Fort Collins, CO water hardness

Tap water hardness
42mg/L
2.5gpg
Soft

Reported by FT Collins City of · August 2025

CO typical
97 mg/L
EPA health violations since 2016
1
Data
Utility report

Tap water in Fort Collins has about 42 mg/L of hardness, which is 2.5 grains per gallon. On the USGS scale that counts as soft. The number comes from FT Collins City of, dated August 2025.

Fort Collins on the hardness scale, with nearby cities
060120180240300360+CO typical 97Longmont: 20 mg/LLongmont 20Loveland: 28 mg/LLoveland 28Windsor: 31 mg/LWindsor 31Berthoud: 36 mg/LBerthoud 36Mead: 36 mg/LMead 36Greeley: 37 mg/LGreeley 37Timnath: 41 mg/LTimnath 41Johnstown: 59 mg/LJohnstown 59Wellington: 218 mg/LWellington 218Evans: 415 mg/LEvans 415Fort Collins 42mg/L as calcium carbonate060120180240300360+CO 97Loveland: 28 mg/LLoveland 28Windsor: 31 mg/LWindsor 31Greeley: 37 mg/LGreeley 37Timnath: 41 mg/LTimnath 41Johnstown: 59 mg/LJohnstown 59Wellington: 218 mg/LWellington 21842 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Fort Collins sits 55 mg/L below the typical Colorado figure of 97. Of the 10 nearest cities we track, 7 have softer water and 3 have harder. The range nearby runs from 20 mg/L in Longmont to 415 in Evans.

What 42 mg/L means at home

Soap and shampoo lather with very little product. Kettles and showerheads stay mostly free of white crust.

Some people notice that soap feels slow to rinse off in soft water. That slippery feel is normal and harmless.

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

Nothing, as far as hardness goes. At 42 mg/L a softener would have almost nothing to remove.

Carbon filter

If the water tastes of chlorine, a pitcher or faucet carbon filter takes care of that. It does not change hardness.

EPA record for Fort Collins's water system

FT Collins City of · PWSID CO0135291

1 health-based violation since 2016

Serves about 179,901 people from surface water.

Health-based
1
Monitoring or reporting
14
Open now
0
20162017201820192020202120222023202420252026Surface Water Treatment Rule'16'18'20'22'24'26Surface Water Treatment Rule
Each dot is one health-based violation, placed at the start of its compliance period.
Contaminant or ruleViolationsPeriodStatus
Surface Water Treatment Rulefiltration and disinfection12017Resolved

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 Fort Collins water hard?

No. It measures about 42 mg/L (2.5 grains per gallon), which the USGS classes as soft.

What is the water hardness in Fort Collins in grains per gallon?

About 2.5 gpg. One grain per gallon equals 17.1 mg/L, so 42 mg/L divided by 17.1 gives 2.5.

Has the Fort Collins water system had EPA violations?

EPA records show 1 health-based violation for FT Collins City of since 2016, involving Surface Water Treatment Rule. There were also 14 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, August 27, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.