Dames & Moore, 1999 - USDA Forest Service

the ventilator portal drainage is not presumed to occur at this rate. The results of the screening for this
medium are presented in Table 7.1-32. All constituents were eliminated as IHSs based on this screening.
Sauna Water (Copper Creek Diversion)
Historical and 1997 analytical data collected for the Copper Creek diversion were screened against the
appropriate screening criteria to evaluate risks associated with the sauna dipping pool. Area background
concentrations of total metals in surface water were statistically derived in Section 5. Total and dissolved
metals data were combined for this screening since very few total metals data were available. The
conservatism in the sauna screening significantly overestimates potential risk to human health posed by
this medium because the screening criteria are for tap water consumption. Incidental ingestion of water in
the sauna dipping pool is not presumed to occur at this rate. The results of the screening for this medium
are presented in 7.1-33. All constituents were eliminated as IHSs based on this screening.
Groundwater
Two samples were collected from the Lucerne USFS well in 1997. These sample results were screened
against drinking water criteria. There was insufficient data to calculate area background concentrations for
groundwater; however, the concentrations detected in background samples are presented in the screening
table for comparison purposes. The results of the screening for this medium are presented in Table 7.1-34.
All constituents were eliminated as IHSs based on this screening.
Fish Muscle Tissue
PNL and Ecology fish muscle tissue data were screened against U.S. EPA Region 111 Risk-Based .
Concentrations for fish. None of the muscle concentrations exceeded the screening concentrations. The
results of this screening are presented in Table 7.1-35. There were insufficient data to calculate background
concentrations for fish tissue; however, the concentrations detected in the upstream samples are presented in
the screening table for comparison purposes. Based on this screening, all constituents were eliminated as
1HSs. Fish ingestion was also evaluated using surface water data particularly because not all metals were
analyzed during the PNL and Ecology sampling efforts.
7.1.3.4 Refined Exposure Pathway Model
Results of the screening level human health assessment were used to refine the exposure pathway model
(Figure 7.1-2). For exposure routes with all source concentrations (i.e., the maximum observed for the
appropriate medium) below the screening criteria, the risk to a human receptor from that route was
considered negligible. These exposure routes, and if appropriate the corresponding exposure pathway, were
eliminated from the exposure model. As illustrated, exposure to IHSs in soil, air, sediments, surface water,
seeps, and mine portal drainage is assumed to represent potential exposure routes of concern for the Site and
were subject to additional evaluation.
7.13.5 Indicator Hazardous Substances
Based on the results of the screening level human health assessment, IHSs were selected for each media.
IHSs selected for each exposure route are detailed in Table 7.1-36. Site-specific cleanup levels and risk
estimates for these IHSs were calculated in the site-specific human health risk assessment.
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17693-00S-019Uuly 27.19995:16 PMDRAFT FINAL RI REPORT