A five month survey of 2,4-D in Buckhorn Lake water and sediment, combined with streamflow data, produced estimates of the chemical in the lake. The peak concentrations in the water alone were significantly higher than the documented uses would permit. Two distinct concentration peaks were shown by the chemical: one during the June milfoil control season, and one in late August, indicating a release of 2,4-D from the collapsed and decaying milfoil beds. The observed rates of disappearance of the chemical agreed with reported values, showing a limited persistence in the lake. The presence of 2,4-D in the spring sediments was attributed to land runoff.