PlainWater

HARDIN CITY OF

PWS ID: MT0000235 · HARDIN, Montana 59034

PFAS Detected

1 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.

Population Served
3,500
Total Violations
63
Health-Based Violations
6
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Local
Connections
1,307
County
Big Horn
School/Daycare
No
MCL Violations
0
Monitoring Violations
37
Treatment Tech Violations
6

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
CARBON, TOTAL MR 12 2004
Consumer Confidence Rule Other 11 2013
Total Haloacetic Acids (HAA5) MR 7 2025
TTHM MR 7 2025
Surface Water Treatment Rule TT 6 1995
Coliform (TCR) MR 4 1996
Arsenic MR 3 2000
Lead and Copper Rule MR 2 2014
CYANIDE MR 1 1994
Asbestos MR 1 2002

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 4 of 120 samples detected PFAS.

Contaminant Date Result MRL Status
PFTrDA 9/17/2024 <0.007 µg/L 0.007 µg/L Not Detected
PFBS 9/17/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 9/17/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFHxS 9/17/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFNA 9/17/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFOS 9/17/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFOA 9/17/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFDA 9/17/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFDoA 9/17/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFHxA 9/17/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFTA 9/17/2024 <0.008 µg/L 0.008 µg/L Not Detected
ADONA 9/17/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFUnA 9/17/2024 <0.002 µg/L 0.002 µg/L Not Detected
HFPO-DA 9/17/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFBA 9/17/2024 <0.005 µg/L 0.005 µg/L Not Detected
6:2 FTS 9/17/2024 <0.005 µg/L 0.005 µg/L Not Detected
4:2 FTS 9/17/2024 <0.003 µg/L 0.003 µg/L Not Detected
8:2 FTS 9/17/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFMPA 9/17/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFPeA 9/17/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFMBA 9/17/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFEESA 9/17/2024 <0.003 µg/L 0.003 µg/L Not Detected
NFDHA 9/17/2024 <0.02 µg/L 0.02 µg/L Not Detected
PFPeS 9/17/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFHpS 9/17/2024 <0.003 µg/L 0.003 µg/L Not Detected
11Cl-PF3OUdS 9/17/2024 <0.005 µg/L 0.005 µg/L Not Detected
NEtFOSAA 9/17/2024 <0.005 µg/L 0.005 µg/L Not Detected
lithium 9/17/2024 22.0000 µg/L 9 µg/L Detected
NMeFOSAA 9/17/2024 <0.006 µg/L 0.006 µg/L Not Detected
9Cl-PF3ONS 9/17/2024 <0.002 µg/L 0.002 µg/L Not Detected
PFEESA 6/11/2024 <0.003 µg/L 0.003 µg/L Not Detected
HFPO-DA 6/11/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFBA 6/11/2024 <0.005 µg/L 0.005 µg/L Not Detected
6:2 FTS 6/11/2024 <0.005 µg/L 0.005 µg/L Not Detected
4:2 FTS 6/11/2024 <0.003 µg/L 0.003 µg/L Not Detected
8:2 FTS 6/11/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFMPA 6/11/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFMBA 6/11/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFUnA 6/11/2024 <0.002 µg/L 0.002 µg/L Not Detected
NFDHA 6/11/2024 <0.02 µg/L 0.02 µg/L Not Detected
PFPeS 6/11/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFHpS 6/11/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFPeA 6/11/2024 <0.003 µg/L 0.003 µg/L Not Detected
ADONA 6/11/2024 <0.003 µg/L 0.003 µg/L Not Detected
11Cl-PF3OUdS 6/11/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFTrDA 6/11/2024 <0.007 µg/L 0.007 µg/L Not Detected
PFHxA 6/11/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFDoA 6/11/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFDA 6/11/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFOA 6/11/2024 <0.004 µg/L 0.004 µg/L Not Detected
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. PFAS data from EPA UCMR5 monitoring program (2023-2025). This data is provided for informational purposes only.