Public water system · NM3505529
ActiveArroyo Seco Mdwca
At a glance
Arroyo Seco Mdwca (PWSID NM3505529) is an active community water system in Taos County, New Mexico. It reports serving 444 people through 182 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, one is health-based, and the most recent began in October 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
444
Service connections
182
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Arroyo Seco Mdwca compare with other water systems in Taos County?
By EPA's size categories, Arroyo Seco Mdwca is a very small system (500 people or fewer). Taos County has 94 active public water systems. Its population served is about 67% above the county average of 266 people per system, and accounts for 1.8% of the 25,046 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 Arroyo Seco Mdwca is well below 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 Arroyo Seco Mdwca?
EPA lists Arroyo Seco Mdwca 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. 36 of the 94 active systems in Taos County (38%) are also owned by a local government.
Does Arroyo Seco Mdwca have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in October 2025. The violations listed here began between October 2020 and October 2025. By type: 5 monitoring and reporting, 5 public notice, recordkeeping or other, 1 required treatment not met and 1 reporting. The contaminant or rule involved most often is Consumer Confidence Rule (5 of them). EPA lists 7 as resolved, 4 as archived and 1 as unaddressed. 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. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2025-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Unaddressed |
| 2025-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2024-10-17 | Required treatment not metLSL Inventory · code 2E | Lead and Copper Rule Revisionscode 5200 | Yes | Resolved |
| 2024-10-17 | ReportingLSL Reporting · code 4G | Lead and Copper Rule Revisionscode 5200 | No | Resolved |
| 2024-10-01 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2024-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2022-09-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Archived |
| 2022-09-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Archived |
| 2021-09-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Archived |
| 2021-09-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Archived |
| 2021-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2020-10-01 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | 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.
Arroyo Seco Mdwca: frequently asked questions
Who runs Arroyo Seco Mdwca?
Arroyo Seco Mdwca (PWSID NM3505529) is a community water system owned by a local government. It is regulated by the NM state drinking water program.
How many people does Arroyo Seco Mdwca serve?
Arroyo Seco Mdwca reports serving 444 people through 182 service connections in Taos County, New Mexico.
Where does Arroyo Seco Mdwca 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 Arroyo Seco Mdwca have any drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in October 2025. 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 Arroyo Seco Mdwca'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, one is health-based, and the most recent began in October 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the NM state drinking water program.
Where can I find Arroyo Seco Mdwca's water quality report?
As a community water system, Arroyo Seco Mdwca 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 Taos County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Taos Municipal Water System | Taos | 5,528 | Community | Groundwater |
| Questa Water System | Taos | 2,337 | Community | Groundwater |
| El Prado Water & Sanitation District | Taos | 1,076 | Community | Groundwater |
| Village of Taos Ski Valley | Taos | 1,025 | Community | Groundwater |
| Llano Quemado Mdwca | Taos | 800 | Community | Groundwater |
| Ranchos De Taos Mdwca | Taos | 750 | Community | Groundwater |
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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, “Arroyo Seco Mdwca, PWSID NM3505529, New Mexico”, https://aquacensus.com/water-systems/new-mexico/arroyo-seco-mdwca-nm3505529 (data as of October 1, 2026).