Montana Water Quality Report

Tap water quality data for 1 cities in Montana, updated 2026.

Avg. Hardness: 246 ppm (Very Hard)1 cities with violationsAll cities below EPA lead limit
Avg. Hardness
246 ppm
Very Hard

US average: 100 ppm

Violations (3yr)
120
52 health-based

0 of 1 cities violation-free

Lead Compliance
100%
Below EPA Limit

1 cities tested

Water Source
Surface Water
0% of systems

1 water systems tracked

Cleanest Tap Water in Montana

Cities with the fewest water quality issues

Most Water Quality Issues in Montana

Cities with the most violations and concerns

Montana Tap Water: What You Need to Know

Montana has 1 tracked water utilities serving approximately 142K residents. The average water hardness is 246 ppm (14.4 GPG), classified as Very Hardabove the national average of 100 ppm. Hardness ranges from 246 ppm in Billings to 246 ppm in Billings.

In the past 3 years, 1 of 1 cities in Montana have recorded water quality violations, totaling 120 violations (52 health-based). All 1 tested cities have lead levels below the EPA action level of 15 ppb.

With very hard water on average, many Montana residents may notice mineral buildup on fixtures, dry skin, or stiff-feeling hair. A shower filter for hard water can help reduce chlorine exposure, while a water softener addresses the mineral buildup directly.

Frequently Asked Questions About Montana Water

Is tap water safe to drink in Montana?

Most tap water in Montana meets EPA standards, but 1 cities have recorded violations in the past 3 years (52 health-based). We recommend checking your specific city's report on TapWater.org and considering a home water test.

How hard is the water in Montana?

Montana's average water hardness is 246 ppm (14.4 GPG), classified as Very Hard. This is above the national average of 100 ppm. Hardness varies significantly by city — use our Water Hardness Calculator to check your specific area.

Which city in Montana has the cleanest tap water?

Based on EPA violation data, lead testing, and water quality metrics, Billings ranks as having the cleanest tap water in Montana. It has zero violations in the past 3 years and lead levels well below the EPA action level.

Which city in Montana has the most water quality issues?

Billings currently has the most water quality concerns in Montana, with 120 violations in the past 3 years. Residents should check their city's detailed water quality report and consider using a certified water filter.

Where does Montana get its water from?

The majority of Montana's water systems (0%) use surface water as their primary source. Surface water comes from rivers, lakes, and reservoirs. Each city's specific source can vary — check individual city reports for details.