Water Quality in Great Falls, MT

Great Falls's water quality is good overall. Hardness is low at 71 PPM, and no contaminants exceed health guidelines. Most homes here do not need a water softener.

City of Great Falls · Source: Missouri River · Serves 60,442 residents

71
Hardness (PPM)
94
TDS (PPM)
0.7
Chlorine (mg/L)
2
PFAS (ppt)
2
Lead (ppb)
71 PPM 0 400 Moderately Hard
CONTAMINANT LEVELS Hardness 71 PPM TDS 94 PPM PFAS 2 ppt Lead 2 ppb Chlorine 0.7 mg/L Nitrate 3 mg/L

Hardness Scale: Where Great Falls Falls

Soft 060120180250400+
Generally good quality

Great Falls draws from the Missouri River near the Great Falls. Mountain-sourced water is moderately soft.

What Great Falls's Water Means for Your Home

Great Falls's water is moderately hard at 71 PPM. At this level, hard water is not a significant concern for most households. Scale buildup is minimal, and a water softener would provide little measurable benefit. If you are considering water treatment in Great Falls, focus on contaminant filtration rather than softening.

Beyond hardness, Great Falls's water quality is generally within EPA guidelines for regulated contaminants. Chlorine is present at 0.7 mg/L as a disinfectant residual, which is normal for municipal water systems. If you notice a pool-like taste or experience dry skin, a whole-house carbon filter is the most common and affordable solution. For homeowners who want to understand the full picture, requesting your utility's annual Consumer Confidence Report provides neighborhood-level data.

ContaminantDetectedHealth GuidelineLegal LimitStatus
Hardness (as CaCO₃)71 PPM< 60 PPMNo federal limit✓ OK
Total Dissolved Solids94 PPM< 300 PPM500 PPM✓ OK
PFAS (total)2 ppt4 ppt (EPA)4 ppt (2024)✓ OK
Lead2 ppb0 ppb (no safe level)15 ppb (action level)✓ Low
Chlorine / Chloramine0.7 mg/LTaste threshold ~1.04.0 mg/L✓ Normal
Nitrate3 mg/L5 mg/L10 mg/L✓ OK

Recommendations for Great Falls Homes

🔄 Salt-Free Conditioner (Optional)
At 71 PPM, Great Falls's water is moderately hard. Scale buildup is slow but noticeable over years, especially in tankless water heaters. A salt-free conditioner is a low-maintenance option if you want to extend appliance life.
Learn more about this solution →

About Great Falls's Water Supply

Water Utility: City of Great Falls

Water Source: Missouri River

Population Served: 60,442

Hardness: 71 PPM (4.2 grains per gallon)

Water quality can vary by neighborhood and season. The values above represent typical averages reported by City of Great Falls. To get exact numbers for your address, request a copy of the most recent Consumer Confidence Report (CCR) from your utility, or have your water independently tested.

Compare Great Falls to Other Montana Cities

Billings

65 PPM · Moderately Hard

Missoula

16 PPM · Soft

Bozeman

79 PPM · Moderately Hard

Helena

160 PPM · Hard

Frequently Asked Questions About Great Falls Water

Is Great Falls tap water safe to drink?
Great Falls's water meets EPA legal standards for drinking water safety. However, legal limits and health-optimal levels are different things. Review the contaminant table above for specific numbers and how they compare to both legal limits and health guidelines.
Do I need a water softener in Great Falls?
At 71 PPM, Great Falls's water is moderately hard. Some homeowners at this level do not notice problems, while others see spotting on glassware, film on shower doors, or reduced soap lathering. Homes with tankless water heaters at this hardness level should strongly consider at least a salt-free conditioner, as scale buildup inside the heat exchanger can void the warranty. For other homes, it depends on your sensitivity and fixtures.
What water filter is best for Great Falls?
The best filter depends on which contaminants you want to address. See our softener vs. filter guide to understand the difference between these categories.
Where does Great Falls's water come from?
Great Falls's drinking water is sourced from Missouri River and treated by City of Great Falls. Great Falls draws from the Missouri River near the Great Falls. Mountain-sourced water is moderately soft.
What is the hardness of Great Falls water in grains per gallon?
Great Falls's water hardness is 4.2 grains per gallon (GPG), which equals 71 parts per million (PPM). This is classified as moderately hard. To convert: 1 GPG = 17.1 PPM.
Does Great Falls water damage tankless water heaters?
At 4.2 GPG, Great Falls's water is unlikely to cause significant issues for tankless water heaters. However, if you notice reduced flow or efficiency over time, scale buildup could be a factor. Annual flushing with vinegar is good maintenance regardless of hardness.
Is Great Falls water safe for babies and infants?
Great Falls's water meets all EPA safety standards and is generally considered safe for preparing infant formula. The hardness minerals (calcium and magnesium) are not harmful. If your home has older plumbing, running cold water for 30 seconds before use is a good precaution to flush any lead from pipes.

Data sources. Water quality data compiled from EPA SDWIS, EWG Tap Water Database, USGS water hardness studies, and the City of Great Falls Consumer Confidence Report. Hardness and contaminant levels represent typical average values and may vary by neighborhood and season. Last updated: 2026-02-12.