CHARACTERIZATION OF AN OLD MUNICIPAL LANDFILL (GRINDSTED, DENMARK) ASA GROUNDWATER POLLUTION SOURCE - LANDFILL HYDROLOGY AND LEACHATE MIGRATION

The migration of leachate from an old municipal landfill (Grindsted, D enmark) was investigated by intensive mapping of groundwater potential s and groundwater quality at the downstream borders of the landfill an d beneath the landfill. A groundwater mound controlling the migration of the leachate into the aquifer was observed beneath the landfill, es pecially after the wet season The lateral spreading in the leachate pl ume was significantly increased due to the water table mound present a nd the seasonal variations of the mound. Also, a significant vertical transport of leachate in the aquifer was observed below the landfill. Detailed information about the spatial and seasonal changes in groundw ater flow directions and location of intensive leaching is needed in o rder to design a cost effective delineation of the plume in the downst ream aquifer and to establish appropriate remediation.