How hard is the water in Lafayette, CO?

Tap water hardness
91mg/L
5.3gpg
Moderately hard

Reported by Lafayette City of · July 2025

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

The water in Lafayette carries roughly 91 mg/L of dissolved calcium and magnesium, or 5.3 grains per gallon. That is moderately hard water. The number comes from Lafayette City of, dated July 2025.

Lafayette on the hardness scale, with nearby cities
060120180240300360+CO typical 97Louisville: 32 mg/LLouisville 32Erie: 33 mg/LErie 33Boulder: 41 mg/LBoulder 41Broomfield: 46 mg/LBroomfield 46Arvada: 93 mg/LArvada 93Thornton: 98 mg/LThornton 98Westminster: 100 mg/LWestminster 100Northglenn: 118 mg/LNorthglenn 118Federal Heights: 119 mg/LFederal Heights 119Shaw Heights: 127 mg/LShaw Heights 127Lafayette 91mg/L as calcium carbonate060120180240300360+CO 97Louisville: 32 mg/LLouisville 32Erie: 33 mg/LErie 33Boulder: 41 mg/LBoulder 41Broomfield: 46 mg/LBroomfield 46Westminster: 100 mg/LWestminster 100Northglenn: 118 mg/LNorthglenn 11891 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

At 91 mg/L, Lafayette is close to the typical Colorado figure of 97 mg/L. Of the 10 nearest cities we track, 4 have softer water and 6 have harder. The range nearby runs from 32 mg/L in Louisville to 127 in Shaw Heights.

What 91 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 Lafayette

3 people × 75 gallons a day × 5.3 gpg = 1,199 grains a day. A 24,000-grain unit regenerates about every 20 days.

Size it for your household

EPA record for Lafayette's water system

Lafayette City of · PWSID CO0107473

No health-based violations since 2016

Serves about 28,700 people from surface water.

Health-based
0
Monitoring or reporting
24
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 Lafayette water hard?

Somewhat. It measures about 91 mg/L (5.3 grains per gallon), which the USGS classes as moderately hard.

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

About 5.3 gpg. One grain per gallon equals 17.1 mg/L, so 91 mg/L divided by 17.1 gives 5.3.

What size water softener do I need in Lafayette?

For 3 people using 75 gallons each per day, 5.3 gpg works out to about 1,199 grains a day. A 24,000-grain softener covers that with a regeneration about every 20 days.

Has the Lafayette water system had EPA violations?

EPA records show no health-based violations for Lafayette City of since 2016. There were also 24 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, July 23, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.