NC0004987_Final Major Modification_20210518 (2)

ROY COOPER.
Governor
DIONNE DELLI-GATTI
Secretary
S. DANIEL SMITH
Director
NORTH CAROL! NA
Environmental Quality
May 18, 2021
Mr. Paul Draovitch, Senior Vice President
Environmental, Health and Safety
Duke Energy Carolinas, LLC
Mail Code EC13K
P.O. Box 1006
Charlotte, North Carolina 28201-1006
Dear Mr. Draovitch:
Subject: Final NPDES Major
Modification
Permit NC0004987
Marshall Steam Station
Catawba County
Facility Class I
The Division of Water Resources is forwarding herewith the Final Major Modification for Marshall
Steam Station. This modification 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).
The Final Major Modification contains the following significant changes from your Draft
Permit:
• The optimization requirement and the reopener clause were added for the FGD Effluent Page
(Internal Outfall 006) in response to the SELC comments.
The Final Major Modification maintains the following significant changes contained
in the Draft Permit:
• The bottom ash purge was added to the list of the contributing sources of wastewater to the
Lined Retention Basin (Outfall 005). Per updated 40 CFR 423.13 (k) (2) (i) (A), the discharge
of pollutants in bottom ash transport water from a properly installed, operated, and
maintained bottom ash system is authorized to maintain system water chemistry where
installed equipment at the facility is unable to manage pH, corrosive substances, substances or
conditions causing scaling, or fine particulates to below levels which impact system operation
or maintenance.
NORTH D `E�
Department of&Mronme�l Ouel sje
North Carolina Department of Environmental Quality 1 Division of Water Resources
512 North Salisbury Street 11617 Mail Service Center I Raleigh, North Carolina 27699-1617
919.707.9000

• The Technology Based Effluent Limits for Total Arsenic, Total Mercury, Total Selenium, and
Nitrate/nitrite as N for Internal Outfall 006 (FGD wastewater) were adjusted in accordance
with updated 40 CFR 423.13.
• The pH limit for FGD wastewater was eliminated (Internal Outfall 006) to correct an error.
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, 6714 Mail Service Center, Raleigh, North Carolina 27699-6714. Unless such
a demand is made, this permit shall be final and binding.
Please note that this permit is not transferable except after notice to the Division. The Division may
require modification or revocation and reissuance of the permit. This permit does not affect the legal
requirements to obtain other permits which may be required by the Division of Water Resources or
any other Federal, State, or Local governmental regulations.
If you have any questions or need additional information, please contact Sergei Chernikov, telephone
number [phone] or email: [e-mail].
cc: Central Files
NPDES Files
Mooresville Regional Office/Water Quality
WSS/Aquatic Toxicology Unit (e-copy)
EPA Region IV (e-copy)
NORTH D `E�
Department of&Mronme�l Ouellty�
Sincerely,
S. Daniel Smith, Director
Division of Water Resources
North Carolina Department of Environmental Quality 1 Division of Water Resources
512 North Salisbury Street 11617 Mail Service Center I Raleigh, North Carolina 27699-1617
919.707.9000