Dames & Moore, 1999 - USDA Forest Service

7.133 Screening Level Evaluation of Data
The screening level evaluation of data consisted of data segregation by exposure pathway, followed by a sis
step comparative evaluation which served as the primary basis of the screening. Criteria used for the
comparative evaluation are discussed above.
The screening tables summarize the results of the data evaluation. As noted above, the mavimum
concentrations presented in the source concentration columns of the tables represent the maximum obsenled
for the medium of interest from the available data. If no toxicity criteria (and thus no Method A or Method
B level) were available for a constituent, it was discussed qualitatively. Each exposure medium is discussed
individually below.
Surface Soil
The maximum concentrations observed for each location were used as the source concentrations for
comparison to the screening criteria based on soil ingestion. The background concentrations used for
screening were statistically derived or obtained from Natural Background Soil Metals Concentrations in
Washington State (Ecology, 1994) for the Yakima basin and Dames & Moore 1998 data. In addition. for
those constituents which did not have an available area background or Ecology natural background level.
background levels for the State of Washington (Dragun, 1991) are presented for comparison purposes. No
constituents were eliminated as MSs based on the Dragun ranges, however.
Holden Village
Soil samples were collected throughout Holden Village. The samples were collected randomly throughout
the village and at the closest proximity to the tailings piles. Given the spatial distribution of the soil
samples, the results should adequately represent surface soil in and around Holden village.' The results of
the screening for this exposure area are presented in Table 7.1-6. The only constituent selected as an IHS
based on the screening was beryllium.
Holden Village Vegetable Garden
One soil sample was collected in the Holden Village vegetable garden. This sample result was used to
evaluate both soil ingestion and ingestion of home-grown produce. The site measurements were compared
against soil cleanup levels based on protection of residential receptors who may contact site-related
constituents through ingestion. Comparisons against these criteria were considered conservative for the
produce ingestion route since these cleanup levels were developed using exposure assumptions that are
more conservative than those that would reasonably be assumed for ingestion of home-grown produce. The
results of the screening for this exposure area are presented in Table 7.1-7. All constituents were eliminated
as IHSs based on this screening.
Baseball Field
One soil sample was collected in the baseball field. The results of the screening for this exposure area are
presented in Table 7.1-8. All constituents were eliminated as IHSs based on this screening.
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17693-005-019Uuly 27. 1999.5: 16 PM;DRAFT FINAL R1 REPORT