20150610 Ver 4_USACE Permit_20190528

Action ID No. SAW -2015-01381
Mr. Steve Cahoon
Duke Energy
410 South Wilmington Street
Raleigh, North Carolina 27601
Dear Mr. Cahoon:
DEPARTMENT OF THE ARMY
WILMINGTON DISTRICT, CORPS OF ENGINEERS
69 DARLINGTON AVENUE
WILMINGTON, NORTH CAROLINA 28403-1343
May 28, 2019 -
NC Department of r
Environmental
Quality
Received
MAY 31 2019
=:
Winston-Salem
Regional Office
Reference the Department of the Army (DA) permit issued on October 20, 2017, to
Mr. Steve Cahoon, of Duke Energy for impacts associated with several activities at the Duke
Energy Dan River Steam Station in Eden, Rockingham County, North Carolina. These activities
included diverting stormwater away from the Primary Ash Basin and Secondary Ash Basin,
disposal of coal combustion residual (CCR) materials, providing separation between CCR
contact water and non -contact water, and providing maintenance access to the existing
Secondary Ash Basin berm and scarp. These activities involved the permanent discharge of fill
material into 188 linear feet of perennial stream channel, temporary discharge of fill material into
20 linear feet of perennial stream channel, permanent discharge of fill material and dredging of
1.89 acres of riparian, non-riverine wetlands, and overflooding/conversion of 393 linear feet of
perennial streams and 0.41 acre of riparian, non-riverine wetlands to open waters. Compensatory
mitigation was implemented for the unavoidable impacts by payment to the North Carolina
Division of Mitigation Services.
Also reference your permit modification request letter dated February 18, 2019 (received
February 19, 2019), proposing the following activities related to compliance with the Coal Ash
Management Act (CAMA) and decommissioning of the on-site Primary and Secondary Ash
Basins:
1). Authorization for the permanent discharge of fill material into a total of 48 linear feet
(0.025 acre) of riverbank/open water, related to installing four outfalls into the Dan
River consisting of gabions constructed of woven steel wire mesh and filled with rip
rap;
2) Authorization of the temporary discharge of dredged or fill material into 0.125 acre of
open water related to construction access and dewatering necessary to construct the
four gabion outfalls;

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3) Authorization of activities in Wetlands A, H, and I, including localized grading to a
depth of 18 inches below existing grade to remove Coal Combustion residual (CCR)
materials (potential removal of a total of approximately 1,421 cubic yards of material)
and promote drainage, removing culvert pipe plugs, and installation of headwalls.
These areas are also referred to as the 364nch Pipe Closure Project, 48 -inch Pipe
Closure Project, Wetland A Stormwater Diversion Project, and Dredge Basin
Stormwater Diversion Project.
Note that your permit modification request letter, was advertised to the public, as well as
relevant Federal and State agencies, on March 12, 2019, for a 30 -day Public Notice period.
Following evaluation of the information submitted in your modification request and comments
made during the agency Public Notice period, the U.S. Army Corps of Engineers, Wilmington
District has determined that it is appropriate and reasonable and not contrary to the public
interest. Therefore, the permit is modified per your request. This work must be constructed per
Drawing Nos. "Figure -01", "Figure -02", and "Figure -03" included in the permit modification
request letter dated February 18, 2019.
All other conditions of the permit, including the permit expiration date of December 31,
2022, remain in effect as written. Should you have questions, contact Mr. David E. Bailey,
Raleigh Regulatory Field Office at telephone [phone], Extension 30.
FOR THE COMMANDER
Robert J. Clark
Colonel, U.S. Army
District Commander
Enclosure
Copies Furnished with Enclosure:
Ms. Sue Homewood
Division of Water Resources
North Carolina Department of
Environment and Natural Resources
450 West Hanes Mill Road, Suite 300'
Winston Salem, North Carolina 27105

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Mr. Richard Harmon
Wood Environment & Infrastructure, Inc.
4.021 Stirrup Creek Drive, Suite 100
Durham, North Carolina 27703
Copies Furnished without Enclosure:
Mr. Pete Benjamin
U.S. Fish and Wildlife Services
Fish and Wildlife Enhancement
Post Office.Box 33726
Raleigh, North Carolina 28516
Mr. Todd Bowers
Wetlands Regulatory Project Manager —North Carolina
Region 4 Water Protection Division
U.S. Environmental Protection Agency
61 Forsyth Street Southwest
Atlanta, Georgia 30303