A GEOPHYSICAL AND HYDROGEOLOGICAL STUDY OF AQUIFERS CONTAMINATION BY A LANDFILL

Landfills are the classical solution for waste disposal. During the la st years there has been a growing concern about the effect of landfill s in public health, because leaching water can contaminate nearby aqui fers. Hydrogeological studies are very important to investigate and re medy these contamination problems but an integrated use of both geophy sical and hydrological methods can be even more effective. In this pap er, the groundwater contamination by a landfill, located on very porou s and permeable formations, is assessed by both geophysical and hydrog eological techniques. Bearing in mind the geological and hydrogeologic al characteristics of the area, electrical methods were chosen to carr y out the geophysical survey. At first, electromagnetic methods were u sed and a ground conductivity survey was carried out to determine the contamination plume. Then several resistivity soundings were proposed and two resistivity pseudo-sections obtained so that a more detailed s tudy of the contamination was accomplished. From the geophysical data interpretation, strategically located boreholes were drilled, water sa mples obtained and chemical analysis carried out. Finally, the overall results are integrated and discussed as well as the merits and disadv antages of the techniques that have been employed.