NC0003425_More Information Received_20181106

DUKE Duke Energy Progress LLC
Roxboro Steam Station
ENERGY,- 1700 Dunnaway Road
Semora, NC 27343
File: 12520-B November 06, 2018
Ms.Julie Grzyb
North Carolina Division of Water Resources
1617 Mail Service Center
Raleigh,NC 27699-1617
RECEIVED/DENR/pVl/R
Re: NPDES Wastewater Permit Application Update
Coal Pile Runoff Pond—Outfall 006 NOV 19 2018
Duke Energy Progress, LLC. Water Resources
Roxboro Steam Electric Plant Permitting Section
Permit#: NC0003425
Person County
Dear Ms. Grzyb,
Duke Energy Progress, LLC (Duke Energy) is submitting herewith supplemental information in
support of the NPDES renewal application initially submitted in 2011 for the subject facility.
Please include this supplemental information for your review.
NPDES outfall 006, the coal pile runoff pond currently functions as stormwater retention pond
for management of suspended solids produced by runoff form the coal yard and associated
handling areas, limestone pile, emergency gypsum stack and truck wheel wash. Releases from
this pond are batched and controlled by a standpipe and skimmer structure with discharge
directly to Hyco Reservoir.
Duke Energy is undertaking a project to redirect the coal pile runoff pond discharge to a new
lined coal pile holding basin to be built within the plant railroad loop north of the coal yard. The
new basin will be designed for a 25 year rain event and be constructed of concrete to facilitate
sediment removal. The discharge from this new coal pile holding basin will be pumped to the
new lined retention basin (internal outfall 12B) before comingling with the final discharge at
NPDES outfall 003. Because of these future modification in water flows at the site, Duke Energy
requests that the permit under development include all of the areas and activities currently
permitted to outfall 006 also be listed as contributing flows to internal outfall 12B in the reissued
permit. Outfall 006 will be eliminated at some point during the next permit term.

Ms. Grzyb
Roxboro NPDES Permit Updates
November 06, 2018
Page 2
In order to facilitate clean out of the existing coal pile runoff pond and continued operation of
this portion of the wastewater treatment process, Duke Energy proposes to complete this project
in two phases.
Phase 1 will include installation of a pumping station with redundant pumps and a single walled
HDPE pipe near the existing coal pile runoff pond. This new line will tie into an existing HDPE
line west of the Unit 4 cooling tower.
Wastewater from the pond will be pumped to the holding cell in the Lined Retention Basin
arrangement (see attachment). The new pumping station will have appropriate monitoring and
control system functions integrated into the station's digital control system. The discharge
structure and weir will be abandoned with the discharge pipe permanently sealed.
Phase 2 of the project will include the construction of a new lined concrete holding basin
capable of holding a 25 year/24 hour storm event. The discharge from the new basin will tie into
the HDPE lines installed during Phase 1.
Should you have any questions regarding this letter or require additional information, please
contact Ms. Lori Tollie at(336) 854-4916 or at [e-mail].
"I certify, under penalty of law, that this document and all attachments were prepared under my
direction or supervision in accordance with a system designed to assure that qualified personnel
properly gather and evaluate the information submitted. Based on my inquiry of the person or
persons who manage the system, or those persons directly responsible for gathering the
information, the information submitted is, to the best of my knowledge and belief true, accurate,
and complete. I am aware that there are significant penalties for submitting false information,
including the possibility offines and imprisonment for knowing violations."
Sincerely,
f(P44449/
Jason Haynes
General Manager—Roxboro Steam Station
Enclosures
NCDEQ cc:Teresa Rodriguez
Duke Energy cc:Richard Baker,Jim Wells, Shannon Langley,Anne Pifer

Roxboro Steam Plant Outfall 006 —Phase 1
2 pumps installed here to pump water from
pond to holding basin of LRB. Capacity of Installation of 12"HDPE line to tie
holding basin is 6 MG into existing HDPE line west of unit
#4 cooling tower
i:
'sr"'"'"'"%""''''"':"'".'''.*."*"'.k•.' ,,,,
Current Discharge * + Runoff from Coal Pile
to Hyco Lake to be
abandoned during 1 rf
phase 1 R
a
t 4(// ...... ...114 ,
Discharge to holding cell
of lined retention basin

Roxboro Steam Plant Coal Pile Holding Basin - Phase 2
Raw water
tank drainage
Stormwater (maintenance)
lined retention basin
Coal Pile Runoff Treatment Basin ' Internal outfall 12B
Limestone pile runoff -y-T
Absorber seal
Leakage(rare)
Emergency Gypsum Truck wheel wash
stack
Heated Water Discharge Pond
Y
NPDES outfall 003
Form 2C —Item II A-Flews,
Sources of Pollution, and
Treatment Technologies
Outfall 006 November 2018

Roxboro Lined Retention Basin(LRB)Arrangement
LSecondary Basin ...._,
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Primary Basins /7: ('''' :MP
o/q�rK!. .� ii/r`Holdin Basin %rg rii� � rrig
/r \°r te L��.� /,
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WM RAM
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