Publication Summary

A Class II inspection was conducted at the METRO Renton Wastewater Treatment Plant on January 24-26, 1994. The plant was performing well during the inspection with effective removal of the conventional parameters BOD5 and TSS. The effluent met all permit limits.

A Class II inspection was conducted at the METRO Renton Wastewater Treatment Plant on January 24-26, 1994. The plant was performing well during the inspection with effective removal of the conventional parameters BOD5 and TSS. The effluent met all permit limits.

Bioassays showed toxicity to four of the five species tested. The rainbow trout results did not meet the whole effluent toxicity performance standard. An effluent ammonia concentration of 19.5 mg/L may be responsible for the toxicity found in the effluent. Split sample general chemistry results showed close agreement between Ecology and METRO for both sampling and analysis. Of the five priority pollutant metals detected in the effluent samples, only copper (16 mg/L est.) exceeded EPA marine water quality criteria, exceeding the acute criterion by a factor of 6. The effluent copper concentration was lower than theoretical water quality based limits based on calculated dilution factors. All priority pollutant metals found in the sludge sample were in concentrations below EPA sludge limits and ceiling concentrations for land application. A fecal coliform count for the sludge sample exceeded the EPA Class A pathogen limitation.