Analysis of cleanups of lead-contaminated residential soils at u.s. smelter superfund sites

Abstract

Lead contamination from historic smelting operations continues to pose a public health risk in the United States, particularly from exposure to contaminated soils. Epidemiological studies have shown that concentrations of lead in residential soils can result in unacceptable exposures, and that there is no apparent blood lead concentration that may entirely avoid adverse health effects. These findings have caused regulatory agencies to gradually reevaluate previous blood lead targets and cleanup levels for lead sites. The U.S. Environmental Protection Agency (EPA), which is responsible for conducting cleanups of large-scale lead smelting sites that are on the National Priorities List, has acknowledged current literature that demonstrates risks from trace exposures, but has not yet revised the 1994 blood lead level target of 10 ?g/dL. This ambiguity is coupled with regional delegations of authority that have resulted in varied approaches to addressing lead contamination within the Superfund program. These inconsistencies create a challenge to remedial project teams tasked with determining strategies to address these future sites. I address this challenge by conducting a first-of-its-kind comprehensive evaluation of residential cleanups at lead smelter Superfund sites. By using publicly available data from decision documents for 31 lead smelter sites across the US, I identify predominant cleanup strategies. Although the evaluations demonstrate inconsistent blood lead targets and cleanup levels used between sites, they also illustrate commonalities in the type of remedy selected as well as general costs for residential cleanups conducted by EPA's removal and remedial programs. My results indicate that remedial project teams should embrace strategies that use both removal and remedial actions to address residential soil contamination and should expect to select a remedy based on excavation and backfill of contaminated properties. Soil amendments may be able to reduce lead bioavailability but have only been used for residential properties at one site and were unable to achieve residential cleanup standards. Last, my paper provides average preliminary cost estimates for residential cleanups, ranging from $434 per yd3 removal actions, and $125 per yd3 for remedial actions. Although costs differ substantially between sites, these general estimates provide a starting point for early planning efforts.