PlainWater
States → New Mexico

Community Water System · PWS NM3500115

Los Alamos Municipal Water System

Los Alamos, New Mexico 87544 - drinking water served from groundwater sources to 25,000 people, tracked in EPA SDWIS and UCMR5.

25,000
People served
67
EPA violations
2
Health-based
No PFAS
UCMR5 result

The verdict

EPA records 67 drinking-water violations at Los Alamos Municipal Water System, 3% of them health-based - below the New Mexico per-system average.

67
Total EPA violations on record
3%
Health-based (MCL / treatment failure)
25,000
People served by this system
0
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Los Alamos Municipal Water System

Los Alamos Municipal Water System is a local-owned community water system that delivers drinking water to 25,000 residents in Los Alamos, New Mexico (Los Alamos County) through 7,000 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 67 total violations for this system , of which 2 (3%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 52 monitoring and reporting violations are on file. The most recent violation on record dates to 2016.

The most frequently cited contaminant at this system is TTHM, recorded in 20 violations (MR). This system was sampled under EPA's UCMR5 PFAS monitoring program and no PFAS compounds were detected above the minimum reporting level.

Across New Mexico, EPA tracks 1,037 public water systems serving 2,027,497 people, with 154,522 cumulative violations and 38,650 health-based violations on record. About 97% of systems in the state carry at least one violation, and state-wide the average per system is 149 violations. Statewide, 70 of 72 UCMR5-tested systems have reported PFAS detections (97.2%).

Los Alamos Municipal Water System's 67 violations sit below the New Mexico average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

Population Served
25,000
Total Violations
67
Health-Based Violations
2
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
7,000
County
Los Alamos
School/Daycare
No
MCL Violations
2
Monitoring Violations
52
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
TTHM MR 20 2014
Total Haloacetic Acids (HAA5) MR 20 2014
Consumer Confidence Rule Other 11 2014
Chlorine MR 4 2012
Lead and Copper Rule MR 4 2014
Coliform (TCR) MCL 2 1993
Coliform (TCR) MR 2 2009
Fluoride MR 2 1981
Public Notice Other 1 2016

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 174 samples detected PFAS.

Contaminant Date Result MRL Status
6:2 FTS 7/28/2023 <5.00 ppt 5.00 ppt Not Detected
NMeFOSAA 7/28/2023 <6.00 ppt 6.00 ppt Not Detected
NEtFOSAA 7/28/2023 <5.00 ppt 5.00 ppt Not Detected
PFTrDA 7/28/2023 <7.00 ppt 7.00 ppt Not Detected
PFTA 7/28/2023 <8.00 ppt 8.00 ppt Not Detected
PFHpS 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
PFPeS 7/28/2023 <4.00 ppt 4.00 ppt Not Detected
NFDHA 7/28/2023 <20.00 ppt 20.00 ppt Not Detected
PFEESA 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
PFMBA 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
PFPeA 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
PFMPA 7/28/2023 <4.00 ppt 4.00 ppt Not Detected
PFBS 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
4:2 FTS 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
PFBA 7/28/2023 <5.00 ppt 5.00 ppt Not Detected
ADONA 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
11Cl-PF3OUdS 7/28/2023 <5.00 ppt 5.00 ppt Not Detected
PFUnA 7/28/2023 <2.00 ppt 2.00 ppt Not Detected
PFHxA 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
PFDoA 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
PFDA 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
PFOA 7/28/2023 <4.00 ppt 4.00 ppt Not Detected
PFOS 7/28/2023 <4.00 ppt 4.00 ppt Not Detected
PFNA 7/28/2023 <4.00 ppt 4.00 ppt Not Detected
PFHxS 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
PFHpA 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
9Cl-PF3ONS 7/28/2023 <2.00 ppt 2.00 ppt Not Detected
8:2 FTS 7/28/2023 <5.00 ppt 5.00 ppt Not Detected
HFPO-DA 7/28/2023 <5.00 ppt 5.00 ppt Not Detected
NEtFOSAA 7/28/2023 <5.00 ppt 5.00 ppt Not Detected
PFHxA 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
PFDoA 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
PFDA 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
PFOA 7/28/2023 <4.00 ppt 4.00 ppt Not Detected
PFOS 7/28/2023 <4.00 ppt 4.00 ppt Not Detected
PFNA 7/28/2023 <4.00 ppt 4.00 ppt Not Detected
PFHxS 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
PFHpA 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
PFTA 7/28/2023 <8.00 ppt 8.00 ppt Not Detected
NMeFOSAA 7/28/2023 <6.00 ppt 6.00 ppt Not Detected
PFUnA 7/28/2023 <2.00 ppt 2.00 ppt Not Detected
PFTrDA 7/28/2023 <7.00 ppt 7.00 ppt Not Detected
PFMPA 7/28/2023 <4.00 ppt 4.00 ppt Not Detected
PFBS 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
PFHpS 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
4:2 FTS 7/28/2023 <3.00 ppt 3.00 ppt Not Detected
11Cl-PF3OUdS 7/28/2023 <5.00 ppt 5.00 ppt Not Detected
PFPeS 7/28/2023 <4.00 ppt 4.00 ppt Not Detected
NFDHA 7/28/2023 <20.00 ppt 20.00 ppt Not Detected
PFEESA 7/28/2023 <3.00 ppt 3.00 ppt Not Detected

