Adopted Sewer Service Charges for Fiscal Year 2026/2027 and Annual Report of Charges for Collection on the Contra Costa County Tax Roll

At its regular meeting on June 10, 2026, the Delta Diablo Board of Directors conducted a public hearing to consider adoption of a resolution establishing Sewer Service Charges (SSCs) for Fiscal Year 2026/2027 (FY26/27) (July 1, 2026-June 30, 2027), consistent with and not exceeding maximum SSCs previously approved in compliance with Proposition 218 and adoption of a resolution approving and adopting a report of SSCs to be collected on the Contra Costa County tax roll for FY26/27. Following a public hearing, the Board considered testimony and comments, as well as  protests received against adopting the report of SSCs to be collected on the tax roll. The Board of Directors unanimously voted to adopt both resolutions. The presentation provided to the Board of Directors during the public hearing and the report of SSCs are provided below.

What Services Does Delta Diablo Provide to Customers?

Proposed FY26/27 Sewer Service Charges (SSCs) Board Presentation

Preliminary FY26/27 Sewer Service Charges Tax Roll

Prior Board Action: Adopted Five-Year Maximum Sewer Service Charge Rate Increases for Fiscal Years 2025/26-2029/30

The Delta Diablo Board of Directors held a public hearing on Thursday, June 26, 2025 to consider adoption of proposed Sewer Service Charges (SSCs) rate increases for wastewater utility services. After the public hearing, the Board of Directors adopted an ordinance establishing SSCs for ​Fiscal Year 2025/2026 (FY25/26) (July 1, 2025-June 30, 2026) and setting maximum allowable SSC increase​s for FY26/27 through FY29/30.  A summary of the adopted rates and associated financial needs and information are provided below. In addition, related fact sheets are available below.

What Services Does Delta Diablo Provide to Customers?

Delta Diablo (“District”) provides wastewater conveyance and treatment services for approximately 73,273 customer accounts (residential and non-residential), representing over 218,000 residents in the cities of Antioch and Pittsburg, and the unincorporated community of Bay Point. As part of our core mission to protect public health and the environment, the District treats 14.0 million gallons of wastewater each day with a focus on exemplary regulatory compliance, innovative and sustainable approaches, and sound stewardship of the public’s resources and trust. The District has transformed its Wastewater Treatment Plant (WWTP) into a “resource recovery facility” by producing approximately 7.0 million gallons per day of recycled water, generating onsite renewable energy to meet over 50% of WWTP power needs, reusing biosolids as fertilizer, providing household hazardous waste (HHW) collection services, and further protecting the Delta by providing street sweeping services to remove pollutants that would otherwise enter local stormwater systems.

Why is Delta Diablo Proposing Rate Increases?

Adopted Five-Year Maximum Sewer Service Charge Increases Through FY29/30

The District collects SSCs from its customers each year as the primary revenue source needed to fund capital infrastructure investments, labor, energy, biosolids, chemicals, regulatory compliance, infrastructure maintenance, and Delta HHW Collection Facility operations. For FY26/27, the District adopted SSC increases of $43.68 (+8.5%) per year for residential customers in Antioch and Pittsburg, and $60.04 (+8.5%) per year for residential customers in Bay Point. In 2025, the District adopted an ordinance establishing maximum SSC increases equivalent to 8.5% per year for residential and non-residential customers in Antioch/Pittsburg and Bay Point customers. The District continues to maintain rates below the average of peer agencies in the San Francisco Bay Area region.

In compliance with California Constitution Article XIII(D), Section 6 (“Proposition 218”), the FY26/27-FY29/30 maximum SSCs incorporate FY25/26 Cost-of-Service Study findings (prepared by IB Consulting), which updated growth in the service area and corresponding additional wastewater flow to the District’s WWTP. The Study is available at the District’s offices and website. SSCs for non-residential customers (i.e., commercial, industrial) were adjusted accordingly for each fiscal year based on customer class.

Most District customers are billed on a fiscal-year basis and pay SSCs via annual property tax bills. The District’s Board of Directors will consider approval of SSC increases for each future fiscal year, subject to the maximum allowable SSC increases. Property tax bills also include a street sweeping service charge that varies by community based on service frequency.

Delta Diablo is committed to fair and reasonable rates. As a not-for-profit public agency, state law only allows the District to recover costs necessary to operate and maintain our system and ensure that it is stable and safe for the future. SSCs are required to prioritize sustained capital investment to maintain the integrity of our aging infrastructure while ensuring sufficient funding to meet progressive increases in operating costs and associated regulatory compliance obligations.

