Well Water in Milwaukee County: What to Test and Why

High Risk
Testing Strongly Recommended 228 well tests on record
Top Concerns in This County
Iron Manganese Sulfate

Why This Happens Here

Groundwater in Milwaukee County contains iron, manganese, chloride, and sulfate. These contaminants exceed EPA health standards, which is a serious concern for well owners.

The bedrock beneath Milwaukee County naturally releases iron and manganese into groundwater as water moves slowly through the rock layers. Sulfate also dissolves from minerals in the same formations. Chloride enters partly from road salt applied during winter months. The low-oxygen conditions deep underground speed up the release of these metals and minerals.

Groundwater in this county is very hard, driven by elevated calcium and magnesium from the limestone bedrock, along with high levels of iron and sulfate. As water sits in contact with these rock layers over time, it picks up hard minerals and metals. Very hard water and elevated iron are common across wells in this county.

What This Means for You

Wells in Milwaukee County commonly contain chloride, iron, manganese, and sulfate at levels that exceed EPA health standards. Chloride at elevated levels can increase blood pressure in some people. Manganese is especially concerning for infants and young children because it can affect brain development. Iron and sulfate at these levels can also cause digestive problems.

The extremely hard water in this county leaves white, crusty scale buildup on fixtures and in pipes. Iron causes orange and brown staining on sinks, toilets, and laundry. The water may taste metallic or slightly bitter from the sulfate. This extreme hardness can shorten the lifespan of water heaters, dishwashers, and other appliances.

We recommend a comprehensive metals and minerals panel test for your well, since every well is different and your water could have higher or lower levels than what is common in the county. Testing is the only way to know what is actually in your well so it can be properly treated. A comprehensive panel typically costs $200 to $400. Treatment options like water softeners and iron removal systems can address multiple concerns.

Not sure if your well is affected? Get certified results in 5–7 days.

Test Your Well Water with Tap Score →

Contaminant Detection Data

Contaminant Samples ⓘ % Above MCL ⓘ Distribution ⓘ Confidence ⓘ Risk ⓘ
Iron 164 66%
High High
Sulfate 180 32%
High High
Manganese 159 10%
High Moderate
Chloride 180 1%
High Low
Arsenic 12 0%
Low Low
Fluoride 163 0%
High Low
HFPO-DA (GenX) ⓘ municipal 61 0%
Moderate Safe
Lead 12 0%
Low Safe
Nitrate 107 0%
High Low
Nitrite 63 0%
Moderate Low
PFHxS ⓘ municipal 61 0%
Moderate Low
PFNA ⓘ municipal 61 0%
Moderate Safe
PFOA ⓘ municipal 61 0%
Moderate Safe
PFOS ⓘ municipal 61 0%
Moderate Safe
Radon 1 0%
Low Low ⓘ
Uranium 11 0%
Low Low
Hardness 181 —
High Low
PFBS ⓘ municipal 61 —
Moderate Low
pH 184 —
High Low
Sodium 110 —
High Low

MCL = Maximum Contaminant Level (EPA limit for public water; used as benchmark for private wells). Distribution shows % of sampled wells in each concentration band. Methodology.
* Microbial contaminants (E. coli, coliform) reflect only samples from the last 10 years.

Data shows potential risk — a certified test confirms whether your water is affected.

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Population Health Context

Population-level CDC data. Not individual risk prediction.

5.7%
Cancer Prevalence
(state avg: 7.0%)
3.1%
Kidney Disease Rate
(state avg: 2.9%)
5.8%
Heart Disease Rate
(state avg: 6.5%)

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