NC0003468_Request for Administrative Update_20180629

(iN DUKE Dan River Combined Cycle
ENERGY® Duke Energy Carolinas
864 South Edgewood Road
Eden,NC 27288
June 29, 2018
Mr. Jeff Poupart
North Carolina Division of Water Resources
1617 Mail Service Center
Raleigh, NC 27699-1617
RECENE.DIDE�WDWR
Subject: Duke Energy Carolinas, LLC. jai 7 2.018
Dan River Combined Cycle
Request for administrative update Water Resources
Removal of Domestic wastewater Permitting $ectlon
Dear Mr. Poupart:
Duke Energy Carolinas, LLC (Duke Energy) hereby request the suspension of ongoing sampling
for Fecal Coliform and BOD at the subject facility.
The Dan River Combined Cycle (DRCC) Facility, working with DEQ, removed domestic
wastewater from its discharge in November 2017 by installation of a conventional septic system
and complete removal of the discharging sewage package plant. Prior to this, DRCC had been
sending the domestic wastewater offsite since May 2017.
While there is no longer any source of fecal coliform that can be attributed to the plant's
operations, DRCC recently experienced an exceedence of the permit limit because of influence
from submergence of its outfall pipe by the rising Dan River after rainfall events. Upon
receiving this result for fecal coliform, Duke Energy staff consulted with the regional office staff
in Winston Salem who agreed that the values were as a result of river influence. The Dan River
is listed on the State 303(d) list of impaired waters for fecal coliform, bacteria, and turbidity.
Following heavy rain events, the discharge pipe for outfall 001 can become submerged by the
rising Dan River. During the months of April and May the DRCC site received 4.37 and 7.79
inches of rain respectively. The Dan River experienced flooding on 4/24/2018 and 4/25/2018
prior to sample collection on 5/10/2018. The site experienced flooding again on 5/19/2018 and
5/20/2018. The analytical result for the 5/10/2018 fecal sampling event was 1600 CFU/100 ml
with no source from the plant. DRCC staff collected samples from the plant's wastewater sump
and from the Dan River on 5/21/2018. The fecal coliform results were <2 CFU/100 ml at the
wastewater sump and 833 CFU/100 ml in the Dan River. This confirms the plant operations is
not causing the fecal levels but they are instead a result of river influence.
Based upon removal of domestic wastewater from our ongoing discharge at the DRCC facility,
Duke Energy requests administrative suspension of ongoing testing requirements for fecal
coliform and BOD from outfall 001.