Natural attenuation: A feasible approach to remediation of ground water pollution at landfills?

Remediation of ground water pollution at old landfills with no engineered l eachate collection system is a demanding and costly operation. It requires control of the landfill body, since the majority of the pollutants are stil l present in the landfilled waste for decades after the site has been close d. However, natural attenuation of the plume without removing the source is an attractive approach to managing leachate plumes. Natural attenuation ha s been implemented for petroleum hydrocarbon plumes and for chlorinated sol vent plumes, primarily in the United States. Natural attenuation has not ye t gained a foothold with respect to leachate plumes, however. Based on the experiences gained from 10 years of research on two Danish landfills, it is suggested that natural attenuation is a feasible approach but is more comp licated and demanding than in the case of petroleum hydrocarbons and chlori nated solvent.