Waukesha County, WI water hardness
Waukesha County water hardness, town by town
The list on this page gathers the hardness each Waukesha County water system publishes, or that DNR sampling shows, from lake water near 8 grains to groundwater past 30. Here is how to read it, and what it cannot tell you about your own house.
Call (262) 829-5961Mon to Fri, 7am to 5pm- Brookfield23–34City of Brookfield water-quality FAQ; City of Brookfield Water Utility chloride-reduction guidance; for the Town of Brookfield, Sanitary District No. 4
- Elm Grove23–34Village of Elm Grove, Municipal Water page; City of Brookfield Water Utility
- New Berlin~8 / 18–32New Berlin Water Utility; Milwaukee Water Works published hardness
- Menomonee Falls7–9 / 27–32Village of Menomonee Falls water utility FAQ
- Oconomowoc19–25City of Oconomowoc Water Utility annual water quality reports (current and prior)
- Delafield14–23Wisconsin DNR compliance sampling, City of Delafield waterworks; City of Delafield utilities page
- Hartland~23Village of Hartland 2024 Consumer Confidence Report, system 26802050
- Mukwonago22–23Wisconsin DNR compliance sampling, Mukwonago waterworks; Village of Mukwonago 2024 Consumer Confidence Report
- Pewaukee16–22City of Pewaukee Water Utility; Village of Pewaukee 2022 Water System Master Plan
- Sussex~17.5Village of Sussex water utility published water quality report
- Waukesha~8City of Waukesha / Great Water Alliance, switch completed October 2023
Hardness in grains per gallon, as each utility publishes it.
What each row shows
Each row is one community's water system: its hardness in grains per gallon and the source of the figure, ordered from the hardest published figure down to the softest.
Most figures come from the utilities themselves. Two come from Wisconsin DNR compliance samples: Delafield's, measured at its two municipal wells, and Mukwonago's, measured at its two entry points because the village's annual reports give no hardness figure. A range means readings differ across wells, entry points or samples, and a figure marked with a tilde is approximate.
Lake water towns
Three systems on the list buy Lake Michigan water: the City of Waukesha since October 2023, New Berlin's city system since July 2009 and the lake side of Menomonee Falls. Their figures sit around 7 to 10 grains.
Milwaukee Water Works, which supplies New Berlin and Menomonee Falls, puts its water at 137 milligrams per liter, close to 8 grains, and Waukesha's lake water arrives at roughly 8 as well. On the USGS scale that falls within the 121 to 180 range called hard, short of very hard.
Groundwater towns
Every other row is groundwater pumped from wells: Brookfield at 23 to 34 grains, Oconomowoc at 19 to 25, Hartland at about 23, Mukwonago at 22 to 23, Delafield at 14 to 23, Pewaukee at 16 to 22 and Sussex at about 17.5, plus the village wells in Menomonee Falls at 27 to 32.
Every one of those figures clears 10.5 grains, where the USGS very hard band begins, several of them by double or more. Brookfield kept its wells when neighbors moved to the lake, and Oconomowoc is outside the Great Lakes basin altogether, so neither has a switch in view.
Rows with two numbers, and one that borrows
New Berlin's row reads about 8 and 18 to 32. The first is the purchased lake water in the city mains; the second is what the utility published for the groundwater it used to pump before 2009, the aquifer private wells there still tap. Menomonee Falls shows 7 to 9 and 27 to 32 because the village runs both supplies at once, and the address decides which one a house gets.
Elm Grove's row repeats Brookfield's 23 to 34 grains because the village gets its municipal water by way of Brookfield's utility. It describes only the connected houses, a minority of the village; the rest are on private wells.
What the list leaves out
Muskego is missing because its utility publishes no figure, only a statement that its water is relatively hard and that most residents use softeners. DNR samples from April 27, 2026 show why one number would mislead: about 3 grains at one municipal well and about 24 at another.
The Town of Brookfield's Sanitary District No. 4, which publishes 32 to 35 grains, has no row of its own. And no private well appears anywhere, whether in the Village of Waukesha, the Town of Genesee, Lisbon, Vernon or the well side of a mixed town.
Common questions
How do I find my own number?
Start with the row for the utility on your water bill, then that utility's annual water quality report. On a private well, look to your lab report; milligrams per liter over 17.1 gives grains.
How is the figure used on the quote call?
It sets the size of the system along with how many people the house holds. The softener is then set from the plumber's own test at your tap on install day, made before any pipe is opened, rather than from your town's row.
More for Waukesha County homes
- Water softener installation in Waukesha County, WI
- Water softener replacement in Waukesha County, WI
- Well water softeners in Waukesha County, WI
- Waukesha County water guides
- About Waukesha County Water Softener Co.
- Water softener quotes in Waukesha County, WI
- Which Waukesha County homes are on Lake Michigan water?
- Reading your Waukesha County water quality report
- Why hardness differs from well to well in Waukesha County
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