Single Tank Activated Sludge Pretreatment System for Paper Mill Whitewater, 1992 Environmental Conference Proceedings

Willamette Industries, Inc. owns a corrugating medium mill in Port Hueneme, California. The mill produces approximately 450 tons of finished product per day using a variety of wastepaper furnishes.

Excess whitewater from the paper machine operations are discharged to the City of Oxnard Wastewater Treatment Plant. In August, the municipal treatment plant requested the mill and all other industrial contributors to voluntarily reduce BOD discharges by at least 10% in attempt to reduce the municipality’s effluent and avoid future exceedances of the treatment plant’s NPDES effluent limitations.

At the request of Willamette, Eder Associates designed a unique single tank activated sludge pretreatment system for a portion of the mill’s effluent utilizing an existing 60’ diameter 25’ deep tank on the mill property. The tank was modified to include a proprietary internal settling compartment design and a 75 HP floating surface aerator. The treatment system was designed and built in 5 days and was under full operation within 10 days.