A synoptic sampling of five surface-water sites in central Nebraska wa
s conducted by the U.S. Geological Survey as part of its National Wate
r-Quality Assessment Program during storm runoff in May 1992 to relate
transport, yields, and concentrations of atrazine to environmental se
tting. Atrazine was the most extensively applied pesticide in the stud
y unit. Atrazine transport was related to the size of contributing dra
inage area, quantity of atrazine applied, amount of precipitation, and
volume of streamflow. Estimated yields and mean concentrations of atr
azine were related to the percentage of cropland in a drainage area. T
he largest estimated yields and mean concentrations of atrazine in sur
face water were associated from drainage areas with the highest percen
tage of cropland, and the smallest was associated with the smallest am
ount of cropland. Atrazine concentrations increased as streamflows, in
creased but decreased at or near the time of peak streamflows, perhaps
due to dilution. Atrazine concentrations then increased and remained
elevated far into the stream recession. Atrazine is a regulated contam
inant in finished public-water supplies. Large concentrations of atraz
ine could affect the management of public-water supplies because atraz
ine remains in solution in contrast to many other pesticides that are
more easily removed.