F13/100
Mashantucket Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 26,445 residents · Connecticut
What's In Mashantucket's Tap Water?
69
Contaminants Tested
1
Exceed EPA Limits
2
Above EPA Goals
3 contaminants above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
PFOA | 0.007 µg/L | 0.004 µg/L | Over Limit |
chlorate | 370.00 µg/L | — | Above Goal |
Lead (90th percentile) | 0.001 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
1
Violation (last 5yr)
1
Unresolved
0
Health-Related
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
Mashantucket Pequot Water System
Population Served
26,445
Water Source
Groundwater Under Influence of Surface Water
System ID
010106001
Frequently Asked Questions About Mashantucket Water
Is Mashantucket tap water safe to drink?
Mashantucket, Connecticut tap water receives a grade of F (13/100), which is considered failing. 1 contaminant(s) exceed EPA maximum contaminant levels and 45 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.
What contaminants are in Mashantucket's water?
Of the 69 contaminants tested in Mashantucket's water supply, the most notable include PFOA, Lead (90th percentile), chlorate. 1 contaminant(s) exceed EPA legal limits (MCLs). 3 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Mashantucket have any water quality violations?
Yes, Mashantucket has 45 EPA violation(s) on record, with the most recent in 2024. Violation types include Other, RPT, MCL. 7 of these are health-based violations, which are the most serious category.
Do I need a water filter in Mashantucket?
Based on EPA data, using a water filter in Mashantucket is recommended. 1 contaminant(s) exceed legal limits. An NSF-certified filter — such as a reverse osmosis or activated carbon system — can effectively reduce many common contaminants. Choose a filter certified to remove the specific contaminants found in your area.
Where does Mashantucket's tap water come from?
Mashantucket's drinking water is sourced from groundwater under influence of surface water and supplied by Mashantucket Pequot Water System. The system serves approximately 26,445 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Mashantucket's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Mashantucket's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Mashantucket's water compare to other cities in Connecticut?
Mashantucket's water quality score of 13/100 earns a grade of F, which is considered failing. This is a concerning score that suggests significant water quality issues. Visit our Connecticut state page to see how all cities in the state compare.
What should I do if I'm concerned about Mashantucket's water quality?
If you have concerns about Mashantucket's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (Mashantucket Pequot Water System) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.