Hard water in Exton, PA
Reported by Aqua PA Main System · October 2025
- PA typical
- 127 mg/L
- EPA health violations since 2016
- 2
- Softener for 3 people
- 24k grain
- Data
- Utility report
The water in Exton carries roughly 152 mg/L of dissolved calcium and magnesium, or 8.9 grains per gallon. That is hard water. The number comes from Aqua PA Main System, dated October 2025.
Exton sits 25 mg/L above the typical Pennsylvania figure of 127. Of the 10 nearest cities we track, 6 have softer water and 4 have harder. The range nearby runs from 125 mg/L in Audubon to 153 in Paoli.
What 152 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 152 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 × 8.9 gpg = 2,005 grains a day. A 24,000-grain unit regenerates about every 11 days.
EPA record for Exton's water system
2 health-based violations since 2016
Serves about 822,600 people from surface water.
- Health-based
- 2
- Monitoring or reporting
- 44
- Open now
- 0
TapWaterData ties Exton to this system. EPA's service-area records do not name Exton, so check the utility printed on your water bill.
| Contaminant or rule | Violations | Period | Status |
|---|---|---|---|
| Groundwater Ruletreatment of well water | 1 | 2024 | Resolved |
| Total Coliform Rulebacteria | 1 | 2017 | 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 Exton water hard?
Yes. It measures about 152 mg/L (8.9 grains per gallon), which the USGS classes as hard.
What is the water hardness in Exton in grains per gallon?
About 8.9 gpg. One grain per gallon equals 17.1 mg/L, so 152 mg/L divided by 17.1 gives 8.9.
What size water softener do I need in Exton?
For 3 people using 75 gallons each per day, 8.9 gpg works out to about 2,005 grains a day. A 24,000-grain softener covers that with a regeneration about every 11 days.
Has the Exton water system had EPA violations?
EPA records show 2 health-based violations for Aqua PA Main System since 2016, involving Groundwater Rule, Total Coliform Rule. There were also 44 monitoring or reporting violations, which are about late or missing tests and notices.
Nearby cities
- Lionville135 mg/LHard
- Downingtown135 mg/LHard
- West Chester133 mg/LHard
- Paoli153 mg/LHard
- Phoenixville153 mg/LHard
- Chesterbrook153 mg/LHard
- Wayne153 mg/LHard
- Audubon125 mg/LHard
- King of Prussia150 mg/LHard
- Trooper125 mg/LHard
All 172 cities in Pennsylvania
Hardness data: TapWaterData US Water Hardness (utility report, October 14, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.