title
Receive an update from Resource Management on a request from the Fairfield-Suisun Sewer District (FSSD) to conduct a sewer service study for the Suisun Valley area in response to the County’s request for the FSSD to provide sewer service to various properties; Provide direction to staff on the study scope; and Delegate authority to the Director of Resource Management to coordinate with the FSSD on a proposed scope of work, and to execute the study agreement within budgeted appropriations
body
Published Notice Required? Yes ____ No _X _
Public Hearing Required? Yes ____ No _X _
DEPARTMENTAL RECOMMENDATION:
The Department of Resource Management recommends that the Board of Supervisors:
1. Receive an update from Resource Management on a request from the Fairfield-Suisun Sewer District (FSSD) to conduct a sewer service study for the Suisun Valley area in response to the County’s request for the FSSD to provide sewer service to various properties;
2. Provide direction to staff on the study scope; and
3. Delegate authority to the Director of Resource Management to coordinate with the FSSD on a proposed scope of work, and to execute the study agreement within budgeted appropriations.
SUMMARY:
On June 22, 2025, the Board directed staff to continue conversations related to the Fairfield Suisun Sewer District comprehensive study related to current and future sewer requests in the Suisun Valley to the fall Sustainable Agricultural Lands Conservation Grant public meeting with a town hall led by Supervisor Williams to take place an hour in advance of that meeting. Supervisor Williams facilitated a town hall on September 30, 2025 and a package plant (self-contained wastewater treatment plant) educational town hall on June 24, 2026.
Solano County and the Fairfield-Suisun Sewer District (FSSD) have an existing 2003 Agreement to Provide Disposal of Sewage that governs sewer service eligibility for certain unincorporated parcels. The Board previously authorized staff to request that FSSD consider providing sewer services to properties in Suisun Valley, including the Woodcreek 60 project and a property with a failing septic system on Rockville Road.
In response to the County's requests, FSSD requested that the County conduct a sewer service study to identify the parcels, land uses and potential sewer demands the County would like FSSD to evaluate. FSSD is currently assessing its greater long term capacity needs and has indicated that a broader planning-level analysis by the County is necessary to evaluate the cumulative impacts of potential out-of-agency sewer service requests and to determine the technical, legal, financial and governance considerations associated with any future service expansion.
The purpose of this item is to obtain Board direction on the general scope of the study. Any future consideration by FSSD of expanded sewer service to unincorporated parcels would likely be limited to the parcels, areas and land use assumptions included in the study. Staff recommends that, at a minimum, the study evaluate parcels currently eligible for sewer service consideration under the 2003 Agreement and sites with failed or failing septic systems, while also providing the Board with an opportunity to consider whether broader areas should be included for planning and economic development purposes. This study does not approve sewer service, development projects, infrastructure construction or expansion of FSSD boundaries and is intended to gather information for further discussion, serving as a planning tool to support future decision-making by the County, FSSD and other agencies as applicable.
Once the study is complete, Staff will conduct a community meeting with interested parties within the Suisun Valley prior to coming back to the Board for a presentation of the results of the study and for any discussion on next steps.
Board Priorities
This action supports Board Priorities A1-A (Right to Farm), A3-A (Agricultural Infrastructure and General Plan Updates), E1-A (Economic Development), E2-A (General Plan Economic Development Strategy), and E3-A (County Utility Master Plan).
FINANCIAL IMPACT:
The costs associated with preparing the agenda item are nominal and absorbed by the Department’s FY2025/26 Working Budget.
Staff will coordinate with FSSD to develop a proposed scope of work, cost estimate, potential cost-sharing and resource-sharing approaches, consultant needs, and procurement strategy.
DISCUSSION:
Background
The Suisun Valley Strategic Plan, adopted by the Board of Supervisors on February 1, 2011, was developed to implement the 2008 General Plan and balance agricultural preservation with compatible economic development, particularly wine production, agritourism, and visitor-serving uses. The Strategic Plan designates Agricultural Tourist Centers as focused areas for limited visitor-serving development, including wineries, tasting rooms, lodging, event venues, and related agricultural-supporting uses.
