Overview of Clean-Up Methods for Contaminated Sites

The selection of clean-up methods for contaminated land depends upon the nature and degree of contamination and on standards for clean up. There have been two approaches to clean-up standards, namely 'multifunctionality', where the site is cleaned up to a standard suitable for any use, and the 'end use'approach, as used in the UK, where clean up is to a standard suitable for the immediate use proposed for the site.
Clean-up options fall into four categories: (i) excavation and off-site removal; (ii) encapsulation and cover; (iii) retention of contaminated soil on site after treatment; and (iv) removal of contaminants from soil and reuse of cleaned soil on site.
In the UK, clean up has been dominated by off-site disposal and encapsulation/cover, while soil treatment techniques have been used mainly in the US and some European countries such as the Netherlands. This is largely as a result of the availability and relatively low cost of landfill in the UK and the lesser importance attached to date to groundwater considerations.
Soil treatment processes include biological, physicochemical, and thermal processes, all generally of much higher cost.