Public water system · CA2210001
ActiveMariposa Public Utility Dist
At a glance
Mariposa Public Utility Dist (PWSID CA2210001) is an active community water system in Mariposa County, California. It reports serving 2,000 people through 684 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, 12 are health-based, and the most recent began in April 2013.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
2,000
Service connections
684
Primary source
SW
Surface water
System type
CWS
Community water system
System record
How does Mariposa Public Utility Dist compare with other water systems in Mariposa County?
By EPA's size categories, Mariposa Public Utility Dist is a small system (501 to 3,300 people). Mariposa County has 67 active public water systems, and Mariposa Public Utility Dist is the 3rd-largest of them by population served. Its population served is about 5.3 times the county average of 381 people per system, and accounts for 7.8% 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 Public Utility Dist 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 Mariposa Public Utility Dist?
EPA lists Mariposa Public Utility Dist 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. 21 of the 67 active systems in Mariposa County (31%) are also owned by a local government.
Does Mariposa Public Utility Dist have drinking water violations?
Of the 12 most recent violations in EPA's records, 12 are health-based, and the most recent began in April 2013. The violations listed here began between January 2012 and April 2013. By type: 9 contaminant level above the legal limit and 3 required treatment not met. The contaminant or rule involved most often is Total trihalomethanes (TTHM) (6 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 |
|---|---|---|---|---|
| 2013-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2013-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2013-01-01 | Required treatment not metTreatment Technique Precursor Removal · code 46 | Carbon, totalcode 2920 | Yes | Resolved |
| 2012-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Haloacetic acids (HAA5)code 2456 | Yes | Resolved |
| 2012-10-01 | Required treatment not metTreatment Technique Precursor Removal · code 46 | Carbon, totalcode 2920 | Yes | Resolved |
| 2012-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2012-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Haloacetic acids (HAA5)code 2456 | Yes | Resolved |
| 2012-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2012-07-01 | Required treatment not metTreatment Technique Precursor Removal · code 46 | Carbon, totalcode 2920 | Yes | Resolved |
| 2012-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Haloacetic acids (HAA5)code 2456 | Yes | Resolved |
| 2012-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2012-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | 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.
Mariposa Public Utility Dist: frequently asked questions
Who runs Mariposa Public Utility Dist?
Mariposa Public Utility Dist (PWSID CA2210001) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does Mariposa Public Utility Dist serve?
Mariposa Public Utility Dist reports serving 2,000 people through 684 service connections in Mariposa County, California.
Where does Mariposa Public Utility Dist 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 Mariposa Public Utility Dist have any drinking water violations?
Of the 12 most recent violations in EPA's records, 12 are health-based, and the most recent began in April 2013. 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 Public Utility Dist'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, 12 are health-based, and the most recent began in April 2013. 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 Public Utility Dist's water quality report?
As a community water system, Mariposa Public Utility Dist 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 |
| 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-Badger Pass | Mariposa | 1,000 | Transient non-community | Groundwater |
| 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 Public Utility Dist, PWSID CA2210001, California”, https://aquacensus.com/water-systems/california/mariposa-public-utility-dist-ca2210001 (data as of October 1, 2026).