How hard is the water in Grosse Pointe, MI?

Tap water hardness
95mg/L
5.5gpg
Moderately hard

Reported by Detroit City of · September 2025

MI typical
112 mg/L
EPA health violations since 2016
0
Softener for 3 people
24k grain
Data
Utility report

The water in Grosse Pointe carries roughly 95 mg/L of dissolved calcium and magnesium, or 5.5 grains per gallon. That is moderately hard water. The number comes from Detroit City of, dated September 2025.

Grosse Pointe on the hardness scale, with nearby cities
060120180240300360+MI typical 112Hamtramck: 87 mg/LHamtramck 87Grosse Pointe Park: 95 mg/LGrosse Pointe Park 95Harper Woods: 95 mg/LHarper Woods 95Warren: 95 mg/LWarren 95Detroit: 96 mg/LDetroit 96St. Clair Shores: 101 mg/LSt. Clair Shores 101Roseville: 101 mg/LRoseville 101Fraser: 101 mg/LFraser 101Grosse Pointe Farms: 110 mg/LGrosse Pointe Farms 110Eastpointe: 266 mg/LEastpointe 266Grosse Pointe 95mg/L as calcium carbonate060120180240300360+MI 112Hamtramck: 87 mg/LHamtramck 87Grosse Pointe Park: 95 mg/LGrosse Poi. 95Harper Woods: 95 mg/LHarper Woo. 95St. Clair Shores: 101 mg/LSt. Clair. 101Grosse Pointe Farms: 110 mg/LGrosse Poi. 110Eastpointe: 266 mg/LEastpointe 26695 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 95 mg/L, Grosse Pointe is 17 mg/L below the typical Michigan figure of 112. Of the 10 nearest cities we track, 1 has softer water and 6 have harder. The range nearby runs from 87 mg/L in Hamtramck to 266 in Eastpointe.

What 95 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 Grosse Pointe

3 people × 75 gallons a day × 5.5 gpg = 1,249 grains a day. A 24,000-grain unit regenerates about every 19 days.

Size it for your household

EPA record for Grosse Pointe's water system

Grosse Pointe, City of · PWSID MI0002880

No health-based violations since 2016

Serves about 5,421 people from surface water.

Health-based
0
Monitoring or reporting
6
Open now
0

EPA lists Grosse Pointe, City of as the system serving Grosse Pointe. The hardness figure above comes from a different system's report, which TapWaterData uses for Grosse Pointe.

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 Grosse Pointe water hard?

Somewhat. It measures about 95 mg/L (5.5 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Grosse Pointe in grains per gallon?

About 5.5 gpg. One grain per gallon equals 17.1 mg/L, so 95 mg/L divided by 17.1 gives 5.5.

What size water softener do I need in Grosse Pointe?

For 3 people using 75 gallons each per day, 5.5 gpg works out to about 1,249 grains a day. A 24,000-grain softener covers that with a regeneration about every 19 days.

Has the Grosse Pointe water system had EPA violations?

EPA records show no health-based violations for Grosse Pointe, City of since 2016. There were also 6 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 118 cities in Michigan

Hardness data: TapWaterData US Water Hardness (utility report, September 3, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.