Tap Water Quality Report
Tap water quality in WATERTOWN, Connecticut
Tap water in WATERTOWN, Connecticut receives a grade of D (66/100) from TapWaterSafety.org. It's served by WATERBURY WATER DEPARTMENT. The most significant water quality concerns are: PFAS contamination; Haloacetic acids (HAA9) significantly above health guideline; Haloacetic acids (HAA5) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in WATERTOWN's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving WATERTOWN.
PFAS contamination
Severe concernPerfluorooctane sulfonate (PFOS) detected. PFAS are persistent chemicals linked to cancer and immune effects with no known safe exposure threshold.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 43.5 ppb, 725x above the EWG health guideline of 0.06 ppb.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 43.4 ppb, 434x above the EWG health guideline of 0.1 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 45.4 ppb, 303x above the EWG health guideline of 0.15 ppb.
EPA compliance record
Official U.S. EPA records for WATERBURY WATER DEPARTMENT (system ID CT1510011) for the last 3 years. Checked 2026-10-07.
| Rule | Type | Since | Status |
|---|---|---|---|
| Consumer Confidence Rule | Other (e.g. public notice) | 07/01/2024 | Resolved |
| Lead and Copper Rule | Missed testing or reporting | 12/30/2025 | Resolved |
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Recommended filters for WATERTOWN
Filters matched to the specific contaminants in WATERTOWN's water supply.
Filter certified for PFOA/PFOS (NSF/ANSI 53 or 58)
$180-$750Reverse osmosis and some carbon block filters reduce PFAS. Look for certification to NSF/ANSI 53 or 58 for PFOA/PFOS.
Carbon filter certified for VOCs (NSF/ANSI 53)
$180-$599Activated carbon is effective for disinfection byproducts. Look for NSF/ANSI 53 VOC reduction.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
All contaminants detected in WATERTOWN's tap water
Every contaminant identified, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal. Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Haloacetic acids (HAA9) Disinfection byproduct |
43.5 ppb | 0.06 | — | — | — | — | — | 725× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
43.4 ppb | 0.1 | 60.0 | 60 | — | — | — | 434× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
45.4 ppb | 0.15 | 80.0 | 100 | — | — | — | 303× over |
| Chloroform Disinfection byproduct |
37.1 ppb | 0.4 | — | — | — | — | — | 93× over |
| 1,2,3-Trichloropropane Other |
0.0556 ppb | 0.0007 | — | — | — | — | — | 79× over |
| Bromodichloromethane Disinfection byproduct |
4.3 ppb | 0.06 | — | — | — | — | — | 72× over |
| Cadmium Heavy metal |
0.222 ppb | 0.04 | 5.0 | 5 | 3 | 0.04 | — | 5.6× over |
| Chromium (hexavalent) Heavy metal |
0.0398 ppb | 0.02 | — | — | — | — | — | 2.0× over |
| Chlorate Disinfection byproduct |
159.0 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Perfluorooctane sulfonate (PFOS) PFAS |
0.13 ppt | 0.3 | 4.0 | 100 | 100 | 1 | — | Below guideline |
| Nitrate and nitrite Inorganic |
0.0233 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | Below guideline |
| Nitrate Inorganic |
0.0224 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | Below guideline |
| Manganese Heavy metal |
6.4 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Chloromethane Other |
0.0556 ppb | 2.69 | — | — | — | — | — | Below guideline |
| 1,1-Dichloroethane Volatile organic compound |
0.0556 ppb | 3.0 | — | — | — | — | — | Below guideline |
| Barium Heavy metal |
6.67 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Vanadium Other |
0.095 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Perfluorohexanoic Acid (PFHxA) PFAS |
0.133 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.0362 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Bromomethane Other |
0.0556 ppb | — | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.21 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| n-Propylbenzene Volatile organic compound |
0.1 ppb | — | — | 1 | 10 | 0.15 | — | Below guideline |
| Nitrite Inorganic |
0.00122 ppm | — | 1.0 | — | — | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines, California OEHHA PHGs, EWG Tap Water Database.
Treatment plant contact info
For service issues, water quality concerns, or to request a Consumer Confidence Report from WATERBURY WATER DEPARTMENT.