CA / Yosemite Np
CA · Tap water records
Yosemite Np tap water, in plain English
Here is what the EPA's own data shows about tap water in Yosemite Np. According to EPA SDWIS data retrieved June 2026, Yosemite Np is served by 4 active community water systems, together reported to serve about 1,836 people.
As of June 2026, EPA records show 21 violations across the community water system(s) serving Yosemite Np, going back to the earliest EPA record. 3 of these are classified by the EPA as health-based (a contaminant recorded above the limit the EPA tracks); the rest are monitoring or reporting violations. Each is listed by system below, with its status.
What the EPA has on record, by system
Yosemite Nps-Yosemite Valley
1,000 served · groundwater · PWSID CA2210503 - Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between July 2005 and July 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2007. All have since returned to compliance, per EPA records.
Yosemite Nps-El Portal
635 served · groundwater · PWSID CA2210515 - Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 2005 and July 2007. All have since returned to compliance, per EPA records.
- Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between January 2004 and July 2005. All have since returned to compliance, per EPA records.
Yosemite Nps-Wawona
150 served · surface water · PWSID CA2210510 - Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between July 2005 and July 2025. EPA records do not show all of these as returned to compliance.
Yosemite Nps-Hodgdon Meadow
51 served · groundwater · PWSID CA5510503 - Health-based COPPER, FREE: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times between January 2009 and July 2009. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- Health-based Lead and Copper Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in July 2008. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between May 2006 and October 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between July 2005 and July 2025. EPA records do not show all of these as returned to compliance.
What this means
A health-based violation means a contaminant was recorded above the limit the EPA tracks for it. A monitoring or reporting violation means a required test or report was late or missed — not that a contaminant was measured above a limit. “Returned to compliance” means the EPA recorded the issue as resolved.
This page summarizes the EPA's own records and does not assess whether your water is safe to drink. For the most current details, you can verify every record directly with the EPA, and contact your water system with questions.
Source: U.S. EPA Envirofacts SDWIS, retrieved June 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.