Public water system · CA2310004
ActiveWillits, City of
At a glance
City of Willits (PWSID CA2310004) is an active community water system in Mendocino County, California. It reports serving 6,175 people through 2,399 service connections. Its primary water source is surface water, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 11 are health-based, and the most recent began in October 2015.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
6,175
Service connections
2,399
Primary source
SW
Surface water
System type
CWS
Community water system
System record
How does City of Willits compare with other water systems in Mendocino County?
By EPA's size categories, City of Willits is a medium system (3,301 to 10,000 people). Mendocino County has 144 active public water systems, and City of Willits is the 3rd-largest of them by population served. Its population served is about 11 times the county average of 576 people per system, and accounts for 7.5% 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 Willits is roughly in line with 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 Willits?
EPA lists City of Willits 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 Willits have drinking water violations?
Of the 12 most recent violations in EPA's records, 11 are health-based, and the most recent began in October 2015. The violations listed here began between January 2008 and October 2015. By type: 9 contaminant level above the legal limit, 2 required treatment not met and 1 monitoring and reporting. The contaminant or rule involved most often is Total trihalomethanes (TTHM) (7 of them). EPA lists 12 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 |
|---|---|---|---|---|
| 2015-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2015-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2015-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2015-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2015-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2015-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2015-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2013-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Haloacetic acids (HAA5)code 2456 | Yes | Resolved |
| 2013-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Haloacetic acids (HAA5)code 2456 | Yes | Resolved |
| 2012-04-01 | Required treatment not metSingle Turbidity Exceed (Enhanced SWTR) · code 43 | Interim Enhanced Surface Water Treatment Rulecode 0300 | Yes | Resolved |
| 2011-08-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2008-01-01 | Required treatment not metMonthly Turbidity Exceed (Enhanced SWTR) · code 44 | Interim Enhanced Surface Water Treatment Rulecode 0300 | Yes | Resolved |
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 Willits: frequently asked questions
Who runs City of Willits?
City of Willits (PWSID CA2310004) 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 Willits serve?
City of Willits reports serving 6,175 people through 2,399 service connections in Mendocino County, California.
Where does City of Willits 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 Willits have any drinking water violations?
Of the 12 most recent violations in EPA's records, 11 are health-based, and the most recent began in October 2015. 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 Willits' 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, 11 are health-based, and the most recent began in October 2015. 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 Willits' water quality report?
As a community water system, City of Willits 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 |
|---|---|---|---|---|
| Ukiah, City of | Mendocino | 16,607 | Community | Surface water |
| Fort Bragg, City of | Mendocino | 6,919 | 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, “Willits, City of, PWSID CA2310004, California”, https://aquacensus.com/water-systems/california/willits-city-of-ca2310004 (data as of October 1, 2026).