Public water system · CA5710001
ActiveCity of Davis
At a glance
City of Davis (PWSID CA5710001) is an active community water system in Yolo County, California. It reports serving 67,457 people through 17,326 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 12 are health-based, and the most recent began in March 2005.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
67,457
Service connections
17,326
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does City of Davis compare with other water systems in Yolo County?
By EPA's size categories, City of Davis is a large system (10,001 to 100,000 people). Yolo County has 88 active public water systems, and City of Davis is the largest of them by population served. Its population served is about 23 times the county average of 2,951 people per system, and accounts for 26% of the 259,714 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active community water system reports serving 6,703 people, so City of Davis is about 10 times that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. California has 2,997 active community water systems, 40% of the state's 7,479 active systems. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 506 California systems (6.8%) list purchased surface water as their primary source.
Who owns and regulates City of Davis?
EPA lists City of Davis as owned by a local government. The CA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 15 of the 88 active systems in Yolo County (17%) are also owned by a local government.
Does City of Davis have drinking water violations?
Of the 12 most recent violations in EPA's records, 12 are health-based, and the most recent began in March 2005. The violations listed here began between April 1989 and March 2005. By type: 12 contaminant level above the legal limit. The contaminant or rule involved most often is Selenium (10 of them). EPA lists 9 as archived and 3 as resolved. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2005-03-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1996-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1990-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Seleniumcode 1045 | Yes | Resolved |
| 1989-12-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Seleniumcode 1045 | Yes | Archived |
| 1989-11-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Seleniumcode 1045 | Yes | Archived |
| 1989-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Seleniumcode 1045 | Yes | Archived |
| 1989-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Seleniumcode 1045 | Yes | Archived |
| 1989-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Seleniumcode 1045 | Yes | Archived |
| 1989-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Seleniumcode 1045 | Yes | Archived |
| 1989-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Seleniumcode 1045 | Yes | Archived |
| 1989-05-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Seleniumcode 1045 | Yes | Archived |
| 1989-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Seleniumcode 1045 | Yes | Archived |
The 12 most recent violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
City of Davis: frequently asked questions
Who runs City of Davis?
City of Davis (PWSID CA5710001) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does City of Davis serve?
City of Davis reports serving 67,457 people through 17,326 service connections in Yolo County, California.
Where does City of Davis get its water?
EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.
Does City of Davis have any drinking water violations?
Of the 12 most recent violations in EPA's records, 12 are health-based, and the most recent began in March 2005. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is City of Davis' water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. Of the 12 most recent violations in EPA's records, 12 are health-based, and the most recent began in March 2005. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find City of Davis' water quality report?
As a community water system, City of Davis must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in Yolo County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| City of Woodland | Yolo | 61,462 | Community | Purchased surface water |
| City of West Sacramento | Yolo | 53,355 | Community | Surface water |
| Uc - Davis | Yolo | 49,616 | Community | Purchased surface water |
| City of Winters | Yolo | 7,115 | Community | Groundwater |
| Esparto C.S.D. | Yolo | 3,574 | Community | Groundwater |
| Wild Wings Golf Community | Yolo | 1,115 | Community | Groundwater |
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About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “City of Davis, PWSID CA5710001, California”, https://aquacensus.com/water-systems/california/city-of-davis-ca5710001 (data as of October 1, 2026).