Detection and Characterization of Preferential Flow Paths in the Downstream Area of a Hazardous Landfill

Détails

ID Serval
serval:BIB_A9FD9A226F45
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Detection and Characterization of Preferential Flow Paths in the Downstream Area of a Hazardous Landfill
Périodique
Journal of Environmental Engineering Geophysics
Auteur⸱e⸱s
Perozzi L., Holliger K.
ISSN-L
1083-1363
Statut éditorial
Publié
Date de publication
2008
Peer-reviewed
Oui
Volume
13
Pages
343 - 350
Langue
anglais
Notes
Perozzi2008
Résumé
We have used surface-based electrical resistivity tomography to detect
and characterize preferential hydraulic pathways in the immediate
downstream area of an abandoned, hazardous landfill. The landfill
occupies the void left by a former gravel pit and its base is close
to the groundwater table and lacking an engineered barrier. As such,
this site is remarkably typical of many small- to medium-sized waste
deposits throughout the densely populated and heavily industrialized
foreland on both sides of the Alpine arc. Outflows of pollutants
lastingly contaminated local drinking water supplies and necessitated
a partial remediation in the form of a synthetic cover barrier, which
is meant to prevent meteoric water from percolating through the waste
before reaching the groundwater table. Any future additional isolation
of the landfill in the form of lateral barriers thus requires adequate
knowledge of potential preferential hydraulic pathways for outflowing
contaminants. Our results, inferred from a suite of tomographically
inverted surfaced-based electrical resistivity profiles oriented
roughly perpendicular to the local hydraulic gradient, indicate that
potential contaminant outflows would predominantly occur along an
unexploited lateral extension of the original gravel deposit. This
finds its expression as a distinct and laterally continuous high-resistivity
anomaly in the resistivity tomograms. This interpretation is ground-truthed
through a litholog from a nearby well. Since the probed glacio-fluvial
deposits are largely devoid of mineralogical clay, the geometry of
hydraulic and electrical pathways across the pore space of a given
lithological unit can be assumed to be identical, which allows for
an order-of-magnitude estimation of the overall permeability structure.
These estimates indicate that the permeability of the imaged extension
of the gravel body is at least two to three orders-of-magnitude higher
than that of its finer-grained embedding matrix. This corroborates
the preeminent role of the high-resistivity anomaly as a potential
preferential flow path.
Création de la notice
25/11/2013 17:31
Dernière modification de la notice
20/08/2019 15:14
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