THORNTON CITY OF
High Risk2 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.
9
PFAS Detected
2
Above EPA Limits
7
ZIPs Served
Surface
Water Source
PFAS Test Results
| Compound | Detected | vs. EPA Limit | EPA Limit | Status |
|---|---|---|---|---|
PFOA Perfluorooctanoic acid | 7.10ppt | 178% of limit
| 4 ppt | ⚠ Exceeds MCL |
PFOS Perfluorooctane sulfonic acid | 5.00ppt | 125% of limit
| 4 ppt | ⚠ Exceeds MCL |
PFHxS Perfluorohexane sulfonic acid | 5.90ppt | 59% of limit
| 10 ppt | Below limit |
lithium | 34000.00ppt | No federal limit | — | Unregulated |
PFHxA Perfluorohexanoic acid | 12.60ppt | No federal limit | — | Unregulated |
PFPeA Perfluoropentanoic acid | 12.40ppt | No federal limit | — | Unregulated |
PFBA Perfluorobutanoic acid | 10.40ppt | No federal limit | — | Unregulated |
PFBS Perfluorobutane sulfonic acid | 8.10ppt | No federal limit | — | Unregulated |
Show 1 more compound detected at low levels
| PFHpAPerfluoroheptanoic acid | 3.70 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)
CO0101150
Detection threshold (MRL)
~1.5–2 ppt — "Not detected" means below this floor