Constructed wetlands for mitigation of atrazine-associated agricultural runoff

Atrazine was amended into constructed wetlands (59-73 x 14 x 0.3 m) for the purpose of monitoring transport and fate of the pesticide to obtain inform ation necessary to provide future design parameters for constructed wetland s mitigation of agricultural runoff. Following pesticide amendment, a simul ated storm and runoff event equal to three volume additions was imposed on each wetland. Targeted atrazine concentrations were 0 mu g/l (unamended con trol), 73 mu g/l, and 147 mu g/l. Water, sediment, and plant samples were c ollected weekly for 35 days from transects longitudinally distributed throu ghout each wetland and were analyzed for atrazine using gas chromatography. Between 17 and 42% of measured atrazine mass was within the first 30-36 m of wetlands. Atrazine was below detection limits (0.05 mu g/kg) in all sedi ment and plant samples collected throughout the duration of this study. Aqu eous half lives ranged from 16 to 48 days. According to these data, conserv ative buffer travel distances of 100-280 m would be necessary for effective runoff mitigation. Published by Elsevier Science Ltd.