Hardness
Very Hard
329 PPM · 19.2 GPG
Local water dashboard
Official source aggregationA source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Polk County.
At a glance
EPA quarter 2026Q2
Hardness
Very Hard
329 PPM · 19.2 GPG
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0.0056 mg/L
37% of action level
Utility match
2 systems
Serves 19,565 people system-wide
Hardness meter
Estimated local hardness
USGS hardness classification scale
329 PPM
Parts per million
329
mg/L as CaCO₃ equivalent
Grains per gallon
19.2
1 GPG ≈ 17.1 PPM
What this means at home
At 329 PPM, mineral scale can build up on fixtures and heating elements, reduce soap lather, and leave visible spotting. Hardness is primarily an aesthetic and appliance concern—not itself a tap-water safety rating.
USGS sites used
15
Nearest site
14.5 mi
Observation range
May 30, 2017–Aug 1, 2024
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: 081N23W10BAA (Well).USGS source documentation ↗
Regional context
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Altoona median
329 PPM
About the same1 indexed ZIP readings · Range 329–329 PPM
Iowa median
281 PPM
48 PPM higher721 indexed ZIP readings · Range 182–834 PPM
EPA benchmark screen
Available numerical results from associated SDWIS community water systems, compared with the applicable action level or federal MCL. Federal measured-value coverage is incomplete.
Lead (PB90)
0.0056 mg/L
Reported Dec 31, 2025
Copper (CU90)
Not available
No numerical 90th-percentile result
Numerical coverage
2 comparable results
Missing values remain blank; absence is not treated as a pass.
Measured in mg/L
Local 0.0056
EPA limit 0.015
Measured in PCI/L
Local 15.65
EPA limit 15
100% line = listed limit
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Gross Alpha, Excl. Radon and U | IA7707030 | Archived | Jul 1, 2025through Sep 30, 2025 |
| Gross Alpha, Excl. Radon and UHealth-basedReported 15.65 PCI/L · MCL 15 | IA7707030 | Archived | Jul 1, 2024through Sep 30, 2024 |
No reported violation does not prove that every contaminant was tested or absent; SDWIS measured values are incomplete and lag state records.
Solutions matcher
Matched to Altoona ZIP 50009 using 329 PPM nearby hardness and 2 reported measurement benchmarks.
Scale protection
329 PPM is 3× the high-hardness trigger used by this matcher.
Designed to reduce scale on fixtures, water heaters, glassware, and plumbing throughout the home.
Compare whole-house systemsDrinking water protection
Gross Alpha, Excl. Radon and U has a measured benchmark flag or active health-based SDWIS record in this profile.
A certified multi-stage RO system targets a broader range of dissolved contaminants at the kitchen tap.
Explore under-sink filtrationAffiliate disclosure: we may earn a commission from qualifying purchases, at no added cost to you. Product matching is educational and does not replace certified water testing.
Frequently asked
EPA ECHO shows no active health-based violation for the associated systems in this reporting snapshot. This does not prove every contaminant is absent; federal records can lag and household plumbing can change tap conditions.
Nearby USGS observations produce an estimate of 329 PPM, or 19.2 grains per gallon, classified as very hard. This is not a household tap measurement.
At 329 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.