How does Oak Creek's water compare to the national average?

The USA national average is 151 mg/L. Oak Creek (≈ 120–179 mg/L) is 1 mg/L softer than average.

Oak Creek Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

reservoir

pH Level

8.5

neutral = 7.0

Lead

0.007 mg/L

✓ Below action level

TDS

747.5 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 Oak Creek, your appliances are currently losing 20% efficiency due to mineral buildup.

Appliance	In Oak Creek	Soft Water City	Efficiency 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 Oak Creek compares to its nearest neighbours

City	Hardness	Risk	Source
▶ Oak Creek, Wisconsin	≈ 120–179 mg/L	🟠 Hard	reservoir
South Milwaukee, Wisconsin	≈ 120–179 mg/L	🟠 Hard	reservoir
Cudahy, Wisconsin	≈ 120–179 mg/L	🟠 Hard	reservoir
Caledonia, Wisconsin	≈ 120–179 mg/L	🟠 Hard	reservoir
Greendale, Wisconsin	≈ 120–179 mg/L	🟠 Hard	reservoir

National Benchmark

How Oak Creek compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Oak Creek	≈ 120–179 mg/L	🟠 Moderate
USA National Avg	151 mg/L	🟠 Moderate
Scarsdale Top Rated	0.02 mg/L	🟢 None

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What Makes Oak Creek's Water Unique?

Local geology and source profile

Source: ReservoirTDS: 747.5 mg/LpH: 8.5

The Oak Creek Water and Sewer Utility (OCWS) serves the municipality of Oak Creek in Milwaukee County, Wisconsin. The utility draws from both surface and groundwater sources within the Oak Creek and Root River watershed system. Treatment facilities are located at 170 West Drexel Avenue, Oak Creek, WI 53154. The OCWS has earned recognition for water quality, including a best tasting water award in Wisconsin, and publishes an annual Consumer Confidence Report covering water quality parameters, treatment processes, and compliance with Safe Drinking Water Act standards.

The Oak Creek watershed is part of the larger Root River basin in southeastern Wisconsin. The underlying geology consists of Pleistocene glacial deposits—clay, silt, and sand—overlying Ordovician and Silurian carbonate bedrock formations, particularly the Silurian Niagara Dolomite. These ancient limestone and dolomite layers are highly soluble, and groundwater percolating through them dissolves significant quantities of calcium and magnesium carbonates. This geological setting is characteristic of the Milwaukee County region and results in a naturally hard water supply.

Oak Creek's hard water reduces soap effectiveness, promotes scale buildup in pipes, water heaters, dishwashers, and washing machines, and can shorten appliance lifespan. Residents and businesses benefit from water softening systems to mitigate these effects, particularly for high-temperature applications and laundry. Regular maintenance of water-using appliances is recommended. The utility monitors for regulated contaminants including lead, copper, and inorganic and organic compounds; treatment includes coagulation, filtration, and disinfection to ensure safe water delivery throughout the community.

Geology & Source: Root River basin, Milwaukee County; Pleistocene glacial deposits over Ordovician–Silurian carbonate bedrock; Silurian Niagara Dolomite dissolves readily — calcium and magnesium ions produce hard water typical of southeastern Wisconsin

Other Wisconsin Water Reports

South Milwaukee

≈ 120–179 mg/L

🟠 Hard

Cudahy

≈ 120–179 mg/L

🟠 Hard

Caledonia

≈ 120–179 mg/L

🟠 Hard

Greendale

≈ 120–179 mg/L

🟠 Hard

Report an Issue

Notice an error or missing data? Help us keep this page accurate. If you spot incorrect water hardness, outdated utility info, or missing details, please let us know.

All reports are reviewed by our team. Thank you for supporting data quality!

Frequently Asked Questions

Is Oak Creek's water safe to drink?

Yes. Oak Creek'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 Oak Creek?

At ≈ 120–179 mg/L (Hard), Oak Creek'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 Oak Creek compare to the USA average?

The USA national average is 151 mg/L. Oak Creek (≈ 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 Oak Creek 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

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.