Public water system · CA2210906
ActiveMariposa Pines Mutual
At a glance
Mariposa Pines Mutual (PWSID CA2210906) is an active community water system in Mariposa County, California. It reports serving 284 people through 89 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, 4 are health-based, and the most recent began in October 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
284
Service connections
89
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Mariposa Pines Mutual compare with other water systems in Mariposa County?
By EPA's size categories, Mariposa Pines Mutual is a very small system (500 people or fewer). Mariposa County has 67 active public water systems. Its population served is about 25% below the county average of 381 people per system, and accounts for 1.1% of the 25,508 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 Mariposa Pines Mutual 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. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 6,179 California systems (83%) list groundwater as their primary source.
Who owns and regulates Mariposa Pines Mutual?
EPA lists Mariposa Pines Mutual 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. 33 of the 67 active systems in Mariposa County (49%) are also privately owned.
Does Mariposa Pines Mutual have drinking water violations?
Of the 12 most recent violations in EPA's records, 4 are health-based, and the most recent began in October 2024. The violations listed here began between January 1996 and October 2024. By type: 5 monitoring and reporting, 3 contaminant level above the legal limit, 1 required treatment not met, 1 reporting, 1 public notice, recordkeeping or other and 1 monitoring. The contaminant or rule involved most often is Nitrate (3 of them). EPA lists 10 as resolved 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. 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 |
|---|---|---|---|---|
| 2024-10-17 | Required treatment not metLSL Inventory · code 2E | Lead and Copper Rule Revisionscode 5200 | Yes | Unaddressed |
| 2024-10-17 | ReportingLSL Reporting · code 4G | Lead and Copper Rule Revisionscode 5200 | No | Unaddressed |
| 2024-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2020-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2016-04-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2015-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2013-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2013-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2012-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 1996-01-02 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | 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.
Mariposa Pines Mutual: frequently asked questions
Who runs Mariposa Pines Mutual?
Mariposa Pines Mutual (PWSID CA2210906) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Mariposa Pines Mutual serve?
Mariposa Pines Mutual reports serving 284 people through 89 service connections in Mariposa County, California.
Where does Mariposa Pines Mutual get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does Mariposa Pines Mutual have any drinking water violations?
Of the 12 most recent violations in EPA's records, 4 are health-based, and the most recent began in October 2024. 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 Mariposa Pines Mutual'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, 4 are health-based, and the most recent began in October 2024. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Mariposa Pines Mutual's water quality report?
As a community water system, Mariposa Pines Mutual 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 Mariposa County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Yosemite Nps-Glacier Point | Mariposa | 4,000 | Transient non-community | Surface water |
| Blm-Briceburg Water System | Mariposa | 3,196 | Transient non-community | Groundwater |
| Mariposa Public Utility Dist | Mariposa | 2,000 | Community | Surface water |
| Yosemite Nps-Bridalveil Fall | Mariposa | 1,163 | Transient non-community | Groundwater |
| Mid - Mc Swain Rec Area | Mariposa | 1,119 | Transient non-community | Surface water |
| Yosemite Nps-Yosemite Valley | Mariposa | 1,000 | 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, “Mariposa Pines Mutual, PWSID CA2210906, California”, https://aquacensus.com/water-systems/california/mariposa-pines-mutual-ca2210906 (data as of October 1, 2026).