How hard is the water in Plymouth, MI?

Tap water hardness
104mg/L
6.1gpg
Moderately hard

Reported by Canton Township · September 2025

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

Plymouth water measures 104 mg/L (6.1 gpg) of hardness, moderately hard by USGS standards. The number comes from Canton Township, dated September 2025.

Plymouth on the hardness scale, with nearby cities
060120180240300360+MI typical 112Livonia: 89 mg/LLivonia 89Wayne: 91 mg/LWayne 91Westland: 96 mg/LWestland 96Garden City: 104 mg/LGarden City 104Inkster: 104 mg/LInkster 104Dearborn Heights: 104 mg/LDearborn Heights 104Novi: 116 mg/LNovi 116Farmington Hills: 119 mg/LFarmington Hills 119Northville: 132 mg/LNorthville 132South Lyon: 460 mg/LSouth Lyon 460Plymouth 104mg/L as calcium carbonate060120180240300360+MI 112Livonia: 89 mg/LLivonia 89Wayne: 91 mg/LWayne 91Westland: 96 mg/LWestland 96Garden City: 104 mg/LGarden City 104Novi: 116 mg/LNovi 116Northville: 132 mg/LNorthville 132104 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 104 mg/L, Plymouth is close to the typical Michigan figure of 112 mg/L. Of the 10 nearest cities we track, 3 have softer water and 4 have harder. The range nearby runs from 89 mg/L in Livonia to 460 in South Lyon.

What 104 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 Plymouth

3 people × 75 gallons a day × 6.1 gpg = 1,375 grains a day. A 24,000-grain unit regenerates about every 17 days.

Size it for your household

EPA record for Plymouth's water system

Plymouth Township · PWSID MI0005420

No health-based violations since 2016

Serves about 27,524 people from surface water.

Health-based
0
Monitoring or reporting
0
Open now
0

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

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 Plymouth water hard?

Somewhat. It measures about 104 mg/L (6.1 grains per gallon), which the USGS classes as moderately hard.

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

About 6.1 gpg. One grain per gallon equals 17.1 mg/L, so 104 mg/L divided by 17.1 gives 6.1.

What size water softener do I need in Plymouth?

For 3 people using 75 gallons each per day, 6.1 gpg works out to about 1,375 grains a day. A 24,000-grain softener covers that with a regeneration about every 17 days.

Has the Plymouth water system had EPA violations?

EPA records show no health-based violations for Plymouth Township since 2016.

Nearby cities

All 118 cities in Michigan

Hardness data: TapWaterData US Water Hardness (utility report, September 8, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.