MARIPOSA, CA · Mariposa County
YOSEMITE WEST WATER SYSTEM Water System
Consumer Confidence Report status
YOSEMITE WEST WATER SYSTEM must publish a Consumer Confidence Report — the annual drinking water quality report covering calendar year 2026 — by July 1, 2027.
As of August 1, 2026, EPA's federal records show no open violations for YOSEMITE WEST WATER SYSTEM.
Data sourced from the EPA ECHO database (SDWA bulk download), last refreshed August 1, 2026. This is a record-keeping and public-information tool — it does not replace California’s official records. Always confirm current status with California before making decisions based on this information.
System facts
- System ID (PWSID)
- CA2210924
- System type
- Community Water System
- Population served
- 420
- Service connections
- 185
- Ownership
- local government
- Water source
- groundwater (wells)
YOSEMITE WEST WATER SYSTEM is one of 3,951 community water systems in California in the 500 or fewer people size category, serving 420 people from groundwater.
As of August 1, 2026, its federal record holds 3 entries between 1996 and 2011, all of which EPA lists as closed. Nothing has been added since 2011.
None of the 3 are monitoring or reporting requirements — the category that accounts for about four in five of all violations in EPA's national dataset; these involve water-quality, treatment, or public-notice findings instead. The record involves the Total Coliform Rules.
Violation history
Maximum Contaminant Level Violation, Monthly (TCR)
Health-basedColiform (TCR)
July 1, 2011 – July 31, 2011
ResolvedMaximum Contaminant Level Violation, Monthly (TCR)
Health-basedColiform (TCR)
October 1, 2010 – October 31, 2010
ResolvedMaximum Contaminant Level Violation, Monthly (TCR)
Health-basedColiform (TCR)
December 1, 1996 – December 31, 1996
Resolved
Resolved addressed and confirmed by the state
| Period | Violation | Contaminant / rule | Health-based | Status |
|---|---|---|---|---|
| July 1, 2011 – July 31, 2011 | Maximum Contaminant Level Violation, Monthly (TCR) | Coliform (TCR) | Health-based | Resolved |
| October 1, 2010 – October 31, 2010 | Maximum Contaminant Level Violation, Monthly (TCR) | Coliform (TCR) | Health-based | Resolved |
| December 1, 1996 – December 31, 1996 | Maximum Contaminant Level Violation, Monthly (TCR) | Coliform (TCR) | Health-based | Resolved |
Resolved addressed and confirmed by the state
Enforcement actions
- July 30, 2002State Administrative/Compliance Order without penalty issued19 linked violations
- May 31, 2002State Compliance achieved10 linked violations
Common questions
Is YOSEMITE WEST WATER SYSTEM required to publish a Consumer Confidence Report?
- Yes. YOSEMITE WEST WATER SYSTEM is a community water system, and federal rules (40 CFR 141 Subpart O) require every community water system to publish a Consumer Confidence Report each year.
When is YOSEMITE WEST WATER SYSTEM’s next Consumer Confidence Report due?
- YOSEMITE WEST WATER SYSTEM’s next Consumer Confidence Report is due by July 1, 2027. The report covers calendar year 2026.
Does YOSEMITE WEST WATER SYSTEM have any open drinking water violations on record?
- As of August 1, 2026, EPA's federal records show no open violations for YOSEMITE WEST WATER SYSTEM.
What is a Consumer Confidence Report?
- A Consumer Confidence Report (CCR) is the annual drinking water quality report that community water systems must provide to the people they serve. It lists the contaminants detected in the system’s water during the year, where the water comes from, and how the results compare with federal limits. EPA’s revised CCR rule takes effect January 1, 2027, and the first reports in the new format are due July 1, 2027.
Contact
HANSEN, SHANNON
209-966-5356
MARIPOSA, CA 95338