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Connecticut Tap Water Quality Report

Water quality grades, lead levels, and violation data for all 433 ZIP codes in Connecticut

ZIP Codes

433

Health Violations (5yr)

343

Avg Safety Score

64.9/100

High Lead Risk ZIPs

56.6%

Overview: Drinking Water in Connecticut

The tap water quality in Connecticut currently sits near the national average, registering a composite safety score of 64.9/100 across 433 monitored ZIP codes. While a significant portion of the state maintains adequate water quality and full compliance with federal standards, 2% of ZIP codes in Connecticut have received a failing grade due to recent compliance issues. Monitoring data from the EPA indicates that while the majority of residents receive safe tap water, localized issues remain a challenge for several municipal systems.

Over the past 5 years, water utilities in Connecticut have recorded a total of 3,061 violations, of which 343 were strictly health-based. While administrative and reporting violations are common nationwide, health-based violations mean that certain contaminants exceeded the EPA's Maximum Contaminant Levels (MCLs) at some point. Connecticut Department of Public Health, which acts as the primary regulatory authority in the state, typically works closely with these utilities to issue boil water advisories or mandate infrastructure upgrades when these limits are breached.

One of the most pressing concerns for Connecticut residents is the elevated risk of lead exposure. EPA models and historical monitoring indicate that 56.6% of ZIP codes in Connecticut are classified as High or Very High risk for lead. This is frequently associated with older housing stock built before the 1986 federal ban on lead pipes and solder. Residents living in older homes should strongly consider having their tap water independently tested and utilizing a certified NSF/ANSI 53 water filter for drinking and cooking.

Surface Water

61.7%

of ZIP codes

Total Violations

3,061

5-year record

Grade A ZIPs

57

13% of state

Grade F ZIPs

9

2% of state

Water Quality Grade Distribution in Connecticut

How do Connecticut's 433 ZIP codes stack up by water quality grade?

A
57 ZIP codes13%
B
73 ZIP codes17%
C
187 ZIP codes43%
D
107 ZIP codes25%
F
9 ZIP codes2%

Common Drinking Water Contaminants in Connecticut

The following are common regulated contaminants found in Connecticut drinking water based on EPA violation records. Click any contaminant to learn about EPA safety limits and health effects.

Stage 2 DBP RuleConsumer Confidence Report RuleContaminant 0700BariumFecal ColiformStage 1 DBP RuleHaloacetic Acids (HAA5)Combined Radium

Source: EPA Safe Drinking Water Act Maximum Contaminant Level regulations. For the complete list of regulated contaminants and MCLs, see the Water Quality Safety Guide.

Frequently Asked Questions โ€” Connecticut Drinking Water

Is tap water generally safe to drink in Connecticut?+
Yes, for the majority of residents, tap water in Connecticut is treated, heavily regulated, and safe to drink. However, safety varies significantly by location. Statewide, 57 ZIP codes earn an "A" grade for perfect compliance, while 9 earn an "F" due to historical violations. It is essential to search your specific ZIP code above to view the exact compliance record for your local water utility.
What are the biggest water quality issues in Connecticut?+
Based on a 5-year analysis of EPA violation data, the primary water quality challenges in Connecticut include managing 343 health-based violations statewide and addressing infrastructure age. Additionally, 56.6% of ZIP codes in the state are rated as having a High or Very High probability of lead exposure risk, which is a key metric residents should monitor.
Who regulates and enforces drinking water standards in Connecticut?+
Drinking water in Connecticut is primarily regulated by Connecticut Department of Public Health under a primacy agreement with the U.S. Environmental Protection Agency (EPA). The EPA sets the federal baseline standards (Maximum Contaminant Levels) through the Safe Drinking Water Act, while Connecticut Department of Public Health conducts the day-to-day monitoring, issues compliance orders, and enforces penalties against local water systems that fail to meet these standards.
Where does Connecticut get its drinking water?+
Water sources in Connecticut vary widely by municipality. Statewide, approximately 61.7% of the monitored ZIP codes rely on surface water sources (such as rivers, lakes, and reservoirs), which require extensive filtration and disinfection. The remaining systems primarily rely on groundwater pumped from underground aquifers, which is naturally filtered but can be susceptible to agricultural runoff or naturally occurring minerals.
How do I find the official water quality report for my home in Connecticut?+
You can enter your ZIP code in our search box above for a detailed, easy-to-read report based on EPA data. Furthermore, your local water utility is required by federal law to distribute an annual Consumer Confidence Report (CCR) by July 1 of each year. You can contact your utility directly to request this document, which outlines exact contaminant measurements from the previous year.
View All 433 ZIP Codes in Connecticut

Browse EPA water quality data for every monitored ZIP code. For faster results, use the search bar above.

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+ 133 more ZIP codes โ€” please search by city above