Iowa City Water Hardness & Quality Report (2026)
Water Hardness
15 grains per gallon
Source
river
pH Level
8.5
neutral = 7.0
Lead
0.005 mg/L
✓ Below action level
TDS
549.2 mg/L
Est. Daily Cost
$0.69
energy & soap waste
Source: USGS Water Quality Portal · Updated 2026
0–60
mg/L
Soft
61–120
mg/L
Moderately Hard
121–180
mg/L
Hard
180+
mg/L
Very Hard
Appliance Damage Report
In Iowa City, your appliances are currently losing 34% efficiency due to mineral buildup.
| Appliance | In Iowa City | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 1.5 yrs | 8.5 yrs | -82% |
| Washing Machine | 4.1 yrs | 12 yrs | -66% |
| Water Heater | 5.3 yrs | 15 yrs | -65% |
Regional Water Comparison
How Iowa City compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Iowa City, Iowa | 257 mg/L | 5.3 ppt | 🔴 Very Hard | river |
| Coralville, Iowa | 343.5 mg/L | 7.1 ppt | 🔴 Very Hard | river |
| North Liberty, Iowa | 203 mg/L | 4.3 ppt | 🔴 Very Hard | river |
| Cedar Rapids, Iowa | 167.5 mg/L | 3.6 ppt | 🟠 Hard | river |
| Marion, Iowa | 170.5 mg/L | 3.6 ppt | 🟠 Hard | river |
National Benchmark
How Iowa City compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Iowa City | 257 mg/L | 🔴 High |
| USA National Avg | 150 mg/L | 🟠 Moderate |
| Badger Top Rated | 8.5 mg/L | 🟢 None |
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What Makes Iowa City's Water Unique?
Local geology and source profile
Iowa City, Iowa — home of the University of Iowa and the Iowa Writers' Workshop in Johnson County — draws its municipal water supply from the Iowa River via the City of Iowa City Water Division, treating Iowa River water at the Iowa City Water Treatment Plant serving the Iowa City–Coralville metropolitan area. The Iowa River at Iowa City drains east-central Iowa's agricultural and bedrock carbonate landscape. Water hardness in Iowa City reaches 257 mg/L — classified as very hard.
Iowa City's very hard supply reflects the Iowa River watershed's substantial carbonate geology in east-central Iowa. The Iowa River above Iowa City drains: the Devonian Wapsipinicon Formation (dolomite and cherty limestone — one of Iowa's most reactive carbonate formations, extensively exposed in the Devonian Reef Belt of east-central Iowa); the Devonian Iowa Formation (limestone and dolomite of the Iowa Devonian sequence); the Silurian Hopkinton Dolomite and related Silurian carbonates of northeast Iowa; and the Quaternary loess and calcareous glacial till of the Iowa prairie plain (calcareous Prairie du Chien and Ordovician carbonate-derived till). The east-central Iowa Devonian dolomite and reef belt is one of the most calcareous geological environments in the Midwest, producing very hard water in the Iowa River and its tributaries.
At 257 mg/L, Iowa City residents face significant hard water challenges. Scale deposits form rapidly on faucet aerators, showerheads, shower glass, and tile — monthly descaling with citric acid solution is essential maintenance. Dishwashers require rinse-aid, and water heaters need annual inspection. City of Iowa City Water Division consistently delivers water meeting all Iowa DNR and EPA Safe Drinking Water Act requirements.
Geology & Source: River supply from the Iowa River via the City of Iowa City Water Division — the Iowa River eastern Iowa watershed draining the Devonian Wapsipinicon Formation (dolomite and limestone), Silurian Hopkinton Dolomite, and the Quaternary loess of Johnson County; very hard supply at 257 mg/L in Johnson County.