Fond du Lac Water Hardness & Quality Report (2026)
Water Hardness
6.8 grains per gallon
Source
groundwater
pH Level
7.7
neutral = 7.0
Lead
0.002 mg/L
✓ Below action level
TDS
283.6 mg/L
Est. Daily Cost
$0.31
energy & soap waste
Source: USGS Water Quality Portal · Updated 2026
0–60
mg/L
Soft
61–120
mg/L
Moderately Hard
121–180
mg/L
Hard
180+
mg/L
Very Hard
Appliance Damage Report
In Fond du Lac, your appliances are currently losing 16% efficiency due to mineral buildup.
| Appliance | In Fond du Lac | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 5.7 yrs | 8.5 yrs | -33% |
| Washing Machine | 9.3 yrs | 12 yrs | -22% |
| Water Heater | 10.9 yrs | 15 yrs | -27% |
Regional Water Comparison
How Fond du Lac compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Fond du Lac, Wisconsin | 117 mg/L | 3.5 ppt | 🟡 Moderately Hard | groundwater |
| Oshkosh, Wisconsin | 85 mg/L | 2.8 ppt | 🟡 Moderately Hard | groundwater |
| Neenah, Wisconsin | 160 mg/L | 4.5 ppt | 🟠 Hard | groundwater |
| Menasha, Wisconsin | 233.5 mg/L | 6.2 ppt | 🔴 Very Hard | groundwater |
| West Bend, Wisconsin | 260.5 mg/L | 6.8 ppt | 🔴 Very Hard | groundwater |
National Benchmark
How Fond du Lac compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Fond du Lac | 117 mg/L | 🟡 Low |
| USA National Avg | 150 mg/L | 🟠 Moderate |
| Badger Top Rated | 8.5 mg/L | 🟢 None |
Bring Badger-quality water to your Fond du Lac home
Shop water softeners on Amazon.com →
What Makes Fond du Lac's Water Unique?
Local geology and source profile
Fond du Lac, Wisconsin, the Fond du Lac County seat at the south end of Lake Winnebago — a major Fox River Valley Wisconsin manufacturing and food processing community (Oscar Mayer processed meats, Mercury Marine outboard motor manufacturing), gateway to the Horicon Marsh National Wildlife Refuge (one of the largest freshwater cattail marshes in the US), and a significant Wisconsin lakefront community known for the Walleye Weekend fishing tournament — draws its municipal water supply from the Silurian Dolomite and Mt. Simon–Hinckley Sandstone aquifers via the City of Fond du Lac Water Division. Water hardness in Fond du Lac measures 117 mg/L — classified as moderately hard.
Fond du Lac's moderate hardness reflects the Fond du Lac County calcareous Wisconsin dolomite geology. The Silurian Niagara Dolomite aquifer (the primary shallow Wisconsin aquifer — calcareous dolomite, the same formation that caps Niagara Falls and underlies much of the Lake Michigan basin) contributes significant dissolved calcium and magnesium. The Wisconsin Age Green Bay Lobe calcareous till (calcareous glacial till derived from Michigan Basin dolomite, overlying the Fond du Lac County aquifer zone) further increases dissolved mineral content. Fond du Lac's water treatment reduces hardness from the raw dolomite aquifer supply to the moderate 117 mg/L at household taps.
At 117 mg/L, Fond du Lac residents encounter moderate scale accumulation. Faucet aerators and showerheads develop deposits after several months — monthly cleaning with citric acid solution is practical maintenance. City of Fond du Lac Water Division consistently delivers water meeting all Wisconsin DNR and EPA Safe Drinking Water Act requirements.
Geology & Source: Groundwater from the Mt. Simon–Hinckley Sandstone Aquifer and Silurian Dolomite Aquifer via the City of Fond du Lac Water Division — the Fond du Lac County south Lake Winnebago Wisconsin calcareous glacial till zone (Wisconsin Age Green Bay Lobe calcareous dolomite till and Silurian Niagara Dolomite aquifer); moderately hard supply at 117 mg/L in Fond du Lac County.