Evidencias de pluma de contaminación detectadas por geofísica en el Basurero Municipal de Gualeguaychú, provincia de Entre Ríos, Argentina

POMPOSIELLO, MARIA CRISTINA; FAVETTO, ALICIA; BOUJON, PAMELA; DAPEÑA, CRISTINA; OSTERA, HECTOR

Río Cuarto, provincia de Córdoba

Congreso; IV Congreso Hidrogeológico Argentino y II Seminario Hispano Latinoamericano sobre Temas actuales de Hidrología Subterránea; 2005

Grupo Argentino Asociación Internacional de Hidrogeología, Departamento de Geología de la Facultad de Ciencias Exactas, Fisico-Químicas y Naturales y Universidad de Río Cuarto

This paper presents the geophysical results of a multidisciplinary project at an urban solidwaste landfill in Gualeguaychú, Province of Entre Ríos, Argentina. Several electric sounding(dipole-dipole), (Schlumberger) and GPR profiles (antennas 150 -500 Mhz) were performedwithin and outside the landfill. The depth of the water table was determined by GPR surveyat (2 ? 3) meters. The 2D model obtained within the landfill shows a first layer with athickness of (2 - 3) m and a resistivity range from 100 to 1000 Ohm-m. The second layer hasa thickness of (4 ? 5) m and a low value of resistivity (3 to 6 Ohm-m), which is attributed tothe contaminated zone and is below the water table. The third layer has a thickness of morethan 10 m and a resistivity of 15 Ohm-m. Below this depth is observed another conductivelayer (5 Ohm-m). The 2D model obtained outside the landfill boundary presents a conductivelayer at the same level as that inside the landfill, which shows that contamination exists atthe border of the landfill. The upper limit of the contaminant plume has been identified alongthe GPR profiles by the absence of reflectors or very weak signals. In such zone the 2Dresistivity model shows the presence of high electrical conductivity materials, which do notallow propagation of radar waves to large depth. The dipole-dipole, as Schlumberger andGPR results show a good agreement. The integrated interpretation was supported byregional geology.