NC0004774_CSA Report Appx F_SW and Sediment Characterization_20150823

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Surface Water and Sediment
Characterization
• Sampling Procedures
• Sampling Variances

Sampling Procedures
WITHIN ASH BASIN
Surface water samples was collected from Cells 1, 2, and 3 at the approximate open water
locations (SW-AB1 through SW-AB7). At each location, two water samples were collected —
one sample close to the surface (i.e., 0 to 1 foot from surface) and one sample at a depth just
above the ash surface (i.e., 1 foot to 2 feet above the ash to avoid suspending the ash within the
sample). Prior to sampling, the depth to ash was 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 was noted, and a sample thief was slowly lowered to the desired depth to
collect the sample. The sample thief and sample was retrieved and the sample was transferred
to the appropriate sample containers provided by the laboratory. In areas where the water body
is less than 5 feet deep, one water sample was collected from the location at a depth just above
the ash surface. Ash basin surface water samples were analyzed for the same constituents as
groundwater samples. Select constituents were analyzed for total and dissolved concentrations
as well as speciation.
OUTSIDE ASH BASIN
Two water samples were collected from the surface water located west of the ash basin (SW-1
and SW-2). The SW-2 location was considered a background surface water sample. A third
surface water sample (S-1A) was collected 3-feet below the surface of a small pond located
southeast of Cell 3 outside of Duke Energy property line. Duke will contact the property owner
and request permission to collect this sample. These surface water samples were analyzed for
the same constituents as groundwater samples. Select constituents were analyzed for total and
dissolved concentrations.
Seep Samples
Water samples were collected from the seep sample locations as described herein. These seep
sample locations (designated as S-1 through S-10, S-1 B, and S-1 C) were collected near the
time of the monitoring well sampling to minimize concerns about potential temporal variability
between surface water and groundwater and analyzed. Select constituents were analyzed for
total and dissolved concentrations. Seep samples S-1 B and S-1 C were identified and located
off -site on adjacent property. Sample S-1 B is located in a channel below the dam of a small
pond and sample S-1 C is located where seepage emanates into the channel from the west
bank of the channel. Duke has been in contact the property owner and request permission to
collect this sample, however, as of the date of this report, permission has not been granted.
In March 2014, DENR conducted sampling of seeps and surface water locations at the site.
HDR does not have the analytical results from this sampling event at this time; however, once
data is received, HDR will review the data and determine if changes in the proposed seep or
surface water locations is needed.

After analytical results for seep samples are reviewed, a determination was 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 surface of the surface water located west of the
ash basin (designated as SW-1 and SW-2) and the seep sample locations (designated as S-1
through S-10, S-1 B, and S-1 C, respectively). Sediment samples S-1 B and S-1 C are located off -
site on adjacent property. Sample S-1 B is located in a channel below the dam of a small pond
and sample S-1 C is located where seepage emanates into the channel from the west bank of
the channel. Duke has been in contact the property owner and request permission to collect
this sample, however, as of the date of this report, permission has not been granted.

Sampling Variances

1
2
3
4
5
6
7
8
Variances from Groundwater Assessment Work Plan
Surface Water and Sediment Characterization
' - -
Collect surface water and sediment
samples from SW-1
Collect surface water and sediment
samples from SW-2
Collect surface water samples from
S-1 A, S-1 B, and S-1 C
Collect surface water and sediment
sample from BS SWO01AA S001
Collect surface water and sediment
sample from BS SWO03AA S001
Collect surface water and sediment
sample from BSWO01S001
Collect surface water and sediment
sample from BSW074SO01
Collect surface water and sediment
sample from BSW076SO01
pleted`C7
Not collected I Location was dry at time of sampling.
Not collected I Location was dry at time of sampling.
Not collected Duke legal department unable to reach agreement
with property owner to collect samples.
Not collected Location was dry at time of sampling.
Not collected I Location was dry at time of sampling.
Not collected I Location was dry at time of sampling.
Not collected I Location was dry at time of sampling.
Not collected "' Location was dry at time of sampling.