Groundwater Pollution Case Studies

A large number of groundwater pollution cases are never published. This is especially true for severe cases. Yet an ever-growing number of case studies are being published. Every hydrochemist should read as many of these papers as possible, as each provides examples of possible scenarios and possible modes of diagnosis and remedy. A selection of pollution case studies is reviewed in the following sections. 

Pickens et al. (1978) worked on nitrate contamination in wells drilled in a shallow sandy aquifer. An N03 plume was detected in carefully sampled depth profiles (section 7.3), as shown in Fig. 16.1. The contamination was attributed to extensive use of nitrate fertilizers. 

Marcel Dekker, Inc. 270 Madison Avenue, New York, New York 10016 

Groundwater Profiles and Their Bearing on Nitrate Contamination 

Anderson et al. (1980) worked on nitrate distribution in the Karup Basin, 

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Biotransformation was also strongly indicated as a factor in the degradation of trichloroethylene in a case of soil and groundwater pollution (Milde et al. 1988). The only ethylenes at the point source of pollution were tetrachloroethylene and trichloroethylene however, substantial amounts of known metabolites of these two compounds (dichloroethylene, vinyl chloride, and ethylene) were found at points far from the source. Data from laboratory studies by the same group supported the study authors contention that degradation was due... 

Application of the EDAR Index to a case study of surface water and groundwater pollution... 

Cheng, K.P. and J.J. Jiao. 2008. Metal concentrations and mobility in marine sediment and groundwater in coastal reclamation areas A case study in Shenzhen, China. Environ. Pollut. 151 576-584. 

Monitoring of contaminants is somewhat like troubleshooting, but each contamination case study also has a scientific aspect, because each pollution case serves as a large-scale tracing experiment. The tracing of pollutants complements the methods presented in section 6.5, which is devoted to the establishment of hydraulic interconnections, the basic premise that underlies most groundwater models. 

Barber, C., Briegel, D. J., Power, T. R.,and Hosking, J. K.(1992). Pollution of groundwater by organic compounds leached from domestic solid wastes a case study from Morley, Western Australia. In Groundwater Contamination and Analysis at Hazardous Waste Sites, ed. Lesage, S., and Jackson, R. E., Marcel Dekker, New York, 357-380. 

It is not always necessary or required to digest the entire sample in order to free the metals for analysis. In some cases it is not even desirable. In studies of contaminated soils, for instance, the analyte of interest may be present as a soluble salt from a pollution source, as well as also being present in the structure of the mineral crystals. The soluble form is of concern, as it is available to biota and may eventually contaminate groundwater. That in the insoluble particles is not of interest. In such cases, where the analyte is much more soluble than the matrix or where the metals included in the matrix are not of interest, an extraction process rather than complete solubilization is preferred. This is treated further in Section 5.10. 

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