How hard is the water in Northglenn, CO?

Tap water hardness
118mg/L
6.9gpg
Moderately hard

Reported by Thornton 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 Northglenn carries roughly 118 mg/L of dissolved calcium and magnesium, or 6.9 grains per gallon. That is moderately hard water. The number comes from Thornton City of, dated July 2025.

Northglenn on the hardness scale, with nearby cities
060120180240300360+CO typical 97Broomfield: 46 mg/LBroomfield 46Derby: 79 mg/LDerby 79Welby: 96 mg/LWelby 96Berkley: 96 mg/LBerkley 96Thornton: 98 mg/LThornton 98Twin Lakes: 99 mg/LTwin Lakes 99Westminster: 100 mg/LWestminster 100Sherrelwood: 100 mg/LSherrelwood 100Federal Heights: 119 mg/LFederal Heights 119Shaw Heights: 127 mg/LShaw Heights 127Northglenn 118mg/L as calcium carbonate060120180240300360+CO 97Broomfield: 46 mg/LBroomfield 46Welby: 96 mg/LWelby 96Thornton: 98 mg/LThornton 98Westminster: 100 mg/LWestminster 100Federal Heights: 119 mg/LFederal He. 119Shaw Heights: 127 mg/LShaw Heigh. 127118 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 118 mg/L, Northglenn is 21 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 46 mg/L in Broomfield to 127 in Shaw Heights.

What 118 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 Northglenn

3 people × 75 gallons a day × 6.9 gpg = 1,553 grains a day. A 24,000-grain unit regenerates about every 15 days.

Size it for your household

EPA record for Northglenn's water system

Northglenn City of · PWSID CO0101115

No health-based violations since 2016

Serves about 48,927 people from surface water.

Health-based
0
Monitoring or reporting
0
Open now
0

EPA lists Northglenn City of as the system serving Northglenn. The hardness figure above comes from a different system's report, which TapWaterData uses for Northglenn.

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 Northglenn water hard?

Somewhat. It measures about 118 mg/L (6.9 grains per gallon), which the USGS classes as moderately hard.

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

About 6.9 gpg. One grain per gallon equals 17.1 mg/L, so 118 mg/L divided by 17.1 gives 6.9.

What size water softener do I need in Northglenn?

For 3 people using 75 gallons each per day, 6.9 gpg works out to about 1,553 grains a day. A 24,000-grain softener covers that with a regeneration about every 15 days.

Has the Northglenn water system had EPA violations?

EPA records show no health-based violations for Northglenn City of since 2016.

Nearby cities

All 64 cities in Colorado

Hardness data: TapWaterData US Water Hardness (utility report, July 2, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.