The District has been recognized for excellence in financial reporting by the Government Finance Officers Association and is audited annually by an independent accounting firm. As an industry leader and progressive “Utility of the Future”, the District values community engagement, serving as responsible stewards of the public’s resources and trust, transparency, innovation, and workforce engagement and development to achieve its core mission of protecting public health and the environment.

The following documents are available for more information on the proposed SSC increases:

Delta Diablo Prop. 218 Notice: Proposed Five-Year Maximum SSC Increases

Delta Diablo Wastewater Cost-of-Service Rate Study

Delta Diablo FY25-26 SSC Increases Fact Sheet – April 2025

Delta Diablo Infrastructure Investment Fact Sheet – April 2025

Delta Diablo Nutrient Removal Regulatory Mandate Fact Sheet – April 2025

Delta Diablo Board of Directors Presentation on Proposed Maximum SSC Increases – June 26, 2025

 

Delta Diablo Finalizes Settlement Agreement with Regulators following Sewer Spill in Shore Acres

Following completion of infrastructure repair and site monitoring activities associated with a sewer line break and sanitary sewer overflow (SSO) in the Shore Acreas area of Bay Point in late 2024, Delta Diablo (District) reached a settlement agreement with the San Francisco Bay Reegional Water Quality Control Board (Regional Board)...(click here for more info)

Delta Diablo Reaches Settlement Agreement with Regulators following Sewer Spill in Shore Acres

Following completion of infrastructure repair and site monitoring activities associated with a sewer line break and sanitary sewer overflow (SSO) in the Shore Acres area of Bay Point in late 2024, Delta Diablo (District) has reached a settlement agreement with the San Francisco Bay Regional Water Quality Control Board (Regional Board)...(click here for more info)

Adopted Five-Year Maximum Sewer Service Charge Rate Increases for Fiscal Years 2025/26-2029/30

The Delta Diablo Board of Directors held a public hearing on Thursday, June 26, 2025 to consider adoption of proposed Sewer Service Charges (SSCs) rate increases for wastewater utility services. After the public hearing, the Board of Directors adopted an ordinance establishing SSCs for ​Fiscal Year 2025/2026 (FY25/26) (July 1, 2025-June 30, 2026) and setting maximum allowable SSC increase​s for FY26/27 through FY29/30.  A summary of the adopted rates and associated financial needs and information are provided below. In addition, related fact sheets are available below.

For more information regarding the Rate Increases for Fiscal Years 2025/26-2029/30, please click here.

Delta Diablo Successfully Completes Repair Efforts to Address Sewer Line Break in Bay Point (Updated December 5, 2024 at 10:00 am)

The District completed emergency repair activities to restore the Shore Acres Pump Station forcemain to service at approximately 5:30 pm on Wednesday, December 4, 2024. During construction activities, the District was able to use available onsite storage (800,000 gallons) at the pump station and multiple sewer cleaning vacuum trucks with support from neighboring agencies and private contractors to minimize sanitary sewer overflow (SSO) discharge volumes.

The District anticipates completing installation of a temporary, aboveground forcemain, which will serve as a redundant backup system, by late Friday, December 6, 2024.

Following stabilization of the SSO condition and return of the forcemain to service, the District is focusing on identifying site restoration needs, ensuring compliance with regulatory reporting requirements, and continuing water quality sampling and testing in the adjacent area.

Repair Efforts Nearing Completion to Address Sewer Line Break in Bay Point (Updated December 4, 2024 at 3:15 pm)

 Following identification of the Shore Acres Pump Station forcemain break at 3:30 pm on Monday, December 2, 2024, the District has been working to implement immediate repair work, while mitigating the volume of untreated wastewater discharged to the local environment in the vicinity of a natural flow channel in a marshland area on private property. Emergency construction repair activities are nearing completion and the District anticipates returning the forcemain to active service by 6:00 pm on Wednesday, December 4, 2024. This will effectively cease the current sanitary sewer overflow condition.

 In parallel, the District has been mitigating overflow volumes via onsite flow storage (800,000 gallon tank) and use of nine sewer cleaning vacuum trucks with support from neighboring agencies and private companies to physically remove wastewater from the upstream collection system for discharge downstream of the forcemain break. These activities allowed the District to effectively mitigate the sanitary sewer overflow (SSO) for approximately 22 hours; however, because the onsite storage basin reached capacity and repair activities were still in progress, SSO conditions resumed to the natural flow channel in the adjacent marshland area this morning but at a significantly lower volume due to the continued 24/7 operation of the sewer cleaning vacuum trucks.

The District will continue receiving pipeline materials to construct an above-grade temporary piping system (roughly 0.9 miles in length), which will serve as a redundant forcemain to facilitate further inspection activities. This system is expected to be operational by Friday, December 6, 2024.