Groundwater Flow Model along a Vertical Profile of the Sardas Landfill in Sabiñánigo, Huesca, Spain

Lindane (a harmful contaminant) was produced in Sabiñánigo (Huesca, Spain) and deposited at the Sardas landfill. This site contains a large mass of pollutants, which have an extremely large contamination potential of the Ebre River. The site has undergone numerous human interventions that have modif...

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Main Authors: Javier Samper, Brais Sobral, Bruno Pisani, Acacia Naves, Joaquín Guadaño, Jorge Gómez, Jesús Fernández
Format: Article
Language:English
Published: MDPI AG 2023-09-01
Series:Water
Subjects:
Online Access:https://www.mdpi.com/2073-4441/15/19/3457
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author Javier Samper
Brais Sobral
Bruno Pisani
Acacia Naves
Joaquín Guadaño
Jorge Gómez
Jesús Fernández
author_facet Javier Samper
Brais Sobral
Bruno Pisani
Acacia Naves
Joaquín Guadaño
Jorge Gómez
Jesús Fernández
author_sort Javier Samper
collection DOAJ
description Lindane (a harmful contaminant) was produced in Sabiñánigo (Huesca, Spain) and deposited at the Sardas landfill. This site contains a large mass of pollutants, which have an extremely large contamination potential of the Ebre River. The site has undergone numerous human interventions that have modified the natural conditions. The site exhibits complex hydrogeological patterns and has been monitored systematically for a long period of time, and a large amount of geological, hydrological, and hydrogeological data are available. Here, a 2D finite element groundwater flow model along a vertical profile heading east–west along the thalweg of the former gully is presented. The main goal is modelling groundwater flow through the landfill, the Gállego River alluvial aquifer, and its interactions with the Sabiñánigo reservoir. The numerical model confirms the prevailing conceptual hydrogeological model of the site. The main results include: (1) Groundwater flows into the landfill mainly along perimeter ditches, which do not properly drain the surface and subsurface runoff (13.84 m<sup>3</sup>/d) and from the underlying marly rock (8.84 m<sup>3</sup>/d); (2) The total landfill leachate outflow towards the alluvial floodplain underneath the front slurry wall through a shallow marl layer is equal to 17 m<sup>3</sup>/d; (3) The oscillations of the Sabiñánigo reservoir water level produce a tidal effect that results in periodic changes of the hydraulic gradient between the alluvial gravels and the reservoir; (4) Groundwater flows generally from the alluvial aquifer towards the reservoir in an average E–W direction with an average Darcy velocity equal to 5 cm/d. The flow direction, however, changes to W–E when the reservoir level rises suddenly and; (5) The hydrodynamic parameters of the alluvial silts and reservoir silting sediments are crucial in determining the influence radius of the inversion of groundwater flow direction when the reservoir level rises suddenly. Model results enhance the confidence of the conceptual model, provide the basis for detailed specific models of the landfill and the alluvial aquifer, and highlight the importance of considering the tidal effect of the reservoir level oscillations. They also provide valuable information for managing the landfill and its impact on the surrounding groundwater system.
