The actions undertaken by the regional and national environmental agencies have provided good results for the remediation and containment of contaminants at the INQUINOSA lindane-affected sites in Sabiñanigo (Huesca, Spain). Lindane is an isomer of hexachlorocyclohexane which was a widely used pesticide in the past. Lindane-production wastes were disposed at the Sardas and Bailín landfills. The Sardas landfill is located near the Gallego river. The landfill was sealed in 1993. The quality of the Gállego river water is monitored in a daily basis. Thanks to the remediation and containment actions implemented by the Aragón Regional Government, the Gállego river water meets all the standards for water drinking (Férnández et al., 2013). Here we present a hydrological water balance model of the site to evaluate the groundwater recharge and the water inflows and outflows to the Sardas landfill. We also present 2D numerical groundwater flow and solute transport models along a vertical profile of the site. The steady state flow model confirms the prevailing conceptual model of the site. The transient model corroborates that the underlying Larrés marls prevent groundwater flow, except in shallow layer (< 5 m thickness) where the marls are fractured decompressed and altered. The average groundwater flow underneath the bentonite curtain is about 20 m3/d. The hydrogeological conditions downstream the landfill are strongly affected by the periodic oscillations of the nearby Sabiñánigo reservoir. The models have contributed to deepen the knowledge of the hydrogeology of the site and provide useful tools to screen future studies and remediation measures.
Fernández, J., Arjol, M.A. & Cacho, C. Environ Sci Pollut Res (2013) 20: 1937. https://doi.org/10.1007/s11356-012-1433-8