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Updated 2026-09-16
State water report

Connecticut Water Quality: 20 Cities Ranked by the Records

Water quality across 20 cities in Connecticut, drawn from EPA drinking-water records. Each city page shows the measured contaminants and a reproducible Purity Score.

Finding by finding

What Connecticut's records show

Counts of cities whose serving system reported each result. There is no statewide score: PurityMap does not average local records into a statewide safety verdict.

PFAS above a 2024 limit

MCL

11of 20 cities

Cities whose system reported a PFAS above its federal limit.

PFOS in Connecticut →
City rankings

Connecticut cities ranked by the records

Highest first. A summary of each serving system’s record, not a safety verdict.

  1. 1
    Metropolitan DistrictMETROPOLITAN DISTRICT COMMISSION · CT0640011
    Report →
  2. 2
    New BritainNEW BRITAIN WATER DEPARTMENT · CT0890011
    Report →
  3. 3
    MiddletownMIDDLETOWN WATER DEPARTMENT · CT0830011
    Report →
  4. 4
    GrotonGROTON UTILITIES · CT0590011
    Report →
  5. 5
    New LondonNEW LONDON DEPT. OF PUBLIC UTILITIES · CT0950011
    Report →
  6. 6
    South Norwalk ElectricSOUTH NORWALK ELECTRIC & WATER · CT1030021
    Report →
  7. 7
    WaterfordWATERFORD WPCA · CT1520071
    Report →
  8. 8
    WaterburyWATERBURY WATER DEPARTMENT · CT1510011
    Report →
  9. 9
    WindhamWINDHAM WATER WORKS · CT1630011
    Report →
  10. 10
    BristolBRISTOL WATER DEPARTMENT · CT0170011
    Report →

Showing the top 10 of 20 scored cities.

See all 20 in the table

20 cities, highest Purity Score first

  1. 1Metropolitan District
    METROPOLITAN DISTRICT COMMISSION · PWSID CT0640011 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detectedNot detected
  2. 2New Britain
    NEW BRITAIN WATER DEPARTMENT · PWSID CT0890011 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detectedNot detected
  3. 3Middletown
    MIDDLETOWN WATER DEPARTMENT · PWSID CT0830011 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detectedNot detected
  4. 4Groton
    GROTON UTILITIES · PWSID CT0590011 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detectedNot detected
  5. 5New London
    NEW LONDON DEPT. OF PUBLIC UTILITIES · PWSID CT0950011 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detectedNot detected
  6. 6South Norwalk Electric
    SOUTH NORWALK ELECTRIC & WATER · PWSID CT1030021 · Purity Score 99/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detectedNot detected
  7. 7Waterford
    WATERFORD WPCA · PWSID CT1520071 · Purity Score 98/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 1.5 µg/LDetected
  8. 8Waterbury
    WATERBURY WATER DEPARTMENT · PWSID CT1510011 · Purity Score 95/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 4 µg/LDetected
  9. 9Windham
    WINDHAM WATER WORKS · PWSID CT1630011 · Purity Score 95/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    PFAS detected below their limits; lead 4.3 µg/LDetected
  10. 10Bristol
    BRISTOL WATER DEPARTMENT · PWSID CT0170011 · Purity Score 78/100 (Good) · Confidence: moderate · Assessed at the water-system level
    PFOA 4.1 ng/L, 1.0× the EPA limitAbove reference
  11. 11Cromwell Fire District
    CROMWELL FIRE DISTRICT WATER DEPARTMENT · PWSID CT0330011 · Purity Score 76/100 (Good) · Confidence: moderate · Assessed at the water-system level
    PFOS 4.6 ng/L, 1.1× the EPA limitAbove reference
  12. 12Danbury
    DANBURY WATER DEPARTMENT · PWSID CT0340011 · Purity Score 70/100 (Fair) · Confidence: moderate · Assessed at the water-system level
    PFOA 5.4 ng/L, 1.4× the EPA limitAbove reference
Showing 12 of 20.

Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no state score. The score is computed only from contaminants measured in the published EPA record, so this ranks the record, not which city's water is safest. How the score works. See how Connecticut compares with other states.

By contaminant

PFAS and lead in Connecticut

Counties

Connecticut counties

6 counties with city reports
Suppliers

Largest water systems

All water systems →
Full indexAll 20 Connecticut city reports, A–Z
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Questions

Connecticut water, frequently asked

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How does Connecticut tap water compare across cities?

PurityMap ranks 20 cities in Connecticut by the Purity Score of each city's main water system, computed only from contaminants measured in the published EPA record. Scores belong to water systems, not to cities. The highest published score is Metropolitan District's main water system: METROPOLITAN DISTRICT COMMISSION · PWSID CT0640011 · Purity Score 100 (Excellent) · Confidence: moderate · Assessed at the water-system level. The ranking compares the records, not which city's water is safest, and your own tap can differ with household plumbing.

How many Connecticut cities have PFAS above the federal limit?

11 cities of 20 had at least one regulated PFAS (PFOA, PFOS or PFHxS) measured above the 2024 federal limit in EPA's UCMR 5 testing, including Norwich (PFOS 16.2 ng/L), Manchester (PFOS 16 ng/L), Wallingford (PFOS 13.9 ng/L). PFAS were detected at any level in 12.

Is there lead in Connecticut tap water?

Utilities report lead as a 90th-percentile result from home taps. 4 of 20 Connecticut cities reported a value above zero, and none was above the 15 µg/L federal action level. Lead usually comes from a building's own pipes and fixtures, so only a test at your tap tells you what you drink.

Limits, sources and corrections

A statewide page cannot tell you what reaches a specific address. Water quality varies by supplier, sampling period and household plumbing; open a city report for the evidence behind a local result.

Sources: EPA UCMR 5 (PFAS, 2024), SDWIS Lead and Copper Rule 90th-percentile results and health-based violations, and utility Consumer Confidence Reports where on file. Every city report links its dated source records.

Updated 2026-09-16. How PurityMap analyzes water data · Report an error