Biosolids Digester Facilities Project: Biogas Utilization System

Biosolids Digester Facilities Project: Biogas Utilization System

On March 8, 2018, the San Francisco Planning Commission certified the Final Environmental Impact Report (FEIR) for the Biosolids Digester Facilities Project (Biosolids or approved project) at the Southeast Water Pollution Control Plant (Southeast Plant), located in the southeast part of San Francisco. Originally built in 1952 with major upgrades in 1982 and 1996, the Southeast Plant is the City's largest wastewater treatment facility, treating approximately 80 percent of San Francisco’s sewage and stormwater flows. The approved project includes the construction and operation of a new solids treatment process, odor control, energy recovery, and associated facilities to replace outdated existing facilities with more reliable, efficient, and modern technologies. Biosolids are the recyclable solid materials removed from the wastewater during the wastewater treatment process and digesters are the major facilities used in the solids treatment process. As discussed in the FEIR, a key objective of the approved project is the beneficial reuse of 100 percent of the digester gas generated by the Southeast Plant. To achieve this, the approved project included an energy recovery/cogeneration facility in which boilers and a turbine generator would burn the digester gas (or biogas) in turbines to convert it to heat, steam, and electricity that would then be used to operate the new biosolids facilities (called the “energy recovery system” in the FEIR). However, the SFPUC is now proposing to revise the approved project to convert the digester gas into pipeline-quality, renewable natural gas for injection into PG&E’s existing natural gas pipeline, referred to hereafter as the “biogas utilization system.” Consequently, the energy recovery system components would be removed from the approved project. This alternative end-use of the digester gas would result in a smaller footprint of new facilities to be constructed and simplify Southeast Plant operations.

San Francisco

San Francisco

Citywide

California Air Resources Board (ARB), California Department of Conservation (DOC), California Department of Fish and Wildlife, Bay Delta Region 3 (CDFW), California Department of Fish and Wildlife, Marin Region 7 (CDFW), California Department of Parks and Recreation, California Department of Transportation, District 4 (DOT), California Department of Water Resources (DWR), California Energy Commission, California Highway Patrol (CHP), California Native American Heritage Commission (NAHC), California Natural Resources Agency, California Public Utilities Commission (CPUC), California Regional Water Quality Control Board, San Francisco Bay Region 2 (RWQCB), California State Lands Commission (SLC), San Francisco Bay Conservation and Development Commission (BCDC), State Water Resources Control Board, Division of Drinking Water, State Water Resources Control Board, Division of Water Quality, State Water Resources Control Board, Divison of Financial Assistance

Waste Treatment:Sewer (Wastewater)(MGD 85)

SFPUC Approval

Aesthetics, Agriculture and Forestry Resources, Air Quality, Biological Resources, Cumulative Effects, Drainage/Absorption, Flood Plain/Flooding, Geology/Soils, Growth Inducement, Hazards & Hazardous Materials, Hydrology/Water Quality, Land Use/Planning, Mineral Resources, Noise, Population/Housing, Public Services, Recreation, Schools/Universities, Septic System, Sewer Capacity, Solid Waste, Transportation, Tribal Cultural Resources, Utilities/Service Systems, Vegetation, Wetland/Riparian, Wildfire