Horizontal wells provide a more effective access to subsurface contamination.
Soil vapor extraction can be combined with the injection process to strip the higher concentration, more easily removed contaminants from the subsurface. The types of sites most likely to apply ISB will contain moderately permeable, relatively homogenous sediments contaminated with VOCs, especially if both an extraction and injection component is utilized. However, the presence of clay strata does not preclude its use. The demonstration site was located at one of the source areas within the one-square mile VOC ground water plume. The site is underlain by a thick section of relatively permeable sands with thin lenses of clayey sediments.