Occidental County Sanitation District - Graton Sewer Transfer Pipeline

Occidental County Sanitation District (OCSD) and Graton Community Services District (Graton) both have sewer service charges which are among the highest rates in California. 

The high rates are due to the cost associated with operating a small wastewater systems in areas with stringent wastewater treatment requirements. OCSD is currently hauling wastewater from an Occidental lift station to the Airport/Larkfield/Wikiup Sanitation Zone (ALWSZ) treatment plant for treatment and disposal in north Santa Rosa.

In 2021 OCSD and Graton agreed to conduct a feasibility study to assess transporting untreated wastewater from OCSD to Graton for treatment and disposal, to assess the capacity of the Graton wastewater treatment plant to treat and dispose of the total combined flow, and to construct a pipeline from OCSD to Graton to reduce costs and provide Graton with additional income necessary to prevent significant rate increases in the near future.

Occidental to Graton Wastewater Pipeline Feasibility Study - JUNE 15,2022 

Estimated Timeline

Pipeline design grant funding application (Environmental Protection Agency): October 2023-January 2024

Pipeline design: January 2024 – January 2025

CEQA documents: September 2024 – January 2025

Construction loan application (State Revolving Fund): January 2025 – January 2026

Construction process: January 2027 – December 2028

Outreach: Ongoing

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Community Meetings

Monday, Sept. 18, 2023 (in-person only) Graton Community Services District regular meeting
Press release

Thursday, Dec. 15, 2022 (virtual) 5 - 7 p.m.
Board Meeting - Special Meeting of the Graton Community Services District Board of Directors
PowerPoint Presentation

Tuesday, Oct. 11, 2022 (multi-access) Occidental Community Services District regular meeting.
Sonoma Water Principal Engineer Carlos Diaz provided an update on the project and feasibility study findings.
Power Point presentation

Thursday, Feb. 10, 2022 (virtual) 5:30 - 7 p.m. with Sonoma County 5th District Supervisor and Sonoma Water Director Lynda Hopkins.
Meeting Agenda
PowerPoint Presentation

Occidental County Sanitation District to Airport-Larkfield-Wikiup Sanitation Zone Wastewater Transport Project

In December 2017, the Board of Directors of Sonoma Water, which operates the Occidental County Sanitation District’s Wastewater Treatment Facility, approved a project for transporting untreated wastewater from the  Occidental County Sanitation District  to the Airport-Larkfield-Wikiup Sanitation Zone for treatment, storage, and reuse to avoid future discharges into Dutch Bill Creek and potential violations of the  Occidental County Sanitation District.

The project will allow the Occidental County Sanitation District to comply with conditions set forth by the North Coast Regional Water Quality Control Board in Order No. R1-2012-0101. This order requires the  Occidental County Sanitation District to cease discharging secondary treated recycled water to Dutch Bill Creek by Jan. 31, 2018. The project includes transporting untreated wastewater to the  Airport-Larkfield-Wikiup Sanitation Zone, wastewater treatment facility for treatment, storage, and disposal. The Airport-Larkfield-Wikiup Sanitation Zone wastewater treatment facility currently treats wastewater to secondary and tertiary standards and utilizes irrigation of agricultural lands for disposal of secondary and tertiary-treated recycled water.

Public Meetings

The Occidental County Sanitation District’s regularly holds community meetings to inform, educate, and seek input from ratepayers and surrounding residents on possible solutions for treating, storing, and disposing of wastewater generated in Occidental. The Occidental County Sanitation District currently discharges recycled water into a pond located at the headwaters of Dutch Bill Creek during the summer and to Dutch Bill Creek during the winter. The Occidental County Sanitation District is required by the North Coast Regional Water Quality Control Board to stop releasing recycled water into the pond. The Occidental County Sanitation District is currently examining feasible projects that meet the unique requirements of Occidental.

Materials from the Feb. 16, 2017 Meeting:

Materials from Jan. 7, 2016 Meeting:

Materials from Jan. 8, 2015 Meeting:

Materials from Sept. 30, 2014 Meeting:

Materials from March 13, 2014 Meeting:

Materials from Oct. 24, 2013 Meeting: