SFPUC proposes to construct new solids treatment, odor control, energy recovery, and associated facilities as part of improvements to the wastewater treatment facilities at the existing Southeast Water Pollution Control Plant (Southeast Plant or SEP) in San Francisco. The proposed project, the Biosolids Digester Facilities Project (BDFP or project), would replace the outdated existing solid treatment facilities with more reliable, efficient, and modern technologies and facilities. Biosolids are the recyclable solid materials removed from the wastewater during the treatment process, and digesters are the major facility used in the solids treatment process. Many of the existing SEP solids treatment facilities are over 60 years old, require significant maintenance, and are operating well beyond their useful life. The project would replace the existing digesters with new digesters and other new facilities that would produce higher-quality biosolids, capture and treat odors more effectively, and maximize digester gas utilization and energy recovery for the production of heat, steam, and electrical power. In addition, the project intends to locate the digesters farther away from existing residences, limit project-generated odors to the SEP fence line, and make visual improvements in and around the SEP.
Demolition of about 136,000 sq. ft. of building area to accommodate proposed facilities. Buildings to be demolished would include structures at the project site (the Central Shops buildings and currently used SEP facilities within the SEP boundaries of the project site) and at a potential staging site. In addition, underground structures would be removed at the Asphalt Plant site. Construction of new structures on approx. 206,000 sq. ft. of the project site. The height of new structures would be up to 65 feet above grade; some structures would extend 35 feet below grade. The SFPUC anticipates that project construction would require five years to complete, from 2018 through 2023, followed by a transition period to conduct performance testing and facility commissioning, with full operation commencing in 2025.