Water Hardness in Missouri (MO)
Missouri has an average water hardness of 160 ppm (9.4 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 Missouri 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 120 ppm in Kansas City to 210 ppm in Columbia.
Water Hardness by City in Missouri
The table below shows water hardness data for 8 cities in Missouri, 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 |
|---|---|---|---|---|---|---|---|
| Columbia | 210 ppm | 12.3 gpg | Hard | Ground | 7.8 | 340 | City of Columbia Water and Light |
| Joplin | 190 ppm | 11.1 gpg | Hard | Ground | 7.7 | 305 | City of Joplin |
| Springfield | 180 ppm | 10.5 gpg | Moderately Hard | Ground | 7.7 | 280 | City Utilities of Springfield |
| Jefferson City | 170 ppm | 9.9 gpg | Moderately Hard | Surface | 7.6 | 265 | Jefferson City Water Department |
| St. Joseph | 155 ppm | 9.1 gpg | Moderately Hard | Surface | 7.5 | 245 | St. Joseph Water Department |
| St. Louis | 140 ppm | 8.2 gpg | Moderately Hard | Surface | 7.5 | 220 | Missouri American Water |
| Independence | 130 ppm | 7.6 gpg | Moderately Hard | Surface | 7.4 | 200 | City of Independence Water Pollution Control |
| Kansas City | 120 ppm | 7 gpg | Slightly Hard | Surface | 7.4 | 185 | Kansas City Water Services |
Understanding Water Hardness in Missouri
Water Sources in Missouri
The majority of cities in Missouri draw their water from surface sources such as rivers, lakes, and reservoirs. Surface water generally contains fewer dissolved minerals than groundwater, which helps explain the overall hardness profile of the state. Cities that rely on surface water tend to have softer water because the water has less contact time with mineral-bearing rock formations underground.
Hardness Variation Across Missouri
Water hardness in Missouri ranges from 120 ppm in Kansas City to 210 ppm in Columbia — a difference of 90 ppm. This variation means that treatment recommendations differ significantly between cities. Residents of Columbia and other cities with hard water should seriously consider installing a water softener to protect their homes. At 210 ppm, the annual cost of hard water damage to appliances, plumbing, and increased cleaning product usage can easily exceed $9. Kansas City has the softest water in the state, though at 120 ppm it still contains some dissolved minerals.
Recommended Treatment for Missouri Water
Based on the average water hardness of 160 ppm in Missouri, a water softener is not strictly necessary, but some homeowners may prefer treated water. The most effective treatment options for Missouri'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 Missouri Compares to Other States
Below is a comparison of Missouri 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 |
|---|---|---|---|
| Missouri (MO) | 160 ppm | Moderately Hard | 8 |
| Ohio (OH) | 160 ppm | Moderately Hard | 9 |
| Colorado (CO) | 170 ppm | Moderately Hard | 9 |
| Idaho (ID) | 170 ppm | Moderately Hard | 8 |
| Michigan (MI) | 150 ppm | Moderately Hard | 9 |
| Oklahoma (OK) | 170 ppm | Moderately Hard | 8 |
Find Your City's Water Hardness
Use our water hardness lookup tool to find your specific city in Missouri, 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.