LEAD IN HOMES WITH DOMESTIC WELLS IN THREE ILLINOIS COUNTIES

Lead in drinking water has recently become a national concern on account of the leaching of lead from old water mains and service lines by corrosive water. The Lead and Copper Rule (LCR) requires public water supplies to test the quality of water at taps inside homes within their service area, but this rule does not apply to private water supplies. This study had two main research aims: (1) characterize the distribution of water lead levels (WLLs) and water corrosivity in tap water of homes with private wells in three Illinois counties, and (2) develop and evaluate a screening strategy for predicting Pb detection within a given home.

A total of 151 samples was collected from kitchen taps in Phase I of the study to determine lead and corrosivity levels. Results indicated the potential vulnerability of domestic wells throughout Illinois to have lead contamination in tap water. Almost half (48.3%) had detectable lead (> 0.76 ppb) in the first draw sample, and 22.5% had detectable lead in the seventh liter sample. Five first draw samples (3.3%) exceeded the LCR action level of 15 ppb. Elevated WLLs were associated with older homes and well water with high corrosivity, and most of highest levels were determined to be in particulate form. For the samples with the highest WLLs, most of the lead appeared to be in the particulate form. In Phase II of the study, 28 homes with high lead levels were re-sampled and a more complete water quality analysis was done. Homes that had elevated levels of particulate lead in Phase I showed far lower WLLs in Phase II. This result suggests that the release of lead-containing particles may occur intermittently. This intermittency makes it difficult to conclude with confidence that even homes without detectable WLLs are in fact lead-free.