Fig. 2. Frequencies of herbicide detection in ground water from 1993 to 1995, by study component, during the NAWQA investigation. Numbers of sites sampled for acetochlor given in brackets. LUSs, land-use studies; SUSs, subunit surveys.
Fig. 2. Frequencies of herbicide detection in ground water from 1993 to 1995, by study component, during the NAWQA investigation. Numbers of sites sampled for acetochlor given in brackets. LUSs, land-use studies; SUSs, subunit surveys.