Publication Summary

A Class II Inspection was conducted at the Olympus Terrace Sewer District Wastewater Treatment Plant (WTP) on March 16-19, 1992. The WTP was performing well during the inspection. The conventional parameters of five-day carbonaceous biochemical oxygen demand (CBOD5), total suspended solids (TSS), and fecal coliform indicate a well-treated, high quality effluent. The effluent met permit limits for CBOD5, TSS, fecal coliform, and pH.

A Class II Inspection was conducted at the Olympus Terrace Sewer District Wastewater Treatment Plant (WTP) on March 16-19, 1992. The WTP was performing well during the inspection. The conventional parameters of five-day carbonaceous biochemical oxygen demand (CBOD5), total suspended solids (TSS), and fecal coliform indicate a well-treated, high quality effluent. The effluent met permit limits for CBOD5, TSS, fecal coliform, and pH.

A number of priority and other organic pollutants were detected in the samples collected. Six priority pollutant organics were found in the effluent, all at concentrations well below U.S. Environmental Protection Agency (EPA) water quality criteria. No pesticides were detected. Of the several priority pollutant metals detected in the effluent, cadmium, copper, and silver exceeded EPA water quality criteria. Bioassay organism sensitivity to Olympus Terrace effluent was variable. Microtox® showed some toxicity. Rainbow trout experienced increased mortality. Fathead minnow showed no significant mortality, but impaired growth. No significant toxic effects were found for Ceriodaphnia dubia or Daphnia pulex. A cause of mortality in the tests may have been exposure of organisms to chlorine. The effluent samples were not dechlorinated prior to the bioassay tests.

In the sediment samples, three organic compounds were detected, but did not exceed Department of Ecology, Marine Sediment Quality Standards. No pesticides/PCB compounds were detected. Nine metals were detected in the sediments, all below applicable sediment standards. The sediment samples had a high sand content, indicating the non-depositional character of the receiving environment.