Public water system · CA0500019
ActiveMineral Mountain Mutual Water
At a glance
Mineral Mountain Mutual Water (PWSID CA0500019) is an active community water system in Calaveras County, California. It reports serving 67 people through 34 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 July 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
67
Service connections
34
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Mineral Mountain Mutual Water compare with other water systems in Calaveras County?
By EPA's size categories, Mineral Mountain Mutual Water is a very small system (500 people or fewer). Calaveras County has 51 active public water systems. Its population served is well below the county average of 1,102 people per system, and accounts for 0.1% of the 56,208 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 Mineral Mountain Mutual Water 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 Mineral Mountain Mutual Water?
EPA lists Mineral Mountain Mutual Water 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. 34 of the 51 active systems in Calaveras County (67%) are also privately owned.
Does Mineral Mountain Mutual Water have drinking water violations?
Of the 12 most recent violations in EPA's records, 4 are health-based, and the most recent began in July 2025. The violations listed here began between April 2004 and July 2025. By type: 6 monitoring and reporting, 3 contaminant level above the legal limit, 2 reporting and 1 required treatment not met. The contaminant or rule involved most often is Total coliform bacteria (TCR) (6 of them). EPA lists 9 as resolved and 3 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 |
|---|---|---|---|---|
| 2025-07-02 | ReportingNotification, Known or Potential LSL · code 4H | Lead and Copper Rule Revisionscode 5200 | No | Unaddressed |
| 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 |
| 2015-08-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2014-11-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2009-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2007-08-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2007-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2006-08-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2004-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Bromatecode 1011 | No | Resolved |
| 2004-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Bromatecode 1011 | No | Resolved |
| 2004-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Bromatecode 1011 | 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.
Mineral Mountain Mutual Water: frequently asked questions
Who runs Mineral Mountain Mutual Water?
Mineral Mountain Mutual Water (PWSID CA0500019) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Mineral Mountain Mutual Water serve?
Mineral Mountain Mutual Water reports serving 67 people through 34 service connections in Calaveras County, California.
Where does Mineral Mountain Mutual Water 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 Mineral Mountain Mutual Water 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 July 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 Mineral Mountain Mutual Water'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 July 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 Mineral Mountain Mutual Water's water quality report?
As a community water system, Mineral Mountain Mutual Water 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 Calaveras County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Ccwd - Ebbetts Pass | Calaveras | 11,545 | Community | Surface water |
| Ccwd - Jenny Lind | Calaveras | 9,861 | Community | Surface water |
| Calaveras PUD | Calaveras | 6,286 | Community | Surface water |
| Ccwd - Copper Cove | Calaveras | 5,187 | Community | Surface water |
| Blue Lake Springs Mut Wtr | Calaveras | 4,841 | Community | Purchased surface water |
| Union Public Utility District | Calaveras | 4,774 | 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, “Mineral Mountain Mutual Water, PWSID CA0500019, California”, https://aquacensus.com/water-systems/california/mineral-mountain-mutual-water-ca0500019 (data as of October 1, 2026).