainage Area 4), Outfall
SW006 (Drainage Area 6), and Outfall SW014 (Drainage Area 14) in the permit and fact sheet.
Both Outfall SW017 (Drainage Area 17) and Outfall SW021 (Drainage Area 21) are included in the
paragraph below the heading.
Outfall SW017 (Drainage Area 17) and Outfall SW021 (Drainage Area 21) were added in the
heading with Outfall SW004 (Drainage Area 4), Outfall SW006 (Drainage Area 6), and Outfall
SW014 (Drainage Area 14) in the permit and fact sheet.
5. Duke Energy requests the monitoring for Outfall SW019 be removed from the permit. Outfall
SW019 does not drain areas associated with the industrial activities at the site.
Outfall SW019 has been removed from the final permit.

Mr. Harry Sideris
May 15, 2015
Page 3 of 4
6. Several of the stormwater outfalls are currently inaccessible. Providing safe and secure access to
these outfalls for sampling and monitoring will be difficult and costly. Currently Outfalls SW012,
SW016, SW018, SW019 and SW020 are inaccessible. Sampling SW008 will be possible only at the
inlet catch basin.
We understand the company's concerns about safety and secure access to outfalls, and we fully
support precautions to ensure accessibility is safe and appropriate for your employees. To that
end, it is acceptable to sample at the nearest, safely accessible location upstream of a stormwater
outfall when necessary to obtain a sample. The inaccessible issue will be handled outside the
permit by the Regional Office. Further, the company may wish to pursue a Representative Outfall
Status (ROS) designation for one or more of these outfalls to address its concerns. DEMLR handles
ROS designation outside of the permit because ROS is subject to change if activities or other
circumstances change. This procedure allows designations of and any changes to ROS to be
handled more expeditiously, without reopening the permit for modification. Please coordinate
with the Mooresville Regional Office if you wish to pursue ROS designation or alternative sample
points for any stormwater outfalls.
Failure to complete the monitoring as required is a violation of the permit and any permit
noncompliance constitutes a violation of the Clean Water Act. Reference Part III, Section A, Item 2
"Duty to Comply", Item 9 "Penalties for Tampering" and Item 10 "Penalties for Falsification of Reports"
of your permit for further information.
Per the requirements of the Catawba Riparian Buffer Rule, all stormwater drainage from portions of
this site that have been constructed after June 30, 2001 must be discharged through a correctly
designed level spreader or another device that meets diffuse flow requirements per 15A NCAC 2B
.0243. Diffuse flow requirements are described in Chapter 8 of the North Carolina Stormwater BMP
Manual, available at: http://portal.ncdenr.org/web/lr/bmp-manual.
If any parts, measurement frequencies or sampling requirements contained in this permit are
unacceptable to you, you have the right to an adjudicatory hearing upon written request within thirty
(30) days following receipt of this letter. This request must be in the form of a written petition,
conforming to Chapter 150B of the North Carolina General Statutes, and filed with the Office of
Administrative Hearings, Post Office Drawer 27447, Raleigh, North Carolina 27611-7447. Unless such
demand is made, this decision shall be final and binding.
Please take notice this permit is not transferable. Part III, B.2. addresses the requirements to be
followed in case of change in ownership or control of this discharge. This permit does not affect the
legal requirements to obtain other permits which may be required by the Division of Energy, Mineral,
and Land Resources, or permits required by the Division of Water Resources, Coastal Area
Management Act or any other federal or local governmental permit that may be required.

Mr. Harry Sideris
May 15, 2015
Page 4 of 4
If you have any questions or comments concerning this permit, contact Mike Randall at (919) 807-
6374 or at [e-mail].
Sincerely,
Original signed by Tracy E. Davis
Tracy E. Davis, PE, CPM, Director
Division of Energy, Mineral, and Land Resources
cc: Mooresville Regional Office, DEMLR Land Quality Section
Sam Sampath, Ph.D., EPA Region IV, 61 Forsyth Street, Atlanta, GA 30303
Stormwater Permitting Program
DWR Central Files
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