Hard water in Lincolnshire, IL
Reported by LCPW - Pekara Subdivision · October 2025
- IL typical
- 139 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 48k grain
- Data
- Utility report
The water in Lincolnshire carries roughly 380 mg/L of dissolved calcium and magnesium, or 22.2 grains per gallon. That is very hard water. The number comes from LCPW - Pekara Subdivision, dated October 2025.
At 380 mg/L, Lincolnshire is 241 mg/L above the typical Illinois figure of 139. None of the 10 nearest cities we track has harder water. The range nearby runs from 115 mg/L in Arlington Heights to 250 in Vernon Hills.
What 380 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 380 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.
3 people × 75 gallons a day × 22.2 gpg = 5,000 grains a day. A 48,000-grain unit regenerates about every 9 days.
EPA record for Lincolnshire's water system
No health-based violations since 2016
Serves about 7,940 people from surface water.
- Health-based
- 0
- Monitoring or reporting
- 1
- Open now
- 1
EPA lists Lincolnshire as the system serving Lincolnshire. The hardness figure above comes from a different system's report, which TapWaterData uses for Lincolnshire.
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 Lincolnshire water hard?
Yes. It measures about 380 mg/L (22.2 grains per gallon), which the USGS classes as very hard.
What is the water hardness in Lincolnshire in grains per gallon?
About 22.2 gpg. One grain per gallon equals 17.1 mg/L, so 380 mg/L divided by 17.1 gives 22.2.
What size water softener do I need in Lincolnshire?
For 3 people using 75 gallons each per day, 22.2 gpg works out to about 5,000 grains a day. A 48,000-grain softener covers that with a regeneration about every 9 days.
Has the Lincolnshire water system had EPA violations?
EPA records show no health-based violations for Lincolnshire since 2016. There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.
Nearby cities
- Buffalo Grove154 mg/LHard
- Vernon Hills250 mg/LVery hard
- Deerfield135 mg/LHard
- Wheeling132 mg/LHard
- Highwood120 mg/LModerately hard
- Northbrook131 mg/LHard
- Libertyville250 mg/LVery hard
- Lake Bluff128 mg/LHard
- Mundelein250 mg/LVery hard
- Arlington Heights115 mg/LModerately hard
Hardness data: TapWaterData US Water Hardness (utility report, October 29, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.