How does Great Falls's water compare to the national average?

The USA national average is 151 mg/L. Great Falls (≈ 120–179 mg/L) is 1 mg/L softer than average.

Great Falls Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

reservoir

pH Level

8.4

neutral = 7.0

Lead

0.009 mg/L

✓ Below action level

TDS

432.2 mg/L

Est. Daily Cost

$0.40

energy & soap waste

Source: See methodology section below · Updated 2026

hard~120–179 mg/LHard · est.

0–60

mg/L

Soft

61–120

mg/L

Moderately Hard

121–180

mg/L

Hard

180+

mg/L

Very Hard

Appliance Damage Report

In Great Falls, your appliances are currently losing 20% efficiency due to mineral buildup.

Appliance	In Great Falls	Soft Water City	Efficiency Loss
Kettle	6.8 yrs	8.5 yrs	-20%
Washing Machine	9.6 yrs	12 yrs	-20%
Water Heater	12 yrs	15 yrs	-20%

Regional Water Comparison

How Great Falls compares to its nearest neighbours

City	Hardness	Risk	Source
▶ Great Falls, Montana	≈ 120–179 mg/L	🟠 Hard	reservoir
Helena, Montana	≈ 0–60 mg/L	🟢 Soft	reservoir
Bozeman, Montana	≈ 120–179 mg/L	🟠 Hard	reservoir
Butte, Montana	≈ 120–179 mg/L	🟠 Hard	reservoir
Missoula, Montana	≈ 120–179 mg/L	🟠 Hard	groundwater

National Benchmark

How Great Falls compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Great Falls	≈ 120–179 mg/L	🟠 Moderate
USA National Avg	151 mg/L	🟠 Moderate
Scarsdale Top Rated	0.02 mg/L	🟢 None

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What Makes Great Falls's Water Unique?

Local geology and source profile

Source: ReservoirTDS: 432.2 mg/LpH: 8.4

The City of Great Falls Water Department serves approximately 60,000 residents across Great Falls, Black Eagle, and surrounding areas in Cascade County, Montana. The utility operates multiple water sources including the Missouri River and groundwater wells, with treatment facilities managed by the city. The system supplies water to residential, commercial, and industrial customers throughout the service area. Detailed treatment process information, contaminant data, and pH levels are available in annual Consumer Confidence Reports, with emergency water quality contact available 24/7 through Cascade County.

Great Falls' water supply originates from the Upper Missouri River Basin and groundwater aquifers underlying the region. The watershed flows through terrain dominated by Cretaceous and Paleocene sedimentary rock formations, including calcium- and magnesium-rich sandstones and shales. These geological formations naturally contribute dissolved minerals to both surface and groundwater sources, resulting in a hard water supply typical of central Montana's hydrogeology.

At the hard water level, residents can expect visible scale buildup on fixtures, reduced soap lathering, and potential mineral deposits in appliances such as water heaters and dishwashers. Hard water may shorten appliance lifespan and increase energy consumption. A water softener is recommended for households seeking to reduce scale formation, improve cleaning efficiency, and protect plumbing infrastructure from mineral accumulation. According to recent water quality reports, Great Falls City of has reported contaminants above EPA health-based guidelines and multiple Maximum Contaminant Level (MCL) violations; the utility recommends filtration and encourages residents to review annual Consumer Confidence Reports for specific contaminant and pH data.

Geology & Source: Upper Missouri Basin, Cascade County — Cretaceous and Paleocene sandstones and shales rich in calcium and magnesium; Missouri River surface water and groundwater both pick up dissolved minerals, producing a hard supply

Other Montana Water Reports

Helena

≈ 0–60 mg/L

🟢 Soft

Bozeman

≈ 120–179 mg/L

🟠 Hard

Butte

≈ 120–179 mg/L

🟠 Hard

Missoula

≈ 120–179 mg/L

🟠 Hard

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Notice an error or missing data? Help us keep this page accurate. If you spot incorrect water hardness, outdated utility info, or missing details, please let us know.

All reports are reviewed by our team. Thank you for supporting data quality!

Frequently Asked Questions

Is Great Falls's water safe to drink?

Yes. Great Falls's water meets all federal safety standards. The hardness is ≈ 120–179 mg/L (Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.

Do I need a water softener in Great Falls?

At ≈ 120–179 mg/L (Hard), Great Falls's water will cause significant limescale on kettles, washing machines, and water heaters. A water softener or descaler is strongly recommended to extend appliance lifespan and reduce energy bills by up to 20%.

How does Great Falls compare to the USA average?

The USA national average is 151 mg/L. Great Falls (≈ 120–179 mg/L) is 1 mg/L below the national average. The softest major city is Scarsdale at just 0.02 mg/L.

Data Sources & Methodology

Water quality data for Great Falls is derived from geographic and geological modelling of the surrounding region. No federal monitoring station data was available for this location.

Estimated

Water Hardness

Modelled estimate based on state-level USGS geological survey data for this region. No direct USGS Water Quality Portal measurement was matched to this city — the value reflects a statistical range calibrated to the state's dominant rock types and typical source water characteristics.

Estimated

Estimated from regional geology and source water characteristics. pH is correlated with water hardness and local bedrock — values may differ from utility-reported figures.

Estimated

TDS — Total Dissolved Solids

Estimated using a derived ratio from water hardness and regional conductance profiles. TDS in natural water correlates strongly with total mineral content including hardness ions.

Measured

PFAS — Perfluoroalkyl and Polyfluoroalkyl Substances

EPA UCMR5 (5th Unregulated Contaminant Monitoring Rule, 2023–2025) — sum of PFAS compounds detected at the public water system serving this city. A value of 0 indicates the system was sampled with no detection above reporting limits.

Modelled

Lead

Modelled estimate based on the EPA Lead and Copper Rule 90th-percentile tap-sample methodology. No publicly available per-city lead dataset with sufficient national coverage exists. Values are a conservative baseline derived from city population tier and infrastructure age — all estimates are maintained below the EPA action level of 0.015 mg/L.

Calculated

Appliance Lifespan

Calculated from water hardness using a linear degradation model. Baseline lifespans represent soft-water performance (kettle: 8.5 yrs, washing machine: 12.0 yrs, water heater: 15.0 yrs). Hard water mineral scale progressively reduces operational life in direct proportion to hardness concentration.