Built-in 1952, the Southeast Treatment Plant (SEP) is San Francisco’s largest wastewater facility and treats 80% of the City’s sewage and stormwater flows. Many of the existing SEP solids treatment facilities are over 60 years old, require significant maintenance, and are operating well beyond their useful life.

To ensure our sewer system continues to provide sustainable and reliable operations, we are committed to upgrading our largest and oldest treatment facility. The Biosolids Digester Facilities Project (BDFP) will replace and relocate the outdated existing solids treatment facilities with more reliable, efficient, and modern technologies and facilities that will help transform the SEP into a modern resource recovery facility, a proud neighborhood asset, and an attractive workplace. The new facilities will produce higher-quality biosolids, capture and treat odors more effectively, and maximize biogas utilization. In addition, the project will locate the digesters farther away from existing residences and make visual improvements in and around the SEP.