In July 2020, in conjunction with our JV partner Webcor, MWH broke ground on the Scope 2 phase of the Southeast Water Pollution Control Plant(SEPPC) Biosolids Digester Facilities Project (BDFP) in San Francisco. The San Francisco Public Utilities Commission (SFPUC) is the third largest municipal utility in California, and the SEP is the SFPUC’s largest wastewater treatment facility, treating 80 percent of San Francisco’s sewage and storm water flows. An average of 60 million gallons per day (MGD) of dry weather flow moves through the SEP, reaching up to 250 MGD during rainstorms.

As part of the SFPUC’s Sewer System Improvement Program(SSIP), a 20-year, multi-billion-dollar citywide investment to upgrade aging sewer systems, the BDFP will replace existing digester facilities with expanded relocated facilities and will maximize control of odors, reduce energy consumption, reuse of biogas and present a Class A biosolids, through the thermal hydrolysis process. The new infrastructure will eventually replace almost 50% of the plant’s processes.

The BDFP is one of the first projects in the U.S. to use the Thermal Hydrolysis Process. This technology will enable the new facilities to produce higher-quality class A biosolids, capture and treat odors more effectively, and maximize biogas utilization. MWH’s expertise in these systems is global, having installed THP processes in multiple plants, including several in the UK and the U.S.