How hard is the water in Rochester, MI?

Tap water hardness
104mg/L
6.1gpg
Moderately hard

Reported by Shelby Township · September 2025

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

Tap water in Rochester has about 104 mg/L of hardness, which is 6.1 grains per gallon. On the USGS scale that counts as moderately hard. The number comes from Shelby Township, dated September 2025.

Rochester on the hardness scale, with nearby cities
060120180240300360+MI typical 112Berkley: 85 mg/LBerkley 85Auburn Hills: 90 mg/LAuburn Hills 90Beverly Hills: 90 mg/LBeverly Hills 90Royal Oak: 96 mg/LRoyal Oak 96Rochester Hills: 100 mg/LRochester Hills 100Troy: 100 mg/LTroy 100Utica: 103 mg/LUtica 103Sterling Heights: 103 mg/LSterling Heights 103Pontiac: 121 mg/LPontiac 121Madison Heights: 277 mg/LMadison Heights 277Rochester 104mg/L as calcium carbonate060120180240300360+MI 112Auburn Hills: 90 mg/LAuburn Hil. 90Rochester Hills: 100 mg/LRochester. 100Troy: 100 mg/LTroy 100Utica: 103 mg/LUtica 103Sterling Heights: 103 mg/LSterling H. 103Pontiac: 121 mg/LPontiac 121104 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Rochester sits close to the typical Michigan figure of 112 mg/L. Of the 10 nearest cities we track, 8 have softer water and 2 have harder. The range nearby runs from 85 mg/L in Berkley to 277 in Madison Heights.

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 Rochester

3 people × 75 gallons a day × 6.1 gpg = 1,370 grains a day. A 24,000-grain unit regenerates about every 17 days.

Size it for your household

EPA record for Rochester's water system

Rochester · PWSID MI0005720

No health-based violations since 2016

Serves about 7,130 people from groundwater.

Health-based
0
Monitoring or reporting
0
Open now
0

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

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 Rochester 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 Rochester 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 Rochester?

For 3 people using 75 gallons each per day, 6.1 gpg works out to about 1,370 grains a day. A 24,000-grain softener covers that with a regeneration about every 17 days.

Has the Rochester water system had EPA violations?

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

Nearby cities

All 118 cities in Michigan

Hardness data: TapWaterData US Water Hardness (utility report, September 19, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.