Public water system · NM3500115
ActiveLos Alamos Municipal Water System
At a glance
Los Alamos Municipal Water System (PWSID NM3500115) is an active community water system in Los Alamos County, New Mexico. It reports serving 25,000 people through 7,000 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in February 2016.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
25,000
Service connections
7,000
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Los Alamos Municipal Water System compare with other water systems in Los Alamos County?
By EPA's size categories, Los Alamos Municipal Water System is a large system (10,001 to 100,000 people). Los Alamos County has 2 active public water systems, and Los Alamos Municipal Water System is the largest of them by population served. Its population served is about twice the county average of 12,675 people per system, and accounts for 99% of the 25,350 people reported by systems filed under the county. Across New Mexico, the 1,165 active systems average 1,885 people each. Nationally, the average active community water system reports serving 6,703 people, so Los Alamos Municipal Water System is about 3.7 times that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. New Mexico has 645 active community water systems, 55% of the state's 1,165 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 1,009 New Mexico systems (87%) list groundwater as their primary source.
Who owns and regulates Los Alamos Municipal Water System?
EPA lists Los Alamos Municipal Water System as owned by a local government. The NM state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 1 of the 2 active systems in Los Alamos County (50%) are also owned by a local government.
Does Los Alamos Municipal Water System have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in February 2016. The violations listed here began between October 2013 and February 2016. By type: 10 monitoring and reporting and 2 public notice, recordkeeping or other. The contaminant or rule involved most often is Haloacetic acids (HAA5) (5 of them). EPA lists 12 as resolved. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2016-02-01 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2014-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2014-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2014-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2014-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2014-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2014-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2014-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2014-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2014-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2014-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2013-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
The 12 most recent violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
Los Alamos Municipal Water System: frequently asked questions
Who runs Los Alamos Municipal Water System?
Los Alamos Municipal Water System (PWSID NM3500115) is a community water system owned by a local government. It is regulated by the NM state drinking water program.
How many people does Los Alamos Municipal Water System serve?
Los Alamos Municipal Water System reports serving 25,000 people through 7,000 service connections in Los Alamos County, New Mexico.
Where does Los Alamos Municipal Water System get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does Los Alamos Municipal Water System have any drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in February 2016. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is Los Alamos Municipal Water System's water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in February 2016. For current results, consult the system's annual water quality report, EPA ECHO, or the NM state drinking water program.
Where can I find Los Alamos Municipal Water System's water quality report?
As a community water system, Los Alamos Municipal Water System must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in Los Alamos County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Pajarito Mountain Ski Area | Los Alamos | 350 | Transient non-community | Groundwater |
Related pages
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About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Los Alamos Municipal Water System, PWSID NM3500115, New Mexico”, https://aquacensus.com/water-systems/new-mexico/los-alamos-municipal-water-system-nm3500115 (data as of October 1, 2026).