NC0005088_Special Order By Consent_20190510

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Governor d Sili \P
MICHAEL S.REGAN ''. .
Secretary a",a"" ` -
LINDA CULPEPPER NORTH CAROLINA
Director Environmental Quality
May 10, 2019
Mr. Paul Draovitch, Senior Vice President EHS
Duke Energy
526 S. Church Street
Mail Code EC3XP
Charlotte,NC 28202
Subject: SOC S 17-009—Extension of Coverage for Newly-Identified Seeps
Duke Energy Carolinas, LLC
Allen Steam Station&Rogers Energy Complex
NPDES Permits NC0004979 &NC0005088
Gaston&Rutherford Counties
Dear Mr. Draovitch:
Paragraph 7 of the cited Special Order by Consent (SOC) contains provisions allowing for the
extension of SOC coverage to newly-identified or newly-discovered, non-constructed seeps that
were not included at the time of the original issuance of the SOC. Duke Energy has reported to ,
the Division of Water Resources (the Division)the identification of three new non-constructed
seeps discovered at the Allen Steam Station and the Rogers Energy Complex, and has requested
SOC coverage be extended to those non-constructed seeps.
Pursuant to the terms contained within paragraph 7 of SOC S17-009, SOC coverage is hereby
extended to non-constructed seeps identified as S-12 at the Allen Steam Station and S-37 and S-
38 at the Rogers Energy Complex. Modified Attachment A pages have been prepared for those
facilities and are included as attachments to this letter. The modified Attachment A pages should
replace those included in the SOC at the time of its original issuance.
Additional reference and SOC coverage is also extended to seep S-10 at the Allen Steam Station.
This non-constructed seep is collected in a French drain system and its flow is conveyed to a
collection box, from which its volume is pumped back into the ash basin. This seep was
documented during the development of the SOC,but reference to the seep was not included due
to the seepage being returned to the ash basin with no discharge to surface waters. Because seep
S-12 will potentially exist only during temporary, infrequent episodes during power interruptions
to the seep S-10 pumping apparatus, reference to seep S-10 within the SOC is appropriate.
-4 North Carolina Department of Environmental Quality I Division of Water Resources
NO{iTH cARW A 512 North Salisbury Street 11617 Mail Service Center I Raleigh,North Carolina 27699-1617
D'Dib°°""f 'Il"��/ 919.707.9000

Mr. Paul Draovitch
S17-009 SOC Coverage Extension
p. 2
The extension of SOC coverage to these non-constructed seeps does not include any additional
surface water monitoring requirements, nor have any new interim action levels been established
for surface waters the seeps flow into. Each of the newly-identified seeps exhibited a low flow
condition at the time of its discovery that precluded the collection of a suitable sample for a
chemical characterization of the seep. Duke Energy is reminded that as a term of this extension
of coverage,the newly-identified seeps are to be sampled for the presence of those
characteristics listed in Attachment B of the SOC. Should any of the newly-identified seeps
exhibit flow volume allowing for the collection of an adequate sample for the purposes of
chemical analysis, such sampling and analysis must be performed, and their results reported to
the Division.
If you have any questions concerning this matter, please contact Bob Sledge at(919) 707-3602.
Sincerely,
"l'/ ::====="---
Linda Culpepper
for
Attachments
cc: Central Files
NPDES Unit—SOC File
ec: Mooresville Regional Office—DWR/Water Quality Regional Operations
Asheville Regional Office—DWR/Water Quality Regional Operations
Shannon Langley—Duke Energy
Chris Hallman—Duke Energy

Attachment A
S17-009
Duke Energy Carolinas, LLC—Allen Steam Station
Non-Constructed Seeps
Approximate Location Receiving
Seep ID Coordinates Description Receiving Waterbody Waterbody SOC Monitoring Interim
Number Latitude Longitude Classification Requirements Action Level
Seep located near northwest N/A—Flow is collected
and pumped back to
corner of Primary Pond 1.Seep NPDES-permitted
S-10 35.18055 -81.01354 flow collected in a French drain wastewater system in N/A N/A N/A
system and conveyed to a tank
from which seepage is pumped accordance with the
pumping system's
• back into the ash basin. design capacity.
Overflow discharge of seepage
collected from S-10 occurring
during temporary, infrequent
power outage episodes. Instream
-
S-12 35.18101 -81.01349 Seepage would flow to a Catawba River(Lake WS-V; B Monitoring of N/A
stormwater drainage channel. Wylie) Lake Wylie 2B Standards Apply
Seep flow is collected and
pumped back into the ash basin
during normal operations.
*Location previously investigated as a seep. Monitoring has not indicated the presence of coal combustion residuals.
**Seep dispositioned via repair and/or non-flowing condition to potentially reach WOTUS,or other,as noted.
Monitoring shall be conducted at the approximate locations indicated on the attached site map.
All monitoring shall be conducted per the requirements found in Attachment B of this Order.

Attachment A
S17-009
Duke Energy Carolinas, LLC—Rogers Energy Complex (Cliffside Steam Station), p.5
Approximate Location Receiving
Seep ID Coordinates _ Description Receiving Waterbody SOC Monitoring Interim
Number Latitude Longitude Waterbody Classification Requirements Action Level
Minor diffuse groundwater seepage along
bank of Suck Creek,west of the active ash Suck Creek
-
S-36 35.210258 -81.753983 basin dike. New area identified with no Suck Creek WS-IV Instream N/A
current data. Area to be monitored to Monitoring 2B Standards Apply
determine status.
Small seep emerging approximately 20 feet Suck Creek
S-37 35.210270 -81.753822 north of S-36 and 25 feet east of Suck Creek Suck Creek WS-IV Instream N/A
as shallow standing water. Flow was too low 2B Standards Apply
Monitoring
to obtain a sample for analysis.
Small seep first observed 4/8/19 on the
south bank of the Broad River,east of the Broad River
-
S-38 35.218562 -81.753919 river's confluence with Suck Creek and west Broad River WS-IV Instream N/A
of constructed seep S-04. Flow was too low Monitoring 2B Standards Apply
to obtain a sample for analysis.
*Location previously investigated as a seep. Monitoring has not indicated the presence of coal combustion residuals.
**Seep dispositioned via repair and/or non-flowing condition to potentially reach WOTUS,or other,as noted.
Monitoring shall be conducted at the approximate locations indicated on the attached site map.
All monitoring shall be conducted per the requirements found in Attachment B of this Order.