The Delta Diablo Board of Directors will hold a public hearing on Thursday, June 26, 2025, at 5:30 p.m., in the Board Room at 2500 Pittsburg-Antioch Highway, Antioch, California, to consider adoption of proposed rate increases for wastewater utility services. A summary of the proposed rates and associated financial needs and information, and instructions for protesting the rate increases (if desired) are provided below. In addition, related fact sheets are available at www.deltadiablo.org.

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?

 Proposed Five-Year Maximum Sewer Service Charge Increases for FY25/26-FY29/30

The District collects Sewer Service Charges (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 Fiscal Year 2025/26 (FY25/26) (July 1, 2025-June 30, 2026), the District is proposing SSC increases of approximately 8.5% per year (+$40.25) for residential customers in Antioch/Pittsburg, and approximately 8.8% (+$57.35) for residential customers in Bay Point. In FY26/27 through FY29/30, the District is proposing maximum SSC increases of 8.5% and 8.5% for Antioch/Pittsburg and Bay Point customers, respectively. The District continues to maintain rates near 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 proposed FY25/26-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 will be made available at the District’s offices and website. SSCs for non-residential customers (i.e., commercial, industrial) were adjusted accordingly for FY25/26-FY29/30 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 fiscal year, subject to the maximum SSC increases included in the tables below. 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.