Since adoption of the Strategic Plan, Suisun Valley has experienced continued interest in wine production, agritourism, rural business activity, and limited development consistent with County land use policies. Most of the Valley relies on individual wells and onsite wastewater treatment systems. Many onsite systems are affected by shallow groundwater, unsuitable soils, aging infrastructure, and limited land area for system components and reserve capacity. These constraints may present public health or environmental concerns where systems are failing or cannot be adequately repaired and may limit opportunities for new or expanded uses that support implementation of the strategic plan.
FSSD Request for a Broader Study
In prior years, the County and FSSD coordinated on individual sewer service requests in and near Suisun Valley and Old Cordelia. The County and FSSD entered into the 2003 Agreement, which identifies certain parcels eligible for sewer service consideration and establishes conditions for connection to FSSD’s municipal sewer system.
More recently, the County submitted requests to FSSD related to sewer service in Suisun Valley, including requests associated with 2280 Rockville Road and the Woodcreek 60 project. In response, FSSD requested that the County conduct a sewer service study to identify the parcels, land uses, and potential sewer demands that could reasonably request service in the future. This study would allow the cumulative impacts of potential out-of-agency sewer service requests in Suisun Valley to be evaluated in conjunction with FSSD’s service responsibilities within its existing service area.
FSSD has indicated that this type of analysis is consistent with how it evaluates sewer service planning for properties within Fairfield and Suisun City, properties proposing to annex into Fairfield or Suisun City, and properties outside the FSSD boundary. Sewer infrastructure operates as an interconnected system, and individual connection requests may have cumulative impacts that are not fully understood without a broader planning context.
The study would identify the extent of the proposed sewer service area and analyze the technical, legal, financial and governance considerations associated with potential service. FSSD has indicated that multiple study area options could be evaluated, but that the scope selected by the County would likely constrain what FSSD considers as part of any potential future sewer service area. Areas excluded from the County’s study may not be evaluated by FSSD for potential future sewer service as part of this effort. FSSD has also noted that it was not established, is not currently organized, and does not have broad legal authority under its Enabling Act to provide sewer service to areas outside Fairfield and Suisun City.
A key issue for the study is how to estimate future sewer demand. There is a balance between assuming maximum buildout for infrastructure planning and avoiding over-design of sewer infrastructure based on development assumptions that may not occur. Board direction on the general study area, intensity assumptions, desired level of future flexibility, and public outreach expectations will help staff and FSSD determine the appropriate next steps.
The question before the Board is not whether sewer service should be extended to Suisun Valley, nor whether any specific development project should be approved. Rather, the question is the scope of the study.
Public Outreach and Input Received
During a town hall on September 30, 2025, Supervisor Williams and staff provided information and received public input regarding the potential sewer service study.
Public comments and questions focused primarily on:
• The potential cost of new sewer infrastructure
• The potential geographic extent of sewer service in Suisun Valley
• Whether property owners could be required to connect to sewer
• Whether sewer availability could result in additional housing subdivisions
• Whether alternatives such as package treatment plants should be evaluated
• Consideration of the protection of agriculture, rural character, and landowner choice
• Discussion on the relationship between sewer planning, economic development, and the Suisun Valley Strategic Plan
These concerns are directly relevant to the potential scope of a sewer service study and these topics can be incorporated into the scope of work and future public outreach process.
Potential Study Scope Options
Staff is seeking Board direction on the appropriate scope of a potential sewer service study. The Board may select any combination of the following options, modify the options, or direct staff to study only specific elements. A map of the various option areas is provided as attachment D.
A sewer service study would not, by itself, approve sewer service for any parcel, require property owners to connect to sewer, approve any development project, change land use designations, expand FSSD boundaries, or commit the County or FSSD to fund or construct infrastructure. The study would be an information-gathering and planning tool to assist future decision-making by the Board, FSSD, LAFCO, and other agencies as applicable.
Option 1 - 2003 Agreement Area and Potential Failed or Failing Septic System Sites
This option would evaluate potential expanded or intensified uses for parcels currently eligible for sewer service consideration within the 2003 Agreement area, including the Woodcreek 60 project and Rockville Corners/Rockville Road parcels located within the 2003 Agreement area, as well as any other potential sites with failed or failing septic systems in Suisun Valley.
This is the minimum study scope because these parcels either have a defined relationship through prior County/FSSD sewer service coordination or may involve public health concerns associated with failed or failing septic systems. This option would focus on existing service eligibility, known pending service requests, and public health considerations.
