Public water system · CA2310003
ActiveUkiah, City of
At a glance
City of Ukiah (PWSID CA2310003) is an active community water system in Mendocino County, California. It reports serving 16,607 people through 4,935 service connections. Its primary water source is surface water, and EPA lists it as owned by a local government. EPA's records list 3 violations for this system; 1 is health-based, and the most recent began in October 2022.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
16,607
Service connections
4,935
Primary source
SW
Surface water
System type
CWS
Community water system
System record
How does City of Ukiah compare with other water systems in Mendocino County?
By EPA's size categories, City of Ukiah is a large system (10,001 to 100,000 people). Mendocino County has 144 active public water systems, and City of Ukiah is the largest of them by population served. Its population served is about 29 times the county average of 576 people per system, and accounts for 20% of the 82,868 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 Ukiah is about 148% above 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. Surface water means the system draws its water from rivers, lakes, streams or reservoirs. 609 California systems (8.1%) list surface water as their primary source.
Who owns and regulates City of Ukiah?
EPA lists City of Ukiah 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. 26 of the 144 active systems in Mendocino County (18%) are also owned by a local government.
Does City of Ukiah have drinking water violations?
EPA's records list 3 violations for this system; 1 is health-based, and the most recent began in October 2022. The violations listed here began between May 1986 and October 2022. By type: 1 monitoring and reporting, 1 contaminant level above the legal limit and 1 public notice, recordkeeping or other. The contaminants or rules involved are Lead and Copper Rule and Total coliform bacteria (TCR). EPA lists 1 as unaddressed, 1 as resolved and 1 as archived. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement. 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. 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.
| 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 | Unaddressed |
| 1996-02-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1986-05-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
All 3 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 Ukiah: frequently asked questions
Who runs City of Ukiah?
City of Ukiah (PWSID CA2310003) 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 Ukiah serve?
City of Ukiah reports serving 16,607 people through 4,935 service connections in Mendocino County, California.
Where does City of Ukiah get its water?
EPA SDWIS lists this system's primary water source as surface water. Surface water means the system draws its water from rivers, lakes, streams or reservoirs.
Does City of Ukiah have any drinking water violations?
EPA's records list 3 violations for this system; 1 is 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 City of Ukiah's 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 3 violations for this system; 1 is 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 City of Ukiah's water quality report?
As a community water system, City of Ukiah 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 Mendocino County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Fort Bragg, City of | Mendocino | 6,919 | Community | Surface water |
| Willits, City of | Mendocino | 6,175 | Community | Surface water |
| Millview County Water District | Mendocino | 5,500 | Community | Surface water |
| Redwood Valley County Water District | Mendocino | 5,200 | Community | Surface water |
| Willow County Water District | Mendocino | 3,797 | Community | Purchased surface water |
| Brooktrails Township Csd | Mendocino | 3,632 | Community | Surface water |
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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, “Ukiah, City of, PWSID CA2310003, California”, https://aquacensus.com/water-systems/california/ukiah-city-of-ca2310003 (data as of October 1, 2026).