Wastewater Division

The Wastewater Division protects public health and the environment, and serves as the first line of defense in protecting the Monterey Bay's precious water quality. The Watsonville Wastewater Treatment Facility, first constructed during the 1920s, has seen its mission grow from servicing a small agricultural community to treating wastewater for tens of thousands of residents, as well as commercial and industrial businesses. Over 120 miles of sanitary sewer pipeline and 13 lift stations are used to transport wastewater to the facility for treatment that can process up to 12 million gallons of wastewater every day during dry weather, and 36 million gallons during wet weather.

The wastewater is treated to the advanced secondary treatment level for ocean discharge and advanced tertiary treatment for food crop irrigation. Both levels of treatment undergo extensive monitoring and testing to insure compliance with all Local, State and Federal pollution prevention laws prior to being discharged to the Monterey Bay over a mile off shore, or for agricultural reuse. 

Biosolids, the organic residual of wastewater treatment processes, are applied to farmland used to grow hay crops for livestock.  Biosolids are produced by an anaerobic digestion process which also produces methane (biogas).  An energy recovery facility uses the methane in a generator to produce electricity and hot water.  At times the energy recovery facility generates more energy than is needed for the entire wastewater plant and exports electricity to the power grid.

Wastewater treatment, drinking water quality, and landfill analysis are performed at the Public Works & Utilities Laboratory located at the Water Resources Center to insure compliance with all applicable State and Federal Laws.

Wastewater Division Facts

Service Area

  • 21 Square miles
  • Composed of City of Watsonville, Pajaro, Freedom, and Salsipuedes sanitary districts consisting of a population of approximately 60,000


  • 1 Division Manager 
  • 1 Executive Assistant
  • 1 Collection System Manager
  • 1 Wastewater Operations Supervisor
  • 1 Utilities Maintenance Supervisor
  • 4 Collection System Operators
  • 4 Mechanics
  • 7 Wastewater Treatment Plant Operators