Every Iowa city water number we have checked is moderately hard, hard or very hard. Two things set yours: where your water comes from and whether your city softens it at the plant. Type your town in the lookup below to get its number, where the number comes from, and what it actually changes in your house. Every number it shows comes from a water utility or a state sample record, and we name the source. Where we have not checked a number at its source yet, or none has been published, we say so.
Start typing and pick your town. You will see its hardness in grains per gallon (gpg, what water pros use) and milligrams per liter (mg/L, what your city's report usually prints), the band it falls in, and where the number comes from. Where a town publishes only one unit, we convert at the standard 1 gpg = 17.1 mg/L and round.
A few Eastern Iowa towns do something at the plant that changes the answer entirely. If you live in one of these, your tap water is not typical of the region around it.
| City | What the utility does | What that means for you |
|---|---|---|
| Maquoketa | Municipally softened since 2006 | Softening already happens at the plant, so check your finished-water number before buying a whole-home softener. Drinking-water filtration is often the more useful upgrade. |
| West Liberty | Municipal reverse osmosis | Treatment happens at city scale before the water reaches you. Ask your utility what the finished hardness is before buying anything. |
| Atkins | Municipal reverse osmosis | Same as West Liberty — the heavy lifting is done centrally, so test your own tap before assuming you need equipment. |
Coralville, Cedar Falls and Independence sit at the other end: none of the three softens municipally, so whatever the source water carries is what shows up in your shower. If you want the plumbing behind all of this, read where Eastern Iowa's water comes from.
The USGS uses four hardness bands, and every number on this page falls into one of them:
The two units trip people up constantly. Utilities publish milligrams per liter; water treatment people talk in grains per gallon. The conversion is fixed: 1 gpg = 17.1 mg/L.
Worked example, using Waukee: the city publishes 7.5–8.5 gpg, and 8.5 × 17.1 = about 145 mg/L, which lands in the USGS hard band of 121–180 mg/L. Going the other way, Dubuque's roughly 100 mg/L ÷ 17.1 = about 5.8 gpg — moderately hard. Same water, two vocabularies, one multiplication.
You do not need a softener. What people in this band usually want is better-tasting drinking water: a reverse osmosis system at the kitchen sink, $897 for a tank unit or $997 for a tankless one, installed.
A softener is a preference, not a necessity. Homeowners in this band buy one to stop the spotting on glassware and the film on shower doors, and to be easier on the water heater. A whole-home softener is $2,500 all-in, or $2,850 bundled with reverse osmosis.
This is where scale starts costing you: crusty aerators, stiff laundry, more soap and detergent than the box calls for. A standard softener at $2,500 handles it. On city water, a salt-free conditioner is $3,050 if you would rather not carry salt.
Size up: our XL softener is $2,800, or $3,150 with reverse osmosis. High-capacity units mean fewer regenerations and less salt handling, which is the part homeowners actually notice. Our Eastern Iowa cost breakdown shows what is included at each price, and the salt guide covers upkeep.
Every price above is all-in: equipment, professional installation by licensed local plumbing professionals we vet, schedule and stand behind, taxes, and a lifetime parts warranty. Add the yearly care plan, $199 with a tank RO or $249 with a tankless RO, and your RO filters are included. 0% financing is available, and military and first responders take $100 off. Want a number without a phone call? Use the instant quote.
For a longer, city-by-city write-up of the same data, see Iowa water hardness by city, or pull your city's contaminant summary from the Eastern Iowa water reports.
If your water comes from your own well, nothing in the lookup above describes your house. There is no plant, no treatment, no annual report — your water is whatever your aquifer and your well are doing this season, and it can differ from your neighbor's.
The Iowa DNR recommends testing private wells annually, and Iowa's Private Well Grants program pays for county lab testing at no cost to you. Start there. Our guide to free well water testing in Iowa walks through who to call in your county, and the well water hub covers the symptoms most Eastern Iowa wells show.
