US Water Score: B
Water Quality Summary
Tap water quality in Great Falls, Montana (59403) receives an overall grade of B (Moderate-low record-based concern) with a score of 84 out of 100, based on analysis of EPA compliance data, contaminant testing, and violation history. This is 6 points below the Montana state average of 90. The area is served by 2 water systems providing water to approximately 60,000 people, using surface water sources. Testing has found elevated levels of Lead that warrant attention. The area has a clean violation record over the past 5 years — a positive indicator of consistent water quality management.
A score of 84/100 means Great Falls, MT performs well in the US Water Score model, with only minor system-level concerns. Residents should still review their utility's Consumer Confidence Report for official compliance information and household-specific context.
Health Information
Lead is a toxic metal that can leach from aging pipes and plumbing fixtures.
Even low levels of lead exposure can cause developmental delays in children, kidney damage, and cardiovascular effects in adults. The EPA action level is 15 ppb, but health experts recommend no safe level of lead in drinking water.
Lead enters water primarily through corrosion of lead service lines, lead solder, and brass fixtures — especially in homes built before 1986.
If lead is detected above 1 ppb, consider using a certified lead-removal filter (NSF/ANSI 53) for drinking and cooking water. Run cold water for 30 seconds before use if water has been sitting in pipes.
Common Questions
Based on public water-system records, Great Falls, Montana receives an internal US Water Score grade of B (Moderate-low record-based concern) with a score of 84/100. This indicates relatively few system-level concerns in our model, but it is not an EPA safety rating and does not guarantee tap conditions inside individual homes.
ZIP code 59403 is served by 2 water systems using surface water sources, providing water to approximately 60,000 people. Surface water systems are more susceptible to contamination from agricultural runoff, industrial discharge, and weather events, but typically undergo more extensive treatment including filtration and disinfection.
Lead was reported at 12.0 ppb in public-system records for Great Falls, Montana. This is below the currently applicable EPA action level of 15 ppb, but may be above more protective health guidance; EPA's future LCRI action level is 10 ppb. Household plumbing can materially change tap-level exposure, so consider certified filtration and individual tap testing, especially where children are present.
No PFAS ("forever chemicals") were detected in water systems serving Great Falls, Montana during the most recent EPA monitoring period (UCMR5). However, not all water systems have been tested for all PFAS compounds, and new contamination can occur over time.
Water systems serving Great Falls, Montana have zero violations in the last 5 years. This is a positive indicator of consistent regulatory compliance and water quality management.
Based on detected contaminants (lead), residents in Great Falls, Montana should consider: NSF/ANSI 53 certified filter — specifically rated for lead reduction. Pitcher filters (like Brita Longlast or PUR) and under-sink systems both work. Always look for filters with NSF/ANSI certification for the specific contaminants you want to remove.
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