HardnessCheck

How hard is the water in Dubuque County, IA?

18.7 grains per gallon

The median hardness measured in Dubuque County, IA is 320 mg/L as calcium carbonate, which is 18.7 gpg. That is very hard on the USGS scale. It comes from 34 samples at 8 sites between 1990 and 2007, 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 14.2 and 20.9 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: medium (how it is measured).

What to do next

At 18.7 gpg a softener pays its way here. Before you buy, check the quoted unit's grain capacity against the sizing table below, and ask whether it regenerates on demand, which uses less salt than a timer. Call your utility for its own report if you are on city water.

More on sizing a softener for your household.

From 12.0 to 25.7 gpg

The softest single sample on record in Dubuque County was 205 mg/L and the hardest 440 mg/L, a 2-fold gap. The top quarter of sites read above 20.9 gpg and the bottom quarter below 14.2 gpg.

Wells 18.7 gpg, rivers and lakes 15.7 gpg

34 groundwater samples from 8 wells put the median at 320 mg/L. 11 surface samples from 2 sites put it at 269.3 mg/L. In Dubuque County the wells come out 3.0 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. A utility here that draws from the river can deliver noticeably different water from a private well next door.

What a softener would cost to run

For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 408 lb of salt a year (11 bags of 40 lb, about $73), 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 $173 a year.

Sizing at 18.7 gpg

PeopleGrains a dayUnitSalt a year
11,12224,000137 lb
22,24424,000273 lb
44,48832,000546 lb
66,73248,000819 lb

Dubuque County against the rest of Iowa

Among the 93 Iowa counties with data, Dubuque County is number 58 of 93 counting from the hardest. Across the whole country it is harder than 81% of counties.

Softest in Iowa: Taylor County at 8.2 gpg. Hardest: Pocahontas County at 45.3 gpg. Closest to Dubuque County: Jackson County (18.7), Washington County (18.7), Benton County (18.6).