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records, or to file a complaint, request a Consumer Confidence Report, or check current monitoring status, go directly to the federal and state regulators that enforce the Safe Drinking Water Act for Los Alamos Municipal Water System.

Federal Source of Truth

EPA SDWIS, Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID NM3500115 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

New Mexico Drinking Water Authority

New Mexico's primacy agency administers the Safe Drinking Water Act locally. Search EPA SDWIS for the current state contact, or use the state's public health or environment department portal.

Find NM regulator via EPA SDWIS

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2016 Public Notice Other 1 SDWIS / NM3500115 / 7500
2014 TTHM MR 20 SDWIS / NM3500115 / 2950
2014 Total Haloacetic Acids (HAA5) MR 20 SDWIS / NM3500115 / 2456
2014 Consumer Confidence Rule Other 11 SDWIS / NM3500115 / 7000
2014 Lead and Copper Rule MR 4 SDWIS / NM3500115 / 5000
2012 Chlorine MR 4 SDWIS / NM3500115 / 0999
2009 Coliform (TCR) MR 2 SDWIS / NM3500115 / 3100
1993 Coliform (TCR) MCL 2 SDWIS / NM3500115 / 3100
1981 Fluoride MR 2 SDWIS / NM3500115 / 1025

How Los Alamos Municipal Water System Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric Los Alamos Municipal Water System New Mexico avg Federal benchmark
Total violations 67 149 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 2 37.3 Indicates a contaminant exceeded a federal MCL
PFAS detection None 97.2% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 25,000 1,955 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 1,037 regulated public water systems in New Mexico.

Federal MCL reference, Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029 (EPA proposed extending to 2031, not yet final as of May 2026)
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is Los Alamos Municipal Water System water safe to drink? ▼
Los Alamos Municipal Water System (PWS ID: NM3500115) has 67 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 25,000 people using Groundwater sources.
How many people does Los Alamos Municipal Water System serve? ▼
Los Alamos Municipal Water System serves 25,000 people in Los Alamos, New Mexico. It is a Local-owned system using Groundwater water sources with 7,000 service connections.
What type of violations does Los Alamos Municipal Water System have? ▼
Los Alamos Municipal Water System has 67 total violations: 2 health-based violations (MCL exceedances or treatment failures), 52 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Los Alamos Municipal Water System water? ▼
No. Los Alamos Municipal Water System was tested for PFAS under the EPA's UCMR5 monitoring program and no PFAS contamination was detected.
What water source does Los Alamos Municipal Water System use? ▼
Los Alamos Municipal Water System uses Groundwater as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. PFAS data from EPA UCMR5 monitoring program (2023-2025). This data is provided for informational purposes only.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This system's figures are rendered directly from EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.