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States → New Mexico

Community Water System · PWS NM3575029

Upper Des Montes Mdwca

Arroyo Seco, New Mexico 87514 - drinking water served from groundwater sources to 222 people, tracked in EPA SDWIS and UCMR5.

222
People served
783
EPA violations
1
Health-based
Untested
UCMR5 result

The verdict

EPA records 783 drinking-water violations at Upper Des Montes Mdwca - above the New Mexico per-system average.

783
Total EPA violations on record
0%
Health-based (MCL / treatment failure)
222
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Upper Des Montes Mdwca

Upper Des Montes Mdwca is a local-owned community water system that delivers drinking water to 222 residents in Arroyo Seco, New Mexico (Taos County) through 78 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 783 total violations for this system , of which 1 (0%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 727 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 Consumer Confidence Rule, recorded in 32 violations (Other). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

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%).

Upper Des Montes Mdwca's 783 violations sit above 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
222
Total Violations
783
Health-Based Violations
1
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
78
County
Taos
School/Daycare
No
MCL Violations
0
Monitoring Violations
727
Treatment Tech Violations
1

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Consumer Confidence Rule Other 32 2012
BHC-GAMMA MR 21 2006
Toxaphene MR 21 2006
Dalapon MR 21 2006
Endothall MR 21 2006
Di(2-ethylhexyl) adipate MR 21 2006
OXAMYL MR 21 2006
Simazine MR 21 2006
Picloram MR 21 2006
Hexachlorocyclopentadiene MR 21 2006
Aldicarb sulfoxide MR 21 2006
Aldicarb sulfone MR 21 2006
Aldicarb MR 21 2006
Atrazine MR 21 2006
LASSO MR 21 2006
Heptachlor epoxide MR 21 2006
2,4,5-TP MR 21 2006
HEXACHLOROBENZENE MR 21 2006
Benzo(a)pyrene MR 21 2006
1,2-DIBROMO-3-CHLOROPROPANE MR 21 2006
ETHYLENE DIBROMIDE MR 21 2006
Diquat MR 21 2006
Di(2-ethylhexyl) phthalate MR 21 2006
Dinoseb MR 21 2006
Carbofuran MR 21 2006
Heptachlor MR 21 2006
Pentachlorophenol MR 21 2006
Chlordane MR 21 2006
Endrin MR 21 2006
Glyphosate MR 21 2006

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 Upper Des Montes Mdwca.

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 NM3575029 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 11 SDWIS / NM3575029 / 7500
2016 Total Haloacetic Acids (HAA5) MR 11 SDWIS / NM3575029 / 2456
2016 TTHM MR 11 SDWIS / NM3575029 / 2950
2016 Revised Total Coliform Rule MON 4 SDWIS / NM3575029 / 8000
2014 Lead and Copper Rule MR 15 SDWIS / NM3575029 / 5000
2012 Consumer Confidence Rule Other 32 SDWIS / NM3575029 / 7000
2012 Chlorine MR 7 SDWIS / NM3575029 / 0999
2011 Groundwater Rule TT 1 SDWIS / NM3575029 / 0700
2009 Coliform (TCR) MR 15 SDWIS / NM3575029 / 3100
2006 BHC-GAMMA MR 21 SDWIS / NM3575029 / 2010
2006 Toxaphene MR 21 SDWIS / NM3575029 / 2020
2006 Dalapon MR 21 SDWIS / NM3575029 / 2031
2006 Endothall MR 21 SDWIS / NM3575029 / 2033
2006 Di(2-ethylhexyl) adipate MR 21 SDWIS / NM3575029 / 2035
2006 OXAMYL MR 21 SDWIS / NM3575029 / 2036

How Upper Des Montes Mdwca Compares

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

Metric Upper Des Montes Mdwca New Mexico avg Federal benchmark
Total violations 783 149 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 1 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 222 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 Upper Des Montes Mdwca water safe to drink? ▼
Upper Des Montes Mdwca (PWS ID: NM3575029) has 783 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 222 people using Groundwater sources.
How many people does Upper Des Montes Mdwca serve? ▼
Upper Des Montes Mdwca serves 222 people in Arroyo Seco, New Mexico. It is a Local-owned system using Groundwater water sources with 78 service connections.
What type of violations does Upper Des Montes Mdwca have? ▼
Upper Des Montes Mdwca has 783 total violations: 1 health-based violations (MCL exceedances or treatment failures), 727 monitoring/reporting violations, and 1 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Upper Des Montes Mdwca water? ▼
No PFAS testing data is available for Upper Des Montes Mdwca under the EPA's UCMR5 monitoring program.
What water source does Upper Des Montes Mdwca use? ▼
Upper Des Montes Mdwca 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. 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.