radon and groundwater in York 6

https://noon-wiki.win/index.php/Why_Radon_Testing_for_Home_Buyers_Matters_in_York_County

In York, radon from underlying granite can seep into groundwater and concentrate in well water, posing a health risk when the water is used indoors. Homeowners on private wells should test for radon and consider aeration or granular activated carbon filters if levels are high.