Hard water in Lemont, IL

Tap water hardness
228mg/L
13.3gpg
Very hard

Reported by Lemont · May 2025

IL typical
139 mg/L
EPA health violations since 2016
2
Softener for 3 people
24k grain
Data
Utility report

Tap water in Lemont has about 228 mg/L of hardness, which is 13.3 grains per gallon. On the USGS scale that counts as very hard. The number comes from Lemont, dated May 2025.

Lemont on the hardness scale, with nearby cities
060120180240300360+IL typical 139Westmont: 127 mg/LWestmont 127Downers Grove: 131 mg/LDowners Grove 131Woodridge: 134 mg/LWoodridge 134Orland Park: 147 mg/LOrland Park 147Orland Hills: 147 mg/LOrland Hills 147Homer Glen: 287 mg/LHomer Glen 287Darien: 287 mg/LDarien 287Bolingbrook: 287 mg/LBolingbrook 287Romeoville: 303 mg/LRomeoville 303Lockport: 458 mg/LLockport 458Lemont 228mg/L as calcium carbonate060120180240300360+IL 139Woodridge: 134 mg/LWoodridge 134Homer Glen: 287 mg/LHomer Glen 287Darien: 287 mg/LDarien 287Bolingbrook: 287 mg/LBolingbrook 287Romeoville: 303 mg/LRomeoville 303Lockport: 458 mg/LLockport 458228 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Lemont sits 89 mg/L above the typical Illinois figure of 139. Of the 10 nearest cities we track, 5 have softer water and 5 have harder. The range nearby runs from 127 mg/L in Westmont to 458 in Lockport.

What 228 mg/L means at home

Scale forms fast here. Kettles and coffee makers need regular descaling, and showerheads clog unless you clean them.

Tank water heaters collect mineral sediment that insulates the water from the burner, so flushing the tank matters more than usual.

Dishes and glass shower doors spot easily. Soap scum and a dull film on hair or laundry are common complaints.

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

At 228 mg/L most of the trouble is scale, and only a few things deal with it.

Ion-exchange water softener

The standard whole-house fix. It swaps calcium and magnesium for sodium or potassium and needs salt plus a drain. Size it with the calculator below.

Salt-free conditioner

No salt and no drain line. It changes how minerals form scale instead of removing them, so water still tests hard.

Reverse osmosis or carbon filter

Under-sink reverse osmosis removes minerals from drinking water only. Plain carbon filters improve taste but do not soften.

Softener size for Lemont

3 people × 75 gallons a day × 13.3 gpg = 2,997 grains a day. A 24,000-grain unit regenerates about every 8 days.

Size it for your household

EPA record for Lemont's water system

Lemont · PWSID IL0311620

2 health-based violations since 2016

Serves about 18,513 people from groundwater.

Health-based
2
Monitoring or reporting
2
Open now
1
20162017201820192020202120222023202420252026Lead and Copper Rule'16'18'20'22'24'26Lead and Copper Rule
Each dot is one health-based violation, placed at the start of its compliance period.
Contaminant or ruleViolationsPeriodStatus
Lead and Copper Rulecorrosion control and lead sampling22025–20261 open

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 Lemont water hard?

Yes. It measures about 228 mg/L (13.3 grains per gallon), which the USGS classes as very hard.

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

About 13.3 gpg. One grain per gallon equals 17.1 mg/L, so 228 mg/L divided by 17.1 gives 13.3.

What size water softener do I need in Lemont?

For 3 people using 75 gallons each per day, 13.3 gpg works out to about 2,997 grains a day. A 24,000-grain softener covers that with a regeneration about every 8 days.

Has the Lemont water system had EPA violations?

EPA records show 2 health-based violations for Lemont since 2016, involving Lead and Copper Rule. 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, May 19, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.