Public water system · CA2010500
ActiveYosemite Nps-Mariposa Grove
At a glance
Yosemite Nps-Mariposa Grove (PWSID CA2010500) is an active transient non-community water system in Madera County, California. It reports serving 3,500 people through 3 service connections. Its primary water source is groundwater, and EPA lists it as owned by the federal government. EPA's Safe Drinking Water Act records list no violations for this system.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
3,500
Service connections
3
Primary source
GW
Groundwater
System type
TNCWS
Transient non-community water system
System record
How does Yosemite Nps-Mariposa Grove compare with other water systems in Madera County?
By EPA's size categories, Yosemite Nps-Mariposa Grove is a medium system (3,301 to 10,000 people). Madera County has 202 active public water systems. Its population served is about 3.8 times the county average of 915 people per system, and accounts for 1.9% of the 184,760 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active transient non-community water system reports serving 144 people, so Yosemite Nps-Mariposa Grove is about 24 times that figure.
What does “transient non-community water system” mean?
A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. California has 3,016 active transient non-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 Yosemite Nps-Mariposa Grove?
EPA lists Yosemite Nps-Mariposa Grove as owned by the federal 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. 11 of the 202 active systems in Madera County (5.4%) are also owned by the federal government.
Does Yosemite Nps-Mariposa Grove have drinking water violations?
No SDWA violations on record.
EPA's SDWA violation and enforcement data (via EPA ECHO, updated quarterly) lists no violations for Yosemite Nps-Mariposa Grove. For the latest compliance status, check EPA ECHO for current compliance history.
Yosemite Nps-Mariposa Grove: frequently asked questions
Who runs Yosemite Nps-Mariposa Grove?
Yosemite Nps-Mariposa Grove (PWSID CA2010500) is a transient non-community water system owned by the federal government. It is regulated by the CA state drinking water program.
How many people does Yosemite Nps-Mariposa Grove serve?
Yosemite Nps-Mariposa Grove reports serving 3,500 people through 3 service connections in Madera County, California.
Where does Yosemite Nps-Mariposa Grove 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 Yosemite Nps-Mariposa Grove have any drinking water violations?
EPA's Safe Drinking Water Act records list no violations for this system.
Is Yosemite Nps-Mariposa Grove'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. EPA's Safe Drinking Water Act records list no violations for this system. For current results, consult EPA ECHO, or the CA state drinking water program.
Where can I find Yosemite Nps-Mariposa Grove's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Yosemite Nps-Mariposa Grove is a transient non-community water system, so it is not required to publish one; like every public water system, it must notify the people it serves about violations under EPA's public notification rules.
Other water systems in Madera County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| City of Madera | Madera | 66,560 | Community | Groundwater |
| Chowchilla City Water Dept | Madera | 13,916 | Community | Groundwater |
| Lupine Bass Lake | Madera | 11,930 | Transient non-community | Groundwater |
| Madera Valley Water Company | Madera | 6,494 | Community | Groundwater |
| Riverstone/Rootcreek Water District | Madera | 5,507 | Community | Groundwater |
| Yosemite Spring Park Util Co | Madera | 5,300 | 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, “Yosemite Nps-Mariposa Grove, PWSID CA2010500, California”, https://aquacensus.com/water-systems/california/yosemite-nps-mariposa-grove-ca2010500 (data as of October 1, 2026).