SFPUC outlines $2.7B collection plan and $400M green program as part of $7B SSIP

San Francisco — At a Commission workshop on the Sewer System Improvement Program (SSIP), SFPUC staff on July 24 laid out a 20-year validation for the city’s collection system that pairs traditional “gray” repairs with an expanded green infrastructure program.

Staff recommended $2.7 billion in collection-system investments over 20 years, including pump-station and outfall rehabilitation, operational odor and grit control, and redundancy measures for critical force mains. In addition they proposed a $400 million green infrastructure program to manage stormwater in an urban watershed framework. Staff said the combined treatment and collection recommendations remain within the program target of about $7 billion over 30 years when coupled with earlier treatment recommendations.

Ed Harrington, the general manager, and program leads emphasized the SSIP’s priorities: system reliability, regulatory compliance, and flexibility for future permit requirements. Marty Dorward, leading the validation effort, said condition assessments identified 22 of 24 pump stations and 35 of 36 outfalls requiring rehabilitation and placed a $838 million estimate on reliability and operational improvements. "These are essential to the reliability of the system," he said.

Rosie Jenks presented the staff proposal for green infrastructure, calling for a target to manage more than 400 acres with green tools — roughly 22 miles of green streets, about 100 acres of rooftop redirection to rainwater harvesting, and the daylighting of one creek as demonstration. She said staff recommends eight Early Implementation Projects (EIPs), one per watershed, with an EIP budget of about $57 million within the overall $400 million program to validate local performance and maintenance needs.

On the Central Bayside redundancy challenge — staff identified the aging Channel force main and a single-line vulnerability — engineers presented several options. A conventional redundant force main was estimated at about $400 million; tunnel alternatives ranged from smaller-diameter tunnels to larger ones. Staff recommended carrying a 30-foot-diameter tunnel as a placeholder because, in modeling presented to the commission, that size meets the current design-criteria target of 10 combined sewer discharge (CSD) occurrences in the central basin. The 30-foot option was presented with a planning-line cost of approximately $1.2 billion.

Staff stressed trade-offs between tunnel size and green infrastructure: a smaller tunnel combined with strategic green projects could, in modeling, meet the same regulatory target but would require validated EIP performance and clearer regulatory direction. "Various sized tunnels will be looked at, various combinations of green and gray to get us to the 10," staff said.

On the West Side, staff analyzed options to reduce beach discharges at Ocean Beach, where three outfalls produce the most visible CSDs. Models showed that increasing conveyance and pumping (options of about 70, 100 or 200 million gallons per day) could dramatically reduce occurrences; they identified a 100-MGD pumping option as a practical way to reach a target of three occurrences at an estimated cost of roughly $277 million, while also exploring how green projects could reduce the gray scope.

Commissioners pressed staff on measurable outcomes and public communication. Several commissioners asked for clearer metrics for flooding and stormwater goals and asked staff to supply triple-bottom-line analyses to support trade-offs. Staff committed to returning with refined project lists, clearer level-of-service language, results from EIP monitoring, and costed options before the final SSIP in late August.

What’s next: staff said the August 28 workshop will incorporate feedback from this session, EIP performance data and further watershed assessments to refine the mix of green and gray investments and to better define timing and rate impacts.