NCS000572_Dan River FINAL PERMIT Transmittal Letter_20150930

North Carolina Department of Environmental Quality
Pat McCrory
Governor
Mr. Harry K. Sideris, Senior Vice President
Environmental, Health, & Safety
Duke Energy
526 South Church Street
Mail Code EX3XP
Charlotte, NC 28202
Dear Mr. Sideris:
Donald R. van der Vaart
Secretary
September 30, 2015
Subject: NPDES Stormwater Permit Application
Dan River Combined Cycle Station
Permit Number NCS000572
Rockingham 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, NCS000572.
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 significant changes from the draft permit published on our website
on August 2, 2015:
Part II Section A paragraph 6 of the permit has been revised to allow the use of either electronic records or
employee signatures to document annual stormwater pollution prevention training.
Draft permit effective dates and monitoring schedules have been revised to reflect the actual issuance date
and minor adjustments to the monitoring periods.
Thank you for your comments submitted on September 8, 2015 and September 10, 2015 for Dan River and the
Rogers Energy Complex, respectively. As Duke Energy requested we have considered which comments on Rogers
might also apply to Dan River. Please see our responses below:
1. In the single comment specific to the Dan River facility, Duke Energy requested coverage for former
outfall SW005, and noted that you have also requested coverage for this commingled discharge under
the pending revisions to wastewater permit NC0003486. Discussions with Duke staff indicate that the
request was an attempt to provide some level of temporary coverage for the discharge while DEQ is
processing the wastewater permit renewal application. Former outfall SW005 is located adjacent to the
ongoing demolition of the Dan River Steam Station facility, and was not included in your initial
stormwater permit application received August 1, 2014.
Response: The Division concludes that for this commingled discharge coverage under the wastewater permit
is appropriate, but that coverage under the stormwater permit is not. The two DEQ Divisions administering the
NPDES programs had already coordinated on this specific outfall during the development of the stormwater
Draft Permit for Dan River which was published for public comment in August, 2015. Both NPDES programs
have a long established history of regulating commingled discharges as wastewater discharges. On this basis
the final stormwater permit has not been expanded to include this wastewater discharge.
1601 Mail Service Center, Raleigh, North Carolina 27699-1601
Phone: [phone] Internet: www.ncdenr.gov
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Mr. Harry Sideris, Duke Energy
Dan River Combined Cycle Station
Duke Energy requested that we amend the Draft Permit to allow electronic records of employee
training, in lieu of requiring individual signatures to document stormwater pollution prevention
training.
Response: We have amended the final permit to allow either electronic record keeping or employee
signatures. However, we are requiring that a printout of the electronic training record be maintained in the
Stormwater Pollution Prevention Plan kept on site.
3. Duke Energy requested that the monitoring period dates be adjusted to reflect the actual issuance date
of the permit, rather than the dummy dates included in the Draft. Further, Duke Energy requested that
the semi-annual monitoring periods be delayed until January 1, 2016.
Response: We have adjusted the dummy dates to reflect the actual issue date of the permit. Further, while we
have not delayed the start of the first monitoring period to January 1, 2016 as Duke Energy requested, we have
extended just the first semi-annual analytical monitoring period to a nine-month duration, and shortened the
last monitoring period in 2020 to a three-month duration. This allows us to keep most of the analytical
monitoring on a schedule that corresponds with the calendar half -years, which we see as a potential
convenience for the permittee in keeping track of his monitoring obligations.
4. Similarly, Duke Energy requested a delay of the monitoring period start date for the quarterly visual
monitoring required under the Draft Permit. Duke reported that it may take some time to establish
access areas for visual observation of some outfalls at Rogers.
Response: We have not incorporated this suggestion in the final permit for Dan River. It seems to us
reasonable to conclude that accomplishing quarterly visual monitoring is not an unusual burden considering
the observed site conditions and outfalls at the Dan River facility.
S. Duke Energy noted that the copper and silver benchmark concentration values were very low, and
requested that the numerical values be re-evaluated, and presumably increased or eliminated. Duke
Energy noted that copper and silver might be naturally present in site soils and so not indicative of
stormwater pollution from industrial activity.
Response: The stormwater discharge benchmark values are designed to protect the aquatic biota from
pollutants generated at industrial sites. Copper and silver benchmarks are derived from the one-half Final
Acute Value (1/2 FAV) reported in studies from the water quality and bioassay literature. Ultimately the
benchmark values are based on what concentrations of what pollutants will be detrimental to the aquatic biota,
not on other considerations. While Duke Energy advanced the possibility of naturally occurring copper and
silver in site soils, no substantiating information was provided: on the other hand, the literature available on
coal and coal ash confirms the presence of these contaminants. The final Permit remains unchanged for the
copper and silver benchmark concentrations.
6. Duke Energy requested several changes to the Fact Sheet that accompanied the publication of the Draft
Permit.
Response: Our administrative procedures use the Fact Sheet as the rationale document supporting the scope
and content of the published Draft Permit. Once published we consider it a record document that we do not go
back and revise. When we make revisions to any Draft Permit the rationale for those revisions is captured in
either a stand-alone Response to Comments document, or in the final permit transmittal letter to the applicant.
No changes have been made to the Fact Sheet.
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.

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Mr. Harry Sideris, Duke Energy
Dan River Combined Cycle Station
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.
If you have any questions or comments concerning this permit, please contact Ken Pickle at [phone] or at
[e-mail].
Sincerely,
Original signed by
Tracy E. Davis, PE, CPM, Director
Division of Energy, Mineral, and Land Resources
cc: Winston-Salem Regional Office, DEMLR Land Quality Section
Sam Sampath, Ph.D., EPA Region IV, 61 Forsyth Street, Atlanta, GA 30303
Stormwater Permitting Program Files
DWR Central Files
DWR NPDES Wastewater Permitting
Attachments: NCS000572