Publication Summary

The Washington State Department of Ecology sampled the Spokane River upstream and downstream of Kaiser Aluminum and Chemical Corporation, Trentwood Works (Kaiser). The samples were analyzed for PCB Aroclors and congeners to determine concentrations and possible sources of PCBs to the river. Kaiser outfall 001 was also sampled for PCB Aroclors and congeners.

The Washington State Department of Ecology sampled the Spokane River upstream and downstream of Kaiser Aluminum and Chemical Corporation, Trentwood Works (Kaiser). The samples were analyzed for PCB Aroclors and congeners to determine concentrations and possible sources of PCBs to the river. Kaiser outfall 001 was also sampled for PCB Aroclors and congeners.

Results were incomplete as a result of laboratory PCB-1254 and 1260 contamination. A single grab sample of river water downstream of Kaiser showed 1.1 pptr PCB-1248. Four other grab samples of river water downstream of Kaiser resulted in nondetected PCB Aroclors at detection limits between 0.9 and 1.0 pptr. Because river water concentrations of PCB-1248 were lower than expected, most samples yielded nondetectable results.

Results of samples from the Kaiser outfall were inconclusive. The four grab sample results were highly variable as a result of apparent non-homogeneity of the effluent. PCB-1248 was the only Aroclor detected in the effluent, with concentrations ranging from 53 pptr to nondetection at 0.9 pptr. A more precise measure of the PCBs in the Kaiser effluent will require a larger number of samples to be taken, or the production by Kaiser of a more homogeneous effluent.

Future characterizations of PCBs in Spokane River water may require ultra-low level detection methods or field sampling techniques that concentrate PCBs from the water.

Link to EIM data for User Study ID SGOL001