13.01.2013 Views

Dames & Moore, 1999 - USDA Forest Service

Dames & Moore, 1999 - USDA Forest Service

Dames & Moore, 1999 - USDA Forest Service

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Measurement Endpoints<br />

Measurement endpoints are parameters obtained by site-specific environmental sampling or laboratory<br />

testing. The measurement endpoints selected for the Site include a variety of anal>zical and observational<br />

data. Information derived from these measurement endpoints were used to evaluate assessment endpoints.<br />

The specific measurement endpoints (data) used in this assessment are:<br />

Surface water samples. These provide data on PCOC distributions and concentrations<br />

at the Site, and permit evaluation of potential ecological risks to aquatic receptors<br />

exposed via PCOCs in surface water and to terrestrial receptors through ingestion<br />

(drinking).<br />

Sediment samples. These provide information on PCOC distributions in sediments at<br />

the Site, and permit evaluation of ecological risk to aquatic receptors exposed via PCOCs<br />

in sediment.<br />

Tailings piles and soils samples. These provide data on PCOC distributions in soils and<br />

tailings piles at the Site, and provide an estimate of PCOC concentrations in the soil<br />

ingestion fraction in dose modeling for mammals (where applicable).<br />

Fish tissue samples. These provide baseline evidence of presence/absence of PCOCs in<br />

the Site's aquatic food-web, can be used to estimate PCOC concentrations in diet for<br />

calculating dietary dose to fish-eating birds or mammals, and may be used to directly<br />

assess impacts to fish where applicable body burden toxicity information is available.<br />

Benthic community assessments. These are indicative of potential impacts as expressed<br />

directly by the characteristics of the benthic communities.<br />

~ i scommunity h assessments. These are indicative of potential impacts as expressed<br />

directly by the populations in fish communities.<br />

7.23.2 Toxicity Benchmarks<br />

Toxicity benchmarks are screening level estimates of the concentrations of chemicals that are expected to<br />

cause no adverse effects on plants or animal populations. These generally take the form of state or federal<br />

promulgated criteria, but may also include databases or guidelines developed by state, federal, or private<br />

organizations which are recognized as estimates of safe concentrations. In this document. several tiers of<br />

toxicity analysis were conducted. In the first tier, media concentrations of metals were compared to federal<br />

or state screening values. Those metals that were below these screening values were eliminated from hrther<br />

analysis. Those metals that exceeded these screening values were carried through the risk assessment. In<br />

the second tier of analysis, more site- and receptor-specific toxicity was sought in the peer-reviewed toxicity<br />

literature and these values became the toxicity benchmarks for evaluating risk. The following section deals<br />

with tier 1, elimination of COCs. The tier I1 toxicity reference values are also found according to specific<br />

receptor, below.<br />

G:\~uWOJLcpomUloldrn-2\n17-O.doc<br />

17693-005419Uuly 27. <strong>1999</strong>.5:16 PMDRAFT FINAL RI REPORT<br />

,

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!