ZIP Code 06831
High RiskPFAS above EPA limits detected
3 compounds exceed EPA Maximum Contaminant Levels in water serving this ZIP code. Standard pitcher filters like Brita do not remove PFAS. See filter recommendations below.
7
PFAS Detected
3
Above EPA Limits
2
Water Systems
140%
Highest % of MCL
Compounds Exceeding EPA Limits
PFOA Exceeds EPA limit
0 ppt MCL: 4 ppt 140% of limit
Detected: 5.60 ppt
PFOS Exceeds EPA limit
0 ppt MCL: 4 ppt 103% of limit
Detected: 4.10 ppt
AQUARION WATER CO OF CT-GREENWICH SYSTEM
CT0570011 High RiskWater Type
Surface Water
PFAS Detected
4
Above MCL
2
State
Connecticut
Data Period
2023–2025
PFAS Test Results
| Compound | Detected | vs. EPA Limit | EPA Limit | Status |
|---|---|---|---|---|
PFOA Perfluorooctanoic acid | 5.60ppt | 140% of limit
| 4 ppt | ⚠ Exceeds MCL |
PFOS Perfluorooctane sulfonic acid | 4.10ppt | 103% of limit
| 4 ppt | ⚠ Exceeds MCL |
PFHxA Perfluorohexanoic acid | 4.00ppt | No federal limit | — | Unregulated |
PFPeA Perfluoropentanoic acid | 3.80ppt | No federal limit | — | Unregulated |
AQUARION WATER CO OF CT-STAMFORD
CT1350011 High RiskWater Type
Surface Water
PFAS Detected
3
Above MCL
1
State
Connecticut
Data Period
2023–2025
PFAS Test Results
| Compound | Detected | vs. EPA Limit | EPA Limit | Status |
|---|---|---|---|---|
PFOA Perfluorooctanoic acid | 4.30ppt | 108% of limit
| 4 ppt | ⚠ Exceeds MCL |
PFPeA Perfluoropentanoic acid | 3.10ppt | No federal limit | — | Unregulated |
PFHxA Perfluorohexanoic acid | 3.00ppt | No federal limit | — | Unregulated |
Note: ZIP code 06831 is served by 2 separate water utilities.
Results above show data for each system independently.
Data source: EPA Unregulated Contaminant Monitoring Rule, 5th cycle (UCMR 5) — January 2026 release.
UCMR 5 tested ~10,000 public water systems serving more than 25 people between 2023-2025 for 29 PFAS compounds.
Detection values represent the highest single-sample result measured at entry points to the distribution system.