Abstract

This report is the result of the RIVM-project "International evaluation of in-situ biorestoration of contaminated soil and groundwater". As a fellowship project, it was associated with the international NATO/CCMS pilot project on "Demonstration of Remedial Action Technologies for Contaminated Land and Groundwater". The philosophy of in-situ biorestoration is to stimulate the indigenous soil microorganisms by improving the environmental conditions in the soil using a water recirculation system. The objective of the project is to show the possibilities for application of the technique in relation with contaminants, soil conditions and other site-specific circumstances by means of integration and evaluation of results of in-situ biorestoration projects. It can be used especially for locations at which both the unsaturated zone and the groundwater are contaminated with hydrocarbons. A precondition is a good permeability of the soil. If applicable, in-situ biorestoration is generally more cost-effective than other remediation techniques; costs are approximately between 40-80 US $/m3.