Option 2 - Broader I-80 and Rockville Road Study Area Outside the 2003 Agreement Area
This option would include Option 1 and would also evaluate potential sewer service opportunities associated with the I-80 corridor and Rockville Road area outside the 2003 Agreement area.
This option would allow the County and FSSD to evaluate whether limited sewer service could support economic development projects or other uses consistent with existing zoning, the 2008 General Plan, and the Suisun Valley Strategic Plan. This option would not approve any project, create sewer entitlement, require extension of sewer infrastructure, or change land use designations.
Option 3 - Broader Suisun Valley Future Opportunity Area
This option would include Options 1 and 2 and would evaluate a broader geography within Suisun Valley, potentially including additional areas such as northern Suisun Valley or other future opportunity areas identified by the Board.
This option would allow the County and FSSD to evaluate whether additional future sewer service opportunities should be accounted for at a planning level. The purpose would be to preserve future planning flexibility for future Board consideration and allow FSSD and the County to understand broader system implications of potential future service.
As with all study options, this option would require planning-level sewer load assumptions, including assumptions regarding land use, density, and anticipated wastewater generation. This option would not create development rights, service commitments, sewer entitlements, or changes to land use designations.
Option 4 - Board-Defined Scope
The Board may choose any combination of the above options, add specific study elements, or narrow the geographic scope.
Technical Study Components and Board Direction
Regardless of the study area selected, a sewer service study would need to include evaluation of infrastructure capacity, land use assumptions, wastewater flow generation, legal authority, LAFCO-related governance considerations, and planning-level costs and funding considerations for infrastructure outside FSSD’s existing boundary.
The Board’s direction is requested primarily on the policy assumptions that will shape the study, including:
• The geographic area to be evaluated
• The level of development intensity or buildout assumptions to be used
• The desired level of future flexibility to include in the analysis
• Whether alternatives such as package treatment plants or decentralized systems should be evaluated
• Public outreach expectations
• Whether broader sewer service policy questions should be addressed through this study or deferred to the General Plan update
General Plan, Strategic Plan, and Board Priorities
The 2008 General Plan identifies Suisun Valley as an important agricultural region and supports preservation of agriculture while allowing compatible economic development. The Suisun Valley Strategic Plan further implements this direction by identifying Agricultural Tourist Centers and other strategies intended to support agriculture, wine production, agritourism, and rural economic development.
The Board has also identified priorities related to economic development, agricultural infrastructure, Right to Farm protections, General Plan updates, and utility planning. A sewer service study could provide information to help evaluate whether wastewater infrastructure options are available, appropriate, and consistent with these priorities.
The study would use land use assumptions to develop sewer flow and loading estimates but would not determine land use outcomes. Any future project would remain subject to applicable County land use review, environmental review, public process, and separate action by the Board or other decision-making body. Conducting a planning-level sewer service study does not presume future sewer service will be provided. Rather, it enables the County, FSSD, and other agencies to better understand existing wastewater constraints, evaluate potential alternatives, and identify long-term infrastructure considerations before future land use, economic development, or public health issues arise.
Broader questions pertaining to long-term sewer service policy, service boundaries, and infrastructure needed to support countywide economic development may also be appropriate for consideration through the General Plan update process. The current General Plan generally anticipates continued reliance on onsite wastewater treatment systems in rural areas unless public sewer service is otherwise authorized. A Suisun Valley sewer service study would not replace the General Plan update or make countywide sewer policy decisions, but can provide useful technical information regarding wastewater constraints, potential service alternatives, infrastructure costs, and coordination needs with municipal sewer providers.
ALTERNATIVES:
The Board could choose to direct staff to defer broader sewer service policy discussions, including potential future service areas and long-term infrastructure planning, to the General Plan update process while limiting any sewer service study to parcels currently eligible for service consideration under the 2003 Agreement and sites with failed or failing septic systems. This alternative is not recommended because it may limit the County’s ability to provide timely input to the FSSD capacity assessment underway, as well as delay the evaluation of broader infrastructure needs and economic development opportunities in Suisun Valley.
OTHER AGENCY INVOLVEMENT:
The Fairfield-Suisun Sewer District requested that the study be conducted and will participate in development of the study scope and technical review process.
CAO RECOMMENDATION:
APPROVE DEPARTMENTAL RECOMMENDATION