Well Water in Allegheny County: What to Test and Why

Manganese, iron, sulfate, and chloride are present in Allegheny County groundwater, along with radon and PFOA/PFOS chemicals. Several of these contaminants exceed EPA health standards and require attention.

The bedrock beneath Allegheny County is Pennsylvanian-age shale and sandstone that formed in ancient swamps and contain coal seams. As groundwater moves slowly through cracks in these tight rock layers, it dissolves manganese and iron naturally present in the stone. Radon seeps from trace uranium in the rock, while sulfate, chloride, and PFOA/PFOS enter from both natural minerals and human sources like road salt and industrial contamination.

Groundwater in this county is moderately hard, with elevated iron and sulfate as the defining characteristics. Iron and sulfate dissolve into water as it contacts the coal-bearing rock layers underground. These mineral concentrations are common across wells throughout the county, though individual wells vary in their exact levels.

Wells in Allegheny County commonly contain manganese, radon, PFOA, PFOS, and PFHXS at levels above EPA health standards. Manganese can damage the nervous system and affect brain development. Radon is a radioactive gas that increases lung cancer risk over time. PFOA, PFOS, and PFHXS are human-made chemicals linked to serious health problems including kidney damage, thyroid disease, and increased cancer risk. Chloride and sulfate also exceed safe levels in many county wells and can cause digestive problems and affect blood pressure.

Wells in this county produce hard water with moderate iron and elevated minerals. You may notice orange-brown stains on sinks, toilets, and laundry from iron. Scale buildup can form on pipes and inside appliances. Hard water can shorten the lifespan of water heaters and dishwashers. Elevated sulfate may give water a bitter or unpleasant taste.

We recommend testing your well water through a certified lab. Every well is different--yours 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 well so it can be treated properly. Since multiple contaminants exceed health standards, a comprehensive metals and radon panel typically costs $200-400. Water softeners combined with aeration and filtration systems can address these concerns.