Dicamba residues in streams after forest spraying.

Control of hardwoods is vitally important in the establishment of Douglas-fir seedlings on Pacific Northwest forest lands. In reducing the competition of these brushy species, herbicides have become nearly an indispensable tool. However, with the increasing awareness of the importance of a clean environment, it has become apparent that the safe use of these chemicals requires a knowledge of their behavior, particularly with respect to water contamination (NORRIS 1971).