Article pubs.acs.org/est
Cite This: Environ. Sci. Technol. XXXX, XXX, XXX−XXX
Elevated Lead in Water of Private Wells Poses Health Risks: Case Study in Macon County, North Carolina Kelsey J. Pieper,*,† Victoria E. Nystrom,† Jeffrey Parks,† Kyle Jennings,‡ Harold Faircloth,‡ Jane B. Morgan,‡ Jim Bruckner,‡ and Marc A. Edwards† †
Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, 418 Durham Hall, Blacksburg, Virginia 24061, United States ‡ Environmental Health Services, Macon County Public Health Department, 1830 Lakeside Drive, Franklin, North Carolina 28734, United States S Supporting Information *
ABSTRACT: Recent research has indicated that lead in water of private wells is in the range of that which caused problems in Flint, Michigan. However, there is limited understanding of the mechanisms for water lead release in these systems. We evaluated water lead at the homes of two children with elevated blood lead in Macon County (North Carolina), which did not have identifiable lead paint or lead dust hazards, and examined water lead release patterns among 15 private wells in the county. Water lead release patterns differed among the 15 private wells. Problems with lead release were associated with (1) dissolution of lead from plumbing during periods of stagnation; (2) scouring of leaded scales and sediments during initial water use; and (3) mobilization of leaded scales during continued water use. Accurate quantification of water lead was highly dependent on sample collection methods, as flushing dramatically reduced detection of lead hazards. The incidence of high water lead in private wells may be present in other counties of North Carolina and elsewhere in the United States. The underestimation of water lead in wells may be masking cases of elevated blood lead levels attributed to this source and hindering opportunities to mitigate this exposure.
1. INTRODUCTION The corrosion of drinking water infrastructure and potential for water lead exposure has been of heightened national concern since the DC (2000−2004) and Flint Water Crises (2014− 2015), water lead contamination events that were demonstrated to increase the percentage of children with elevated blood lead levels (BLLs).1−5 While Flint’s corrosive drinking water source and absence of corrosion control may be considered an outlier among modern municipal water systems, prior research illustrates that the high lead levels during the crisis are typical for some residents dependent on private wells for potable water.6−8 For example, the 90th and 99th percentile water lead levels (WLLs) during the Flint Water Crisis and a 2012−2014 survey of private wells in Virginia were 26.8 and 26.7 μg/L and 118.9 and 95.0 μg/L, respectively.6,9 The 90th percentile WLLs for both were almost twice the U.S. Environmental Protection Agency (USEPA) Lead and Copper Rule lead action level (AL) of 15 μg/L (Figure 1).10 However, the AL is not a health-based standard, rather it is used to identify system-wide contamination.10,11 There is no safe level of lead exposure, as even low WLLs (
