CheckPFAS

ZIP Code 51101

High Risk
High Risk PFAS Risk Level

PFAS 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.

10
PFAS Detected
3
Above EPA Limits
1
Water System
350%
Highest % of MCL

Compounds Exceeding EPA Limits

PFHxS Exceeds EPA limit
0 ppt MCL: 10 ppt 350% of limit
Detected: 35.00 ppt
PFOA Exceeds EPA limit
0 ppt MCL: 4 ppt 150% of limit
Detected: 6.00 ppt
PFOS Exceeds EPA limit
0 ppt MCL: 4 ppt 108% of limit
Detected: 4.30 ppt

SIOUX CITY WATER SUPPLY

IA9778054 High Risk
Water Type
GU
PFAS Detected
10
Above MCL
3
State
Iowa
Data Period
2023–2025

PFAS Test Results

CompoundDetectedvs. EPA LimitEPA LimitStatus
PFHxS
Perfluorohexane sulfonic acid
35.00ppt
350% of limit
10 ppt⚠ Exceeds MCL
PFOA
Perfluorooctanoic acid
6.00ppt
150% of limit
4 ppt⚠ Exceeds MCL
PFOS
Perfluorooctane sulfonic acid
4.30ppt
108% of limit
4 ppt⚠ Exceeds MCL
lithium
240000.00pptNo federal limitUnregulated
PFHxA
Perfluorohexanoic acid
33.00pptNo federal limitUnregulated
PFPeA
Perfluoropentanoic acid
22.00pptNo federal limitUnregulated
PFBS
Perfluorobutane sulfonic acid
21.00pptNo federal limitUnregulated
PFPeS
14.00pptNo federal limitUnregulated
Show 2 more compounds detected at low levels
PFBAPerfluorobutanoic acid9.20 pptNo federal limit
PFHpAPerfluoroheptanoic acid4.80 pptNo federal limit

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 →