Woodacre/San Geronimo Flats Wastewater Recycling Project

Community Development Agency

The semi-rural communities of Woodacre and San Geronimo are located in the Lagunitas Creek watershed, which drains to Tomales Bay. Homes in these communities are currently served by individual on-site septic systems, many of which are sub-standard and a source of public health and water quality concern.

Tomales Bay and the Lagunitas Creek Watershed are designated impaired water bodies for pathogens (bacteria) under Section 303(d) of the Federal Clean Water Act. (see Pathogens in Tomales Bay Watershed TMDL).Faulty on-site wastewater systems, especially for properties in close proximity to streams, have been identified as one of the sources contributing to the impaired water quality.

In 2010, Marin County and a group of concerned property owners, now called the Woodacre & San Geronimo Flats Wastewater Group, conducted a study of alternatives for managing wastewater in the Woodacre Flats area. The final report 2011 feasibility report, prepared by Questa Engineering Corp., indicated that one of the preferred alternatives would be to replace existing on-site septic tanks with a community wastewater system that would produce tertiary recycled water suitable for irrigating the nearby San Geronimo Golf Course.

In response to increased public interest and with funding from the State Water Resources Control Board, the County expanded the study area to include portions of the adjacent San Geronimo Flats. The project evaluated the feasibility of the community wastewater recycling option for approximately 300 homes in the flat area of Woodacre and San Geronimo 2019 final feasibility report The County also initiated the environmental impact report for the wastewater recycling project. The environmental review was prepared by Leonard Charles and Associates.However, the project came to a halt when the Trust for Public Land (TPL) purchased the San Geronimo Golf Course.

If you have questions or would like further information, please contact the EHS office at (415) 473-6907 Monday through Friday from 8:00 AM to 4:00 PM, or the Woodacre & San Geronimo Flats Wastewater Group.


Map of Service Area

Woodacre & San Geronimo Flats Wastewater Group

Background Reports - New Project Report

Meeting Announcements

Upcoming Community Meeting:

Learn About Septic Systems! (Free educational presentation)

Date: Tuesday, March 14, 5:30 PM - 7:00 PM

Location: San Geronimo Valley Community Center Valley Room (6350 Sir Francis Drake Blvd, San Geronimo, CA 94963)

Past Meetings

Marshall Field Trip: Saturday, September 16, 9:30 AM - 11:30 AM

Location: 19225 CA-1, Marshall, CA 94940

Community Meeting: June 7, 2023, at 7 PM

The San Geronimo/Woodacre community meeting was held on November 1, 2022, at 11 AM at the San Geronimo Commons clubhouse.

Project Updates

Recent Meetings

June 7, 2023, Woodacre-San Geronimo Wastewater Project

March 13, 2023, Woodacre-San Geronimo Wastewater Project

  • Theme: Feasibility Study Updates
  • Location: Virtual Meeting

March 29, 2023, Woodacre-San Geronimo Wastewater Project

  • Theme: Feasibility Study Updates
  • Location: Virtual Meeting

Media and Press Releases

Frequently Asked Questions