How hard is the water in Silverthorne, CO?

Tap water hardness
112mg/L
6.5gpg
Moderately hard

Reported by Silverthorne Town of · June 2025

CO typical
97 mg/L
EPA health violations since 2016
0
Softener for 3 people
24k grain
Data
Utility report

Tap water in Silverthorne has about 112 mg/L of hardness, which is 6.5 grains per gallon. On the USGS scale that counts as moderately hard. The number comes from Silverthorne Town of, dated June 2025.

Silverthorne on the hardness scale, with nearby cities
060120180240300360+CO typical 97Louisville: 32 mg/LLouisville 32Boulder: 41 mg/LBoulder 41Arvada: 93 mg/LArvada 93Wheat Ridge: 96 mg/LWheat Ridge 96Lakewood: 97 mg/LLakewood 97Littleton: 97 mg/LLittleton 97Westminster: 100 mg/LWestminster 100Sheridan: 101 mg/LSheridan 101Aspen: 168 mg/LAspen 168Eagle: 226 mg/LEagle 226Silverthorne 112mg/L as calcium carbonate060120180240300360+CO 97Boulder: 41 mg/LBoulder 41Arvada: 93 mg/LArvada 93Wheat Ridge: 96 mg/LWheat Ridge 96Lakewood: 97 mg/LLakewood 97Aspen: 168 mg/LAspen 168Eagle: 226 mg/LEagle 226112 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Silverthorne sits 15 mg/L above the typical Colorado figure of 97. Of the 10 nearest cities we track, 8 have softer water and 2 have harder. The range nearby runs from 32 mg/L in Louisville to 226 in Eagle.

What 112 mg/L means at home

You may see faint white spots on glasses and shower doors after the water dries.

Scale builds up slowly. A kettle or coffee maker needs descaling now and then, maybe every few months.

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

Optional. Plenty of households at this level live with it and descale the kettle now and then.

Water softener

Worth a look if spots on glass bother you, or if your tankless water heater manual asks for softer water.

Carbon filter

Improves taste and removes chlorine. It leaves calcium and magnesium in place.

Softener size for Silverthorne

3 people × 75 gallons a day × 6.5 gpg = 1,469 grains a day. A 24,000-grain unit regenerates about every 16 days.

Size it for your household

EPA record for Silverthorne's water system

Silverthorne Town of · PWSID CO0159095

No health-based violations since 2016

Serves about 8,400 people from groundwater.

Health-based
0
Monitoring or reporting
4
Open now
0

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 Silverthorne water hard?

Somewhat. It measures about 112 mg/L (6.5 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Silverthorne in grains per gallon?

About 6.5 gpg. One grain per gallon equals 17.1 mg/L, so 112 mg/L divided by 17.1 gives 6.5.

What size water softener do I need in Silverthorne?

For 3 people using 75 gallons each per day, 6.5 gpg works out to about 1,469 grains a day. A 24,000-grain softener covers that with a regeneration about every 16 days.

Has the Silverthorne water system had EPA violations?

EPA records show no health-based violations for Silverthorne Town of since 2016. There were also 4 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 64 cities in Colorado

Hardness data: TapWaterData US Water Hardness (utility report, June 12, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.