HomeMy WebLinkAboutNCS000548_FINAL PERMIT Cover Letter_20150515A'741
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WDENR
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
Marshall Steam Station
Permit Number NCS000548
Catawba 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,
NCS000548. 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:
Part II Section B of the permit acknowledges the ongoing replacement of SW001, SWO01A and
SWO02 outfall pipes by newer pipes, and provides that the permittee can monitor the three new
discharge pipes under the same outfall number designation as the previous corresponding
discharge pipes.
Text has been added to clarify the monitoring requirements for SW009. As it did previously, the text
now more clearly requires the monitoring of stormwater-only flows from the contributing drainage
area prior to commingling with the ID fan non -contact cooling water.
Thank you for your comments submitted on May 5, 2015. Please see our responses below:
1. Duke Energy reports that the company will be requesting representative outfall status (ROS) for
several outfalls, and it appears from your letter that Duke will propose to sample three outfalls
instead of fourteen. As noted in your comment letter, DEMLR handles ROS designation outside of the
permit. ROS can be subject to change if activities or other site circumstances change, and keeping ROS
separate from the permit itself allows the Division to handle more expeditiously the designations of, and
any changes to, ROS without reopening the permit for modification. Please coordinate with the
Mooresville Regional Office when you are ready to pursue ROS designation for any stormwater outfalls.
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: 919-715-8801
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 3
2. Duke Energy requested that the text of the permit acknowledge the planned replacement of
discharge pipes SW0O1, SWO01A and SW0O2 with new pipes, noting that they still drain the same
area. As noted above, the final permit text incorporates this acknowledgement, and provides that the
same outfall numbers shall be assigned to the three new discharge pipes.
Duke Energy requested that the monitoring requirements for outfall SW009 be removed from
the permit based on a continuing discharge of non -contact cooling water in the outlet pipe and
difficulty in accessing the discharge pipe during high lake levels. While we appreciate the
difficulties to monitoring presented on both counts, we note that the draft permit text already provided
that Duke would sample the stormwater flows prior to commingling with the non -contact cooling water
flow. The permit text anticipates that Duke will retrieve a surface runoff stormwater-only sample at a
location upstream of the commingling with the non -contact cooling water flow. We have not removed
the monitoring requirements on SW009 from the permit text.
4. Duke Energy noted that some of the outfalls are pipes overhanging steep banks or submerged
below the discharge canal water elevation. And that providing safe and secure access under these
conditions to six of the fourteen outfalls would be costly and difficult. Duke further suggests that
representative outfall status might be a tool to avoid the disproportionate costs of providing safe
and secure access. We concur that where the specific conditions of exposure in the sub -drainage area
and the discharge characteristics of the flow meet ROS criteria, the accompanying benefits of reduced
cost and reduced risk are welcome. Again, please contact the DEMLR Mooresville Regional Office when
you are ready to seek ROS.
However, we note that the company provided stormwater discharge samples for some of the outfalls
named in this part of your comment letter (SW007 and SW012). We understand this does not
necessarily mean the outfalls are routinely safely accessible, but it does demonstrate that sampling is
possible at some of the outfalls named in your comment letter. We understand the company's concerns
about the cost of safe and secure access to outfalls, and we fully support precautions to ensure
accessibility is safe and appropriate for your employees. To that end, please note that it is generally
acceptable to sample at the nearest, safely accessible location upstream of a stormwater outfall when
necessary, as we believe was the case for the sampling results previously reported as from outfall
SW007.
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.
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.
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 213.0243. Diffuse flow
requirements are described in Chapter 8 of the North Carolina Stormwater BMP Manual, available at:
httl2://nortal.ncdenr.org/web/lr/bmp-manual.
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
Mr. Harry Sideris
May 15, 2015
Page 3 of 3
permits required by the Division of Water Resources, Coastal Area Management Act, or any other federal or
local governmental permit that may be required.
If you have any questions or comments concerning this permit, please contact Ken Pickle at (919) 807-6376
or at ken.pickleOncdenr.gov.
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
Attachments: NCS000548