HomeMy WebLinkAboutNC0003468_DRSS CSA Rpt_Appx F_Ash Basin, Sedi, and SW Chara_20150814
Appendix F
Surface Water and Sediment
Characterization
• Sampling Procedures
• Sampling Variances
Sampling Procedures
Surface Water Samples
There are no surface waters located in the anticipated groundwater flow direction at the site
between the ash basin and Lake Wylie. Therefore, no surface waters are proposed outside of
the ash basin.
WITHIN ASH BASIN
Surface water samples will be collected from the active ash basin at the approximate open
water locations (SW-1 through SW-4). At each location, one water samples was collected –
sample close to the surface (i.e., 0 foot to 1 foot from surface). Although a second sample was
to be taken at the approximate middle depth of the water body, all samples were collected at the
waters edge due to safety. Prior to sampling, the depth to ash will be measured by slowly
lowering a measuring stick or tape until the ash surface is encountered, being careful to avoid
suspending the ash. The depth to ash will be noted and a sample thief will be slowly lowered to
the desired depth to collect the sample. The sample thief and sample will be retrieved and the
sample will be transferred to the appropriate sample containers provided by the laboratory. Ash
basin surface water samples will be analyzed for the same constituents as groundwater
samples. Select constituents will be analyzed for total and dissolved concentrations as well as
speciation.
Seep Samples
Water samples will be collected from the seep sample locations shown on (S-1 through S-9).
The seep samples will be analyzed for the same constituents as groundwater samples. Select
constituents will be analyzed for total and dissolved concentrations as well as speciation.
Water samples were previously collected from seep sample locations S-1 through S-9 in
September 2014 as part of Duke Energy’s NPDES permit renewal application package. The
analytical results indicated exceedances of 2B Standards for several constituents: boron, iron,
manganese, zinc, and thallium. Duke Energy collects surface water samples from Lake Wylie
from upstream and downstream locations for their existing NPDES permit requirements. If seep
sample analytical results indicate potential for impacts to Lake Wylie, then surface water quality
data collected in Lake Wylie will be reviewed at a later date.
In March 2014, DENR conducted seep sampling at the site. HDR reviewed the data and
determined all of the seep sample locations were needed.
After analytical results for seep samples are reviewed, a determination will be made concerning
collection of additional off-site seep samples. If it is determined that additional off site seep
samples are to be collected, the DWR regional office will be contacted.
Sediment Samples
Sediment samples were collected from the bed of the seep samples at the locations described
in Section 9 (designated as S-1 through S-9) in conjunction with collection of the seep samples.
The sediment samples were analyzed for total inorganics using the same constituents list
proposed for soil and ash samples.
Sampling Variances
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