Historical detections of four corn herbicides in ground water compared to relative ground water vulnerability (alachlor, atrazine, metolachlor, and simazine). Data are from the University of Nebraska-Lincoln Conservation Services Division (CSD) (1999) and Nebraska (2000).
Nebraska Conservation and Survey Division. 1999. Pesticides and Groundwater: An Applicator's Map and Guide to Prevent Groundwater Contamination.