Two things worth knowing before you shop. First, iron: the EPA's secondary standard for iron is 0.3 mg/L and manganese 0.05 mg/L — both aesthetic standards, about staining and taste rather than compliance. Penn State Extension advises that a softener alone should only be asked to handle dissolved iron below 5 mg/L; above that you want dedicated iron treatment, which we quote after your free water test rather than off a price list. Second, nitrate: Iowa State University Extension notes that nitrate is odorless and tasteless, so you cannot tell it is there without testing. More on that in nitrates in Iowa water.
Look up your city above, convert it if you need to, and you will know which band you are in before anyone knocks on your door. If you want it confirmed on your own tap, the in-home test is free and the prices are published — no home visit required to find out what something costs. Book a free water test or build your instant quote. If you already own a system that has stopped keeping up, start with softener repair; if your water simply tastes like a swimming pool, read why tap water tastes like chlorine.
Of the city water numbers we have checked at their source, the hardest are in Western Iowa: Sergeant Bluff publishes 25 grains per gallon (about 428 mg/L), and Sioux Center reported 23 grains in 2023. Next come Dixon in Scott County, where Iowa American Water lists up to 388 mg/L, and Grinnell at 22 grains (about 376 mg/L), which the city expects its new treatment plant to bring down to 7 grains. Iowa American Water's published range for the Iowa Quad Cities tops out at 350 mg/L, and Waterloo Water Works reports 332 mg/L (about 19.4 gpg) for 2025. All of these sit above the USGS very-hard threshold of 180 mg/L.
Cedar Rapids tap water runs about 6.5–7 grains per gallon, roughly 111–120 mg/L, which is the top edge of the USGS moderately hard band of 61–120 mg/L. The city softens at the plant from 15.8 gpg raw, and the City of Cedar Rapids water FAQ describes finished water at 6–9 gpg, whose upper end converts to about 154 mg/L.
Multiply grains per gallon by 17.1, because 1 gpg equals 17.1 mg/L. Des Moines Water Works' hardness goal of 8.76 gpg × 17.1 = about 150 mg/L, the same figure the utility gives. To reverse it, divide: Dubuque's roughly 100 mg/L ÷ 17.1 is about 5.8 gpg. Iowa utilities usually publish mg/L while water treatment companies quote gpg, which is why the same water gets two very different-looking numbers.
Des Moines Water Works softens at its treatment plants, and its three plants averaged about 145–152 mg/L in 2025. Indianola lime-softens to 5.8–7 gpg. In Eastern Iowa, Cedar Rapids, Iowa City and Dubuque all soften municipally: Cedar Rapids drops from 15.8 gpg raw to about 6.5–7 gpg, and Dubuque from about 280 mg/L to about 100 mg/L. Maquoketa has softened since 2006, and West Liberty and Atkins run municipal reverse osmosis. Waterloo, Cedar Falls, Coralville and Independence do not soften.
Two ways. Kind Water Co runs a free in-home water test in the towns we serve, and you keep the results whether or not you buy anything. Or read your utility's annual water quality report, often called a Consumer Confidence Report. Hardness is frequently left out, since those reports focus on regulated contaminants — if so, call the water department and ask for finished-water hardness.
Usually not for protection. In Eastern Iowa's softened cities the plant has already done most of the work: Cedar Rapids finishes at about 6.5–7 grains per gallon (about 111–120 mg/L) and Dubuque near 100 mg/L, so both land in the moderately hard range. Homeowners there who still install a softener are chasing spot-free glassware and film-free shower doors, not scale damage. Des Moines Water Works softens too, but its three plants averaged about 145–152 mg/L (8.5–8.9 gpg) in 2025, which the USGS still calls hard.
No city figure applies to a private well — your hardness depends on your own aquifer and well, and can differ from a neighbor's. For scale, USGS sampling of Black Hawk County wells since 1990 shows a median of 271 mg/L, about 15.8 grains per gallon, which is very hard. The Iowa DNR recommends annual testing, and Iowa's Private Well Grants cover county lab testing free.
Whole-home water softening, filtration, and reverse-osmosis drinking water — professionally installed and built to last a lifetime.
Serving Des Moines, Polk County & homes across Iowa
Kind Water Co is a d/b/a of Zero Cap Investments LLC · 600 SE 15th St, Des Moines, IA 50317
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