LOWER PIONEER MOUNTAIN WATER SYSTEM

BIG SKY, MT · ~350 people served

Check your exact address → BIG SKY overview

100

Excellent

PurityRadar safety score

PWSID

MT0004462

State

Montana

City

BIG SKY

Population served

350

Primary source

Groundwater

Score history

No change since tracking began Jun 18, 2026.

Jun 18, 2026 · score 100 Jun 18, 2026 · score 100

2 score updates logged since tracking began Jun 18, 2026. Each future EPA re-score adds a point.

PFAS & contaminant readings

No PFAS detections are on record for this system from EPA’s UCMR5 monitoring (2023–25). Absence of a detection isn’t a guarantee — not every system was sampled, and this dataset doesn’t cover other contaminants.

Violations & enforcement

Violations on record

Unaddressed

Health-based

Enforcement actions

From EPA ECHO (SDWIS), most recent enforcement Oct 2020. Official EPA record →

Max contaminant level (MCL) · Lead & Copper Rule health-based began Sep 2020 Resolved

Other · EPA contaminant 7000 began Jul 2020 Resolved

Max contaminant level (MCL) · Total coliform health-based began Feb 2015 Resolved

Monitoring & reporting · EPA contaminant 3014 began Dec 2010 Resolved

Monitoring & reporting · Total coliform began Feb 2010 Resolved

Monitoring & reporting · Lead & Copper Rule began Oct 2009 Resolved

Monitoring & reporting · Total coliform began Mar 2009 Resolved

Monitoring & reporting · Gross alpha began Jul 2008 Resolved

Monitoring & reporting · Uranium began Jul 2008 Resolved

Monitoring & reporting · EPA contaminant 2980 began Apr 2008 Resolved

Monitoring & reporting · EPA contaminant 2985 began Apr 2008 Resolved

Recent enforcement actions

State action · SOX Oct 2020
State action · SIE Sep 2020
State action · SIA Sep 2020
State action · SOX Jul 2020
State action · SIA Jul 2020
State action · SOX Mar 2015
State action · SIE Feb 2015
State action · SIA Feb 2015

This profile is built from EPA public records for system MT0004462 — SDWIS violations and UCMR5 PFAS sampling. The score is system-level and can’t account for your home’s plumbing (older pipes can add lead at the tap). For health decisions, check your exact address, read the utility’s Consumer Confidence Report, and confirm with your provider.