Environmental engineering consulting firm Brown and Caldwell has been awarded an $80 million contract by the San Francisco Public Utilities Commission (SFPUC) to provide planning and engineering services for the Southeast Plant Biosolids Digester Facilities Project, a $1.5 billion capital investment that will provide critical upgrades for San Francisco’s wastewater system.

The project will result in the replacement of all biosolids processes at San Francisco’s Southeast Water Pollution Control Plant, including anaerobic digesters, solids dewatering, solids thickening, odor control and energy recovery facilities.

SFPUC’s Southeast Plant is in the Bayview-Hunters Point neighborhood and is the largest wastewater treatment facility in San Francisco, treating 80 percent of the city’s total flow. Some of the biosolids facilities date back to the plant’s original construction in the 1950s and have reached the end of their useful life. SFPUC’s goal is to leverage the need to replace this aging system in a way that enhances the city’s goals for sustainability, flexibility and community benefits.

Early in the project, Brown and Caldwell’s team will help SFPUC determine which biosolids treatment technology to use. SFPUC has expressed interest in and is now piloting an emerging technology — thermal hydrolysis process (THP) pretreatment. Across Europe, THP has proved to reduce digester volume and offer many resource recovery 2 benefits.

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"With our company roots beginning in San Francisco on Sansome Street in 1947, we are delighted to be working with the SFPUC on this project," said Craig Goehring, CEO of Brown and Caldwell. “We have an accomplished team of international experts and local businesses joining us, and a fully engaged group of community stakeholders.”

Brown and Caldwell is leading a team that includes major partner CH2M HILL, as well as a variety of subconsultants that include 12 San Francisco local business enterprises.

The new biosolids facilities are expected to be fully designed, constructed and operational within 10 years.