Hard water in Gillette, WY
County estimate from 1,144 water samples in Campbell County · July 2026
- WY typical
- 191 mg/L
- EPA health violations since 2016
- 0
- Data
- County estimate
Water samples from around Gillette put hardness at about 926 mg/L (54.1 gpg), which would be very hard on the USGS scale. Treat this as a rough guide: it is the median of 1,144 samples taken across Campbell County, mostly wells and streams, not a test of Gillette's treated tap water.
Gillette sits 735 mg/L above the typical Wyoming figure of 191. None of the 5 nearest cities we track has harder water. The range nearby runs from 27 mg/L in Sheridan to 327 in Casper.
What 926 mg/L means at home
Scale forms fast here. Kettles and coffee makers need regular descaling, and showerheads clog unless you clean them.
Tank water heaters collect mineral sediment that insulates the water from the burner, so flushing the tank matters more than usual.
Dishes and glass shower doors spot easily. Soap scum and a dull film on hair or laundry are common complaints.
Hardness is not a health problem, and EPA sets no limit for it. It is a matter of scale and soap.
What to do about it
At 926 mg/L most of the trouble is scale, and only a few things deal with it.
Ion-exchange water softener
The standard whole-house fix. It swaps calcium and magnesium for sodium or potassium and needs salt plus a drain. Size it with the calculator below.
Salt-free conditioner
No salt and no drain line. It changes how minerals form scale instead of removing them, so water still tests hard.
Reverse osmosis or carbon filter
Under-sink reverse osmosis removes minerals from drinking water only. Plain carbon filters improve taste but do not soften.
EPA record for Gillette's water system
No health-based violations since 2016
Serves about 32,222 people from groundwater.
- Health-based
- 0
- Monitoring or reporting
- 2
- Open now
- 0
EPA lists this system as serving Gillette.
Health-based means a contaminant above its legal limit or a missed treatment step. Monitoring and reporting violations are late or missing tests and notices. Source: EPA ECHO, 2026Q3 export, violations with periods starting 2016 or later. Full EPA record.
Questions
Is Gillette water hard?
Yes. It measures about 926 mg/L (54.1 grains per gallon), which the USGS classes as very hard.
What is the water hardness in Gillette in grains per gallon?
About 54.1 gpg. One grain per gallon equals 17.1 mg/L, so 926 mg/L divided by 17.1 gives 54.1.
Has the Gillette water system had EPA violations?
EPA records show no health-based violations for Gillette, City of since 2016. There were also 2 monitoring or reporting violations, which are about late or missing tests and notices.
Nearby cities
- Sheridan27 mg/LSoft
- Casper327 mg/LVery hard
- Cheyenne49 mg/LSoft
- Rock Springs210 mg/LVery hard
- Jackson163 mg/LHard
Hardness data: TapWaterData US Water Hardness (county estimate, July 4, 2026), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.