Tap Truth EPA drinking water records, in plain English

County drinking water records

Mariposa County, CA drinking water systems

12 community water systems serve Mariposa County, CA, reporting 9,792 people served in all. A system that also serves other counties counts all of its customers here.

4 of them (33%) had at least one health-based violation in the last 10 years. 4 systems still have one unresolved.

8 rely mainly on groundwater and 4 on surface water, counting water bought from other systems.

11 systems filed a lead service line inventory listing 0 lead lines, 0 galvanized lines that must be replaced and 155 lines of unknown material.

Community water systems
12
People served, sum of each system's own figure
9,792
Systems with a health-based violation, last 10 years
4
Systems with one unresolved
4
Lead service lines in inventories
0

Water systems serving Mariposa County

12 systems

People served is each system's own figure for its whole service area. Violation counts cover the last 10 years of EPA records.

System Serves People served Main source Health-based violations, 10 years Unresolved Lead lines
Lake Don Pedro CSD Lake Don Pedro 3,240 Surface water 1 2 0
Mariposa Public Utility Dist Mariposa 2,000 Surface water 0 0 0
Yosemite NPS-Yosemite Valley Yosemite Valley 1,000 Groundwater 0 0 0
Ponderosa Basin Mutual Wtr Co Outside cities and towns 798 Groundwater 0 0 0
Cedar Lodge Outside cities and towns 656 Groundwater 0 0 0
Yosemite NPS-El Portal Outside cities and towns 635 Groundwater 0 0 0
Yosemite West Water System Yosemite West 420 Groundwater 0 1 0
McClure Boat Club, Inc. Lake Don Pedro 286 Surface water 1 0 0
Mariposa Pines Mutual Outside cities and towns 284 Groundwater 1 2 No inventory
MPWD-Coulterville CSA 1 Coulterville 193 Groundwater 0 0 0
Yosemite NPS-Wawona Outside cities and towns 150 Surface water 0 0 0
Yosemite Terrace Estates Greeley Hill 130 Groundwater 1 2 0

Cities and towns in Mariposa County

6 places

Back to California

Counties come from the counties EPA lists each system serving, matched to 2024 Census counties; where EPA lists none, from the county coded in the system's ID, its service area map, or its mailing address. A county holding at least a fifth of a system's service area map is added when at least a fifth of that map lies in those counties. Towns are the ones EPA lists and the Census places such a map covers, always inside those counties. In New England, where EPA's town names a whole Town, it is not matched to the village of the same name. A system is not listed in a county holding less than a fifth of its map, or in a county or town its map reaches when the map lies mostly outside the counties EPA lists, so a page can leave out a system that serves part of the area. Methodology and limitations