Publication Summary

Ecology conducted a Class II Inspection at the city of Marysville Wastewater Treatment Plant on July 16-17, 1990. Timing of the inspection was prompted by a Notice of Violation issued to the City in February 1990 for repeated violations of permit conditions. The resultant Consent Order contained revised effluent limits which were to be met by July 15, 1990. The plant was probably violating these limits for BOD5.

Ecology conducted a Class II Inspection at the city of Marysville Wastewater Treatment Plant on July 16-17, 1990. Timing of the inspection was prompted by a Notice of Violation issued to the City in February 1990 for repeated violations of permit conditions. The resultant Consent Order contained revised effluent limits which were to be met by July 15, 1990. The plant was probably violating these limits for BOD5.

Short-circuiting, limited use of available aerators, and a single inlet in the system were contributing to reduced performance. Very little nitrification was occurring. Effluent ammonia concentrations exceeded freshwater criteria for chronic toxicity. Effluent back-up during high tide likely promotes elevated concentrations of chlorine. Copper and lead exceeded criteria for protection of freshwater and marine life. Arsenic and Aroclor-1254 were present in lagoon sludge in significant concentrations. High chronic toxicity was indicated by the echinoderm bioassay; mild toxicity by several other bioassays.

All three flow measuring devices had deficiencies, and the accuracy of their flow data is open to question. There were a number of problems with their composite samplers, creating the opportunity for collection of unrepresentative samples. A laboratory evaluation found a well run lab with no significant problems. However, the lone plant operator/lab technician appeared to be fully committed with present duties.