Mashantucket Pequot Water System
PWSID: 010106001
This system has unresolved violations related to monitoring, reporting, or procedural requirements, but none involve contaminant levels exceeding EPA health limits.
This system has more violations on record than 94% of water systems in Connecticut.
Violation trend: 0.2 per year over the last 5 years, down from 3.8 per year in the previous 5.
System Details
| Population Served | 26,445 |
| Service Connections | 154 |
| Water Source | Groundwater Under Influence |
| System Type | Community Water System |
| Owner | Native American |
| Status | Active |
| City | Mashantucket |
| EPA ZIP on File | 06339-3060 |
Lead & Copper Testing
| Contaminant | Level | EPA Action Level | Status |
|---|---|---|---|
| Lead (90th percentile) | 0.0040 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0040 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0039 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0027 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0023 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0020 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0020 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0018 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0014 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0010 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0010 mg/L | 0.015 mg/L | Below Action Level |
1 Active Violations
| Contaminant | Violation | Date | Health-Based | Status |
|---|---|---|---|---|
| 7000 | Other | 2024-07-01 | Open |
Violation History (107 total)
| Contaminant | Violation | Date | Health-Based | Status |
|---|---|---|---|---|
| 8000 | RPT | 2018-11-01 | Returned to Compliance | |
| 8000 | RPT | 2018-11-01 | Returned to Compliance | |
| 8000 | RPT | 2018-11-01 | Returned to Compliance | |
| 2950 | MCL Measured: 0.0839 MG/L | 2018-10-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0839 MG/L | 2018-10-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0839 MG/L | 2018-10-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0839 MG/L | 2018-10-01 | Yes | Returned to Compliance |
| 2950 | MR | 2018-08-09 | Returned to Compliance | |
| 2950 | MR | 2018-08-09 | Returned to Compliance | |
| 2950 | MR | 2018-08-09 | Returned to Compliance | |
| 2950 | MCL Measured: 0.0880 MG/L | 2018-07-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0880 MG/L | 2018-07-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0880 MG/L | 2018-07-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0880 MG/L | 2018-07-01 | Yes | Returned to Compliance |
| 2950 | MR | 2018-07-01 | Returned to Compliance | |
| 2950 | MR | 2018-07-01 | Returned to Compliance | |
| 2950 | MR | 2018-07-01 | Returned to Compliance | |
| 7500 | Other | 2018-04-02 | Acknowledged | |
| 7500 | Other | 2018-04-02 | Acknowledged | |
| 2005 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2005 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2005 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2010 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2010 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2010 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2015 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2015 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2015 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2020 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2020 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2020 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2031 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2031 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2031 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2032 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2032 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2032 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2033 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2033 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2033 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2034 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2034 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2034 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2035 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2035 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2035 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2036 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2036 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2036 | MR | 2016-01-01 | Major | Returned to Compliance |
| 2037 | MR | 2016-01-01 | Major | Returned to Compliance |
Showing 50 of 106 historical violations.
Understanding This Water System's Record
Mashantucket Pequot Water System is a community water system water system that draws from groundwater under influence sources and serves a population of 26,445 in Mashantucket, Connecticut. This page shows its complete compliance history as reported to the EPA's Safe Drinking Water Information System (SDWIS), the federal database that tracks every public water system in the United States.
What Do These Violations Mean?
Health-based violations mean the system exceeded an EPA maximum contaminant level (MCL) or failed to provide required treatment. These indicate potential health risks from contaminants like lead, arsenic, bacteria, nitrates, or disinfection byproducts. Non-health-based violations involve monitoring, reporting, or procedural requirements — the system missed a testing deadline or failed to notify customers, but contaminant levels were not necessarily unsafe.
What Should You Do?
Your water utility is required to publish an annual Consumer Confidence Report (CCR) that details test results and any violations. If your system has active health-based violations, consider a certified water filter rated for the specific contaminants involved. The contaminant guides on this site explain health risks and filter options for common pollutants. For the most current results, contact your water utility directly — EPA data can lag weeks or months behind real-time testing.