How hard is the water in Pittsburgh, PA?

Tap water hardness
100mg/L
5.8gpg
Moderately hard

Reported by PA Amer Water CO-Pittsburgh · October 2025

PA typical
127 mg/L
EPA health violations since 2016
1
Softener for 3 people
24k grain
Data
Utility report

The water in Pittsburgh carries roughly 100 mg/L of dissolved calcium and magnesium, or 5.8 grains per gallon. That is moderately hard water. The number comes from PA Amer Water CO-Pittsburgh, dated October 2025.

Pittsburgh on the hardness scale, with nearby cities
060120180240300360+PA typical 127McKees Rocks: 82 mg/LMcKees Rocks 82Swissvale: 90 mg/LSwissvale 90Wilkinsburg: 90 mg/LWilkinsburg 90Baldwin: 102 mg/LBaldwin 102Dormont: 102 mg/LDormont 102Brentwood: 102 mg/LBrentwood 102Crafton: 102 mg/LCrafton 102Munhall: 102 mg/LMunhall 102Whitehall: 102 mg/LWhitehall 102Castle Shannon: 102 mg/LCastle Shannon 102Pittsburgh 100mg/L as calcium carbonate060120180240300360+PA 127McKees Rocks: 82 mg/LMcKees Roc. 82Swissvale: 90 mg/LSwissvale 90Baldwin: 102 mg/LBaldwin 102Dormont: 102 mg/LDormont 102Brentwood: 102 mg/LBrentwood 102Crafton: 102 mg/LCrafton 102100 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

At 100 mg/L, Pittsburgh is 27 mg/L below the typical Pennsylvania figure of 127. Of the 10 nearest cities we track, 3 have softer water and 7 have harder. The range nearby runs from 82 mg/L in McKees Rocks to 102 in Baldwin.

What 100 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 Pittsburgh

3 people × 75 gallons a day × 5.8 gpg = 1,316 grains a day. A 24,000-grain unit regenerates about every 18 days.

Size it for your household

EPA record for Pittsburgh's water system

PA Amer Water CO-Pittsburgh · PWSID PA5020039

1 health-based violation since 2016

Serves about 686,000 people from surface water.

Health-based
1
Monitoring or reporting
2
Open now
0

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

20162017201820192020202120222023202420252026Surface Water Treatment Rule'16'18'20'22'24'26Surface Water Treatment Rule
Each dot is one health-based violation, placed at the start of its compliance period.
Contaminant or ruleViolationsPeriodStatus
Surface Water Treatment Rulefiltration and disinfection12017Resolved

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 Pittsburgh water hard?

Somewhat. It measures about 100 mg/L (5.8 grains per gallon), which the USGS classes as moderately hard.

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

About 5.8 gpg. One grain per gallon equals 17.1 mg/L, so 100 mg/L divided by 17.1 gives 5.8.

What size water softener do I need in Pittsburgh?

For 3 people using 75 gallons each per day, 5.8 gpg works out to about 1,316 grains a day. A 24,000-grain softener covers that with a regeneration about every 18 days.

Has the Pittsburgh water system had EPA violations?

EPA records show 1 health-based violation for PA Amer Water CO-Pittsburgh since 2016, involving Surface Water Treatment Rule. There were also 2 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, October 6, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.