How hard is the water in Erie, PA?

Tap water hardness
91mg/L
5.3gpg
Moderately hard

Reported by Erie City Water Authority · December 2023

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

The water in Erie carries roughly 91 mg/L of dissolved calcium and magnesium, or 5.3 grains per gallon. That is moderately hard water. The number comes from Erie City Water Authority, dated December 2023.

Erie on the hardness scale, with nearby cities
060120180240300360+PA typical 127Treasure Lake: 26 mg/LTreasure Lake 26Franklin Park: 82 mg/LFranklin Park 82West View: 82 mg/LWest View 82Allison Park: 88 mg/LAllison Park 88Glenshaw: 88 mg/LGlenshaw 88Oakmont: 90 mg/LOakmont 90Northwest Harborcreek: 91 mg/LNorthwest Harborcreek 91Fox Chapel: 102 mg/LFox Chapel 102New Castle: 166 mg/LNew Castle 166Ellwood City: 166 mg/LEllwood City 166Erie 91mg/L as calcium carbonate060120180240300360+PA 127Treasure Lake: 26 mg/LTreasure L. 26Franklin Park: 82 mg/LFranklin P. 82Allison Park: 88 mg/LAllison Pa. 88Northwest Harborcreek: 91 mg/LNorthwest. 91New Castle: 166 mg/LNew Castle 166Ellwood City: 166 mg/LEllwood Ci. 16691 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 91 mg/L, Erie is 36 mg/L below the typical Pennsylvania figure of 127. Of the 10 nearest cities we track, 6 have softer water and 3 have harder. The range nearby runs from 26 mg/L in Treasure Lake to 166 in New Castle.

What 91 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 Erie

3 people × 75 gallons a day × 5.3 gpg = 1,197 grains a day. A 24,000-grain unit regenerates about every 20 days.

Size it for your household

EPA record for Erie's water system

Erie City Water Authority · PWSID PA6250028

2 health-based violations since 2016

Serves about 220,001 people from surface water.

Health-based
2
Monitoring or reporting
21
Open now
0
20162017201820192020202120222023202420252026Surface Water Treatment RuleTotal trihalomethanes (TTHM)'16'18'20'22'24'26Surface Water Treatment RuleTotal trihalomethanes (TTHM)
Each dot is one health-based violation, placed at the start of its compliance period.
Contaminant or ruleViolationsPeriodStatus
Surface Water Treatment Rulefiltration and disinfection12018Resolved
Total trihalomethanes (TTHM)a disinfection byproduct12017Resolved

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 Erie water hard?

Somewhat. It measures about 91 mg/L (5.3 grains per gallon), which the USGS classes as moderately hard.

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

About 5.3 gpg. One grain per gallon equals 17.1 mg/L, so 91 mg/L divided by 17.1 gives 5.3.

What size water softener do I need in Erie?

For 3 people using 75 gallons each per day, 5.3 gpg works out to about 1,197 grains a day. A 24,000-grain softener covers that with a regeneration about every 20 days.

Has the Erie water system had EPA violations?

EPA records show 2 health-based violations for Erie City Water Authority since 2016, involving Surface Water Treatment Rule, Total trihalomethanes (TTHM). There were also 21 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, December 7, 2023), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.