Public water system · CA5710009
ActiveUc - Davis
At a glance
Uc - Davis (PWSID CA5710009) is an active community water system in Yolo County, California. It reports serving 49,616 people through 4,656 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a state government. EPA's records list 4 violations for this system; 3 are health-based, and the most recent began in October 2022.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
49,616
Service connections
4,656
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Uc - Davis compare with other water systems in Yolo County?
By EPA's size categories, Uc - Davis is a large system (10,001 to 100,000 people). Yolo County has 88 active public water systems, and Uc - Davis is the 4th-largest of them by population served. Its population served is about 17 times the county average of 2,951 people per system, and accounts for 19% 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 Uc - Davis is about 7.4 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 Uc - Davis?
EPA lists Uc - Davis as owned by a state 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. 3 of the 88 active systems in Yolo County (3.4%) are also owned by a state government.
Does Uc - Davis have drinking water violations?
EPA's records list 4 violations for this system; 3 are health-based, and the most recent began in October 2022. The violations listed here began between September 1992 and October 2022. By type: 3 contaminant level above the legal limit and 1 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (3 of them). EPA lists 4 as resolved. 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 |
|---|---|---|---|---|
| 2022-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2010-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2002-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1992-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
All 4 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.
Uc - Davis: frequently asked questions
Who runs Uc - Davis?
Uc - Davis (PWSID CA5710009) is a community water system owned by a state government. It is regulated by the CA state drinking water program.
How many people does Uc - Davis serve?
Uc - Davis reports serving 49,616 people through 4,656 service connections in Yolo County, California.
Where does Uc - 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 Uc - Davis have any drinking water violations?
EPA's records list 4 violations for this system; 3 are health-based, and the most recent began in October 2022. 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 Uc - 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. EPA's records list 4 violations for this system; 3 are health-based, and the most recent began in October 2022. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Uc - Davis' water quality report?
As a community water system, Uc - 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 Davis | Yolo | 67,457 | Community | Purchased surface water |
| City of Woodland | Yolo | 61,462 | Community | Purchased surface water |
| City of West Sacramento | Yolo | 53,355 | Community | 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, “Uc - Davis, PWSID CA5710009, California”, https://aquacensus.com/water-systems/california/uc-davis-ca5710009 (data as of October 1, 2026).