How they cleaned up Lead (Pb) in Utah....

"Type of Cleanup Utilized: In July 1992, surface soil screening samples were collected to identify the perimeter
of the high lead contamination areas. This was known as Phase I. Between November 1992 and March 1993,
Phase II required the collection of soil samples, in addition to dust, tap water, and paint samples from the interior
of residences. Removal in 1994 occurred for all properties with surface soil lead concentrations greater than 4000
ppm. Contaminated soil was removed and taken to an industrial landfill or other acceptable disposal facilities.
Cleanup levels for this action consisted of excavating soil to a depth of eighteen inches or to depths where lead
contamination levels were less than 800 ppm. Some excavation included the demolition of small structures and
the removal of trees and shrubbery, which were then tested for residual lead contamination. The debris was then,
if applicable, disposed of in a construction or municipal landfill. Dust control and hazardous materials release
controls were established for stockpiles of contaminated materials during the removal, including air monitoring for
releases of hazardous substances during removal operations. Clean soil was brought in to replace the removed
soil, and the site was returned to its original grade. All areas which were excavated or regraded were contoured to
assist in drainage, which was directed away from the foundations of houses and buildings. Irrigation ditches were
replaced in the same configuration as they were originally found and constructed of compacted clay to prevent
erosion. Residential sprinkler systems were also replaced."
from: CERCLA IMMINENT HAZARD MINING AND MINERAL PROCESSING FACILITIES Office of Solid Waste U.S. Environmental Protection Agency February 1997