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Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
Real EPA measurements of haloacetic acids (haa5) for Connecticut water systems — Six-Year Review compliance samples 2012–2019 (historical). Methodology
These cities have haloacetic acids (haa5) levels above 50% of the EPA limit but within compliance
Every Connecticut system with a haloacetic acids (haa5) result in EPA's data, sorted by level. Averages of 2012–2019 finished-water samples, non-detects counted as zero — historical, not today's tap.
| City | Level | Period | EPA Limit | % of Limit | Status |
|---|---|---|---|---|---|
| WaterburyGrade A | 39.93 ug/LAverage of 252 samples | 2012–2019 | 60.00 ug/L | 66.6% | Warning |
| SheltonGrade C | 36.00 ug/LAverage of 384 samples | 2012–2019 | 60.00 ug/L | 60.0% | Warning |
| New HavenGrade C | 35.12 ug/LAverage of 400 samples | 2012–2019 | 60.00 ug/L | 58.5% | Warning |
| StamfordGrade B | 33.02 ug/LAverage of 254 samples | 2012–2019 | 60.00 ug/L | 55.0% | Warning |
| NorwichGrade C | 32.56 ug/LAverage of 233 samples | 2012–2019 | 60.00 ug/L | 54.3% | Warning |
| TorringtonGrade A | 29.69 ug/LAverage of 162 samples | 2012–2019 | 60.00 ug/L | 49.5% | Safe |
| HartfordGrade A | 28.50 ug/LAverage of 380 samples | 2012–2019 | 60.00 ug/L | 47.5% | Safe |
| MiddletownGrade A | 26.40 ug/LAverage of 182 samples | 2012–2019 | 60.00 ug/L | 44.0% | Safe |
| BristolGrade B | 26.27 ug/LAverage of 268 samples | 2012–2019 | 60.00 ug/L | 43.8% | Safe |
| MeridenGrade C | 25.95 ug/LAverage of 349 samples | 2012–2019 | 60.00 ug/L | 43.2% | Safe |
| GrotonGrade A | 23.28 ug/LAverage of 128 samples | 2012–2019 | 60.00 ug/L | 38.8% | Safe |
| New LondonGrade A | 23.21 ug/LAverage of 128 samples | 2012–2019 | 60.00 ug/L | 38.7% | Safe |
| DanburyGrade B | 21.16 ug/LAverage of 280 samples | 2012–2019 | 60.00 ug/L | 35.3% | Safe |
| NorwalkGrade C | 20.09 ug/LAverage of 156 samples | 2012–2019 | 60.00 ug/L | 33.5% | Safe |
| NaugatuckGrade A | 11.08 ug/LAverage of 142 samples | 2012–2019 | 60.00 ug/L | 18.5% | Safe |
| ManchesterGrade C | 8.75 ug/LAverage of 265 samples | 2012–2019 | 60.00 ug/L | 14.6% | Safe |
| New BritainGrade A | 8.02 ug/LAverage of 250 samples | 2012–2019 | 60.00 ug/L | 13.4% | Safe |
| EnfieldGrade C | 1.42 ug/LAverage of 128 samples | 2012–2019 | 60.00 ug/L | 2.4% | Safe |
Haloacetic acids are disinfection byproducts formed when chlorine or other disinfectants react with organic matter. The EPA regulates five HAAs (HAA5): monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid. Studies have linked HAAs to increased cancer risk and potential developmental and reproductive effects. Dichloroacetic acid in particular has been shown to cause liver cancer in laboratory animals.
Formed during water disinfection when chlorine reacts with organic compounds; levels vary with source water quality and treatment processes
Based on our analysis of EPA Safe Drinking Water Information System (SDWIS) data and local water utility reports,haloacetic acids (haa5) has been detected in 18 Connecticut water systems. The average level across all tested cities is 40% of the EPA Maximum Contaminant Level (MCL), with the highest detection at 66.6% of the limit.
The EPA MCL for HAA5 is 60 ug/L (60 ppb). The EPA MCL for haloacetic acids (haa5) is 60 ug/L. This limit is set to protect public health based on available scientific evidence about the contaminant's health effects.
18 Connecticut cities have haloacetic acids (haa5) detected in their water supply. All tested cities are within EPA safety limits.
Increased cancer risk, potential liver damage, developmental effects. The most vulnerable groups include pregnant women and people with liver conditions.
The most effective methods for removing haloacetic acids (haa5) include Activated Carbon, Reverse Osmosis, Distillation. Look for filters certified by NSF/ANSI for haloacetic acids (haa5) reduction.
The EPA Maximum Contaminant Level (MCL) for haloacetic acids (haa5) is 60 ug/L.The EPA MCL for HAA5 is 60 ug/L (60 ppb).
This page shows what Connecticut utilities reported for haloacetic acids (haa5). It cannot tell you what is coming out of your own tap: utility samples are taken across a whole system and averaged, levels vary by address and season, and anything picked up after the water leaves the main never appears in their report.
Home water test kitscheck your own tap before buying any filterRecommended filtration methods for haloacetic acids (haa5) removal:
Granular activated carbon effective for HAAs
Removes most HAAs
Effective removal
Paid links. We earn a commission if you buy, at no extra cost to you. Filters are matched to the removal methods listed above for haloacetic acids (haa5).