CheckPFAS

ZIP Code 21788

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
1200%
Highest % of MCL

Compounds Exceeding EPA Limits

PFOS Exceeds EPA limit
0 ppt MCL: 4 ppt 1200% of limit
Detected: 48.00 ppt
PFOA Exceeds EPA limit
0 ppt MCL: 4 ppt 375% of limit
Detected: 15.00 ppt
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TOWN OF THURMONT

MD0100023 High Risk
Water Type
Groundwater
PFAS Detected
4
Above MCL
2
State
Maryland
Data Period
2023–2025

PFAS Test Results

CompoundDetectedvs. EPA LimitEPA LimitStatus
PFOS
Perfluorooctane sulfonic acid
48.00ppt
1200% of limit
4 ppt⚠ Exceeds MCL
PFOA
Perfluorooctanoic acid
15.00ppt
375% of limit
4 ppt⚠ Exceeds MCL
PFHxS
Perfluorohexane sulfonic acid
5.30ppt
53% of limit
10 pptBelow limit
PFBS
Perfluorobutane sulfonic acid
4.30pptNo 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 →