Drinking water quality · 2024
· Verified
What's in Stamford, CT tap water
22 contaminants were measured in the Stamford, CT water system's 2024 annual report. Each is shown below against its federal limit — 1 sit at or above that limit.
- Reporting year
- 2024
- Contaminants measured
- 22
- Over federal limit
- 1
- Approaching the limit
- 2
- Worst contaminant
- PFOA
- Service area
- CT
PFAS — EPA UCMR5 (2023–2025)
2 PFAS compounds above EPA limits in Stamford, CT
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
PFOA (Perfluorooctanoic acid)
● Over EPA limit (2.7×)PFOS (Perfluorooctane sulfonic acid)
● Over EPA limit (1.6×)PFPeA
● Detected (no federal limit)PFBA
● Detected (no federal limit)PFHpA
● Detected (no federal limit)PFBS
● Detected (no federal limit)PFHxA
● Detected (no federal limit)Where your water comes from · EPA SDWIS
Stamford, CT's drinking water comes from surface water, drawn from 17 sources.
Source
- WESTPORT · 4
- COLEYTOWN · 2
- ASPETUCK RESERVOIR
- EASTON LAKE RESERVOIR INTAKE
- + 9 more
Treatment
- COLEYTOWN WELLFIELD TREATMENT PLANT
- EASTON WATER TREATMENT PLANT
- HEMLOCKS WATER TREATMENT PLANT
- + 3 more
Distribution
Also buys water from NORWALK FIRST TAXING DISTRICT, AQUARION-STAMFORD, and 1 more.
Compliance history
Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.
- Treatment technique violationHealth-based2 violations on record · most recent Jan 1992resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 51 ug/LAverageSystem-wide | None set | Approaching the limit |
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 64 ug/LAverageSystem-wide | None set | Approaching the limit |
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChlorineA disinfectant added to drinking water to kill bacteria and viruses. | 0.87 mg/LAverageSystem-wide | 4 mg/LMRDLG | Within the limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | 0.003 mg/L90th percentileAt the tap | 0.015 mg/LAction level | Within the limit |
| CopperA metal that enters water from corroding household plumbing. | 0.17 mg/LAverageSystem-wide | 1.3 mg/LMCLG | Within the limit |
| BariumA metal from erosion of natural deposits and industrial discharge. | 0.015 mg/LAverageSystem-wide | 2 mg/LMCLG | Within the limit |
| SodiumA naturally occurring salt component. | 33 mg/LAverageSystem-wide | 100 mg/LNL | Detected — no federal limit |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| FluorideA mineral often added to drinking water to help prevent tooth decay. | 0.71 mg/LAverageSystem-wide | 4 mg/LMCLG | Within the limit |
| SulfateA naturally occurring mineral from rock and soil. | 35 mg/LAverageSystem-wide | 250 mg/LSecondary MCL | Within the limit |
| NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits. | 0.339 mg/LAverageSystem-wide | 10 mg/LMCLG | Within the limit |
| ChlorideA naturally occurring salt compound. | 36 mg/LAverageSystem-wide | None set | Detected — no federal limit |
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.15 NTUAverageSystem-wide | 1 NTUMCL | Within the limit |
| ColorA measure of visible tint in the water. | 2AverageSystem-wide | None set | Detected — no federal limit |
| HardnessA measure of dissolved calcium and magnesium minerals. | 3Reported levelAverage | None set | Detected — no federal limit |
| pHA measure of how acidic or basic the water is. | 7.4AverageSystem-wide | None set | Detected — no federal limit |
| TOCTotal organic carbon — a measure of organic material dissolved in the water. | 1.6AverageSystem-wide | None set | Detected — no federal limit |
PFAS ("forever chemicals")
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Perfluorohexanesulfonic acidPerfluorohexanesulfonic acid, a PFAS 'forever chemical.' | Not detected ng/LAverageSystem-wide | None set | Within the limit |
VOCs & pesticides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Dalapon | Not detected ug/LAverageSystem-wide | 200 ug/LMCLG | Within the limit |
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Total ColiformA group of bacteria used as an indicator of overall water-system sanitation. | 0AverageSystem-wide | 0MCLG | Detected — no federal limit |
People also ask about Stamford, CT's water
+Is Stamford, CT tap water safe to drink in 2024?
The 2024 Consumer Confidence Report for the Stamford, CT water utility lists 1 contaminant at or above the federal limit: PFOA. Whether that means the water is "unsafe" depends on which contaminant, how long the exposure, and individual health factors. The table on this page shows the measured value, the federal threshold, and the regulated statistic used for compliance.
+What contaminants are in Stamford, CT tap water?
22 contaminants were measured in Stamford, CT's 2024 Consumer Confidence Report, spanning physical & aggregate, inorganic chemicals, and metals. 11 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Which contaminants exceed federal limits in Stamford, CT tap water?
One contaminant in Stamford, CT's 2024 report sits at or above the federal limit: PFOA (1.0× the limit). The EPA enforces these limits against the regulated reporting statistic — typically a running annual average or 90th percentile — not a one-off sample spike.
+What is the worst contaminant in Stamford, CT tap water?
The contaminant with the highest measured value relative to its federal limit in the 2024 report is PFOA, at 1.0× the federal threshold. It belongs to the pfas ("forever chemicals") family of contaminants.
+Are any contaminants in Stamford, CT tap water approaching the federal limit?
2 contaminants are between 80% and 100% of the federal limit in this report: HAA5 and TTHM. Approaching means measured but not in violation — a margin that can close quickly if conditions change.
+Where does the data on this page come from?
Every value is transcribed from Stamford, CT's 2024 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is Stamford, CT's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2024 report; a new report will replace it once the utility publishes its next annual update.