Davis WWTP Aerial June 2018 - 1 
Wastewater is water that has been impacted from ordinary living processes, including household, commercial, and industrial uses. It is essentially used water, containing materials and particles that would negatively impact people and the environment if left untreated. Wastewater entering a treatment plant is also called influent, and treated wastewater is called effluent.


Check out Wastewater Utility 101 – an in-depth look at the City’s wastewater utility.

The City’s Wastewater Division operates and maintains the City’s wastewater system, supporting the residential, commercial, and industrial activities of the community. This includes the operation and maintenance of the collection system, treatment plant, and restoration wetlands, as well as the treatment of the wastewater generated in the Yolo County service areas of El Macero, North Davis Meadows, Davis Creek (formerly Royal Oaks) Mobile Home Park, and the Teichert Construction Complex.

As with most municipalities in California, the City of Davis wastewater collection and storm drain systems are separate. Wastewater flows to the wastewater treatment plant via the collection system and stormwater flows directly to local waterways, untreated.

Cowell BPS The Collection System

The City’s wastewater collection system serves a population of about 66,630 people in Davis’ 10.5 square mile service area. The system serves 15,665 residential connections, and 540 commercial, industrial and institutional customers (as of 2019).
What makes up the Collection System?
  • 164 miles of gravity sewers (approximately 3,300 line segments) ranging in size from 6 to 66 inches in diameter – to transport the wastewater to the pump stations
  • 3,224 manholes – to provide access to sewer mains
  • 6 pump stations  - Davis’ wastewater collection system moves wastewater via gravity, and in certain areas of the City, there are pump stations to raise the wastewater higher so it can continue to flow via gravity to the wastewater treatment plant. By the time the wastewater piles reach the treatment plant, they are 40 feet below the surface.
  • 2.63 miles of force mains ranging in size from 4 to 14 inches – to transport the wastewater from the pump stations
  • Roughly 123 miles of sewer laterals – the piping from the sewer main to the building. 

Site Content Includes:

Sewer Back-up Information

Includes important information to know if you’re experiencing a sewer back-up, such as the sewer lateral maintenance procedure, and sewer maintenance responsibilities for property owners

Wastewater Treatment Plant

Learn more about how wastewater is treated at the City's Wastewater Treatment Plant, and the upgrade  project completed in 2019


Learn how to keep pollutants and other unwanted items out of the wastewater collection system

Davis Wetlands

Read about the Wetlands, which utilizes reclaimed wastewater to provide wildlife habitat, recreation, and environmental learning opportunities. It is one of the City's most valuable open space resources

Wastewater Rate Studies

Includes important information related to wastewater (also called sanitary sewer) rate studies, which evaluate the utility's revenue requirements and provide recommendations for rates.  Also includes information on the Proposition 218 process for rate setting



Free viewers are required for some of the attached documents.
They can be downloaded by clicking on the icons below.

Acrobat Reader Download Acrobat Reader Flash Player Download Flash Player Windows Media Player Download Windows Media Player Microsoft Silverlight Download Microsoft Silverlight Word Viewer Download Word Viewer Excel Viewer Download Excel Viewer PowerPoint Viewer Download PowerPoint Viewer