Hard water in Mayville, WI

Tap water hardness
324mg/L
18.9gpg
Very hard

Reported by Mayville Waterworks · August 2022

WI typical
170 mg/L
EPA health violations since 2016
0
Softener for 3 people
32k grain
Data
Utility report

Mayville water measures 324 mg/L (18.9 gpg) of hardness, very hard by USGS standards. The number comes from Mayville Waterworks, dated August 2022.

Mayville on the hardness scale, with nearby cities
060120180240300360+WI typical 170Columbus: 144 mg/LColumbus 144Fond du Lac: 170 mg/LFond du Lac 170Watertown: 249 mg/LWatertown 249Oconomowoc: 310 mg/LOconomowoc 310Lisbon: 332 mg/LLisbon 332West Bend: 340 mg/LWest Bend 340Jackson: 352 mg/LJackson 352Hartford: 426 mg/LHartford 426Slinger: 485 mg/LSlinger 485Ripon: 385 mg/LRipon 385Mayville 324mg/L as calcium carbonate060120180240300360+WI 170Fond du Lac: 170 mg/LFond du Lac 170Watertown: 249 mg/LWatertown 249West Bend: 340 mg/LWest Bend 340Jackson: 352 mg/LJackson 352Hartford: 426 mg/LHartford 426Slinger: 485 mg/LSlinger 485324 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 324 mg/L, Mayville is 154 mg/L above the typical Wisconsin figure of 170. Of the 10 nearest cities we track, 4 have softer water and 6 have harder. The range nearby runs from 144 mg/L in Columbus to 485 in Slinger.

What 324 mg/L means at home

Scale forms fast here. Kettles and coffee makers need regular descaling, and showerheads clog unless you clean them.

Tank water heaters collect mineral sediment that insulates the water from the burner, so flushing the tank matters more than usual.

Dishes and glass shower doors spot easily. Soap scum and a dull film on hair or laundry are common complaints.

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

At 324 mg/L most of the trouble is scale, and only a few things deal with it.

Ion-exchange water softener

The standard whole-house fix. It swaps calcium and magnesium for sodium or potassium and needs salt plus a drain. Size it with the calculator below.

Salt-free conditioner

No salt and no drain line. It changes how minerals form scale instead of removing them, so water still tests hard.

Reverse osmosis or carbon filter

Under-sink reverse osmosis removes minerals from drinking water only. Plain carbon filters improve taste but do not soften.

Softener size for Mayville

3 people × 75 gallons a day × 18.9 gpg = 4,264 grains a day. A 32,000-grain unit regenerates about every 7 days.

Size it for your household

EPA record for Mayville's water system

Mayville Waterworks · PWSID WI1140057

No health-based violations since 2016

Serves about 5,112 people from groundwater.

Health-based
0
Monitoring or reporting
1
Open now
0

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 Mayville water hard?

Yes. It measures about 324 mg/L (18.9 grains per gallon), which the USGS classes as very hard.

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

About 18.9 gpg. One grain per gallon equals 17.1 mg/L, so 324 mg/L divided by 17.1 gives 18.9.

What size water softener do I need in Mayville?

For 3 people using 75 gallons each per day, 18.9 gpg works out to about 4,264 grains a day. A 32,000-grain softener covers that with a regeneration about every 7 days.

Has the Mayville water system had EPA violations?

EPA records show no health-based violations for Mayville Waterworks since 2016. There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.

Nearby cities

All 112 cities in Wisconsin

Hardness data: TapWaterData US Water Hardness (utility report, August 8, 2022), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.