MARIPOSA, CA · Mariposa County
PONDEROSA BASIN MUTUAL WTR CO Water System
Consumer Confidence Report status
PONDEROSA BASIN MUTUAL WTR CO 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 PONDEROSA BASIN MUTUAL WTR CO.
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)
- CA2210002
- System type
- Community Water System
- Population served
- 798
- Service connections
- 317
- Ownership
- privately owned
- Water source
- groundwater (wells)
PONDEROSA BASIN MUTUAL WTR CO is one of 728 community water systems in California in the 501 to 3,300 people size category, serving 798 people from groundwater.
As of August 1, 2026, its federal record holds 1 entry in 2001, all of which EPA lists as closed. Nothing has been added since 2001.
All 1 are monitoring and reporting requirements — the category that accounts for about four in five of all violations in EPA's national dataset — rather than findings about the water itself. The record involves the Radionuclides and Revised Rad Rule.
Violation history
Monitoring, Regular
—Radium-228
January 1, 2001 – December 31, 2007
Resolved
Resolved addressed and confirmed by the state
| Period | Violation | Contaminant / rule | Health-based | Status |
|---|---|---|---|---|
| January 1, 2001 – December 31, 2007 | Monitoring, Regular | Radium-228 | — | Resolved |
Resolved addressed and confirmed by the state
Enforcement actions
- August 14, 2015State Compliance achieved8 linked violations
- October 9, 2013State Compliance achieved6 linked violations
- March 28, 2007State Compliance achieved5 linked violations
- December 30, 2004State Compliance achieved8 linked violations
- August 31, 1998State Compliance achieved3 linked violations
Common questions
Is PONDEROSA BASIN MUTUAL WTR CO required to publish a Consumer Confidence Report?
- Yes. PONDEROSA BASIN MUTUAL WTR CO 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 PONDEROSA BASIN MUTUAL WTR CO’s next Consumer Confidence Report due?
- PONDEROSA BASIN MUTUAL WTR CO’s next Consumer Confidence Report is due by July 1, 2027. The report covers calendar year 2026.
Does PONDEROSA BASIN MUTUAL WTR CO have any open drinking water violations on record?
- As of August 1, 2026, EPA's federal records show no open violations for PONDEROSA BASIN MUTUAL WTR CO.
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
DONATI, ALEARDO TUFFY
209-742-6572
MARIPOSA, CA 95338