Water Hardness in Montana (MT)
Montana has an average water hardness of 180 ppm (10.5 grains per gallon), which is classified as Moderately Hard . Water hardness at this level may cause noticeable scale buildup on fixtures and reduced soap lathering. Some Montana households choose to install a water softener or conditioner for improved water quality, though it is not strictly necessary. Water hardness varies between cities — from 75 ppm in Missoula to 250 ppm in Havre.
Water Hardness by City in Montana
The table below shows water hardness data for 8 cities in Montana, sorted from hardest to softest. Click any city name for detailed information including water source, treatment recommendations, and estimated hard water costs.
| City | Hardness (PPM) | Grains/Gallon | Level | Water Source | pH | TDS | Utility |
|---|---|---|---|---|---|---|---|
| Havre | 250 ppm | 14.6 gpg | Hard | Ground | 7.9 | 400 | City of Havre |
| Helena | 220 ppm | 12.9 gpg | Hard | Ground | 7.8 | 350 | City of Helena Public Works |
| Bozeman | 200 ppm | 11.7 gpg | Hard | Mixed | 7.7 | 320 | City of Bozeman Water and Sewer |
| Billings | 170 ppm | 9.9 gpg | Moderately Hard | Surface | 7.6 | 265 | City of Billings Public Utilities |
| Great Falls | 160 ppm | 9.4 gpg | Moderately Hard | Surface | 7.5 | 250 | City of Great Falls |
| Butte | 140 ppm | 8.2 gpg | Moderately Hard | Mixed | 7.5 | 220 | Butte-Silver Bow Water Utility |
| Kalispell | 110 ppm | 6.4 gpg | Slightly Hard | Ground | 7.3 | 170 | City of Kalispell |
| Missoula | 75 ppm | 4.4 gpg | Slightly Hard | Ground | 7.2 | 115 | Mountain Water Company |
Understanding Water Hardness in Montana
Water Sources in Montana
Many cities in Montana rely on groundwater from wells and aquifers as their primary water source. Groundwater tends to be harder than surface water because it spends more time in contact with limestone, dolomite, and other mineral-rich rock formations deep underground. This prolonged contact allows more calcium and magnesium to dissolve into the water, resulting in higher hardness levels.
Hardness Variation Across Montana
Water hardness in Montana ranges from 75 ppm in Missoula to 250 ppm in Havre — a difference of 175 ppm. This variation means that treatment recommendations differ significantly between cities. Residents of Havre and other cities with hard water should seriously consider installing a water softener to protect their homes. At 250 ppm, the annual cost of hard water damage to appliances, plumbing, and increased cleaning product usage can easily exceed $11. Missoula has the softest water in the state, though at 75 ppm it still contains some dissolved minerals.
Recommended Treatment for Montana Water
Based on the average water hardness of 180 ppm in Montana, a water softener is not strictly necessary, but some homeowners may prefer treated water. The most effective treatment options for Montana's water hardness level include:
- Salt-Based Water Softener ($800 - $2,500) — Removes hardness minerals. Highly effective.
- Salt-Free Water Conditioner ($1,000 - $3,000) — Conditions water without removing minerals. Moderately effective.
- Reverse Osmosis System ($200 - $500) — Removes hardness minerals. Highly effective.
- Electronic Descaler ($150 - $400) — Conditions water without removing minerals. Moderately effective.
How Montana Compares to Other States
Below is a comparison of Montana with five states that have similar average water hardness levels. Understanding how your state compares can help you gauge whether your water is typical for the region or unusually hard or soft.
| State | Avg Hardness | Level | Cities |
|---|---|---|---|
| Montana (MT) | 180 ppm | Moderately Hard | 8 |
| Colorado (CO) | 170 ppm | Moderately Hard | 9 |
| Idaho (ID) | 170 ppm | Moderately Hard | 8 |
| Oklahoma (OK) | 170 ppm | Moderately Hard | 8 |
| Wyoming (WY) | 190 ppm | Hard | 8 |
| California (CA) | 200 ppm | Hard | 11 |
Find Your City's Water Hardness
Use our water hardness lookup tool to find your specific city in Montana, or browse all 50 states to compare water hardness across the country. If your water is hard, visit our treatment solutions guide to find the right softener or conditioner for your home.