EPA UCMR 5 DataModerate Detection Rate

PFAS Contamination in Connecticut

Per- and polyfluoroalkyl substances (PFAS) detected in Connecticut drinking water systems. Data from EPA UCMR 5 monitoring covering 148 public water systems.

Systems Tested

148

Detection Rate

39.2%

Exceeding MCL

14

Max Level

42 ppt

PFAS Overview: Connecticut

Detection Rate

39.2%

of systems tested

vs National Average

+4.8%

National avg: 34.4%

PFAS Detections

58

systems with any PFAS

Exceed EPA MCL (4 ppt)

14 (9.5%)

of tested systems

State notes: Dense industrial history; above-average detection rates

EPA PFAS Standards (2024)

In April 2024, the EPA finalized Maximum Contaminant Levels (MCLs) for six PFAS compounds. Water systems must comply by 2029.

CompoundMCL
PFOA4 ppt
PFOS4 ppt
PFNA10 ppt
PFHxS10 ppt
HFPO DA_GenX10 ppt

Source: EPA Final PFAS NPDWR, April 2024. Compliance required by 2029.

Health Effects of PFAS Exposure

Cancer Risk

PFOA and PFOS are associated with kidney, testicular, and other cancers

Thyroid Disruption

PFAS can interfere with thyroid hormone function

Immune Effects

Reduced vaccine response and immune system impairment in children

Reproductive Harm

Linked to pregnancy complications and reduced fertility

Liver Damage

Elevated liver enzymes and liver disease risk

Developmental Effects

Harm to fetal development and child growth

Frequently Asked Questions

Does Connecticut have PFAS in the water?

Yes. Connecticut has a 39.2% PFAS detection rate across 148 tested public water systems, according to EPA UCMR 5 data. This means 58 systems detected at least one PFAS compound. The national average detection rate is 34.4%, so Connecticut is 4.8 percentage points above average.

How bad is PFAS contamination in Connecticut?

Connecticut's PFAS contamination is rated moderate severity. The maximum recorded PFAS level is 42 ppt, compared to the EPA MCL of 4 ppt for PFOA and PFOS. 14 systems exceed the EPA MCL, representing 9.5% of tested systems. Dense industrial history; above-average detection rates

What can I do to reduce PFAS exposure in Connecticut?

The most effective options are reverse osmosis (RO) filtration systems, which remove up to 90-95% of PFAS, and granular activated carbon (GAC) filters certified under NSF/ANSI Standard 58 or 62. Standard pitcher filters provide limited protection. Contact your water utility to request PFAS test results, or check the EPA's UCMR 5 data portal for your system's specific readings.

What is the EPA MCL for PFAS?

The EPA finalized Maximum Contaminant Levels (MCLs) for PFAS in April 2024: 4 parts per trillion (ppt) each for PFOA and PFOS, and 10 ppt each for PFNA, PFHxS, and HFPO-DA (GenX). Water systems have until 2029 to comply. These are the strictest PFAS drinking water standards in the world.

National Comparison

Connecticut Detection Rate39.2%
National Average34.4%
Systems Tested148
Exceeding MCL14
Max PFAS Level42 ppt

Reduce PFAS Exposure

  • +Use a reverse osmosis filter (most effective)
  • +Look for NSF/ANSI 58 or 62 certified systems
  • +Granular activated carbon (GAC) filters reduce PFAS
  • +Standard pitcher filters offer limited protection
  • +Request PFAS test results from your utility