SIOUX CITY WATER SUPPLY
High Risk3 PFAS compound(s) exceed EPA Maximum Contaminant Levels
This utility has until 2029 to install treatment under the EPA's April 2024 PFAS rule. In the meantime, a point-of-use filter certified NSF/ANSI 58 for PFOA/PFOS provides reliable interim protection.
10
PFAS Detected
3
Above EPA Limits
9
ZIPs Served
Groundwater
Water Source
PFAS Test Results
| Compound | Detected | vs. EPA Limit | EPA Limit | Status |
|---|---|---|---|---|
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 | 240000.00ppt | No federal limit | — | Unregulated |
PFHxA Perfluorohexanoic acid | 33.00ppt | No federal limit | — | Unregulated |
PFPeA Perfluoropentanoic acid | 22.00ppt | No federal limit | — | Unregulated |
PFBS Perfluorobutane sulfonic acid | 21.00ppt | No federal limit | — | Unregulated |
PFPeS | 14.00ppt | No federal limit | — | Unregulated |
Show 2 more compounds detected at low levels
| PFBAPerfluorobutanoic acid | 9.20 ppt | No federal limit |
| PFHpAPerfluoroheptanoic acid | 4.80 ppt | No federal limit |
ZIP Codes Served by This Utility
Click any ZIP to see the full result page for that area.
About this data
Source
EPA UCMR 5 — January 2026 release
Sampling period
January 2023 – December 2025
Water system ID (PWSID)
IA9778054
Detection threshold (MRL)
~1.5–2 ppt — "Not detected" means below this floor