NC0000396_Addendum_20150205

�' DUKE Environmental Services
ENERGY. Duke Energy
CAROLINAS 526 South Church Street
Charlotte,NC 28202
Mailing Address:
EC13K/P.O.Box 1006
Charlotte,NC 28201-1006
February 4, 2015
RECEIVED/DENR/DWR
Mr. Jeffrey Poupart, Section Chief FEB 0 5 2015
NC Division of Water Resources
1617 Mail Service Center Water Quality
Raleigh, NC 27699-1617 Permitting Sectior
Subject: Addendum to NPDES Waste Water Permit Application Permit
Chemical characterization of water for dewatering of ash basins
Asheville Steam Electric Plant
NC0000396
Buncombe County
Dear: Mr. Poupart,
Duke Energy hereby submits the attached characterization of wastewaters for the subject
facility. The attached table provides results of chemical analysis of both ash basin free water
and ash basin interstitial water. The ash basin free water sample was taken from water above
the ash in the 1964 ash basin. The ash basin interstitial water samples results from the 1982
basin are presented 1.) without treatment and 2.) after treatment with three different size filters.
The following definitions may be useful as you consider these activities:
Ash basin free water: Water in an ash basin located above the settled layer of ash.
Ash basin free water has undergone treatment in the ash basin, has the same general
characteristics as water discharged when the facility was active sluicing ash to the ash
basin, is largely devoid of Total Suspended Solids and meets all applicable NPDES
permit limits.
Ash basin interstitial water: Water in an ash basin that is located within the pore
space of accumulated wastewater sludge or slurry. Ash basin interstitial water must be
removed from an ash basin by some means such as trenching, well points, etc. and
would likely require additional treatment before being released to the environment.
The process we envision for dewatering of the sites ash basins to enable excavation and ash
removal is detailed in the Coal Ash excavation plan submitted to your agency and dated
November 13, 2014. Specifically, construction of means necessary for handling the sites
ongoing generated wastewater will be necessary. Once all necessary authorizations are
received, dewatering of wastewaters from the 1964 ash basin would begin. Rates of
wastewater removal will be determined by the needs for treatment as well as any restrictions put
in place in order to meet dam safety requirements. Recall that any water from dewatering will

be comingled with active wastewaters generated by the plant and directed to NPDES permitted
outfall 001.
If you have any questions regarding this submittal, please contact Mr. Shannon Langley at (919)
546-2439 or [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 of fines and imprisonment for knowing violations.
Sincerely,
.7,z...) X.--
Harry K. Sideris
SVP, Environmental Health and Safety

Asheville Plant Ash basin water characterization
Water samples taken January 20, 2015
Page 1 of 2
Sample No2+NO3 TKN Bromide Chloride Sulfate Aluminum Barium Beryllium Boron Calcium
(m9IL) (mgn) (m4) (mnn) (m911) (m9n) (m9/I) (m9/I) (m9/I) (WOO
Free water 0.364 0.53 <0.5 10.64 188.5 1.42 0.210 <0.005 1.48 77.1
Interstitial 0.206 0.50 0.596 8.399 110.3 15.4 0.311 <0.005 1.02 44.9
water
Interstitial 0.213 0.50 0.5750 8.431 111.9 9.04 0.217 <0.005 1.06 46.5
(20u filter)
Interstitial 0.244 0.39 0.5970 8.500 112.4 1.27 0.098 <0.005 1.04 44.8
(10u filter)
Interstitial
(0.45u 0.247 0.52 0.5765 8.432 112.1 0.057 0.082 <0.005 1.05 45.0
filter)
Sample Iron(mg/1) Magnesium Phosphorusr Zinc Antimony Arsenic Cadmium Chromium Copper Lead
(mgi) (m9/L) (u9/I) (u9/I) (m9/I) (ugh) (ugh) (ugh)
Free 0.266 3.73 0.063 0.009 6.05 79.2 <1 11.6 4.68 <1
water
•
Interstitial 9.56 11.8 0.473 0.04 <10 72.9 <10 14.6 28.1 16.7
water _ .
Interstitial 5.66 11.7 0.300 0.023 6.66 57.8 <1 8.47 19.1 10.4
(20u filter)
Interstitial 0.779 11.0 0.065 0.006 7.23 21.3 <1 1.19 2.49 1.14
(10u filter) _
•
Interstitial
(0.45u 0.039 10.9 0.030 <0.005 7.18 15.1 <1 <1 <1 <1
filter)

Asheville Plant Ash basin water characterization
Water samples taken January 20. 2015
Page 2 of 2
Sample Molybdenum Nickel Selenium I Thallium Vanadium Mercury TDS TSS pH Conductivity
(ug/l) (ug/I) (ug/I) (ug/I) (ug/l) (ng/1) (mg/I) (mg/I) (s.u.) (umhos/cm)
Free 105 7.59 31.8 0.488 41.3 <0.5 <25 <10 8.03 505
water
Interstitial 228 12.5 15.7 <2 69.2 23.6 250 250 6.87 363
water _
Interstitial 235 12.1 15.7 1.01 44.9 23.9 250 130 N/A N/A
(20u filter)
Interstitial 240 2.72 14.1 0.644 18.8 3.64 250 12 N/A N/A
(10u filter)
Interstitial
(0.45u 236 1.35 13.9 0.576 14.0 0.56 240 <10 N/A N/A
filter)