CheckPFAS

ZIP Code 51102

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

What this means for you

One or more PFAS compounds were measured above the EPA's enforceable drinking water limit at a utility serving ZIP 51102. The EPA set these limits because long-term exposure at higher concentrations is associated with health effects including immune suppression, thyroid changes, and cancer risk increases. Standard pitcher filters (Brita, PUR) are not certified to remove PFAS. The most reliable at-home options are under-sink reverse osmosis systems or activated carbon block filters with an NSF/ANSI 58 certification specifically listing PFOA/PFOS reduction. Your water utility is required to bring levels into compliance by 2029 — filtering at the tap is the practical interim step if you'd like additional protection now.

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
About this data
Source
EPA UCMR 5 (Unregulated Contaminant Monitoring Rule, 5th cycle)
Data released
January 2026
Sampling period
January 2023 – December 2025
Systems tested
~10,000 public water systems serving > 25 people
Water system (PWSID)
IA9778054
Detection threshold (MRL)
~1.5–2 ppt — "Not detected" means below this floor, not zero

Values shown are the highest single-sample concentration measured at entry points to the distribution system. Results reflect water quality at the treatment plant — aging pipes, building plumbing, and on-site storage can affect what actually reaches your tap.