Owner: City and County of San Francisco
Contract value: $15,373,000
The Oceanside Water Pollution Control Plant (OWPCP) is a secondary treatment plant handling one-third of San Francisco's wastewater. The maximum treatment plant capacity is 65 million gallons per day, with the average daily dry weather flow of 17.5 million gallons. The facility was built in 1993 with 70 percent of the structure underground.
The objective of the project is to reconfigure the existing conventional single stage anaerobic flow-through digestion process to a sequencing batch reactor, temperature anaerobic digestion process (SBR TPAD), replacing boilers, replacing the insulation and weather protection on the four existing degester vessels with closed-cell foam and tensioned fabric membrane, installing scum pumps and screening unit, and performing digestion process equipment improvements. The SBR TPAD upgrade is intended to produce a Class A biosolids product, which works to promote sustainable heat recycling techniques and increase volatile solids reduction. The SBR TPAD system will also contribute to bringing the OWPCP close to energy self-sufficiencey.
The majority of the structure is underground, which creates complexity for material handling. The biggest challenge is the logistics of performing the work within the existing OWPCP without affecting plant operations.