SANTA CRUZ, NM · Rio Arriba County

EL LLANO MDWCA Water System

Inactive system

This water system is marked inactive in EPA’s federal records as of January 22, 2013. It is no longer an operating public water system under this PWSID, and no compliance deadlines — including the 2027 Consumer Confidence Report rule — apply to it.

If you are a resident looking for your current water provider, see water systems in Rio Arriba County, NM.

Data sourced from the EPA ECHO database (SDWA bulk download), last refreshed August 1, 2026. This is a record-keeping and public-information tool — it does not replace New Mexico’s official records. Always confirm current status with New Mexico before making decisions based on this information.

System facts

System ID (PWSID): NM3501621
System type: Community Water System
Population served: 105
Service connections: 53
Ownership: local government
Water source: groundwater (wells)

EL LLANO MDWCA is one of 667 community water systems in New Mexico in the 500 or fewer people size category, formerly serving 105 people from groundwater.

EPA's federal records list this system as inactive in 2013; the record below is historical.

As of August 1, 2026, its federal record holds 14 entries between 1994 and 2012, all of which EPA lists as closed. Nothing has been added since 2012.

Of the 14, 2 are monitoring and reporting requirements — the category that accounts for about four in five of all violations in EPA's national dataset — rather than findings about the water itself. The record involves the Radionuclides and Revised Rad Rule, the Public Notice Rule and Revised PN Rule, and the Stage 1 Disinfectants and Disinfection Byproducts Rule.

Violation history

Public Notification Violation for NPDWR Violation
—
Public Notice
May 18, 2012 – August 14, 2012
Resolved
Maximum Contaminant Level Violation, Average
Health-based
Combined Uranium
April 1, 2012 – June 30, 2012
Archived
Monitoring and Reporting (DBP)
—
Chlorine
April 1, 2012 – June 30, 2012
Archived
Public Notification Violation for NPDWR Violation
—
Public Notice
January 8, 2012 – March 13, 2012
Resolved
Maximum Contaminant Level Violation, Average
Health-based
Combined Uranium
January 1, 2012 – March 31, 2012
Archived
Maximum Contaminant Level Violation, Average
Health-based
Combined Uranium
October 1, 2011 – December 31, 2011
Archived
Public Notification Violation for NPDWR Violation
—
Public Notice
March 12, 2011 – December 16, 2010
Resolved
Monitoring, Regular
—
Combined Uranium
October 1, 2010 – December 31, 2010
Archived
Maximum Contaminant Level Violation, Average
Health-based
Combined Uranium
April 1, 2010 – June 30, 2010
Archived
Maximum Contaminant Level Violation, Average
Health-based
Combined Uranium
January 1, 2009 – March 31, 2009
Archived
Public Notification Violation for NPDWR Violation
—
Public Notice
October 1, 2008 – November 6, 2010
Resolved
Maximum Contaminant Level Violation, Average
Health-based
Combined Uranium
October 1, 2008 – December 31, 2008
Archived
Maximum Contaminant Level Violation, Average
Health-based
Combined Uranium
July 1, 2008 – September 30, 2008
Archived
Maximum Contaminant Level Violation, Average
Health-based
Nitrate
January 1, 1994 – December 31, 1994
Archived

Resolved addressed and confirmed by the stateArchived closed in EPA's records (typically due to age or a data correction)

Period	Violation	Contaminant / rule	Health-based	Status
May 18, 2012 – August 14, 2012	Public Notification Violation for NPDWR Violation	Public Notice	—	Resolved
April 1, 2012 – June 30, 2012	Maximum Contaminant Level Violation, Average	Combined Uranium	Health-based	Archived
April 1, 2012 – June 30, 2012	Monitoring and Reporting (DBP)	Chlorine	—	Archived
January 8, 2012 – March 13, 2012	Public Notification Violation for NPDWR Violation	Public Notice	—	Resolved
January 1, 2012 – March 31, 2012	Maximum Contaminant Level Violation, Average	Combined Uranium	Health-based	Archived
October 1, 2011 – December 31, 2011	Maximum Contaminant Level Violation, Average	Combined Uranium	Health-based	Archived
March 12, 2011 – December 16, 2010	Public Notification Violation for NPDWR Violation	Public Notice	—	Resolved
October 1, 2010 – December 31, 2010	Monitoring, Regular	Combined Uranium	—	Archived
April 1, 2010 – June 30, 2010	Maximum Contaminant Level Violation, Average	Combined Uranium	Health-based	Archived
January 1, 2009 – March 31, 2009	Maximum Contaminant Level Violation, Average	Combined Uranium	Health-based	Archived
October 1, 2008 – November 6, 2010	Public Notification Violation for NPDWR Violation	Public Notice	—	Resolved
October 1, 2008 – December 31, 2008	Maximum Contaminant Level Violation, Average	Combined Uranium	Health-based	Archived
July 1, 2008 – September 30, 2008	Maximum Contaminant Level Violation, Average	Combined Uranium	Health-based	Archived
January 1, 1994 – December 31, 1994	Maximum Contaminant Level Violation, Average	Nitrate	Health-based	Archived

Resolved addressed and confirmed by the stateArchived closed in EPA's records (typically due to age or a data correction)

Enforcement actions

December 7, 2012State Public Notification received1 linked violation
December 7, 2012State Public Notification received2 linked violations
September 24, 2012State Violation/Reminder Notice2 linked violations
August 14, 2012State Compliance achieved1 linked violation
August 7, 2012State Compliance achieved2 linked violations
August 2, 2012State Violation/Reminder Notice1 linked violation
August 2, 2012State Violation/Reminder Notice2 linked violations
August 2, 2012State Public Notification requested1 linked violation
July 30, 2012State Violation/Reminder Notice2 linked violations
April 17, 2012State Violation/Reminder Notice2 linked violations
March 16, 2012State Public Notification received6 linked violations
March 13, 2012State Compliance achieved1 linked violation
March 1, 2012State Violation/Reminder Notice2 linked violations
February 9, 2012State Violation/Reminder Notice2 linked violations
February 9, 2012State Public Notification requested2 linked violations
December 8, 2011State Public Notification requested2 linked violations
September 7, 2011State Public Notification requested2 linked violations
February 9, 2011State Violation/Reminder Notice3 linked violations
February 9, 2011State Public Notification requested3 linked violations
February 9, 2011State Violation/Reminder Notice2 linked violations
December 16, 2010State Compliance achieved3 linked violations
December 13, 2010State Public Notification received3 linked violations
March 31, 2010State Violation/Reminder Notice2 linked violations
March 31, 2010State Public Notification requested2 linked violations
March 31, 2010State Violation/Reminder Notice2 linked violations
March 31, 2010State Public Notification requested3 linked violations
March 23, 2010State Compliance achieved5 linked violations
September 30, 2009State Administrative/Compliance Order without penalty issued3 linked violations
September 30, 2009State Administrative/Compliance Order without penalty issued13 linked violations
September 30, 2009State Administrative/Compliance Order without penalty issued7 linked violations
June 9, 2009State Compliance achieved2 linked violations
April 30, 2009State Public Notification requested3 linked violations
June 5, 2006State Compliance achieved5 linked violations
June 5, 2006State Violation/Reminder Notice23 linked violations

Last known contact on file (system is inactive)

MARQUEZ, JOHN

505-753-9869

SANTA CRUZ, NM 87567