Does Atascadero, CA tap water have any EPA-reported violations?

As of June 2026, EPA SDWIS records show 10 violation(s) across the community water systems serving Atascadero, of which 0 are classified by the EPA as health-based. Most older violations have returned to compliance; see the per-system list.

Where does Atascadero, CA tap water come from?

Atascadero is served by 3 active community water system(s). Their primary sources, per EPA records, are: groundwater.

CA / Atascadero

CA · Tap water records

Atascadero tap water, in plain English

Here is what the EPA's own data shows about tap water in Atascadero. According to EPA SDWIS data retrieved June 2026, Atascadero is served by 3 active community water systems, together reported to serve about 35,158 people.

As of June 2026, EPA records show 10 violations across the community water system(s) serving Atascadero, going back to the earliest EPA record. None were health-based; the records are monitoring or reporting violations (a required test or report was late or missed). Each is listed by system below, with its status.

3

Community water systems
~35,158

People served (EPA-reported)
June 2026

EPA records reviewed through

What the EPA has on record, by system

Atascadero Mutual Water Co

30,618 served · groundwater · PWSID CA4010002

As of June 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.

Atascadero State Hospital

4,100 served · groundwater · PWSID CA4010832

Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2023. All have since returned to compliance, per EPA records.

Garden Farms C.W.D.

440 served · groundwater · PWSID CA4000507

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 2017 and October 2025. EPA records do not show all of these as returned to compliance.
Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between January 2021 and February 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.