Public water system · CA2300591
ActivePine Mountain Mutual Water Co.
At a glance
Pine Mountain Mutual Water Co. (PWSID CA2300591) is an active community water system in Mendocino County, California. It reports serving 310 people through 125 service connections. Its primary water source is surface water, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in April 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
310
Service connections
125
Primary source
SW
Surface water
System type
CWS
Community water system
System record
How does Pine Mountain Mutual Water Co. compare with other water systems in Mendocino County?
By EPA's size categories, Pine Mountain Mutual Water Co. is a very small system (500 people or fewer). Mendocino County has 144 active public water systems. Its population served is about half of the county average of 576 people per system, and accounts for 0.4% 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 Pine Mountain Mutual Water Co. is well below 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 Pine Mountain Mutual Water Co.?
EPA lists Pine Mountain Mutual Water Co. as privately owned. 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. 98 of the 144 active systems in Mendocino County (68%) are also privately owned.
Does Pine Mountain Mutual Water Co. have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in April 2025. The violations listed here began between October 1981 and April 2025. By type: 10 monitoring and reporting and 2 monitoring. The contaminant or rule involved most often is Lead and Copper Rule (3 of them). EPA lists 7 as resolved, 3 as archived and 2 as unaddressed. 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. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2025-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Archived |
| 2025-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Archived |
| 2024-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Unaddressed |
| 2022-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Unaddressed |
| 2021-12-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2018-02-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2018-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2018-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitritecode 1041 | No | Resolved |
| 2013-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 1998-08-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1993-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1981-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | 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.
Pine Mountain Mutual Water Co.: frequently asked questions
Who runs Pine Mountain Mutual Water Co.?
Pine Mountain Mutual Water Co. (PWSID CA2300591) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Pine Mountain Mutual Water Co. serve?
Pine Mountain Mutual Water Co. reports serving 310 people through 125 service connections in Mendocino County, California.
Where does Pine Mountain Mutual Water Co. 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 Pine Mountain Mutual Water Co. have any drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in April 2025. 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 Pine Mountain Mutual Water Co.'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. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in April 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Pine Mountain Mutual Water Co.'s water quality report?
As a community water system, Pine Mountain Mutual Water Co. 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 |
| 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 |
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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, “Pine Mountain Mutual Water Co., PWSID CA2300591, California”, https://aquacensus.com/water-systems/california/pine-mountain-mutual-water-co-ca2300591 (data as of October 1, 2026).