Hard water in Park Forest, IL
Reported by Park Forest · August 2025
- IL typical
- 139 mg/L
- EPA health violations since 2016
- 1
- Softener for 3 people
- 24k grain
- Data
- Utility report
The water in Park Forest carries roughly 163 mg/L of dissolved calcium and magnesium, or 9.5 grains per gallon. That is hard water. The number comes from Park Forest, dated August 2025.
Park Forest sits 24 mg/L above the typical Illinois figure of 139. Of the 10 nearest cities we track, 4 have softer water and 6 have harder. The range nearby runs from 91 mg/L in Mokena to 558 in Monee.
What 163 mg/L means at home
Expect white crust on faucets and showerheads, plus spots on dishes that come out of the dishwasher.
Kettles collect scale quickly. Water heaters build up sediment at the bottom of the tank, which makes them work harder over time.
Soap and detergent need a little more to lather, and soap scum shows up in the tub.
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 163 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 × 9.5 gpg = 2,144 grains a day. A 24,000-grain unit regenerates about every 11 days.
EPA record for Park Forest's water system
1 health-based violation since 2016
Serves about 21,687 people from groundwater.
- Health-based
- 1
- Monitoring or reporting
- 32
- Open now
- 0
| Contaminant or rule | Violations | Period | Status |
|---|---|---|---|
| Total Coliform Rulebacteria | 1 | 2019 | Resolved |
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 Park Forest water hard?
Yes. It measures about 163 mg/L (9.5 grains per gallon), which the USGS classes as hard.
What is the water hardness in Park Forest in grains per gallon?
About 9.5 gpg. One grain per gallon equals 17.1 mg/L, so 163 mg/L divided by 17.1 gives 9.5.
What size water softener do I need in Park Forest?
For 3 people using 75 gallons each per day, 9.5 gpg works out to about 2,144 grains a day. A 24,000-grain softener covers that with a regeneration about every 11 days.
Has the Park Forest water system had EPA violations?
EPA records show 1 health-based violation for Park Forest since 2016, involving Total Coliform Rule. There were also 32 monitoring or reporting violations, which are about late or missing tests and notices.
Nearby cities
- Richton Park206 mg/LVery hard
- Chicago Heights229 mg/LVery hard
- Flossmoor146 mg/LHard
- Crete524 mg/LVery hard
- Homewood112 mg/LModerately hard
- Monee558 mg/LVery hard
- Tinley Park300 mg/LVery hard
- South Holland140 mg/LHard
- Frankfort287 mg/LVery hard
- Mokena91 mg/LModerately hard
Hardness data: TapWaterData US Water Hardness (utility report, August 20, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.