Mission, Organization, Facts, and History

What is a "Spill Record"?

Wastewater agencies are required to track and report all overflows from their collection systems to the California State Water Resources Control Board. Union Sanitary District has one of the best spill records statewide. The graph below show USD's average spill record for Fiscal Year 2022 compared to state and regional averages.

FY 22 Spills per 100 Miles chart website

Our Mission

To safely and responsibly collect and treat wastewater, and to recover resources from process waste streams, while protecting human health and improving the environment in a way that benefits the Tri-Cities and all USD stakeholders. Read more about how we accomplish our Mission.

USD uses a strategic planning process to align District operations to best complete our mission. Read our FY 19 - FY 22 Strategic Plan.

View the FY 2021 Strategic Performance Report

Our Organization

See our organizational chart here.

Our Employee Union's Mission

Union Sanitary District is synonymous with quality work. Our highly skilled and qualified labor force is the cornerstone to the overall public health and success of the communities we serve. Through hard work and dedication, we provide customers with value for their dollar.

USD's Sewer System Management Plan

Our Sewer System Management Plan (SSMP) can be found here.

District Facts

When was USD founded? May 27, 1918

What area does USD serve? (annexed areas)
City of Fremont 36.4 sq.mi.
City of Newark 13.8 sq.mi.
City of Union City 9.9 sq.mi.
Total: 60.2 sq.mi.

How many people are served by USD? 

Fremont 229,476
Newark 47,229
Union City 68,150
Total population served (January 2022 California Dept. of Finance demographics)  344,855



What types of customers are served?

Type of customer Number of Connections
Domestic/Residential living unit connections 117,543
Commercial connections 1,770
Industrial connections 1,345
Total connections 120,658

How many miles of sewers does USD maintain?

839 miles of underground pipelines

How many pump stations are in USD's service area?
Seven pump stations

How many gallons of wastewater are treated each day?
2021 Average Daily Flow: 22.86 million gallons

What type of treatment does the plant provide?
Secondary Activated Sludge

Who are the top ten industrial dischargers in the area served by USD and what is their flow? (gallons per day in 2021 calendar year)

Tesla Motors, Inc. 381,903
Lam Research Corporation (CA3/CA3E) 299,804
Western Digital Technologies #1 187,215
U.S. Pipe & Foundry 135,673
Boehringer Ingelheim Fremont, Inc. 103,246
Mission Linen Supply 73,930
Washington Hospital Healthcare System 70,014
Western Digital Technologies Fremont #2 61,938
Thermo Fisher Scientific #1 52,622
Tesla 47700 Kato Road 43,071




How many people does USD employ?


What is USD's annual operating budget?
$50,509,850 (FY 2023)
USD's Fiscal Year 2023: July 1, 2022 through June 30, 2023

What is the annual service charge for a single family residence? 
$530.21 (FY 2023 adopted rate)

What is the current capacity fee? 
$10,027.00 for a single-family swelling dwelling unit less than or equal to 4,500 sq. ft.

Historical Information

  • 1918 Union Sanitary District (USD) founded; first Board of Directors meeting
  • 1923 District reorganized under Sanitary District Act of 1923
  • 1924 First two connections made to USD system
  • 1949 Niles Sanitary District becomes part of USD
  • 1954 Decoto Sanitary District annexed to USD
  • 1956 Irvington Sanitary District becomes part of USD
  • 1962 City of Union City joined USD service area
  • 1974 East Bay Dischargers Authority (EBDA) JPA formed
             USD contracted for 19.7 mgd of capacity in outfall to deep portion of San Francisco Bay.
  • 1981 Alvarado Wastewater Treatment Plant (WWTP) completed
             Abandoned Newark & Irvington plants
             Transport system and EBDA outfall put into operation
  • 1988 Alvarado WWTP expansion completed
  • 1990 Treatment Plant Facilities Plan completed
  • 1994 District-wide Master Plan completed and EIR certified
  • 1996 Alvarado Wastewater Treatment Plant Upgrade construction complete (30 mgd)
  • 1997 Reorganization into a Team-based organization
  • 2001 Consolidated USD Administration, Corp Yard and Wastewater Treatment Facilities at one location in Union City

District Formation and Authority

The Union Sanitary District is an independent special district which provides wastewater collection, treatment and disposal services to the residents and businesses of the cities of Fremont, Newark and Union City, in Southern Alameda County, California. Independent special districts are voted into existence by the citizens they serve and are sanctioned under California law to perform specific local government functions within certain boundaries. The District was formed in 1918 and reorganized under the Sanitary District Act of 1923. It derives its authority in the California Health & Safety Code (Sections 6400-6830). The District is governed by an elected Board of Directors which is accountable to the public. The Directors are members of the community they represent. The District recovers the cost of their service delivery through rates imposed on users of the service. The District is independently audited and subject to state and public scrutiny.

Other special districts in Alameda County provide services such as water, fire service, mosquito abatement, recreation, parks and hospital services.



Learn More.

5072 Benson Road

Union City, CA 94587-2508

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