How hard is the water in Auburn Hills, MI?

Tap water hardness
90mg/L
5.3gpg
Moderately hard

Reported by Bloomfield Township · October 2025

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

Auburn Hills water measures 90 mg/L (5.3 gpg) of hardness, moderately hard by USGS standards. The number comes from Bloomfield Township, dated October 2025.

Auburn Hills on the hardness scale, with nearby cities
060120180240300360+MI typical 112Berkley: 85 mg/LBerkley 85Beverly 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 103Rochester: 104 mg/LRochester 104Pontiac: 121 mg/LPontiac 121Madison Heights: 277 mg/LMadison Heights 277Auburn Hills 90mg/L as calcium carbonate060120180240300360+MI 112Beverly Hills: 90 mg/LBeverly Hi. 90Rochester Hills: 100 mg/LRochester. 100Troy: 100 mg/LTroy 100Utica: 103 mg/LUtica 103Rochester: 104 mg/LRochester 104Pontiac: 121 mg/LPontiac 12190 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Auburn Hills sits 22 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 85 mg/L in Berkley to 277 in Madison Heights.

What 90 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 Auburn Hills

3 people × 75 gallons a day × 5.3 gpg = 1,188 grains a day. A 24,000-grain unit regenerates about every 20 days.

Size it for your household

EPA record for Auburn Hills's water system

Auburn Hills · PWSID MI0005450

No health-based violations since 2016

Serves about 21,412 people from surface water.

Health-based
0
Monitoring or reporting
5
Open now
0

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

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 Auburn Hills water hard?

Somewhat. It measures about 90 mg/L (5.3 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Auburn Hills in grains per gallon?

About 5.3 gpg. One grain per gallon equals 17.1 mg/L, so 90 mg/L divided by 17.1 gives 5.3.

What size water softener do I need in Auburn Hills?

For 3 people using 75 gallons each per day, 5.3 gpg works out to about 1,188 grains a day. A 24,000-grain softener covers that with a regeneration about every 20 days.

Has the Auburn Hills water system had EPA violations?

EPA records show no health-based violations for Auburn Hills since 2016. There were also 5 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 7, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.