CA / Los Alamos
CA · Tap water records
Los Alamos tap water, in plain English
Here is what the EPA's own data shows about tap water in Los Alamos. According to EPA SDWIS data retrieved June 2026, Los Alamos is served by 1 active community water system, together reported to serve about 1,534 people.
As of June 2026, EPA records show 4 violations across the community water system(s) serving Los Alamos, 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.
What the EPA has on record, by system
Los Alamos Community Services District
1,534 served · groundwater · PWSID CA4210002 - Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2018. 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 2 times in January 2018. 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.