Imaging leachate runoff from a landfill using magnetotellurics: The Garraf karst case

Electrical and active source electromagnetic geophysical methods have been traditionally employed to approach and tackle environmental problems, such as those caused by landfills. However, since these problems are more consequential and cover broader areas, it is necessary to use deeper penetration...

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Detalles Bibliográficos
Autores: Martí i Castells, Anna, Queralt i Capdevila, Pilar, Marcuello Pascual, Alejandro, Ledo Fernández, Juanjo, Mitjanas Colls, Gemma, Piña-Varas, Perla, Freixes, A., Solà, Judit, Pons, P., López, J.
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2024
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/208288
Acceso en línea:https://hdl.handle.net/2445/208288
Access Level:acceso abierto
Palabra clave:Geofísica
Abocadors
Carst
Garraf (Catalunya : Massís)
Prospecció magnetotel·lúrica
Lixiviats
Geophysics
Waste disposal sites
Karst
Garraf Mountains (Catalonia)
Magnetotelluric prospecting
Leachate
Descripción
Sumario:Electrical and active source electromagnetic geophysical methods have been traditionally employed to approach and tackle environmental problems, such as those caused by landfills. However, since these problems are more consequential and cover broader areas, it is necessary to use deeper penetration methods, such as magnetotellurics. In the Garraf Massif (Catalan Coastal Ranges, NE Spain), an urban waste disposal landfill had been in operation from 1974 to 2006, during which more than 26 million metric tons of garbage had been deposited. This landfill overlies karstic terrain, thus principally impacting groundwater circulation. Previous electrical resistivity tomography profiles had partially imaged the infill but were not able to penetrate below the base of the original landfill. During 2019 and 2020 we performed a magnetotelluric study over the landfill and its surrounding with the goals of characterizing the electrical resistivity of the infill and below it. The 2D and 3D resistivity models confirmed the highly conductive nature of the leachate and allowed us to identify its presence below the landfill base, which we quantified with maximum thicknesses of 90 m. This proved that landfill leachate had filtered through the original impermeable layer, enhanced by the karstic drainage structure.