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Oshkosh Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

reservoir

pH Level

7.7

neutral = 7.0

Lead

0.001 mg/L

✓ Below action level

TDS

332 mg/L

Est. Daily Cost

$0.40

energy & soap waste

Source: See methodology section below · Updated 2026

hard~120–179 mg/LHard · est.

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 Oshkosh, your appliances are currently losing 20% efficiency due to mineral buildup.

ApplianceIn OshkoshSoft Water CityEfficiency Loss
Kettle
6.8 yrs
8.5 yrs-20%
Washing Machine
9.6 yrs
12 yrs-20%
Water Heater
12 yrs
15 yrs-20%

Regional Water Comparison

How Oshkosh compares to its nearest neighbours

CityHardnessPFAS (ppt)RiskSource
Oshkosh, Wisconsin≈ 120–179 mg/L0 ppt🟠 Hardreservoir
Neenah, Wisconsin160 mg/L0 ppt🟠 Hardreservoir
Menasha, Wisconsin≈ 120–179 mg/L0 ppt🟠 Hardreservoir
Appleton, Wisconsin≈ 120–179 mg/L5.9 ppt🟠 Hardreservoir
Fond du Lac, Wisconsin≈ 120–179 mg/L0 ppt🟠 Hardgroundwater

National Benchmark

How Oshkosh compares to the USA average

BenchmarkHardnessAppliance Risk
Oshkosh≈ 120–179 mg/L🟠 Moderate
USA National Avg151 mg/L🟠 Moderate
Scarsdale Top Rated0.02 mg/L🟢 None

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What Makes Oshkosh's Water Unique?

Local geology and source profile

Source: ReservoirTDS: 332 mg/LpH: 7.7

The City of Oshkosh Water Utility serves the Winnebago County area in east-central Wisconsin, drawing from two surface water sources: the Fox River and Lake Winnebago. The utility operates treatment facilities for the city's public water system. According to the 2024 Water Utility Report Card, the system achieved a water quality-health grade of A (99.7), indicating strong compliance and safety standards.

The Fox River and Lake Winnebago watersheds flow through glaciated terrain underlain by Silurian and Ordovician dolomite and limestone formations. These carbonate rock layers dissolve readily in water, releasing calcium and magnesium ions that create the region's characteristically hard water supply. Passage through the mineral-rich Fox River valley and its connection to Lake Winnebago means the water chemistry is shaped by these formations, resulting in elevated hardness levels typical of the region.

Oshkosh's water is classified as hard, with typical measurements of 14–18 grains per gallon. Scale buildup accumulates in pipes, water heaters, dishwashers, and washing machines, reducing soap and detergent efficiency and leaving visible deposits on fixtures. Many homeowners install water softeners to mitigate these effects and extend appliance lifespan. The City of Oshkosh Water Utility monitors PFAS compounds under EPA UCMR 5; background testing at the Fox River Main Street Bridge detected 0.856 ppt PFOS and 0.831 ppt PFOA — both well below Wisconsin's recommended drinking water standard of 70 ppt combined. The utility publishes annual consumer confidence reports documenting compliance with all federal and state drinking water standards.

Geology & Source: Fox River and Lake Winnebago, glaciated eastern Wisconsin; Silurian and Ordovician dolomite and limestone formations dissolve readily — calcium and magnesium ions elevated by carbonate bedrock drainage; characteristically hard supply

Other Wisconsin Water Reports

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Frequently Asked Questions

Is Oshkosh's water safe to drink?
Yes. Oshkosh's water meets all federal safety standards. The hardness is ≈ 120–179 mg/L (Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.
Do I need a water softener in Oshkosh?
At ≈ 120–179 mg/L (Hard), Oshkosh's water will cause significant limescale on kettles, washing machines, and water heaters. A water softener or descaler is strongly recommended to extend appliance lifespan and reduce energy bills by up to 20%.
How does Oshkosh compare to the USA average?
The USA national average is 151 mg/L. Oshkosh (≈ 120–179 mg/L) is 1 mg/L below the national average. The softest major city is Scarsdale at just 0.02 mg/L.

Data Sources & Methodology

Water quality data for Oshkosh is derived from geographic and geological modelling of the surrounding region. No federal monitoring station data was available for this location.

Estimated

Water Hardness

Modelled estimate based on state-level USGS geological survey data for this region. No direct USGS Water Quality Portal measurement was matched to this city — the value reflects a statistical range calibrated to the state's dominant rock types and typical source water characteristics.

Estimated

pH

Estimated from regional geology and source water characteristics. pH is correlated with water hardness and local bedrock — values may differ from utility-reported figures.

Estimated

TDS — Total Dissolved Solids

Estimated using a derived ratio from water hardness and regional conductance profiles. TDS in natural water correlates strongly with total mineral content including hardness ions.

Measured

PFAS — Perfluoroalkyl and Polyfluoroalkyl Substances

EPA UCMR5 (5th Unregulated Contaminant Monitoring Rule, 2023–2025) — sum of PFAS compounds detected at the public water system serving this city. A value of 0 indicates the system was sampled with no detection above reporting limits.

Modelled

Lead

Modelled estimate based on the EPA Lead and Copper Rule 90th-percentile tap-sample methodology. No publicly available per-city lead dataset with sufficient national coverage exists. Values are a conservative baseline derived from city population tier and infrastructure age — all estimates are maintained below the EPA action level of 0.015 mg/L.

Calculated

Appliance Lifespan

Calculated from water hardness using a linear degradation model. Baseline lifespans represent soft-water performance (kettle: 8.5 yrs, washing machine: 12.0 yrs, water heater: 15.0 yrs). Hard water mineral scale progressively reduces operational life in direct proportion to hardness concentration.