Organic pollutants leaching in agricultural field: patterns in groundwater and subsurface water

Organic pollutants contain a variety of compounds that emerge from pest control as well as irrigation with treated effluents. Physico-chemical properties, as well as the history of application, determine distribution in flowpaths. Field-scale research, concentrated on common compounds or included many pesticides, yet analysis did not take the advantage of multiple behavior ranges of many compounds. Rarely short-term time series were collected for organopollutants.

In the current research subsurface and groundwater samples were collected from agricultural fields having subsurface drainage systems. Appling subsurface water in conditions of floods during winter required a demonstration of the subsurface unique composition, to avoid using samples including mixing with streamwater or groundwater. Samples were collected before, during, and after storm resulting in time series for subsurface and groundwater. No pest control intervention was taken thus results demonstrate authentic filed conditions. Analysis of time series in this study showed patterns indicating transport processes in the subsurface such as piston flow and leaching of stormwater, occurring in two stages of the storm. This result was supported as well in clustering analysis: clustering clearly showed different compositions of water samples taken in each stage. The clustering demonstrated as well differences between runoff, subsurface and, groundwater, as well as differences between adjacent fields.