How hard is the water in River Rouge, MI?

Tap water hardness
96mg/L
5.6gpg
Moderately hard

Reported by Detroit City of · September 2025

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

The water in River Rouge carries roughly 96 mg/L of dissolved calcium and magnesium, or 5.6 grains per gallon. That is moderately hard water. The number comes from Detroit City of, dated September 2025.

River Rouge on the hardness scale, with nearby cities
060120180240300360+MI typical 112Hamtramck: 87 mg/LHamtramck 87Detroit: 96 mg/LDetroit 96Dearborn: 99 mg/LDearborn 99Taylor: 102 mg/LTaylor 102Ecorse: 104 mg/LEcorse 104Melvindale: 104 mg/LMelvindale 104Allen Park: 104 mg/LAllen Park 104Wyandotte: 105 mg/LWyandotte 105Riverview: 109 mg/LRiverview 109Lincoln Park: 128 mg/LLincoln Park 128River Rouge 96mg/L as calcium carbonate060120180240300360+MI 112Dearborn: 99 mg/LDearborn 99Ecorse: 104 mg/LEcorse 104Melvindale: 104 mg/LMelvindale 104Allen Park: 104 mg/LAllen Park 104Wyandotte: 105 mg/LWyandotte 105Lincoln Park: 128 mg/LLincoln Pa. 12896 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

River Rouge sits 16 mg/L below the typical Michigan figure of 112. Of the 10 nearest cities we track, 1 has softer water and 8 have harder. The range nearby runs from 87 mg/L in Hamtramck to 128 in Lincoln Park.

What 96 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 River Rouge

3 people × 75 gallons a day × 5.6 gpg = 1,262 grains a day. A 24,000-grain unit regenerates about every 19 days.

Size it for your household

EPA record for River Rouge's water system

River Rouge · PWSID MI0005690

1 health-based violation since 2016

Serves about 7,224 people from surface water.

Health-based
1
Monitoring or reporting
9
Open now
1

EPA lists River Rouge as the system serving River Rouge. The hardness figure above comes from a different system's report, which TapWaterData uses for River Rouge.

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 disinfection12023Resolved

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 River Rouge water hard?

Somewhat. It measures about 96 mg/L (5.6 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in River Rouge in grains per gallon?

About 5.6 gpg. One grain per gallon equals 17.1 mg/L, so 96 mg/L divided by 17.1 gives 5.6.

What size water softener do I need in River Rouge?

For 3 people using 75 gallons each per day, 5.6 gpg works out to about 1,262 grains a day. A 24,000-grain softener covers that with a regeneration about every 19 days.

Has the River Rouge water system had EPA violations?

EPA records show 1 health-based violation for River Rouge since 2016, involving Surface Water Treatment Rule. There were also 9 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.