Drinking water quality · 2024
· Verified
· PWSID CT0930011
What's in Hamden, CT tap water
3 contaminants in Hamden, CT's water sat at or above a federal limit, led by Turbidity at 98.0x the limit.
- !3 contaminants at or above a federal limit — worst is Turbidity at 98.0x
- !10 of 27 core regulated contaminants reported — 17 never appear in this report
- ✓No open federal violations
+How this score is calculated
Every system starts at 100. Points come off for measured levels, for the federal violation record, and for how much of the core regulated set the utility actually reported. All three inputs are the utility's own published numbers and EPA's own records.
- −60 contaminants at or above a federal limit
- −0 contaminants within 20% of a limit
- −0 open health-based violations
- −0 open monitoring / reporting violations
- −0 health-based violations resolved in the last 5 years
- −14 core regulated contaminants never reported (10/27)
A 90–100 · B 80–89 · C 70–79 · D 60–69 · F below 60. A system reporting under a third of the core set is capped at C however clean its numbers look — a short report is not a clean bill of health.
Full grading methodology, constant for constant →What to worry about
- Turbidity98.0× the federal limit0–98 NTU · limit 1 NTU
High turbidity can shelter microbes from disinfection; the EPA enforces it through a treatment-technique standard.
higher than 95% of U.S. systems
- PFOS (Perfluorooctane sulfonic acid)2.7× the federal limit10.7 ng/L · limit 4 ng/L
Linked to cancer, thyroid disease, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
higher than 80% of U.S. systems
- PFOA (Perfluorooctanoic acid)1.8× the federal limit7.1000000000000005 ng/L · limit 4 ng/L
Linked to cancer, liver damage, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
higher than 80% of U.S. systems
+24 contaminants were measured and came in below the limitShow all
| Contaminant | Measured | Federal limit |
|---|---|---|
| HAA5 | 12.4–40.7 ug/L | 60 ug/L |
| Chlorine | 0–2.7 mg/L | 4 mg/L |
| Nitrate | 0–4.61 mg/L | 10 mg/L |
| Fluoride | 0.17–1.3 mg/L | 4 mg/L |
| Copper | 0.27 mg/L | 1.3 mg/L |
| Barium | 0.004–0.26 mg/L | 2 mg/L |
| Bromodichloromethane | 3.5–10.6 ug/L | — |
| Chloroform | 15.9–52.6 ug/L | — |
| Dibromochloromethane | 0–1.6 ug/L | — |
| Chloride | 2.9–105 mg/L | — |
| Sulfate | 6.4–38.6 mg/L | — |
| Lead | 0.0 mg/L | 0.015 mg/L |
| Manganese | 0–0.21 mg/L | — |
| Sodium | 7.4–50.8 mg/L | — |
| Escherichia coli (E. coli) | 0 % | — |
| Dbaa | 0–0.9 ug/L | — |
| Dcaa | 4.1–15.1 ug/L | — |
| Mbaa | 0–2.6 ug/L | — |
| Mcaa | 1–5.7 ug/L | — |
| Tcaa | 4.5–22.4 ug/L | — |
| TOC | 1.35–2.59 | — |
| Radon | 0–1856 pCi/L | — |
| PFBS | 3.5 ng/L | — |
| PFPeA | 3.1 ng/L | — |
What this report doesn't tell you
17 of the 27 contaminants a community water system normally reports do not appear anywhere in Hamden, CT's data. Absent is not the same as absent-from-the-water — it means nobody published a number.
+Full detail: PFAS testing, water source, historical monitoring, and the federal violation record
PFAS — EPA UCMR5 (2023–2025)
2 PFAS compounds above EPA limits in Hamden, 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.
PFOS (Perfluorooctane sulfonic acid)
● Over EPA limit (2.7×)PFOA (Perfluorooctanoic acid)
● Over EPA limit (1.8×)PFBS
● Detected (no federal limit)PFPeA
● Detected (no federal limit)Where your water comes from · EPA SDWIS
Hamden, CT's drinking water comes from ground water, drawn from 37 sources.
Source
- NORTH SLEEPING GIANT · 5
- NORTH CHESHIRE · 4
- SEYMOUR · 4
- LAKE DAWSON · 2
- + 16 more
Treatment
- LAKE GAILLARD TREATMENT PLANT
- LAKE SALTONSTALL WATER TREATMENT PLANT
- LAKE WHITNEY WATER TREATMENT PLANT
- + 9 more
Distribution
Also buys water from SOUTHINGTON WATER DEPARTMENT, AQUARION-VALLEY, and 3 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.