How hard is the water in Marquette County, MI?
4.2 grains per gallon
Optional: a softener helps, but plenty of homes skip it.
The median hardness measured in Marquette County, MI is 72 mg/L as calcium carbonate, which is 4.2 gpg. That is moderately hard on the USGS scale. It comes from 136 samples at 12 sites between 1993 and 2017, drawn from groundwater wells, which is what most taps and private wells in the county draw on.
How much it varies here
Half the sites came in between 3.7 and 6 gpg. The whole middle of that range gives the same answer, so a test of your own tap is unlikely to change it. Confidence in the county figure: high (how it is measured).
What to do next
At 4.2 gpg this is your call. Look for white film on glasses and crust on the shower head: if you see little of either, you can live without one. If you do want one, a 24,000-grain unit is enough, so ask for that size rather than a bigger one.
More on when a softener is not worth it.
From 1.7 to 12.3 gpg
The softest single sample on record in Marquette County was 28.9 mg/L and the hardest 210 mg/L, a 7-fold gap. The top quarter of sites read above 6 gpg and the bottom quarter below 3.7 gpg.
Wells 4.2 gpg, rivers and lakes 2.2 gpg
136 groundwater samples from 12 wells put the median at 72.3 mg/L. 189 surface samples from 42 sites put it at 38.4 mg/L. In Marquette County the wells come out 2.0 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. The two sources are close, so the county figure should hold whichever one your tap is on.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 92 lb of salt a year (3 bags of 40 lb, about $17), and roughly 2,346 gallons of regeneration water. Installed, most units run $1,000 to $4,500; spread over 15 years with salt, that is about $117 a year.
Sizing at 4.2 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 252 | 24,000 | 31 lb |
| 2 | 504 | 24,000 | 61 lb |
| 4 | 1,008 | 24,000 | 123 lb |
| 6 | 1,512 | 24,000 | 184 lb |
Marquette County against the rest of Michigan
Among the 82 Michigan counties with data, Marquette County is number 73 of 82 counting from the hardest. Across the whole country it is harder than 27% of counties.
Softest in Michigan: Luce County at 1.9 gpg. Hardest: Wayne County at 47.4 gpg. Closest to Marquette County: Ontonagon County (4.2), Schoolcraft County (4.4), Otsego County (4.7).