Well Water in Westchester County: What to Test and Why

High Risk
Testing Strongly Recommended 17493 samples analyzed
Top Concerns in This County
Radon Iron Pfoa

Why This Happens Here

Groundwater in Westchester County contains lead, radon, iron, chloride, sulfate, and PFOA and PFOS compounds. These contaminants exceed EPA health standards and require your attention.

The limestone and carbonate rock beneath Westchester naturally releases iron and minerals into groundwater. Lead and PFOA enter from old pipes and industrial sources on the land above. Radon seeps from radioactive elements in the bedrock itself. Road salt used on roads and parking lots adds chloride to the water below.

Groundwater in this county is moderately hard, with elevated iron, sulfate, and moderate sodium from the carbonate rock that stores your water. The limestone dissolves slowly over time, releasing these minerals as water moves through it. These characteristics show up in wells across Westchester.

What This Means for You

Wells in Westchester County commonly exceed EPA health standards for chloride, iron, lead, PFOA, PFOS, PFNA, PFHxS, radon, and sulfate. Lead damages the brain and kidneys, especially in children. Radon is a radioactive gas that increases lung cancer risk. PFOA and related chemicals are linked to serious health effects including liver damage and immune system problems. Chloride at high levels can harm people with certain health conditions.

County wells show moderate hardness with elevated iron. You may notice rust-colored staining on fixtures and laundry. Iron can cause a metallic taste and smell. Buildup on pipes and appliances shortens the lifespan of water heaters and dishwashers. Your water may also have a salty taste from moderate sodium levels.

We recommend a comprehensive metals and minerals panel, since multiple contaminants exceed health standards. Every well is different--your well may have higher or lower levels than what is common in the county. Testing is the only way to know what is actually in your water so it can be properly treated. A comprehensive panel typically costs $200 to $400. Treatment options include reverse osmosis filters, activated carbon, water softeners, and radon removal systems depending on your results.

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 3 100% 33% · 0% · 67% Low High
Radon 10 70% 20% · 10% · 70% Low High
Iron 118 52% 40% · 8% · 52% High High
Chloride 108 41% 50% · 9% · 41% High High
Sulfate 78 29% 62% · 10% · 28% Moderate High
PFOA ⓘ municipal 137 14% 86% · 0% · 14% High Moderate
PFOS ⓘ municipal 137 7% 93% · 0% · 7% High Moderate
PFHxS ⓘ municipal 137 3% 95% · 2% · 3% High Low
PFNA ⓘ municipal 137 1% 99% · 1% · 1% High Low
Fluoride 4 0% 100% · 0% · 0% Low Low
Arsenic 2 0% 100% · 0% · 0% Low Low
Uranium 12 0% 100% · 0% · 0% Low Low
HFPO-DA (GenX) ⓘ municipal 137 0% 100% · 0% · 0% High Safe
E. coli 1 0% 100% · 0% · 0% Low Safe
Manganese 1 0% 100% · 0% · 0% Low Safe
Nitrate 1 0% 100% · 0% · 0% Low Safe
PFBS ⓘ municipal 137 100% · 0% · 0% High Low
pH 11 Low Low
Sodium 104 High Low
Nitrite 1 0% 100% · 0% · 0% Low Safe
Fecal Coliform 1 0% 100% · 0% · 0% Low Safe
Total Coliform 1 0% 100% · 0% · 0% Low Safe
Hardness 17 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.

5.7%
Heart Disease Rate
(state avg: 6.4%)
7.0%
Cancer Prevalence
(state avg: 6.7%)

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