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spelling doaj.art-8849439334934c8e89a42bb0594e2cff2023-11-30T20:50:12ZengMDPI AGWater2073-44412023-09-011519345710.3390/w15193457Groundwater Flow Model along a Vertical Profile of the Sardas Landfill in Sabiñánigo, Huesca, SpainJavier Samper0Brais Sobral1Bruno Pisani2Acacia Naves3Joaquín Guadaño4Jorge Gómez5Jesús Fernández6Civil Engineering School, Interdisciplinary Center for Biology and Chemistry (CICA), Universidade de A Coruña, Campus de Elviña, 15071 A Coruña, SpainCivil Engineering School, Interdisciplinary Center for Biology and Chemistry (CICA), Universidade de A Coruña, Campus de Elviña, 15071 A Coruña, SpainCivil Engineering School, Interdisciplinary Center for Biology and Chemistry (CICA), Universidade de A Coruña, Campus de Elviña, 15071 A Coruña, SpainCivil Engineering School, Interdisciplinary Center for Biology and Chemistry (CICA), Universidade de A Coruña, Campus de Elviña, 15071 A Coruña, SpainEmpresa para la Gestión de Residuos Industriales, S.A., S.M.E., M.P., EMGRISA, C/ Santiago Rusiñol 12, 28040 Madrid, SpainEmpresa para la Gestión de Residuos Industriales, S.A., S.M.E., M.P., EMGRISA, C/ Santiago Rusiñol 12, 28040 Madrid, SpainUnidad para la Descontaminación Integral del Lindano, Departamento de Medio Ambiente y Turismo, Gobierno de Aragón, San Pedro Nolasco, 7, 50071 Zaragoza, SpainLindane (a harmful contaminant) was produced in Sabiñánigo (Huesca, Spain) and deposited at the Sardas landfill. This site contains a large mass of pollutants, which have an extremely large contamination potential of the Ebre River. The site has undergone numerous human interventions that have modified the natural conditions. The site exhibits complex hydrogeological patterns and has been monitored systematically for a long period of time, and a large amount of geological, hydrological, and hydrogeological data are available. Here, a 2D finite element groundwater flow model along a vertical profile heading east–west along the thalweg of the former gully is presented. The main goal is modelling groundwater flow through the landfill, the Gállego River alluvial aquifer, and its interactions with the Sabiñánigo reservoir. The numerical model confirms the prevailing conceptual hydrogeological model of the site. The main results include: (1) Groundwater flows into the landfill mainly along perimeter ditches, which do not properly drain the surface and subsurface runoff (13.84 m<sup>3</sup>/d) and from the underlying marly rock (8.84 m<sup>3</sup>/d); (2) The total landfill leachate outflow towards the alluvial floodplain underneath the front slurry wall through a shallow marl layer is equal to 17 m<sup>3</sup>/d; (3) The oscillations of the Sabiñánigo reservoir water level produce a tidal effect that results in periodic changes of the hydraulic gradient between the alluvial gravels and the reservoir; (4) Groundwater flows generally from the alluvial aquifer towards the reservoir in an average E–W direction with an average Darcy velocity equal to 5 cm/d. The flow direction, however, changes to W–E when the reservoir level rises suddenly and; (5) The hydrodynamic parameters of the alluvial silts and reservoir silting sediments are crucial in determining the influence radius of the inversion of groundwater flow direction when the reservoir level rises suddenly. Model results enhance the confidence of the conceptual model, provide the basis for detailed specific models of the landfill and the alluvial aquifer, and highlight the importance of considering the tidal effect of the reservoir level oscillations. They also provide valuable information for managing the landfill and its impact on the surrounding groundwater system.https://www.mdpi.com/2073-4441/15/19/3457HCHlindanelandfillgroundwater pollutionprofilenumerical model
spellingShingle Javier Samper
Brais Sobral
Bruno Pisani
Acacia Naves
Joaquín Guadaño
Jorge Gómez
Jesús Fernández
Groundwater Flow Model along a Vertical Profile of the Sardas Landfill in Sabiñánigo, Huesca, Spain
Water
HCH
lindane
landfill
groundwater pollution
profile
numerical model
title Groundwater Flow Model along a Vertical Profile of the Sardas Landfill in Sabiñánigo, Huesca, Spain
title_full Groundwater Flow Model along a Vertical Profile of the Sardas Landfill in Sabiñánigo, Huesca, Spain
title_fullStr Groundwater Flow Model along a Vertical Profile of the Sardas Landfill in Sabiñánigo, Huesca, Spain
title_full_unstemmed Groundwater Flow Model along a Vertical Profile of the Sardas Landfill in Sabiñánigo, Huesca, Spain
title_short Groundwater Flow Model along a Vertical Profile of the Sardas Landfill in Sabiñánigo, Huesca, Spain
title_sort groundwater flow model along a vertical profile of the sardas landfill in sabinanigo huesca spain
topic HCH
lindane
landfill
groundwater pollution
profile
numerical model
url https://www.mdpi.com/2073-4441/15/19/3457
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