How hard is the water in Ferndale, MI?

Tap water hardness
100mg/L
5.8gpg
Moderately hard

Reported by Ferndale · October 2025

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

The water in Ferndale 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 Ferndale, dated October 2025.

Ferndale on the hardness scale, with nearby cities
060120180240300360+MI typical 112Berkley: 85 mg/LBerkley 85Hamtramck: 87 mg/LHamtramck 87Beverly Hills: 90 mg/LBeverly Hills 90Warren: 95 mg/LWarren 95Royal Oak: 96 mg/LRoyal Oak 96Detroit: 96 mg/LDetroit 96Troy: 100 mg/LTroy 100Eastpointe: 266 mg/LEastpointe 266Oak Park: 277 mg/LOak Park 277Madison Heights: 277 mg/LMadison Heights 277Ferndale 100mg/L as calcium carbonate060120180240300360+MI 112Berkley: 85 mg/LBerkley 85Hamtramck: 87 mg/LHamtramck 87Royal Oak: 96 mg/LRoyal Oak 96Detroit: 96 mg/LDetroit 96Oak Park: 277 mg/LOak Park 277Madison Heights: 277 mg/LMadison He. 277100 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Ferndale sits 12 mg/L below the typical Michigan figure of 112. Of the 10 nearest cities we track, 6 have softer water and 3 have harder. The range nearby runs from 85 mg/L in Berkley to 277 in Oak Park.

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 Ferndale

3 people × 75 gallons a day × 5.8 gpg = 1,310 grains a day. A 24,000-grain unit regenerates about every 18 days.

Size it for your household

EPA record for Ferndale's water system

Ferndale · PWSID MI0002280

1 health-based violation since 2016

Serves about 22,105 people from surface water.

Health-based
1
Monitoring or reporting
2
Open now
0
20162017201820192020202120222023202420252026Lead and Copper Rule'16'18'20'22'24'26Lead and Copper Rule
Each dot is one health-based violation, placed at the start of its compliance period.
Contaminant or ruleViolationsPeriodStatus
Lead and Copper Rulecorrosion control and lead sampling12020Resolved

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 Ferndale 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 Ferndale 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 Ferndale?

For 3 people using 75 gallons each per day, 5.8 gpg works out to about 1,310 grains a day. A 24,000-grain softener covers that with a regeneration about every 18 days.

Has the Ferndale water system had EPA violations?

EPA records show 1 health-based violation for Ferndale since 2016, involving Lead and Copper Rule. There were also 2 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, October 20, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.