“…In this technique, the impacted soils are isolated by low permeability caps, slurry walls, grout curtains, or cutoff walls. The contaminant source is covered with low permeability layers of synthetic textiles or clay caps designed to limit the infiltration of precipitation and thus prevent leaching and migration of contaminants away from the site and into the groundwater (Asante-Duah, 1996; Anderson and Mitchell, 2003;Robertson et al, 2003).…”