Tohatchi-Mexican Springs-Twin Lakes NTUA
Arizona — Community Water System — PWSID: NN3500237
System Information
| PWSID | NN3500237 |
| System Name | Tohatchi-Mexican Springs-Twin Lakes NTUA |
| System Type | Community Water System |
| Water Source | Ground Water |
| Activity Status | Active |
| Owner Type | Native American |
| EPA Region | 09 |
| Serves School | No |
| Wholesaler | No |
| First Reported | Feb 2, 1984 |
| Last Reported | Dec 31, 2025 |
Location & Contact
| State | Arizona |
| City | Ft Defiance |
| ZIP Code | 86504 |
| Address | Office of Deputy General Manager |
| Organization | Navajo Tribal Utility Authority |
| Phone | 9287296277 |
Population & Service
| Population Served | 1,669 |
| Service Connections | 488 |
Drinking Water Violations (76)
This water system has 76 violations recorded in the EPA SDWIS database.
| Begin Date | End Date | Contaminant | Category | Health-Based | Major | Measured | Federal MCL | State MCL | Status | Return to Compliance | Rule |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Jan 1, 2020 | Dec 31, 2020 | MR | No | Yes | — | 0.080 mg/L | — | Resolved | Dec 31, 2020 | — | |
| Jan 1, 2020 | Dec 31, 2020 | MR | No | Yes | — | 0.080 mg/L | — | Resolved | Dec 31, 2020 | — | |
| Jan 1, 2020 | Dec 31, 2020 | MR | No | Yes | — | 0.080 mg/L | — | Resolved | Dec 31, 2020 | — | |
| Jan 1, 2020 | Dec 31, 2020 | MR | No | Yes | — | 0.060 mg/L | — | Resolved | Dec 31, 2020 | — | |
| Jan 1, 2020 | Dec 31, 2020 | MR | No | Yes | — | 0.060 mg/L | — | Resolved | Dec 31, 2020 | — | |
| Jan 1, 2020 | Dec 31, 2020 | MR | No | Yes | — | 0.060 mg/L | — | Resolved | Dec 31, 2020 | — | |
| Apr 1, 2016 | — | Other | No | No | — | — | — | Resolved | Sep 30, 2025 | — | |
| Apr 1, 2016 | — | Other | No | No | — | — | — | Resolved | Sep 30, 2025 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.060 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.060 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.080 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.080 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.060 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.080 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jul 1, 2014 | Jul 31, 2014 | MCL | Yes | No | — | 5% of samples | — | Resolved | Jul 31, 2014 | — | |
| Jul 1, 2014 | Jul 31, 2014 | MCL | Yes | No | — | 5% of samples | — | Resolved | Jul 31, 2014 | — | |
| Jul 1, 2014 | Jul 31, 2014 | MCL | Yes | No | — | 5% of samples | — | Resolved | Jul 31, 2014 | — | |
| Oct 1, 2013 | — | MR | No | Yes | — | — | — | Resolved | Feb 18, 2025 | — | |
| Oct 1, 2013 | — | MR | No | Yes | — | — | — | Resolved | Feb 18, 2025 | — | |
| Oct 1, 2013 | — | MR | No | Yes | — | — | — | Resolved | Feb 18, 2025 | — | |
| Dec 1, 2012 | Dec 31, 2012 | MR | No | No | — | 5% of samples | — | Resolved | Dec 31, 2012 | — | |
| Dec 1, 2012 | Dec 31, 2012 | MR | No | No | — | 5% of samples | — | Resolved | Dec 31, 2012 | — | |
