How hard is the water in Forest Hills, PA?

Tap water hardness
90mg/L
5.3gpg
Moderately hard

Reported by Wilkinsburg-Penn JT Water Auth · July 2025

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

The water in Forest Hills carries roughly 90 mg/L of dissolved calcium and magnesium, or 5.3 grains per gallon. That is moderately hard water. The number comes from Wilkinsburg-Penn JT Water Auth, dated July 2025.

Forest Hills on the hardness scale, with nearby cities
060120180240300360+PA typical 127Wilkinsburg: 90 mg/LWilkinsburg 90Swissvale: 90 mg/LSwissvale 90Oakmont: 90 mg/LOakmont 90Monroeville: 96 mg/LMonroeville 96Pittsburgh: 100 mg/LPittsburgh 100Munhall: 102 mg/LMunhall 102Duquesne: 102 mg/LDuquesne 102West Mifflin: 102 mg/LWest Mifflin 102Baldwin: 102 mg/LBaldwin 102Fox Chapel: 102 mg/LFox Chapel 102Forest Hills 90mg/L as calcium carbonate060120180240300360+PA 127Wilkinsburg: 90 mg/LWilkinsburg 90Swissvale: 90 mg/LSwissvale 90Monroeville: 96 mg/LMonroeville 96Munhall: 102 mg/LMunhall 102Duquesne: 102 mg/LDuquesne 102West Mifflin: 102 mg/LWest Miffl. 10290 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Forest Hills sits 37 mg/L below the typical Pennsylvania figure of 127. None of the 10 nearest cities we track has softer water. The range nearby runs from 90 mg/L in Wilkinsburg to 102 in Munhall.

What 90 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 Forest Hills

3 people × 75 gallons a day × 5.3 gpg = 1,186 grains a day. A 24,000-grain unit regenerates about every 20 days.

Size it for your household

EPA record for Forest Hills's water system

Wilkinsburg-Penn JT Water Auth · PWSID PA5020056

2 health-based violations since 2016

Serves about 125,000 people from surface water.

Health-based
2
Monitoring or reporting
31
Open now
0

TapWaterData ties Forest Hills to this system. EPA's service-area records do not name Forest Hills, so check the utility printed on your water bill.

20162017201820192020202120222023202420252026Total trihalomethanes (TTHM)'16'18'20'22'24'26Total trihalomethanes (TTHM)
Each dot is one health-based violation, placed at the start of its compliance period.
Contaminant or ruleViolationsPeriodStatus
Total trihalomethanes (TTHM)a disinfection byproduct22024–2026Resolved

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 Forest Hills water hard?

Somewhat. It measures about 90 mg/L (5.3 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Forest Hills in grains per gallon?

About 5.3 gpg. One grain per gallon equals 17.1 mg/L, so 90 mg/L divided by 17.1 gives 5.3.

What size water softener do I need in Forest Hills?

For 3 people using 75 gallons each per day, 5.3 gpg works out to about 1,186 grains a day. A 24,000-grain softener covers that with a regeneration about every 20 days.

Has the Forest Hills water system had EPA violations?

EPA records show 2 health-based violations for Wilkinsburg-Penn JT Water Auth since 2016, involving Total trihalomethanes (TTHM). There were also 31 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 172 cities in Pennsylvania

Hardness data: TapWaterData US Water Hardness (utility report, July 14, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.