How hard is the water in Highwood, IL?

Tap water hardness
120mg/L
7.0gpg
Moderately hardReports range 120–144

Reported by Highwood · November 2024

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

Highwood water measures 120 mg/L (7.0 gpg) of hardness, moderately hard by USGS standards. The number comes from Highwood, dated November 2024. Reports for this system disagree, with values from 120 to 144 mg/L.

Highwood on the hardness scale, with nearby cities
060120180240300360+IL typical 139Lake Bluff: 128 mg/LLake Bluff 128Northbrook: 131 mg/LNorthbrook 131Wheeling: 132 mg/LWheeling 132Deerfield: 135 mg/LDeerfield 135Winnetka: 135 mg/LWinnetka 135North Chicago: 136 mg/LNorth Chicago 136Buffalo Grove: 154 mg/LBuffalo Grove 154Glenview: 229 mg/LGlenview 229Vernon Hills: 250 mg/LVernon Hills 250Lincolnshire: 380 mg/LLincolnshire 380Highwood 120mg/L as calcium carbonate060120180240300360+IL 139Lake Bluff: 128 mg/LLake Bluff 128Northbrook: 131 mg/LNorthbrook 131Wheeling: 132 mg/LWheeling 132Deerfield: 135 mg/LDeerfield 135Winnetka: 135 mg/LWinnetka 135Lincolnshire: 380 mg/LLincolnshi. 380120 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 120 mg/L, Highwood is 19 mg/L below the typical Illinois figure of 139. None of the 10 nearest cities we track has softer water. The range nearby runs from 128 mg/L in Lake Bluff to 380 in Lincolnshire.

What 120 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 Highwood

3 people × 75 gallons a day × 7.0 gpg = 1,580 grains a day. A 24,000-grain unit regenerates about every 15 days.

Size it for your household

EPA record for Highwood's water system

Highwood · PWSID IL0970550

No health-based violations since 2016

Serves about 5,335 people from surface water.

Health-based
0
Monitoring or reporting
2
Open now
2

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 Highwood water hard?

Somewhat. It measures about 120 mg/L (7.0 grains per gallon), which the USGS classes as moderately hard.

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

About 7.0 gpg. One grain per gallon equals 17.1 mg/L, so 120 mg/L divided by 17.1 gives 7.0.

What size water softener do I need in Highwood?

For 3 people using 75 gallons each per day, 7.0 gpg works out to about 1,580 grains a day. A 24,000-grain softener covers that with a regeneration about every 15 days.

Has the Highwood water system had EPA violations?

EPA records show no health-based violations for Highwood since 2016. There were also 2 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 192 cities in Illinois

Hardness data: TapWaterData US Water Hardness (utility report, November 30, 2024), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.