Hardness
Very Hard
402.5 PPM · 23.5 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 Washington County.
At a glance
EPA quarter 2026Q2
Hardness
Very Hard
402.5 PPM · 23.5 GPG
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0.0031 mg/L
21% of action level
Utility match
1 system
Serves 5,659 people system-wide
Hardness meter
Estimated local hardness
USGS hardness classification scale
402.5 PPM
Parts per million
402.5
mg/L as CaCO₃ equivalent
Grains per gallon
23.5
1 GPG ≈ 17.1 PPM
What this means at home
At 402.5 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
54
Nearest site
4 mi
Observation range
Jun 10, 2020–Aug 20, 2024
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: WN-10/19E/13-0997 (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.
Slinger median
403 PPM
About the same1 indexed ZIP readings · Range 402.5–402.5 PPM
Wisconsin median
288 PPM
115 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)
0.0031 mg/L
Reported Sep 30, 2023
Copper (CU90)
1.7 mg/L
Reported Dec 31, 1996
Numerical coverage
2 comparable results
Missing values remain blank; absence is not treated as a pass.
Measured in mg/L
Local 0.0031
EPA limit 0.015
Measured in mg/L
Local 1.7
EPA limit 1.3
100% line = listed limit
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| LEAD AND COPPER RULE REVISIONSHealth-based | WI2670116 | Resolved | Oct 17, 2024through Jun 6, 2025 |
| Public Notice | WI2670116 | 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 Slinger ZIP 53086 using 402.5 PPM nearby hardness and 2 reported measurement benchmarks.
Scale protection
402.5 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
Copper (90th percentile) 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 402.5 PPM, or 23.5 grains per gallon, classified as very hard. This is not a household tap measurement.
At 402.5 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.