| Nov 1, 2012 | Nov 30, 2012 | MR | No | No | — | 5% of samples | — | Resolved | Nov 30, 2012 | — | |
| Jan 1, 2012 | Dec 31, 2012 | MR | No | Yes | — | 0.060 mg/L | — | Resolved | Dec 31, 2012 | — | |
| Jan 1, 2012 | Dec 31, 2012 | MR | No | Yes | — | 0.060 mg/L | — | Resolved | Dec 31, 2012 | — | |
| Jan 1, 2012 | Dec 31, 2012 | MR | No | Yes | — | 0.080 mg/L | — | Resolved | Dec 31, 2012 | — | |
| Jan 1, 2012 | Dec 31, 2012 | MR | No | Yes | — | 0.080 mg/L | — | Resolved | Dec 31, 2012 | — | |
| Jan 1, 2011 | Dec 31, 2011 | MR | No | Yes | — | 0.080 mg/L | — | Resolved | Dec 31, 2011 | — | |
| Jan 1, 2011 | Dec 31, 2011 | MR | No | Yes | — | 1 mg/L | — | Resolved | Dec 31, 2010 | — | |
| Jan 1, 2011 | Dec 31, 2011 | MR | No | Yes | — | 1 mg/L | — | Resolved | Dec 31, 2010 | — | |
| Jan 1, 2011 | Dec 31, 2011 | MR | No | Yes | — | 1 mg/L | — | Resolved | Dec 31, 2010 | — | |
| Jan 1, 2011 | Dec 31, 2011 | MR | No | Yes | — | 0.060 mg/L | — | Resolved | Dec 31, 2011 | — | |
| Jan 1, 2011 | Dec 31, 2011 | MR | No | Yes | — | 0.060 mg/L | — | Resolved | Dec 31, 2011 | — | |
| Jan 1, 2011 | Dec 31, 2011 | MR | No | Yes | — | 0.080 mg/L | — | Resolved | Dec 31, 2011 | — | |
| Jan 1, 2011 | Dec 31, 2011 | MR | No | Yes | — | 0.080 mg/L | — | Resolved | Dec 31, 2011 | — | |
| Jan 1, 2011 | Dec 31, 2011 | MR | No | Yes | — | 10 mg/L | — | Resolved | Dec 31, 2010 | — | |
| Jan 1, 2011 | Dec 31, 2011 | MR | No | Yes | — | 10 mg/L | — | Resolved | Dec 31, 2010 | — | |
| Jan 1, 2011 | Dec 31, 2011 | MR | No | Yes | — | 10 mg/L | — | Resolved | Dec 31, 2010 | — | |
| Jan 1, 2011 | Dec 31, 2011 | MR | No | Yes | — | 0.060 mg/L | — | Resolved | Dec 31, 2011 | — | |
| Jan 1, 2010 | Dec 31, 2010 | MR | No | Yes | — | 0.080 mg/L | — | Resolved | Dec 31, 2010 | — | |
| Jan 1, 2010 | Dec 31, 2010 | MR | No | Yes | — | 0.080 mg/L | — | Resolved | Dec 31, 2010 | — | |
| Jan 1, 2010 | Dec 31, 2010 | MR | No | Yes | — | 0.060 mg/L | — | Resolved | Dec 31, 2010 | — | |
| Jan 1, 2010 | Dec 31, 2010 | MR | No | Yes | — | 0.080 mg/L | — | Resolved | Dec 31, 2010 | — | |
| Jan 1, 2010 | Dec 31, 2010 | MR | No | Yes | — | 1 mg/L | — | Resolved | Dec 31, 2010 | — | |
| Jan 1, 2010 | Dec 31, 2010 | MR | No | Yes | — | 0.060 mg/L | — | Resolved | Dec 31, 2010 | — | |
| Jan 1, 2010 | Dec 31, 2010 | MR | No | Yes | — | 0.060 mg/L | — | Resolved | Dec 31, 2010 | — | |
| Jan 1, 2005 | Dec 31, 2010 | MR | No | Yes | — | 0.005 mg/L | — | Resolved | Dec 31, 2010 | — | |
| Jan 1, 2005 | Dec 31, 2010 | MR | No | Yes | — | 0.005 mg/L | — | Resolved | Dec 31, 2010 | — | |
| Jan 1, 2005 | Dec 31, 2010 | MR | No | Yes | — | 0.6 mg/L | — | Resolved | Dec 31, 2010 | — | |
| Jan 1, 2005 | Dec 31, 2010 | MR | No | Yes | — | 1 mg/L | — | Resolved | Dec 31, 2010 | — |
About This Water System
Public water system data comes from the EPA Safe Drinking Water Information System (SDWIS). Systems with violations must notify customers. Contact your water utility for the latest annual water quality report.