| The fate and transport of atrazine and three of its major degradation products were studied in a restored forested riparian buffer system to examine the effectiveness of the system in attenuating the chemicals. Concentrations of atrazine, deethylatrazine, deisopropylatrazine, and hydroxyatrazine were measured in groundwater, surface runoff water, surface runoff sediments, and soils throughout the buffer system following application of the parent compound on a 10 x 100 m strip immediately upslope from the buffer system. The restored buffer consisted of an 8 m grass zone adjacent to the application strip, a 20 m pine forested zone, and a final streamside hardwood zone. The grass and upper 10 m of pines were most instrumental in removal of the target chemicals based on net concentrations per meter of zone width. Deethylatrazine was the predominant degradation product in both water matrices, but removal efficiency (84.2% in ground water and 92.0% in surface runoff water) was also lowest for deethylatrazine. Atrazine, deisopropylatrazine, and hydroxyatrazine each exhibited between 94.7% and 100% removal between mass loads entering the upslope landscape position beginning at the application strip and the final stream side landscape position in both ground water and surface runoff water. Loads of each analyte associated with surface runoff sediments were least efficiently removed (67.4%--100%) within the system. Adsorption of the analytes to subsurface soils was minimal in this system. It is suggested that further degradation of the analytes and plant uptake are the primary processes involved in the removal of the compounds within the system. |
