CA / Plymouth
CA · Tap water records
Plymouth tap water, in plain English
Here is what the EPA's own data shows about tap water in Plymouth. According to EPA SDWIS data retrieved June 2026, Plymouth is served by 3 active community water systems, together reported to serve about 1,399 people.
As of June 2026, EPA records show 42 violations across the community water system(s) serving Plymouth, going back to the earliest EPA record. 7 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
Plymouth, City Of
1,060 served · surface water · PWSID CA0310004 - Health-based TTHM: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times between April 2017 and October 2021. The EPA record lists a level of 0.081 MG/L; the limit (MCL) is 0.08 MG/L. All have since returned to compliance, per EPA records.
- Monitoring LEAD AND COPPER RULE REVISIONS: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between April 2016 and August 2017. All have since returned to compliance, per EPA records.
- Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2005. All have since returned to compliance, per EPA records.
- Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2005. All have since returned to compliance, per EPA records.
- Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2001. All have since returned to compliance, per EPA records.
- Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between January 1997 and January 2000. All have since returned to compliance, per EPA records.
- Monitoring Nitrite: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between January 1997 and January 2000. All have since returned to compliance, per EPA records.
- Monitoring Nitrate-Nitrite: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between January 1997 and January 2000. All have since returned to compliance, per EPA records.
- Monitoring Gross Alpha Particle Activity: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 1997. All have since returned to compliance, per EPA records.
Hope Foundation/Moriah Heights
299 served · groundwater · PWSID CA0300062 - Health-based contaminant code null: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 4 times between February 2021 and July 2021. 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 November 2008. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- 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 2020 and July 2025. All have since returned to compliance, per EPA records.
- Monitoring contaminant code null: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between February 2021 and July 2021. All have since returned to compliance, per EPA records.
- Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2017. All have since returned to compliance, per EPA records.
- Monitoring Coliform (TCR): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between June 1998 and February 2004. All have since returned to compliance, per EPA records.
Ione Band Of Miwok Indians
40 served · groundwater · PWSID CA0300078 - 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 October 2013 and October 2022. All have since returned to compliance, per EPA records.
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.