Patrick Sutton
    Aerially-Deposited Lead
    Topic posted June 11, 2010 by Patrick SuttonSuper Contributor , last edited January 19, 2012
    691 Views, 3 Comments
    Aerially-Deposited Lead

    Beginning in 1973, the EPA ordered a gradual phase out of lead from gasoline that significantly reduced the prevalence of leaded gasoline by the mid-1980s.  Shallow soils in highway corridors have the potential to be contaminated with aerially-deposited lead (ADL) due to historic car emissions from automobile exhausts prior to the elimination of lead in gasoline. 

    Does anyone have some thoughts on how ADL would fit into the language of a Phase I report?  I'm not sure if calling it an REC is technically correct.  Maybe there is no wrong or right answer here, but I'd appreciate some feedback. 




    • Tom Speight

      Depending on the concentration, it could be de minimis.

    • Patrick Sutton

      I've conducted several ADL investigations along highway corridors in California and concentrations of lead generally range from low concentrations up to about 3,000 ppm.  I guess it's still a release and therefore it's an REC.  If there was a court case regarding cleanup, I wonder who would be found responsible.  I assume the highway department, but maybe the property owner would get stuck with the costs.   



    • ks

      I'd call it a REC, but would need to back it up with suitable historic information.  An old two lane road might not cut it, but a 80 year old major freeway would. 

      Unless you have sample results, there is no way in knowing what the concentration is.  I have heard of sites in the Bay Area of California where ADL required excavation - unfortunately, the site was several acres in size and the price tag was pretty high.  A few hundred for an initial round of sampling (at a minimum) would be an appropriate followup if warranted.