No health-based violations on EPA record since 2016.
Serves about 7,775 people (3,805 connections) with groundwater from its own wells.
From EPA's record for MT0001744. PurityMap is independent of Flathead County Water and Sewer.
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No health-based violations in the last 10 years, from EPA's SDWIS compliance database.
EPA required this system to test for 30 unregulated and emerging contaminants, from January 2025 to August 2025.
| Contaminant | Result | Limit | Status | Sampled | Source |
|---|---|---|---|---|---|
| 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals) | < 5 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Lithium | < 9 µg/L | 10 µg/L EPA health reference level (screening, not a legal limit)Screening level, not a legal limit | Not detected above the reporting limit | 2025-01-22 to 2025-07-21 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | < 6 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) | < 20 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluoro-3-methoxypropanoic acid (PFMPA) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluoro-4-methoxybutanoic acid (PFMBA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluorobutanesulfonic acid (PFBS) | < 3 ng/L | 2,000 ng/L EPA health advisory (screening, not a legal limit)Screening level, not a legal limit | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluorobutanoic acid (PFBA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluorodecanoic acid (PFDA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluorododecanoic acid (PFDoA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluoroheptanesulfonic acid (PFHpS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluoroheptanoic acid (PFHpA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluorohexanesulfonic acid (PFHxS) | < 3 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluorohexanoic acid (PFHxA) | < 3 ng/L | 400,000 ng/L Michigan EGLE state MCL (strictest US state) | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluorononanoic acid (PFNA) | < 4 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluorooctanesulfonic acid (PFOS) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluorooctanoic acid (PFOA) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluoropentanesulfonic acid (PFPeS) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluoropentanoic acid (PFPeA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluorotetradecanoic acid (PFTA) | < 8 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluorotridecanoic acid (PFTrDA) | < 7 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
| Perfluoroundecanoic acid (PFUnA) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-22 to 2025-08-12 | UCMR5 Analytical Results: FLATHEAD COUNTY WATER AND SEWER (MT0001744) |
Screening tells you if something is worth a closer look; a lab result is the number you can act on.
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Screening: quick check, not lab-grade
Safe Home (EnviroTestKits)
Lead, read as one of three ranges: 0–4, 5–15 or 15+ ppb
Turnaround: 5 minutes
What it can't tell you: It shows a lead range, not an exact level, and tests nothing else unless you pay extra for the optional lab test.
Lab-certified results
ETR Laboratories
50+ substances, including lead, copper, arsenic, nitrate, hardness and coliform bacteria
Environmental Testing and Research Laboratories (ETR Labs), Leominster, MA · ISO/IEC 17025:2017, ANAB certificate AT-2638 · 2–4 business days after the lab receives it
What it can't tell you: It does not test PFAS, and not every result on the panel falls under the lab's accredited scope.
Get PurityMap updates about this water system.
Follow this water →Flathead County Water and Sewer's phone number on EPA record is 406-257-5861. Its mailing address is 108 COOPERATIVE WAY, KALISPELL, MT 59901.
According to EPA's record, Flathead County Water and Sewer uses groundwater from its own wells.
No health-based violations on EPA record since 2016. EPA also lists 1 missed or late test or report in 10 years. The record comes from EPA's SDWIS compliance database.
The 90th-percentile lead result in Flathead County Water and Sewer's latest lead and copper round, which ended in December 2025, was 1 µg/L, below the federal action level of 15 µg/L.
PurityMap has no verified website for Flathead County Water and Sewer. Its phone number on EPA record is 406-257-5861. Its mailing address on EPA record is 108 COOPERATIVE WAY, KALISPELL, MT 59901. Your water bill lists the ways to contact your supplier and pay. PurityMap does not take payments.