Water Quality and Backflow Prevention
The City of Napa is committed to providing a safe and reliable supply of drinking water that meets all State and Federal health standards. The Water Division's three treatment plants transform raw source water into clean and safe drinking water using three basic steps - sedimentation, filtration, and disinfection. The water supply is continuously sampled and tested for contaminants to ensure that health standards are met and that taste, odor, and appearance are optimized.
Reporting a Problem with your Drinking Water
Before reporting a problem, please note whether your concern is with the water's color, taste, odor, or something other, and be prepared to answer the following questions:
- Is the problem in the hot water, cold water, or both?
- Is the problem observed at all faucets?
- Do neighbors see a similar problem?
- Is there construction activity nearby?
Call Water Division staff at 707-257-9521.
Annual Drinking Water Quality Report
As required by law, by July 1 each year the City provides its water customers with a summary of any contaminants detected for the previous calendar year. The 2015 Drinking Water Quality Report is currently available. Click on the image to view an electronic version (printable PDF). Alternatively, hard copies are available at the Water Division, 1340 Clay Street and at the Public Works Department, 1600 First Street. A primary purpose of the report is to provide detailed information regarding contaminants, related potential adverse health effects, and possible sources of contamination. For 2015, the City met all of the stringent State and Federal standards for finished drinking water. In the distribution system however, select areas did not meet the recently adopted standard (based on annual average) for Stage II of the Disinfection Byproduct Rule (DBPR-II) at all times throughout the year. Informational notices were sent directly to affected customers to reflect disinfection byproduct information for the affected monitoring periods.
To protect the public water mains from potential contamination by non-potable "used water" that could be drawn in during a sudden pressure drop, the City requires installation of a backflow prevention device on new services. The device must be approved by the State Water Resources Control Board. To see the current list of approved backflow prevention devices, stop by the Water Division's 1340 Clay Street office, or contact the State Board's Division of Drinking Water directly at 916-449-5577 to request a copy. To minimize the visual impact of these devices, consult City of Napa Backflow Screening Guidelines.
All installed devices must be tested annually and immediately repaired if necessary.