Tap Water Quality Report
Tap water quality in WINDSOR LOCKS, Connecticut
Tap water in WINDSOR LOCKS, Connecticut receives a grade of D (65/100) from TapWaterSafety.org. It's served by 2 public water systems, primarily METROPOLITAN DISTRICT COMMISSION. The most significant water quality concerns are: Haloacetic acids (HAA9) significantly above health guideline; Haloacetic acids (HAA5) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline; PFAS contamination; Arsenic detected. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in WINDSOR LOCKS's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utilities serving WINDSOR LOCKS.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 31.3 ppb, 522x above the EWG health guideline of 0.06 ppb.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 32.3 ppb, 323x above the EWG health guideline of 0.1 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 46.0 ppb, 306x above the EWG health guideline of 0.15 ppb.
PFAS contamination
Severe concernPerfluorooctane sulfonate (PFOS), Perfluorooctanoic acid (PFOA) detected. PFAS are persistent chemicals linked to cancer and immune effects with no known safe exposure threshold.
Arsenic detected
Moderate concernArsenic detected at 0.525 ppb.
EPA compliance record
Official U.S. EPA records for METROPOLITAN DISTRICT COMMISSION (system ID CT0640011) for the last 3 years. Checked 2026-10-07.
| Rule | Type | Since | Status |
|---|---|---|---|
| Interim and Long Term 1 Enhanced Surface Water Treatment Rule | Missed testing or reporting | 06/01/2025 | Resolved |
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Water systems serving WINDSOR LOCKS
WINDSOR LOCKS is served by 2 public water systems. Click any utility to see its complete grade card and treatment plant contact info.
METROPOLITAN DISTRICT COMMISSION
- Haloacetic acids (HAA9) significantly above health guideline
- Haloacetic acids (HAA5) significantly above health guideline
- Total trihalomethanes (TTHMs) significantly above health guideline
CTWC - NORTHERN REG-WESTERN SYSTEM
- PFAS contamination
- Haloacetic acids (HAA9) significantly above health guideline
- Total trihalomethanes (TTHMs) significantly above health guideline
Recommended filters for WINDSOR LOCKS
Filters matched to the specific contaminants in WINDSOR LOCKS's water supply.
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 WINDSOR LOCKS'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 |
31.3 ppb | 0.06 | — | — | — | — | — | 522× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
32.3 ppb | 0.1 | 60.0 | 60 | — | — | — | 323× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
46.0 ppb | 0.15 | 80.0 | 100 | — | — | — | 306× over |
| Trichloroacetic acid Disinfection byproduct |
24.5 ppb | 0.1 | — | — | — | — | — | 245× over |
| Bromodichloromethane Disinfection byproduct |
9.05 ppb | 0.06 | — | — | — | — | — | 151× over |
| Arsenic Heavy metal |
0.525 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 131× over |
| Chloroform Disinfection byproduct |
40.2 ppb | 0.4 | — | — | — | — | — | 100× over |
| Dichloroacetic acid Disinfection byproduct |
7.62 ppb | 0.2 | — | — | — | — | — | 38× over |
| Dibromochloromethane Disinfection byproduct |
2.37 ppb | 0.1 | — | — | — | — | — | 24× over |
| Nitrate Inorganic |
2.16 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 15× over |
| Nitrate and nitrite Inorganic |
2.02 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 14× over |
| Chromium (hexavalent) Heavy metal |
0.256 ppb | 0.02 | — | — | — | — | — | 13× over |
| Perfluorooctanoic acid (PFOA) PFAS |
1.0 ppt | 0.09 | 4.0 | 100 | 100 | 0.007 | — | 11× over |
| Perfluorooctane sulfonate (PFOS) PFAS |
0.8 ppt | 0.3 | 4.0 | 100 | 100 | 1 | — | 2.7× over |
| Radium, combined (-226 and -228) Radiological |
0.12 pCi/L | 0.05 | 5.0 | — | — | — | — | 2.5× over |
| Strontium-90 Radiological |
0.75 pCi/L | 0.35 | — | — | — | — | — | 2.1× over |
| Uranium Radiological |
0.39 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | Below guideline |
| Dibromoacetic acid Disinfection byproduct |
0.0188 ppb | 0.03 | — | — | — | — | — | Below guideline |
| Chlorate Disinfection byproduct |
113.5 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Benzo[a]pyrene Other |
0.00177 ppb | 0.007 | 0.2 | — | — | — | — | Below guideline |
| Barium Heavy metal |
144.7 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Vanadium Other |
2.57 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
10.7 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Bromoform Disinfection byproduct |
0.029 ppb | 0.5 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
1.17 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Selenium Heavy metal |
0.154 ppb | 30.0 | 50.0 | 20 | 40 | 30 | — | Below guideline |
| Monochloroacetic acid Disinfection byproduct |
0.214 ppb | 53.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.177 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Chromium (total) Heavy metal |
0.154 ppb | — | 100.0 | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.298 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Lithium Other |
2.53 ppb | — | — | — | — | — | — | Below guideline |
| 4-Androstene-3,17-dione Other |
0.083 ppt | — | — | — | — | — | — | Below guideline |
| Nitrite Inorganic |
0.00407 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 METROPOLITAN DISTRICT COMMISSION.
General Contact
Treatment Plant
ZIP codes served
WINDSOR LOCKS's public water systems serve the following ZIP codes: