Hardness
Very Hard
242 PPM · 14.2 GPG
Local water dashboard
Official source aggregationWater quality in Waukesha, WI 53188
A 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.
2 reported benchmark flags
- Primary matched system
- Waukesha Water Utility
- Source water
- Surface water + Groundwater
- County
- Waukesha 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
5.6e-4 mg/L
4% of action level
Utility match
2 systems
Serves 70,718 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
242 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
242
mg/L as CaCO₃ equivalent
Grains per gallon
14.2
1 GPG ≈ 17.1 PPM
What this means at home
At 242 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
20
Nearest site
9.6 mi
Observation range
Apr 12, 2016–Jun 10, 2026
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: OKAUCHEE LAKE AT OKAUCHEE, WI (Lake, Reservoir, Impoundment).USGS source documentation ↗
Regional context
Is 53188 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Waukesha median
242 PPM
About the same3 indexed ZIP readings · Range 242–242 PPM
Wisconsin median
288 PPM
46 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 pass2 fail
Lead (PB90)
5.6e-4 mg/L
Reported Dec 31, 2024
Copper (CU90)
Not available
No numerical 90th-percentile result
Numerical coverage
3 comparable results
Missing values remain blank; absence is not treated as a pass.
Lead (90th percentile)
Measured in mg/L
Local 5.6e-4
EPA limit 0.015
Combined Radium (-226 and -228)
Measured in PCI/L
Local 5.6
EPA limit 5
Gross Alpha, Excl. Radon and U
Measured in PCI/L
Local 16.95
EPA limit 15
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 75
- Health-based
- 60
- Active health-based
- 0
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Combined Radium (-226 and -228)Health-basedReported 5.6 PCI/L · MCL 5 | WI2680238 | Resolved | Oct 1, 2023through Oct 15, 2023 |
| Combined Radium (-226 and -228)Health-basedReported 7.79 PCI/L · MCL 5 | WI2680238 | Resolved | Oct 1, 2023through Oct 15, 2023 |
| Public Notice | WI2680238 | Unaddressed | Sep 29, 2023 |
| Public Notice | WI2680238 | Unaddressed | Sep 29, 2023 |
| Public Notice | WI2680238 | Resolved | Sep 20, 2023through Jan 24, 2024 |
| Combined Radium (-226 and -228)Health-basedReported 7.79 PCI/L · MCL 5 | WI2680238 | Resolved | Jul 1, 2023through Sep 30, 2023 |
| Combined Radium (-226 and -228)Health-basedReported 6.6 PCI/L · MCL 5 | WI2680238 | Resolved | Jul 1, 2023through Sep 30, 2023 |
| Combined Radium (-226 and -228)Health-basedReported 9.79 PCI/L · MCL 5 | WI2680238 | Resolved | Apr 1, 2023through Jun 30, 2023 |
| Gross Alpha, Excl. Radon and UHealth-basedReported 16.95 PCI/L · MCL 15 | WI2680238 | Resolved | Apr 1, 2023through Jun 30, 2023 |
| Combined Radium (-226 and -228)Health-basedReported 7.41 PCI/L · MCL 5 | WI2680238 | Resolved | Apr 1, 2023through Jun 30, 2023 |
| Combined Radium (-226 and -228)Health-basedReported 6.18 PCI/L · MCL 5 | WI2680238 | Resolved | Apr 1, 2023through Jun 30, 2023 |
| Public Notice | WI2680238 | Resolved | Mar 6, 2023through Jun 29, 2023 |
| Gross Alpha, Excl. Radon and UHealth-basedReported 19.13 PCI/L · MCL 15 | WI2680238 | Resolved | Jan 1, 2023through Mar 31, 2023 |
| Gross Alpha, Excl. Radon and UHealth-basedReported 16.95 PCI/L · MCL 15 | WI2680238 | Resolved | Jan 1, 2023through Mar 31, 2023 |
| Combined Radium (-226 and -228)Health-basedReported 6.96 PCI/L · MCL 5 | WI2680238 | Resolved | Jan 1, 2023through Mar 31, 2023 |
| Combined Radium (-226 and -228)Health-basedReported 9.79 PCI/L · MCL 5 | WI2680238 | Resolved | Jan 1, 2023through Mar 31, 2023 |
| Combined Radium (-226 and -228)Health-basedReported 9.19 PCI/L · MCL 5 | WI2680238 | Resolved | Jan 1, 2023through Mar 31, 2023 |
| Public Notice | WI2680238 | Resolved | Dec 9, 2022through Mar 1, 2023 |
| Public Notice | WI2680238 | Resolved | Dec 9, 2022through Mar 1, 2023 |
| Public Notice | WI2680238 | Resolved | Nov 21, 2022through Mar 1, 2023 |
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 Waukesha ZIP 53188 using 242 PPM nearby hardness and 3 reported measurement benchmarks.
Scale protection
High-Capacity Whole House Water Softener
242 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 systemsDrinking water protection
Under-Sink Reverse Osmosis System
Combined Radium (-226 and -228), Gross Alpha, Excl. Radon and U have 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.
Nearby indexed reports
Compare ZIPs in Waukesha
Estimates can differ across a city because monitoring locations and associated systems differ.
Frequently asked
Water questions for Waukesha
Is tap water safe in Waukesha?+
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 242 PPM, or 14.2 grains per gallon, classified as very hard. This is not a household tap measurement.
Do I need a water softener?+
At 242 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.