CheckPFAS

ZIP Code 53027

High Risk
High Risk PFAS Risk Level

PFAS above EPA limits detected

2 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.

4
PFAS Detected
2
Above EPA Limits
1
Water System
170%
Highest % of MCL

Compounds Exceeding EPA Limits

PFOA Exceeds EPA limit
0 ppt MCL: 4 ppt 170% of limit
Detected: 6.80 ppt
PFOS Exceeds EPA limit
0 ppt MCL: 4 ppt 138% of limit
Detected: 5.50 ppt
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HARTFORD WATERWORKS, WI

WI2670110 High Risk
Water Type
Groundwater
PFAS Detected
4
Above MCL
2
State
Wisconsin
Data Period
2023–2025

PFAS Test Results

CompoundDetectedvs. EPA LimitEPA LimitStatus
PFOA
Perfluorooctanoic acid
6.80ppt
170% of limit
4 ppt⚠ Exceeds MCL
PFOS
Perfluorooctane sulfonic acid
5.50ppt
138% of limit
4 ppt⚠ Exceeds MCL
PFHxS
Perfluorohexane sulfonic acid
6.10ppt
61% of limit
10 pptBelow limit
PFBS
Perfluorobutane sulfonic acid
3.20pptNo federal limit—Unregulated

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.

View raw EPA data →