Selected Fish Tissue Contaminant Data from the U.S. EPA Columbia River Toxic Substances Study.

The Columbia River and segments of the Snake and Willamette Rivers are
currently water quality limited due to the presence of elevated levels
of 2,3,7,8 - TCDD. As a result, U.S. EPA Region 10 established a
Total Maximum Daily Load (TMDL) of 6 mg of 2,3,7,8-TCDD/day based upon
state water quality standards applicable to the Columbia River basin
and the volume of water in the Columbia River. This project is part
of an effort to add to the data base on contaminant levels in aquatic
organisms in the Columbia River. The project focused on one or two
sampling locations in a limited segment of the river. Criteria for
choosing these locations were: (1) sampling at fishing sites has been
limited, (2) collecting organisms that are consumed by Native
Americans and others fishing in the Columbia River basin, (3)
collecting organisms that are of good indicators of contaminant levels
in the river and of levels of contaminants that may be ingested by
aquatic and terrestrial predators. Sediment samples were taken
between RM 146-149 and consisted of five grabs per station.

The area of the study was Columbia River - RM 146-149 above Bonneville
Dam.

Samples consist of a composite of five grabs per station.

Target analytes were dioxins and furans; pesticides; PCBs; semi-volatiles
including PAHs; metals (including Hg and As).

Analytical techniques included dioxins and furans (EPA Method 1613A);
pesticides and PCBs (EPA 8081); semi-volatiles (EPA 8270/GPC); PAHs
(EPA 8270); metals (EPA 200.3 and 6010A); Hg (EPA 7471A); As (200.3
and 7060A). Results are reported on a dry weight basis. Total dioxin

and furan concentrations were determined by the laboratory as the sum
of the individual congeners that were detected.