The SFPUC Biosolids Digester Facility Project (BDFP) is a multi-year, multi-structure infrastructure modernization effort aimed at upgrading San Francisco’s aging Southeast Water Pollution Control Plant (SEP). As the city’s largest wastewater treatment facility—processing 80% of San Francisco’s sewage and stormwater—this $2.3 billion, 400,000-square-foot project strengthens infrastructure resilience, promotes environmental sustainability, and enhances community well-being.

The project introduces cutting-edge wastewater treatment solutions, including advanced biosolids processing and odor control measures. It optimizes biogas recovery for energy reuse and relocates digesters away from residential areas to reduce impacts on the Bayview community. These upgrades improve treatment efficiency, enhance operational performance, and ensure long-term resilience to major earthquakes and sea-level rise

New operational and maintenance facilities further enhance plant efficiency and reliability. Key infrastructure includes the Cambi Thermal Hydrolysis Process (THP), advanced pretreatment, anaerobic digestion, digestion cooling towers, biosolids dewatering systems, and solids odor control. The reclaimed water treatment system incorporates a testing lab, sampling spaces, steam boilers, and waste gas burners. A new control center provides access to critical process control systems, electrical distribution, and odor mitigation technologies. Given the complexity of these systems, an on-site quality assurance team ensures compliance with city regulations while overseeing all construction activities.

A major sustainability focus of the project is freshwater conservation and environmental protection. The plant’s process systems use recycled effluent instead of fresh water, reclaiming biosolid water for on-site reuse or safe treatment and discharge into San Francisco Bay, free of pollutants. Biogas is captured for reuse, while Class-A biosolids are processed for agricultural fertilizer. The project is contained within a previously developed site, avoiding new land use. A comprehensive remediation plan removes hazardous materials and contaminated soils, while stormwater retention systems and natural landscaping improve water efficiency and ecological health.

The project also delivers significant community benefits. Infrastructure improvements along Jerrold Avenue and Quint Street include ADA-compliant sidewalks and curb ramps, traffic calming measures, upgraded lighting, and modernized streetscapes. Thoughtful facility siting and contemporary building façades minimize visual, noise, and odor impacts. A landscaped courtyard and pedestrian pathways transform the industrial site into a welcoming space for staff and visitors, reinforcing the project’s commitment to community integration.

The SFPUC Biosolids Digester Facility sets a new standard for wastewater management, environmental responsibility, and community-focused infrastructure in San Francisco.

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