A Survey of Lead, Nitrate and Radon Contamination of Private Individual Water Systems in Pennsylvania

Private individual water systems throughout Pennsylvania were sampled for dissolved lead, nitrate-N and radon to determine the prevalence of these primary pollutants. Approximately 1,600 sources were tested for lead and nitrate and 989 were tested for radon. Twenty-eightpercentof sampledhomes hadleadconcentrations above 10µg/Land 19percent were above 15 µg/L. These percentages increased to 60 and 34 percent respectively when calculated total (digested) lead data were used, suggesting that total lead analysis may be appropriate even when dealing with relatively clear, low turbidity samples. Nitrate contamination was less prevalent and more regional than lead. Nine percent of sampled homes contained nitrate-N above 10 mg/L with nearly all (96 percent) of these homes located in the agricultural southcentral and southeastern regions of the state. Nearly 80 percent of the groundwater wells tested contained radon concentrations above the proposed MCL of 300 pCi/L. Excessive radon concentrations existed in all regions of the state but were most prevalent in the eastern regions near the Reading Prong geologic formation.