Pesticides once applied may likely to get sorbed on soil surface, dissolved in runoff water or suspended as particles and carried by runoff water. The water runoff can be a significant route of transport of herbicides from their initial site of application to different places. Often, the ultimate sink for runoff is local surface water such as ponds, lakes and streams, where it is a matter of public concern. Runoff includes not only the water leaving a field in surface drainage but also any dissolved or suspended material it may contain. Contamination of drinking / irrigation water with pesticide residues is a serious environmental problem.