Mashantucket Pequot Water System
Connecticut — Community Water System — PWSID: 010106001
System Information
| PWSID | 010106001 |
| System Name | Mashantucket Pequot Water System |
| System Type | Community Water System |
| Water Source | Ground Water Under Influence |
| Activity Status | Active |
| Owner Type | Native American |
| EPA Region | 01 |
| Serves School | No |
| Wholesaler | Yes |
| First Reported | Jan 4, 1985 |
| Last Reported | Mar 25, 2026 |
Location & Contact
| State | Connecticut |
| City | MASHANTUCKET |
| ZIP Code | 06339-3060 |
| Address | Tribal Office |
| Organization | Mashantucket Pequot Tribal Utilities |
| Phone | 8603966740 |
Population & Service
| Population Served | 26,445 |
| Service Connections | 154 |
Drinking Water Violations (180)
This water system has 180 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Jul 1, 2025 | — | Other | No | No | — | — | — | Resolved | Oct 2, 2025 | — | |
| Jul 1, 2025 | — | Other | No | No | — | — | — | Resolved | Oct 2, 2025 | — | |
| Jul 1, 2025 | — | Other | No | No | — | — | — | Resolved | Oct 2, 2025 | — | |
| Jul 1, 2024 | — | Other | No | No | — | — | — | Resolved | Oct 2, 2025 | — | |
| Jul 1, 2024 | — | Other | No | No | — | — | — | Resolved | Oct 2, 2025 | — | |
| Jul 1, 2024 | — | Other | No | No | — | — | — | Resolved | Oct 2, 2025 | — | |
| Nov 1, 2018 | — | RPT | No | No | — | — | — | Resolved | Jan 8, 2019 | — | |
| Oct 1, 2018 | Dec 31, 2018 | MCL | Yes | No | .0839 MG/L | 0.080 mg/L | — | Resolved | Dec 31, 2018 | — | |
| Oct 1, 2018 | Dec 31, 2018 | MCL | Yes | No | .0839 MG/L | 0.080 mg/L | — | Resolved | Dec 31, 2018 | — | |
| Oct 1, 2018 | Dec 31, 2018 | MCL | Yes | No | .0839 MG/L | 0.080 mg/L | — | Resolved | Dec 31, 2018 | — | |
| Sep 28, 2018 | — | Other | No | No | — | — | — | Resolved | Dec 27, 2018 | — | |
| Sep 28, 2018 | — | Other | No | No | — | — | — | Resolved | Dec 27, 2018 | — | |
| Sep 28, 2018 | — | Other | No | No | — | — | — | Resolved | Dec 27, 2018 | — | |
| Aug 9, 2018 | — | MR | No | No | — | 0.080 mg/L | — | Resolved | Dec 26, 2018 | — | |
| Aug 9, 2018 | — | MR | No | No | — | 0.080 mg/L | — | Resolved | Dec 26, 2018 | — | |
| Aug 9, 2018 | — | MR | No | No | — | 0.080 mg/L | — | Resolved | Dec 26, 2018 | — | |
| Jul 1, 2018 | — | MR | No | No | — | 0.080 mg/L | — | Resolved | Dec 26, 2018 | — | |
| Jul 1, 2018 | Sep 30, 2018 | MCL | Yes | No | .088 MG/L | 0.080 mg/L | — | Resolved | Sep 30, 2018 | — | |
| Jul 1, 2018 | Sep 30, 2018 | MCL | Yes | No | .088 MG/L | 0.080 mg/L | — | Resolved | Sep 30, 2018 | — | |
| Jul 1, 2018 | — | MR | No | No | — | 0.080 mg/L | — | Resolved | Dec 26, 2018 | — | |
| Jul 1, 2018 | Sep 30, 2018 | MCL | Yes | No | .088 MG/L | 0.080 mg/L | — | Resolved | Sep 30, 2018 | — | |
| Jul 1, 2018 | — | MR | No | No | — | 0.080 mg/L | — | Resolved | Dec 26, 2018 | — | |
| Apr 2, 2018 | Apr 4, 2018 | Other | No | No | — | — | — | Archived | Apr 4, 2018 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.002 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.1 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.0002 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.0002 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.001 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.001 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.004 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.004 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.05 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.05 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.07 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.07 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.4 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.0004 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.0004 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.5 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.002 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.02 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.2 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.2 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.2 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.04 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.04 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.04 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.007 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.007 mg/L | — | Resolved | Dec 31, 2016 | — | |
| Jan 1, 2016 | Dec 31, 2016 | MR | No | Yes | — | 0.007 mg/L | — | Resolved | Dec 31, 2016 | — |
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.