Publication Summary

Priority pollutant polynuclear aromatic hydrocarbon (PAH), chlorophenol, and polychlorinated biphenyl (PCB) analyses were conducted on surface sediment samples from the cove at the southern end of the J.H. Baxter site and a reference station in Lake Washington. To assess sediment toxicity, Hyalella azteca and Microtox bioassays were also conducted.

Priority pollutant polynuclear aromatic hydrocarbon (PAH), chlorophenol, and polychlorinated biphenyl (PCB) analyses were conducted on surface sediment samples from the cove at the southern end of the J.H. Baxter site and a reference station in Lake Washington. To assess sediment toxicity, Hyalella azteca and Microtox bioassays were also conducted.

Total PAH concentrations, on a dry weight basis ranged from 43-33,000 mg/kg. Peak PAH concentrations in the J.H. Baxter Cove are the highest yet recorded in Lake Washington near either Quendall Terminals or the J.H. Baxter site. The highest PAH concentration measured in the Baxter Cove (3.3% total PAH) would be sufficient to designate these sediments as extremely hazardous waste under Washington State's Dangerous Waste Regulations.

The distribution of PAH and chlorophenols (especially pentachlorophenol) point to an abandoned stormwater retention pond outfall located in the J.H. Baxter Cove, as the most likely source of these compounds to sediments in the cove. PCBs were not detected at any of the locations sampled during the present survey.