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Groundwater record of halocarbon transport by the Danube River

Environmental Science and Technology

By:
, , , , ,
DOI: 10.1021/es970336h

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Abstract

Groundwater dating studies have supported the concept that aquifers with low coefficients of dispersion may contain coherent records of past conditions in recharge areas. Groundwater records can provide unique information about natural or anthropogenic changes in the atmosphere and hydrosphere where long-term monitoring data are not available. Here we describe a 40-year record of halocarbon contamination in the Danube River that was retrieved from a shallow aquifer in northwest Hungary. The time scale is based on 3H and He isotope dating of groundwaters that were recharged by the Danube River and moved horizontally away from the river in a surficial gravel aquifer with minor dispersion at a maximum rate of at least 500 m/yr. Analyses of dated groundwaters along a flow path indicate that the river loads of selected compounds (including CFC-12, CFC-113, and trichloroethane) were negligible before about 1950, rose rapidly to peak values in the 1960s and 1970s, and then decreased by varying degrees to the present. Peak concentrations are tentatively attributed to point sources in upstream urban-industrial centers; while recent decreases presumably resulted from declining manufacturing rates and(or) improvements in control of urban- industrial runoff and sewage effluent entering the river in upstream areas.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Groundwater record of halocarbon transport by the Danube River
Series title:
Environmental Science and Technology
DOI:
10.1021/es970336h
Volume
31
Issue:
11
Year Published:
1997
Language:
English
Publisher:
ACS
Publisher location:
Washington, DC, United States
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
3293
Last page:
3299
Number of Pages:
7