NC0000396_Release of Interstitial Water_20180425

ROY COOPER
INIC
Govet not
MICHAEL S.REGAN
Secretary
Water Resources LINDA CULPEPPER
Environmental Quality Interim Darectot
April 25, 2018
Richard Baker
EHS CCP Environmental Programs
526 South Church St,
Charlotte,NC 28202
Subject: Release of Interstitial Water for Ash Basin Excavation
Asheville Steam Station NC0000396 Buncombe County
Dear Mr. Baker:
The Division of Water Resources has reviewed your April 18 letter regarding pumping of
interstitial wastewater from excavated areas of 1964 ash pond to active nm ditch at the Asheville
Steam Station.
The Division has determined that this interstitial pumped water cannot be added to the rim ditch
without treatment at this time. We have consistently stated that decanting and potentially
dewatering can only occur under an administratively continued permit only if they do not
significantly change the flow and characteristics of the effluent. The data included in this request
indicate that the arsenic concentrations in the final discharge will rise by 21%which is
significant and precludes addition of this water without treatment.
The NPDES permit for this facility will be reissued later this year. The reissued permit
contemplates the dewatering phase of ash pond closure and may allow for the discharge of this
water to the rim ditch without further treatment depending on the outcome of calculations for the
final effluent.
If you have any questions about this letter,please contact me at(919) 807-6309, or via e-mail at
[e-mail].
Sincerely,
Jeff Poupart
Water Quality Permitting Section Chief
cc: Central Files
ARO
Permit file
—- Nothing Compares_.
State of North Carolina I Environmental Quality
1611 Mail Service Center I Raleigh,North Carolina 27699-1611
919-707-9000