Hard water in Altoona, IA
County estimate from 415 water samples in Polk County · July 2026
- IA typical
- 183 mg/L
- EPA health violations since 2016
- 1
- Softener for 3 people
- 32k grain
- Data
- County estimate
Water samples from around Altoona put hardness at about 296 mg/L (17.3 gpg), which would be very hard on the USGS scale. Treat this as a rough guide: it is the median of 415 samples taken across Polk County, mostly wells and streams, not a test of Altoona's treated tap water.
At 296 mg/L, Altoona is 113 mg/L above the typical Iowa figure of 183. Of the 10 nearest cities we track, 8 have softer water and 1 has harder. The range nearby runs from 68 mg/L in Clive to 302 in Waukee.
What 296 mg/L means at home
Scale forms fast here. Kettles and coffee makers need regular descaling, and showerheads clog unless you clean them.
Tank water heaters collect mineral sediment that insulates the water from the burner, so flushing the tank matters more than usual.
Dishes and glass shower doors spot easily. Soap scum and a dull film on hair or laundry are common complaints.
Hardness is not a health problem, and EPA sets no limit for it. It is a matter of scale and soap.
What to do about it
At 296 mg/L most of the trouble is scale, and only a few things deal with it.
Ion-exchange water softener
The standard whole-house fix. It swaps calcium and magnesium for sodium or potassium and needs salt plus a drain. Size it with the calculator below.
Salt-free conditioner
No salt and no drain line. It changes how minerals form scale instead of removing them, so water still tests hard.
Reverse osmosis or carbon filter
Under-sink reverse osmosis removes minerals from drinking water only. Plain carbon filters improve taste but do not soften.
3 people × 75 gallons a day × 17.3 gpg = 3,895 grains a day. A 32,000-grain unit regenerates about every 8 days.
EPA record for Altoona's water system
1 health-based violation since 2016
Serves about 22,436 people from groundwater.
- Health-based
- 1
- Monitoring or reporting
- 4
- Open now
- 0
EPA lists this system as serving Altoona.
| Contaminant or rule | Violations | Period | Status |
|---|---|---|---|
| Gross alpha radioactivitynaturally occurring radioactivity | 1 | 2024 | Resolved |
Health-based means a contaminant above its legal limit or a missed treatment step. Monitoring and reporting violations are late or missing tests and notices. Source: EPA ECHO, 2026Q3 export, violations with periods starting 2016 or later. Full EPA record.
Questions
Is Altoona water hard?
Yes. It measures about 296 mg/L (17.3 grains per gallon), which the USGS classes as very hard.
What is the water hardness in Altoona in grains per gallon?
About 17.3 gpg. One grain per gallon equals 17.1 mg/L, so 296 mg/L divided by 17.1 gives 17.3.
What size water softener do I need in Altoona?
For 3 people using 75 gallons each per day, 17.3 gpg works out to about 3,895 grains a day. A 32,000-grain softener covers that with a regeneration about every 8 days.
Has the Altoona water system had EPA violations?
EPA records show 1 health-based violation for Altoona Water Supply since 2016, involving Gross alpha radioactivity. There were also 4 monitoring or reporting violations, which are about late or missing tests and notices.
Nearby cities
- Ankeny120 mg/LModerately hard
- Des Moines296 mg/LVery hard
- Johnston126 mg/LHard
- Polk City151 mg/LHard
- Urbandale99 mg/LModerately hard
- Norwalk132 mg/LHard
- Clive68 mg/LModerately hard
- West Des Moines135 mg/LHard
- Waukee302 mg/LVery hard
- Ames150 mg/LHard
Hardness data: TapWaterData US Water Hardness (county estimate, July 4, 2026), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.