How hard is the water in Four Square Mile, CO?

Tap water hardness
96mg/L
5.6gpg
Moderately hard

Reported by Denver Water Board · October 2025

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

Four Square Mile water measures 96 mg/L (5.6 gpg) of hardness, moderately hard by USGS standards. The number comes from Denver Water Board, dated October 2025.

Four Square Mile on the hardness scale, with nearby cities
060120180240300360+CO typical 97Cherry Hills Village: 96 mg/LCherry Hills Village 96Greenwood Village: 96 mg/LGreenwood Village 96Cherry Creek: 96 mg/LCherry Creek 96Centennial: 96 mg/LCentennial 96Dove Valley: 96 mg/LDove Valley 96Denver: 97 mg/LDenver 97Littleton: 97 mg/LLittleton 97Aurora: 100 mg/LAurora 100Englewood: 101 mg/LEnglewood 101Sheridan: 101 mg/LSheridan 101Four Square Mile 96mg/L as calcium carbonate060120180240300360+CO 97Cherry Hills Village: 96 mg/LCherry Hil. 96Greenwood Village: 96 mg/LGreenwood. 96Cherry Creek: 96 mg/LCherry Cre. 96Centennial: 96 mg/LCentennial 96Denver: 97 mg/LDenver 97Englewood: 101 mg/LEnglewood 10196 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 96 mg/L, Four Square Mile is close to the typical Colorado figure of 97 mg/L. None of the 10 nearest cities we track has softer water. The range nearby runs from 96 mg/L in Cherry Hills Village to 101 in Englewood.

What 96 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 Four Square Mile

3 people × 75 gallons a day × 5.6 gpg = 1,267 grains a day. A 24,000-grain unit regenerates about every 18 days.

Size it for your household

EPA record for Four Square Mile's water system

Denver Water Board · PWSID CO0116001

No health-based violations since 2016

Serves about 1,287,000 people from surface water.

Health-based
0
Monitoring or reporting
35
Open now
0

TapWaterData ties Four Square Mile to this system. EPA's service-area records do not name Four Square Mile, so check the utility printed on your water bill.

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 Four Square Mile water hard?

Somewhat. It measures about 96 mg/L (5.6 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Four Square Mile in grains per gallon?

About 5.6 gpg. One grain per gallon equals 17.1 mg/L, so 96 mg/L divided by 17.1 gives 5.6.

What size water softener do I need in Four Square Mile?

For 3 people using 75 gallons each per day, 5.6 gpg works out to about 1,267 grains a day. A 24,000-grain softener covers that with a regeneration about every 18 days.

Has the Four Square Mile water system had EPA violations?

EPA records show no health-based violations for Denver Water Board since 2016. There were also 35 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, October 7, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.