NM / Los Alamos
NM · 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 3 active community water systems, together reported to serve about 25,743 people.
As of June 2026, EPA records show 269 violations across the community water system(s) serving Los Alamos, going back to the earliest EPA record. 71 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
Los Alamos Municipal Water System
25,000 served · groundwater · PWSID NM3500115 - Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in February 2016. 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 once in October 2014. 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 5 times between July 2000 and July 2014. All have since returned to compliance, per EPA records.
Regina Mdwca
705 served · groundwater · PWSID NM3509523 - Health-based Groundwater Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 64 times between January 2015 and October 2024. The EPA record for these does not include a measured level. 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 21 times between October 2015 and October 2025. All have since returned to compliance, per EPA records.
- Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 33 times between June 2017 and August 2024. All have since returned to compliance, per EPA records.
- Monitoring Groundwater Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2024. All have since returned to compliance, per EPA records.
- Monitoring Asbestos: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. 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 10 times between January 2014 and October 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 10 times between January 2014 and October 2018. 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 26 times between June 2016 and May 2017. 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 3 times between January 1999 and October 2016. All have since returned to compliance, per EPA records.
- Monitoring Stage 1 Disinfectants and Disinfection Byproducts Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2004. All have since returned to compliance, per EPA records.
Cielo Lindo
38 served · groundwater · PWSID NM3573126 - Health-based LEAD AND COPPER RULE REVISIONS: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in October 2024. The EPA record for these does not include a measured level. EPA records do not show all of these as returned to compliance.
- Health-based Groundwater Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 6 times between April 2019 and March 2024. 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 31 times between October 1999 and October 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 20 times between October 2010 and July 2025. EPA records do not show all of these as returned to compliance.
- 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 October 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Groundwater Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2019 and January 2024. All have since returned to compliance, per EPA records.
- Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 15 times between November 2011 and July 2018. 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 14 times between June 2016 and June 2017. 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.