Hartford, WI water hardness
Hartford water hardness, by the City's count and the state's
Hartford's tap water is very hard by every official measure. The City and the state put different numbers on it, both well inside the highest band of the USGS scale, and neither number appears in the water utility's own annual report.
Call (262) 829-5961Mon to Fri, 7am to 5pmSource: City of Hartford Sewer Utility chloride FAQ, revised January 2023; Wisconsin DNR compliance sampling, Hartford waterworks
Groundwater from 50 to 180 feet down
All of the city's water starts in the shallow sand-and-gravel aquifer the last glacier laid down. Hartford Utilities pumps it from five wells, the shallowest 50 feet deep and the deepest 180, and it reaches the surface at a steady 50 degrees.
Hardness is the calcium and magnesium dissolved in that water. How much of it there is depends on whom you ask.
The City's range and the state's samples
The City's figure comes from the City of Hartford Sewer Utility. Its chloride guidance, revised in January 2023, describes water from the City's utility as typically 18 to 22 grains per gallon.
The state's comes from Wisconsin DNR compliance samples taken at the five wells in February 2026, which measured 390 to 450 milligrams per liter. Divided by 17.1, that is about 23 to 26 grains.
One is a typical range in a guidance sheet and the other a set of measured samples, so they are not the same kind of number. The guide on where Hartford publishes its hardness walks through both documents.
Very hard either way
The USGS scale runs soft up to 60 milligrams per liter, moderately hard from 61 to 120, hard from 121 to 180, and very hard above 180, which equals 10.5 grains per gallon.
The bottom of the City's range, 18 grains, already sits well over that last line, and the state's lowest sample, 390 milligrams, is more than twice it. The two sources disagree on how hard Hartford's water is, never on which band it belongs in.
Homes the figures were never measured for
Both numbers describe water from Hartford Utilities and nothing else. A house in the Town of Hartford, the Town of Erin or the Town of Addison that draws from a private well has a hardness of its own, unpublished until its owner has it tested.
A lab report for such a well may give hardness in milligrams per liter. Divide by 17.1 and it lines up with the City's grains, ready to compare.
How a Hartford quote uses them
On city water there is nothing to look up before calling. Hartford Utilities' annual report would not help anyway, since it lists no hardness, and both official figures are already in hand on our end. From those and the size of your household, we size the softener and name one price.
On install day the plumber reads your faucet before anything is connected, and that reading, not either published range, is what the softener is set to. The visit ends with a retest at the same faucet that has to show zero.
Common questions
Is Hartford's water hard or very hard?
Very hard by either official figure. The USGS draws the very-hard line at 180 milligrams per liter, or 10.5 grains, and the lowest Hartford number in print is 18 grains.
Does the City's range apply to a private well near Hartford?
No. It describes the water Hartford Utilities pumps from its five wells. A private well needs a lab report of its own, or the plumber's reading at the faucet on install day.
More for Hartford homes
- Water softener installation in Hartford, WI
- Water softener replacement in Hartford, WI
- Well water softeners in Hartford, WI
- Hartford water guides
- About Hartford Water Softener Co.
- Water softener quotes in Hartford, WI
- Hartford's chloride guidance, and what it asks of your softener
- Where Hartford's water hardness is published, since the annual report leaves it out
- Inherited a softener with your Hartford house? What to check first
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