Hardness
Very Hard
279 PPM · 16.3 GPG
Local water dashboard
Official source aggregationWater quality in Platteville, WI 53818
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Grant County.
No active health-based violation reported
- Primary matched system
- Platteville Waterworks
- Source water
- Groundwater
- County
- Grant County
- Profile updated
At a glance
What the current records say
EPA quarter 2026Q2
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0.0103 mg/L
69% of action level
Utility match
3 systems
Serves 12,268 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
279 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
279
mg/L as CaCO₃ equivalent
Grains per gallon
16.3
1 GPG ≈ 17.1 PPM
What this means at home
At 279 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
14
Nearest site
23.2 mi
Observation range
Aug 3, 2016–May 15, 2019
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: 28N 1W-24.6f1 (Well).USGS source documentation ↗
Regional context
Is 53818 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Platteville median
279 PPM
About the same1 indexed ZIP readings · Range 279–279 PPM
Wisconsin median
288 PPM
9 PPM lower556 indexed ZIP readings · Range 41.3–467 PPM
EPA benchmark screen
Contaminant snapshot
Available numerical results from associated SDWIS community water systems, compared with the applicable action level or federal MCL. Federal measured-value coverage is incomplete.
1 pass
Lead (PB90)
0.0103 mg/L
Reported Sep 30, 2025
Copper (CU90)
Not available
No numerical 90th-percentile result
Numerical coverage
1 comparable result
Missing values remain blank; absence is not treated as a pass.
Lead (90th percentile)
Measured in mg/L
Local 0.0103
EPA limit 0.015
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 19
- Health-based
- 2
- Active health-based
- 0
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Revised Total Coliform Rule | WI1220095 | Resolved | Jan 1, 2025through Jan 31, 2025 |
| LEAD AND COPPER RULE REVISIONSHealth-based | WI1220095 | Resolved | Oct 17, 2024through Oct 31, 2024 |
| Public Notice | WI1220095 | Unaddressed | Oct 17, 2024 |
| Public Notice | WI1220095 | Unaddressed | Oct 17, 2024 |
| LEAD AND COPPER RULE REVISIONS | WI1220095 | Resolved | Oct 17, 2024through Oct 31, 2024 |
| Revised Total Coliform Rule | WI1220095 | Resolved | Nov 26, 2023through Dec 14, 2023 |
| Revised Total Coliform RuleHealth-based | WI1220095 | Resolved | Nov 26, 2023through Dec 14, 2023 |
| E. COLI | WI1220095 | Resolved | Oct 19, 2023through Oct 24, 2023 |
| Public Notice | WI1220095 | Unaddressed | Dec 1, 2022 |
| Revised Total Coliform Rule | WI1220095 | Resolved | Nov 1, 2022through Nov 30, 2022 |
| Consumer Confidence Rule | WI1220095 | Resolved | Jul 1, 2022through Aug 13, 2022 |
| Consumer Confidence Rule | WI1220095 | Resolved | Jul 1, 2022through Aug 13, 2022 |
| Public Notice | WI1220095 | Resolved | Dec 22, 2021through Apr 24, 2023 |
| E. COLI | WI1220095 | Resolved | Dec 22, 2021through Dec 29, 2021 |
| E. COLI | WI1220095 | Resolved | Oct 24, 2021through Nov 22, 2021 |
| Consumer Confidence Rule | WI1220114 | Resolved | Jul 1, 2021through Jul 12, 2021 |
| Consumer Confidence Rule | WI1220114 | Resolved | Jul 1, 2021through Jul 21, 2021 |
| Revised Total Coliform Rule | WI1220095 | Resolved | May 1, 2021through May 31, 2021 |
| Revised Total Coliform Rule | WI1220114 | Resolved | Mar 1, 2021through Mar 31, 2021 |
No reported violation does not prove that every contaminant was tested or absent; SDWIS measured values are incomplete and lag state records.
Solutions matcher
Your personalized water action plan
Matched to Platteville ZIP 53818 using 279 PPM nearby hardness and 1 reported measurement benchmarks.
Scale protection
High-Capacity Whole House Water Softener
279 PPM is 2× 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 systemsAffiliate 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
Water questions for Platteville
Is tap water safe in Platteville?+
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.
How hard is the water?+
Nearby USGS observations produce an estimate of 279 PPM, or 16.3 grains per gallon, classified as very hard. This is not a household tap measurement.
Do I need a water softener?+
At 279 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.