LEAD CONTAMINATION ASSESSMENT OF DRINKING WATER IN DAVENPORT, IOWA

The recent and ongoing water crisis in Flint, Michigan, has raised awareness of the susceptibility of municipal water supplies to lead contamination from aging infrastructures and household plumbing fixtures. As part of a larger, multifaceted project to assess lead contamination and poisoning in an aging neighborhood, this study focused on lead concentrations in water sampled from high-risk homes of older neighborhoods in Davenport, Iowa. The drinking water in Davenport comes entirely from the Mississippi River, and it is treated by Iowa American Water before being released into the city’s storage and distribution system. The goals of this study are to identify homes likely to contain lead pipes and to assess the amount of lead present in their drinking water in order to determine the efficacy of the water treatment process.

Homes selected for this study were all constructed before 1978 and exist in neighborhoods with high renter occupancy and low median income. Beyond those factors, site selection depended on which occupants gave permission to collect samples. For each home, samples were taken from either kitchen or bathroom faucets. Water was sampled using standard EPA protocols. Initially, a first draw sample was taken without flushing the tap after a minimum 6 hour stagnation time. Follow-up samples were taken after allowing the tap to flush for two minutes. Samples were collected in 1000 ml bottles, and nitric acid was added as a preservative. Samples were analyzed by Iowa American Water’s certified lab using an inductively coupled plasma mass spectrometer. Some water samples did contain detectable lead, ranging between no detectable lead and 4 ppb. No sample concentrations exceeded the EPA’s action level of 15 ppb. These results contrast with a previous study of untreated surface waters in the area, which found lead concentrations above the EPA action levels (Emmer, 2012). This study provides evidence that the water treated in Davenport has lead removed, and it does not acquire an actionable amount of lead as it flows through the system.