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Halaco Engineering Co. IA Section 3
CAD009688052
The definitive metals results for waste samples collected from the Smelter area (two samples),
WDA (four samples), and WMU (35 samples) are presented in Table 3-2. Sample results are
compared to both three-times the value of the highest background soil sample and PRGs. All of
the WDA and Smelter Area samples, as well as 33 of the 35 WMU samples, have metals results
that exceed three-times background for at least one of the following analytes: Al, Sb, As, Ba, Be,
Cd, Cr, Cu, Co, Pb, Mg, Mn, Ni, Ag, Thallium (Tl), and Zn. All of the waste samples collected
from the WDA, one of the two waste samples collected from the Smelter Area, and all but two of
the WMU waste samples exceed the PRGs.
3.2.1.4 Radionuclides
Of the 397 solid-matrix samples collected at the Site, WESTON® submitted 130 samples for
definitive analyses for radionuclides. The analytical methods used to analyze the target suite of
radionuclides include EML HASL 300 for 137 Cs and 40 K, and DOE EML HASL-300, Th-01-RC
Modified for 228 Th, 230 Th, and 232 Th. Radionuclides are reported in picoCuries per gram (pCi/g).
The laboratory results for solid matrix samples are presented in Table 3-3 and are broken out by
matrix (soil, sediment, solid waste), area, and background designation. Laboratory data packages
are included in Appendix G.
The results are compared to the second standard deviation (2 nd StDev) from the mean of the
background samples for each matrix, as prescribed in the HRS. The 2 nd StDev is the common
statistical property describing the range of values that envelop approximately 95% of
observations of a set of data. The resulting value, calculated for each analyte and sample matrix,
was used as the basis of comparison to determine whether radionuclide results in target solids are
significantly above background levels. These values are calculated via the method presented in
Appendix J and presented in Table 3-3 beneath the background samples for each matrix.
The definitive results for the marine sediment samples indicate no significant difference in
concentrations of radionuclides between downgradient and background samples. The exception
is that the 228 Th value for SDM16 is significantly above background; this value is lower than the
highest background concentration for this radionuclide.
The definitive results for the Beach sediment samples indicate that all downgradient samples
yield results that are significantly above background values for at least one of the following
radionuclides: 137 Cs (one of six samples), 228 Th (five of six samples), 230 Th (three of six
samples), and 232 Th (six of six samples) .
The definitive results for the OID sediment samples indicate that eight out of ten downgradient
samples yield results that are significantly above background values for at least one of the
following radionuclides: 228 Th, 230 Th, and 232 Th.
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