Public water system record
Yosemite NPS-Yosemite Valley
Serves Yosemite Valley, Mariposa County, CA · 1,000 people served
Federal records show no health-based violations and 1 monitoring/reporting issue for Yosemite NPS-Yosemite Valley in the last ten years. At least one of these issues remains unresolved.
System profile
- Health-based violations, last 10 years
- 0
- Resolved
- 0
- Unresolved
- 0
- Any acute record
- No
- Monitoring issues, last 10 years
- 1
Key facts
- Yosemite NPS-Yosemite Valley draws water from 3 wells.
- Most recent formal enforcement: compliance order (no penalty) by California, December 2025.
- Record on file since 1993, with 0 health-based violations before October 19, 2016.
- Lead pipe inventory: 0 lead and 155 unknown out of 228 service lines.
Check whether Yosemite NPS-Yosemite Valley serves your address
Health-based violations
Since October 2016Violation data reflects EPA records through March 2026. For the most current status, visit the EPA ECHO database.
None since October 2016.
Monitoring and reporting issues
Since October 2016Missed tests or reports, not contaminants found above a limit.
| Issue | Start date | Status |
|---|---|---|
|
Consumer Confidence Rule
OTHER
|
Jul 1, 2025 |
Active
Enforcement action in place
|
Full record since 1993
EPA's records for Yosemite NPS-Yosemite Valley go back to 1993. Before October 19, 2016 they list no health-based violations and 4 monitoring or reporting violations.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 1990s | 0 | 1 |
| 2000s | 0 | 3 |
| 2020s | 0 | 1 |
Enforcement actions
California regulators took 4 formal enforcement actions against Yosemite NPS-Yosemite Valley between 2006 and 2025. The most recent was a compliance order (no penalty) in December 2025.
| Date | By | Action | Violations covered |
|---|---|---|---|
| Dec 11, 2025 | California | Compliance order (no penalty) | 1 violation: Consumer Confidence Rule |
| Nov 9, 2007 | California | Compliance order (no penalty) | 1 violation: Consumer Confidence Rule |
| Jan 2, 2007 | California | Compliance order (no penalty) | 1 violation: Lead and Copper Rule |
| Nov 14, 2006 | California | Compliance order (no penalty) | 1 violation: Consumer Confidence Rule |
Where the water comes from
Yosemite NPS-Yosemite Valley draws water from 3 wells.
Annual water quality report
Yosemite NPS-Yosemite Valley must give its customers an annual water quality report (Consumer Confidence Report) by July 1, with the levels its tests found in the previous year.
Where the state allows it, systems serving fewer than 10,000 people may publish the report in a local newspaper or news site instead of mailing it, and must provide a copy on request.
Find a posted report with EPA's Consumer Confidence Report search
Testing your own water
To test the water at your tap, or a private well this record does not cover, use a laboratory certified for drinking water by California.
Certified drinking water labs by state EPA guidance for private wells