Well Water in Rock County: What to Test and Why

Moderate Risk
Testing Recommended 8141 samples analyzed
Top Concerns in This County
Lead

Why This Happens Here

Groundwater in Rock County contains lead, e_coli, and chloride that well owners should be aware of. Lead is present at levels that exceed EPA health standards and requires attention.

Lead enters groundwater through corroded pipes and plumbing fixtures in older wells and homes, while bacteria can seep down from the surface through cracks or poor well construction. Chloride comes from road salt applied during winter months, which gradually works its way into the water below.

Groundwater in Rock County is very hard, driven by elevated calcium and magnesium from the limestone bedrock beneath the county. As water moves slowly through these rock layers, it dissolves minerals and picks them up on its way to your well. Very hard water is the standard across most wells in this county.

What This Means for You

Lead shows up in wells across Rock County at levels that exceed EPA health standards. Lead is especially harmful to children because it can damage growing brains and affect how they learn and develop. Even in adults, lead exposure over time can cause kidney problems and high blood pressure.

Rock County has very hard water, which means you may notice white scale buildup on faucets and showerheads. Hard water also makes soap less effective and can leave spots on dishes and glassware. Over time, very hard water can shorten the lifespan of water heaters and dishwashers because of mineral deposits inside them.

Testing is the only way to know what is actually in your well, since every well is different and yours may have higher or lower levels than what is common in the county. We recommend a comprehensive water panel to check for lead and other contaminants, which typically costs between $200 and $400. A water softener can help with hardness, and point-of-use filters designed for lead removal are also available.

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
Lead 9 29% 78% · 0% · 22% Low High
Fluoride 4 0% 100% · 0% · 0% Low Low
Sulfate 2 0% 100% · 0% · 0% Low Low
Chloride 18 0% 100% · 0% · 0% Moderate Low
PFOA ⓘ municipal 42 0% 100% · 0% · 0% Moderate Safe
PFNA ⓘ municipal 42 0% 100% · 0% · 0% Moderate Safe
PFHxS ⓘ municipal 42 0% 100% · 0% · 0% Moderate Safe
PFOS ⓘ municipal 42 0% 100% · 0% · 0% Moderate Safe
HFPO-DA (GenX) ⓘ municipal 42 0% 100% · 0% · 0% Moderate Safe
Uranium 2 0% 100% · 0% · 0% Low Low
E. coli 2 0% 100% · 0% · 0% Low Safe
Nitrite 1 0% 100% · 0% · 0% Low Safe
Manganese 1 0% 100% · 0% · 0% Low Safe
Iron 1 0% 100% · 0% · 0% Low Safe
pH 18 Moderate Low
Sodium 34 Moderate Low
Nitrate 1 0% 100% · 0% · 0% Low Safe
Arsenic 1 0% 100% · 0% · 0% Low Safe
Hardness 9 Low Low
Fecal Coliform 2 Low Safe
PFBS ⓘ municipal 42 100% · 0% · 0% Moderate 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.

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

Order a Tap Score Test →

Population Health Context

Population-level CDC data. Not individual risk prediction.

6.7%
Heart Disease Rate
(state avg: 6.5%)

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