Water Hardness in Wyoming (WY)

Wyoming has an average water hardness of 190 ppm (11.1 grains per gallon), which is classified as Hard . Most households in Wyoming would benefit from a water softener to protect plumbing and appliances from mineral scale buildup. The estimated annual cost of untreated hard water for Wyoming households is approximately $8 per year in extra energy, cleaning products, and premature appliance wear. Water hardness varies between cities — from 125 ppm in Cheyenne to 280 ppm in Gillette.

State Average 190 ppm 11.1 gpg
Hardness Level Hard Softener recommended
Hardest City Gillette 280 ppm
Softest City Cheyenne 125 ppm

Water Hardness by City in Wyoming

The table below shows water hardness data for 8 cities in Wyoming, 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
Gillette 280 ppm 16.4 gpg Very Hard Ground 8 450 City of Gillette
Rock Springs 240 ppm 14 gpg Hard Ground 7.9 385 City of Rock Springs
Riverton 220 ppm 12.9 gpg Hard Ground 7.8 350 City of Riverton
Sheridan 200 ppm 11.7 gpg Hard Mixed 7.7 320 City of Sheridan
Casper 180 ppm 10.5 gpg Moderately Hard Surface 7.6 280 City of Casper
Cody 165 ppm 9.6 gpg Moderately Hard Surface 7.5 260 City of Cody
Laramie 150 ppm 8.8 gpg Moderately Hard Mixed 7.5 235 City of Laramie
Cheyenne 125 ppm 7.3 gpg Moderately Hard Mixed 7.4 192 Cheyenne Board of Public Utilities
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Understanding Water Hardness in Wyoming

Water Sources in Wyoming

Many cities in Wyoming 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 Wyoming

Water hardness in Wyoming ranges from 125 ppm in Cheyenne to 280 ppm in Gillette — a difference of 155 ppm. This variation means that treatment recommendations differ significantly between cities. Residents of Gillette and other cities with hard water should seriously consider installing a water softener to protect their homes. At 280 ppm, the annual cost of hard water damage to appliances, plumbing, and increased cleaning product usage can easily exceed $12. Cheyenne has the softest water in the state, though at 125 ppm it still contains some dissolved minerals.

Recommended Treatment for Wyoming Water

Based on the average water hardness of 190 ppm in Wyoming, a water softener is recommended for most households. The most effective treatment options for Wyoming's water hardness level include:

How Wyoming Compares to Other States

Below is a comparison of Wyoming 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
Wyoming (WY) 190 ppm Hard 8
California (CA) 200 ppm Hard 11
Illinois (IL) 200 ppm Hard 10
Montana (MT) 180 ppm Moderately Hard 8
Colorado (CO) 170 ppm Moderately Hard 9
Idaho (ID) 170 ppm Moderately Hard 8

Find Your City's Water Hardness

Use our water hardness lookup tool to find your specific city in Wyoming, 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.