When biologically degradable contaminants remain in the soil for a longer period of time, something is wrong with the degradation conditions. An in situ remediation operation focuses on improving these conditions. The goal of laboratory research is to find out what conditions must be created in the soil in order to enhance degradation. Furthermore, it leads to a fairly accurate estimate of the degradation rate as well as of the feasible degradation results that may be expected. As a result of conducting this type of research, reasonable estimates can be made regarding the duration and the possible target values of the remediation operation.