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| Titel |
Modeling subsurface transport in extensive glaciofluvial and littoral sediments to remediate a municipal drinking water aquifer |
| VerfasserIn |
M. Bergvall, H. Grip, J. Sjöström, H. Laudon |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 15, no. 7 ; Nr. 15, no. 7 (2011-07-18), S.2229-2244 |
| Datensatznummer |
250012890
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| Publikation (Nr.) |
 copernicus.org/hess-15-2229-2011.pdf |
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| Zusammenfassung |
| Few studies have been carried out that cover the entire transport process of
pesticides, from application at the soil surface, through subsurface
transport, to contamination of drinking water in esker aquifers. In formerly
glaciated regions, such as Scandinavia, many of the most important
groundwater resources are situated in glaciofluvial eskers. The purpose of
the present study was to model and identify significant processes that
govern subsurface transport of pesticides in extensive glaciofluvial and
littoral sediments. To simulate the transport processes, we coupled a vadose
zone model at soil profile scale to a regional groundwater flow model. The
model was applied to a municipal drinking-water aquifer, contaminated with
the pesticide-metabolite BAM (2,6-dichlorobenzoamide). At regional scale,
with the combination of a ten-meter-deep vadose zone and coarse texture, the
observed concentrations could be described by the model without assuming
preferential flow. A sensitivity analysis revealed that hydraulic
conductivity in the aquifer and infiltration rate accounted for almost half
of the model uncertainty. The calibrated model was applied to optimize the
location of extraction wells for remediation, which were used to validate
the predictive modeling. Running a worst-case scenario, the model showed
that the establishment of two remediation wells would clean the aquifer in
four years, compared to nine years without them. Further development of the
model would require additional field measurements in order to improve the
description of macrodispersion in deep, sandy vadose zones. We also suggest
that future research should focus on characterization of the variability of
hydraulic conductivity and its effect on contaminant transport in eskers. |
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