Dames & Moore, 1999 - USDA Forest Service

provide adequate data to cany forward into the decision processes for the FURS. A summary of the
methodology changes is provided in the following paragraphs in individual discussions per media.
The soil analytical plan was adapted to include analyses of ferricrete, flocculent, and portal film samples.
Samples were analyzed for metals by EPA SW846 methods. Sample preparation prior to analysis was
adjusted to account for the matrix. The ferricrete samples were crushed prior to analysis. The matrix was
treated as a solid sample and prepared accordingly. The flocculent samples were centrifuged to separate
the solid material from the water. An aliquot of solid material was then taken for analyses. The liquid
and solid fractions of the portal film samples were allowed to separate. The liquid portion was decanted
and the remaining film component was used for analysis. These procedures were documented in the
laboratory analytical data.
Surface water samples were analyzed for metals, conventional parameters, PCB's, and total petroleum
hydrocarbons by the methods previously described. In order to provide analytical data to achieve MDLs
and PQLs as low as or as near to the RBSLs as technologically possible, modifications to the standard
EPA methodologies were required. The modification for surface water metals analyses consisted of a 5:
fold concentration step to aid in achieving the detection limits below the surface water quality criteria. To
achieve the low level detection limit required to meet the chronic criteria for mercury, a specialized low
level draft method by EPA (1631) was employed during the Phase 1 RI. Mercury analyses was deleted
from the Phase I1 program based on the Phase I results. Evaluation of lead data from surface water
collected during the Phase I and Phase I1 RI indicated that a lower detection limit was necessary to
determine if lead concentrations in surface water were above or below chronic water quality criteria. The
method for lead in surface water was revised in the Phase 111 RI sample collection to low level EPA
Method (1 638). PCBs were analyzed during the Phase I by a modified EPA method to achieve the lowest
detection limits possible. Based on the Phase I results, PCB analyses were also deleted from the Phase 11
RI.
Groundwater and seep samples were analyzed for metals, conventional parameters, PCBs and total
petroleum hydrocarbons by the methods previously described. During the Phase I RI, it was determined
that the detection limits for metals provided in the QAPP were not achievable by the methods requested
due to total dissolved solids present in groundwater and seep samples. A revision to the metal analyses in
the QAPP was made to allow the majority of metals to be analyzed by ICP (EPA Method 60 10) instead of
ICPMS (EPA Method 200.8). The change in methodology was specifically for barium, chromium,
copper, manganese, nickel, and sodium. In the Phase I1 program, the 5-fold concentration step was also
eliminated for groundwater samples. Additional revisions were made to the Phase I QAPP in July due to
similar issues with the seep samples. Samples collected in July were analyzed for metals using ICP (EPA
601 0A) and graphite furnace analysis (GFAA EPA 7000 series) instead of ICPMS, with the exception of
uranium, in an effort to meet the PQLs requested in the QAPP. The methodology for groundwater
samples collected during the Phase I1 RI was revised to reflect the analytical plan provided for seep
samples in the Phase I1 QAPP.
Data validation reviews were performed by Dames & Moore chemists and reviewed by the QNQC
manager for all laboratory analyses for organic and inorganic analytical data packages received from ARI.
The following guidelines were used for data validation reviews of results for metals, PCBs, total
petroleum hydrocarbons, and conventional parameters for surface water, groundwater, soil, sediment,
ferricrete, flocculent, and portal film samples.
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17693-005-019Uuly 19.1999;2:07 PM;DRAFT FINAL RI REPORT