Hardness
Very Hard
236 PPM · 13.8 GPG
Local water dashboard
Official source aggregationWater quality in Green Bay, WI 54229
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Brown County.
1 reported benchmark flag
- Primary matched system
- Green Bay Waterworks
- Source water
- Surface water
- County
- Brown 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
0.0025 mg/L
17% of action level
Utility match
5 systems
Serves 107,369 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
236 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
236
mg/L as CaCO₃ equivalent
Grains per gallon
13.8
1 GPG ≈ 17.1 PPM
What this means at home
At 236 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
7
Nearest site
9.8 mi
Observation range
Jan 8, 2016–Aug 18, 2025
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: FOX RIVER AT OIL TANK DEPOT AT GREEN BAY, WI (Stream).USGS source documentation ↗
Regional context
Is 54229 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Green Bay median
235 PPM
About the same4 indexed ZIP readings · Range 234–236 PPM
Wisconsin median
288 PPM
52 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 pass1 fail
Lead (PB90)
0.0025 mg/L
Reported Sep 30, 2023
Copper (CU90)
1.4 mg/L
Reported Dec 31, 1992
Numerical coverage
2 comparable results
Missing values remain blank; absence is not treated as a pass.
Lead (90th percentile)
Measured in mg/L
Local 0.0025
EPA limit 0.015
Copper (90th percentile)
Measured in mg/L
Local 1.4
EPA limit 1.3
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 9
- Health-based
- 3
- Active health-based
- 0
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Revised Total Coliform Rule | WI4050456 | Resolved | Sep 1, 2025through Sep 30, 2025 |
| LEAD AND COPPER RULE REVISIONSHealth-based | WI4050468 | Resolved | Oct 17, 2024through May 27, 2025 |
| Public Notice | WI4050468 | Resolved | Oct 17, 2024through Jun 27, 2025 |
| Public Notice | WI4050455 | Resolved | Oct 17, 2024through Jun 30, 2025 |
| LEAD AND COPPER RULE REVISIONSHealth-based | WI4050455 | Resolved | Oct 17, 2024through Dec 13, 2024 |
| Groundwater RuleHealth-based | WI4050468 | Resolved | Dec 16, 2023through Dec 19, 2023 |
| Revised Total Coliform Rule | WI4050459 | Resolved | Nov 1, 2021through Nov 30, 2021 |
| Total Haloacetic Acids (HAA5) | WI4050459 | Resolved | Oct 1, 2021through Dec 31, 2021 |
| TTHM | WI4050459 | Resolved | Oct 1, 2021through Dec 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 Green Bay ZIP 54229 using 236 PPM nearby hardness and 2 reported measurement benchmarks.
Scale protection
High-Capacity Whole House Water Softener
236 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
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.
Nearby indexed reports
Compare ZIPs in Green Bay
Estimates can differ across a city because monitoring locations and associated systems differ.
Frequently asked
Water questions for Green Bay
Is tap water safe in Green Bay?+
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 236 PPM, or 13.8 grains per gallon, classified as very hard. This is not a household tap measurement.
Do I need a water softener?+
At 236 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.