Hardness
Very Hard
417 PPM · 24.4 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 Waukesha County.
At a glance
EPA quarter 2026Q2
Hardness
Very Hard
417 PPM · 24.4 GPG
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0.0012 mg/L
8% of action level
Utility match
10 systems
Serves 587 people system-wide
Hardness meter
Estimated local hardness
USGS hardness classification scale
417 PPM
Parts per million
417
mg/L as CaCO₃ equivalent
Grains per gallon
24.4
1 GPG ≈ 17.1 PPM
What this means at home
At 417 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
69
Nearest site
5.7 mi
Observation range
May 31, 2017–Aug 8, 2024
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: 7N19E-29.5f (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.
Delafield median
417 PPM
About the same1 indexed ZIP readings · Range 417–417 PPM
Wisconsin median
288 PPM
129 PPM higher556 indexed ZIP readings · Range 41.3–467 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)
0.0012 mg/L
Reported Sep 30, 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 0.0012
EPA limit 0.015
Measured in UG/L
Local 10.95
EPA limit 0.006
100% line = listed limit
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Revised Total Coliform Rule | WI2686359 | Resolved | Apr 1, 2025through Apr 30, 2025 |
| Lead and Copper Rule | WI2682512 | Resolved | Jan 1, 2025through Jan 2, 2025 |
| Lead and Copper Rule | WI2686359 | Resolved | Jan 1, 2025through Jan 9, 2025 |
| Public Notice | WI2680761 | Unaddressed | Oct 17, 2024 |
| Public Notice | WI2680761 | Unaddressed | Oct 17, 2024 |
| LEAD AND COPPER RULE REVISIONS | WI2680761 | Resolved | Oct 17, 2024through Mar 6, 2025 |
| LEAD AND COPPER RULE REVISIONSHealth-based | WI2680761 | Resolved | Oct 17, 2024through Mar 6, 2025 |
| LEAD AND COPPER RULE REVISIONS | WI2682795 | Resolved | Oct 17, 2024through Dec 9, 2024 |
| Public Notice | WI2682795 | Unaddressed | Oct 17, 2024 |
| Public Notice | WI2682795 | Unaddressed | Oct 17, 2024 |
| LEAD AND COPPER RULE REVISIONSHealth-based | WI2682795 | Resolved | Oct 17, 2024through Dec 9, 2024 |
| LEAD AND COPPER RULE REVISIONS | WI2682229 | Resolved | Oct 17, 2024through Oct 29, 2024 |
| Public Notice | WI2682229 | Unaddressed | Oct 17, 2024 |
| LEAD AND COPPER RULE REVISIONS | WI2682761 | Resolved | Oct 17, 2024through Oct 24, 2024 |
| LEAD AND COPPER RULE REVISIONSHealth-based | WI2682761 | Resolved | Oct 17, 2024through Oct 24, 2024 |
| Public Notice | WI2682761 | Unaddressed | Oct 17, 2024 |
| Public Notice | WI2682761 | Unaddressed | Oct 17, 2024 |
| LEAD AND COPPER RULE REVISIONSHealth-based | WI2686325 | Resolved | Oct 17, 2024through Jun 6, 2025 |
| Public Notice | WI2686325 | Unaddressed | Oct 17, 2024 |
| Public Notice | WI2686325 | Unaddressed | Oct 17, 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 Delafield ZIP 53018 using 417 PPM nearby hardness and 2 reported measurement benchmarks.
Scale protection
417 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
Di(2-ethylhexyl) phthalate 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 417 PPM, or 24.4 grains per gallon, classified as very hard. This is not a household tap measurement.
At 417 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.