PlainWater
States → Montana

HELENA WATER SYSTEM

PWS ID: MT0000241 · HELENA, Montana 59602

PFAS Detected

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

Population Served
32,091
Total Violations
68
Health-Based Violations
13
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Local
Connections
11,684
County
Lewis and Clark
School/Daycare
No
MCL Violations
13
Monitoring Violations
50
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
TTHM MR 9 2006
Total Haloacetic Acids (HAA5) MCL 9 2023
Total Haloacetic Acids (HAA5) MR 9 2006
Coliform (TCR) MR 8 2008
Surface Water Treatment Rule MR 7 2008
Lead and Copper Rule MR 6 2007
Coliform (TCR) MCL 4 2008
Arsenic MR 3 2005
Consumer Confidence Rule Other 3 2011
Asbestos MR 3 2011
Nitrate-Nitrite MR 3 2005
Nitrate MR 1 1993
Combined Radium (-226 and -228) MR 1 2008

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 3 of 270 samples detected PFAS.

Contaminant Date Result MRL Status
6:2 FTS 7/19/2023 <0.005 µg/L 0.005 µg/L Not Detected
9Cl-PF3ONS 7/19/2023 <0.002 µg/L 0.002 µg/L Not Detected
PFBA 7/19/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFHxS 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
HFPO-DA 7/19/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFHpA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
ADONA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
11Cl-PF3OUdS 7/19/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFUnA 7/19/2023 <0.002 µg/L 0.002 µg/L Not Detected
PFHxA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFDoA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFDA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFOA 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFBS 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
4:2 FTS 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFOS 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFPeS 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFHpS 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFMPA 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFPeA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFMBA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFEESA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
NFDHA 7/19/2023 <0.02 µg/L 0.02 µg/L Not Detected
8:2 FTS 7/19/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFTA 7/19/2023 <0.008 µg/L 0.008 µg/L Not Detected
NMeFOSAA 7/19/2023 <0.006 µg/L 0.006 µg/L Not Detected
NEtFOSAA 7/19/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFTrDA 7/19/2023 <0.007 µg/L 0.007 µg/L Not Detected
lithium 7/19/2023 <9 µg/L 9 µg/L Not Detected
PFNA 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
lithium 7/19/2023 78.0000 µg/L 9 µg/L Detected
PFDoA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFOS 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFOA 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFDA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFNA 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFHxA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFUnA 7/19/2023 <0.002 µg/L 0.002 µg/L Not Detected
PFMBA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFPeA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFMPA 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
4:2 FTS 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHxS 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
9Cl-PF3ONS 7/19/2023 <0.002 µg/L 0.002 µg/L Not Detected
8:2 FTS 7/19/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFPeS 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
11Cl-PF3OUdS 7/19/2023 <0.005 µg/L 0.005 µg/L Not Detected
HFPO-DA 7/19/2023 <0.005 µg/L 0.005 µg/L Not Detected
ADONA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
6:2 FTS 7/19/2023 <0.005 µg/L 0.005 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.