1 - paducah environmental information center

Paducah Site
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WAG 28
17he WAG 28 RI was initiated and
completed during 1999, The primary focus of
the WAG' 28 investigation was groundwater
samples, Soils .collected adjacent to a storm
dfain exposed outside the boundary of SWMU
99 were found to contain PCBs, 99'[c, uranium,
J37Cs, 237.Np, and 234Th.·
The WAG 28 RI consisted of four sites
located within the eastern portion of PGDP,
including three SWMUs and one AOC. The four
sites were SWMU 99, the C-745 Kellogg
Building Site; SWMU 193, the McGraw
Construction ";Facilities; SWMU 194, the
McGraw Construction Facilities Leach Fields;
and AOC 204,a heavily vegetated area located
on the eastern side of PGDP.
Table 3.1 lists the total number of samples
collected at the WAG 28 SWMUs by media. Soil
and water samples were collected and analyzed
for . VOCs, semivolatile organics (SVOAs),
PCBs, metals, and radionuclides. An on-site
screening of alpha, beta, and 'gamma activities
was used to identify the' samples that might
require radioisotopic analysis in a fixed-base
laboratory. The analyzed radioisotopes were
241 Am, 237Np, 239Pu, and 2391240Pu.
Sampling of the soils within SWMU 99
detected a limited suite of metals above
screening criteria and isolated occurrences of
SVOAs in the surface soils. Relatively minor
Table 3.1 Samples Collected During
WAG 28 by SWMU and Media
Subsurface Ground·
Soil water
SWMU 99 134 72
SWMU 193 54 74
SWMU 194 21 0
AOe 204 29 8
concentrations of trichloroethylene (TCE) were
seen in the soils and groundwater of the UCRS.
Higher concentrations of TCE reflective of the
Northeast Plume were observed in the RGA
groundwater samples. Soils collected adjacent
to a storm drain exposed outside the boundary of
SWMU 99 were found to contain elevated levels
of PCBs, 99Tc, uranium, mCs, 237Np, and 234Th.
Data collected for this investigation
identified no TCE present in soils at SWMU 193.
TCE is not a widespread contaminant in the RGA
and McNairy at SWMU 193. The maximum
concentration of TCE reported from the
McNairy water samples was 42 fJg/L, and the
deepest penetration of TCE into the McNairy is
to 32 feet below the base of the RGA. 99Tc is the
most widespread of the radionuclides in the
groundwater at SWMU 193. The distribution
and location of highest WTc activities in the RGA
closely mimics the distribution of TCE. WTc was
detected in two McNairy water samples at 145
pCiIL and 14.8 pCiIL.
Metals detected in the shallow subsurface
at SWMU 194 represent both naturally occurring
conditions and possible releases to the
subsurface. Aluminum levels detected at the site
are considered to represent naturally occurring
concentrations. Cadmium, lead, and chromium
that have been. reported from the site may
represent isolated releases to the subsurface
from the leach field.
For AOC 204, TCE was noted primarily in
the RGA, but not in concentrations that would
indicate a nearby source. The lack of significant
concentrations of TCE in the shallow subsurface
does not support the presence of an on-site
source for TCE at AOC 204. Radionuclides were
not observed at levels of concern in either the
groundwater or soils.
As part of the WAG 28 evaluation process,
the impact on RGA groundwater from possible
contaminant releases was investigated at SWMU
99, SWMU 193, and AOC 204. In general, it is
clear that the predominant· contaminants in the
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Environmental Program Information