Water

Drinking Water System

Supply

The City of Poway (Poway) purchases raw (untreated) water from the San Diego County Water Authority (SDCWA), a water wholesaler for the San Diego County region. The SDCWA was formed in 1944 to import water from the Colorado River and Northern California (State Water Project).

Storage

The raw water received from the SDCWA is pumped to the Lester J. Berglund Water Treatment Plant (WTP) for treatment and/or storage in Lake Poway. City staff inspects and monitors Poway Dam and the untreated water in Lake Poway. Lake Poway serves as the City's largest storage and emergency water supply reservoir, and provides fishing, boating and recreation opportunities.

Treatment

Poway is committed to providing a reliable and high quality water that meets or exceeds all state and federal standards. The Lester J. Berglund Water Treatment Plant (WTP), owned by the City of Poway was constructed in 1978 and has the capacity to produce million of gallons of potable water per day. Water treatment at the WTP includes flocculation, sedimentation disinfection and filtration. The process includes mechanical and chemical removal of impurities, followed by inactivation of pathogens (e.g. viruses, bacteria, etc.) through disinfection. The result is high-quality water meeting all state and federal requirements.

• Step 1: Coagulation and Flocculation. The organic materials in untreated water are mixed with chemicals called coagulants that bind with the organic material.
• Step 2: Sedimentation. The coagulants and organic material sinks to the bottom of sedimentation basins. The clarified water, on the surface, flows to the next step of the treatment process. The sediment is removed from the basins.
• Step 3: Disinfection with Chlorine. Disinfection destroys or inactivates any organisms in the water.
• Step 4: Filtration. Dual-media filters, consisting of layers of anthracite, sand, and gravel, remove material and particles too large to pass through the filter media.
• Step 5: Chloramination. State regulations require we maintain a disinfectant residual in our water in the distribution system to protect against contamination. Chloramines provide a longer lasting disinfectant residual to ensure the water is protected from contamination.

Distribution

Potable water is delivered to consumers through a system of storage reservoirs, pipelines, and pumping stations located throughout Poway. Water quality is monitored throughout the water distribution system and test results are reported to the state monthly.