Publication Summary

Ecology conducted a Class II Inspection at Kaiser Aluminum and Chemical Corporation, Trentwood, Washington, on May 21-23, 1990. Kaiser operates an aluminum rolling mill and metal finishing plant. Kaiser is permitted to discharge wastewater to the Spokane River as regulated by NPDES Permit No. WA-000089-2. Wastewater generated at Kaiser is discharged to the river through a four million gallon wastewater lagoon. The influent to the lagoon consists of effluent from industrial and domestic wastewater treatment (DWT) facilities, and contact and non contact cooling water.

Ecology conducted a Class II Inspection at Kaiser Aluminum and Chemical Corporation, Trentwood, Washington, on May 21-23, 1990. Kaiser operates an aluminum rolling mill and metal finishing plant. Kaiser is permitted to discharge wastewater to the Spokane River as regulated by NPDES Permit No. WA-000089-2. Wastewater generated at Kaiser is discharged to the river through a four million gallon wastewater lagoon. The influent to the lagoon consists of effluent from industrial and domestic wastewater treatment (DWT) facilities, and contact and non contact cooling water. Kaiser was operating within the permit limits except for oil and grease samples collected from the lagoon discharge. A moderate removal efficiency of TSS, BOD5, and COD was realized in the domestic wastewater treatment facility; lead concentrations were somewhat elevated. Effluent from the industrial wastewater treatment facility was high in solids, chromium+6, and copper, and moderately high in selenium. Industrial wastewater effluent to the lagoon caused 100% mortality in all four bioassays, both acute and chronic, indicating the presence of toxicity. Kaiser has added multi-media filtration since the inspection. No significant quantities of organic compounds were found in any of the sampled waste streams.