However, like most rules, there are exceptions. Pesticides with solubilities of 1 ppm or less are believed to have a higher likelihood of runoff. Likewise, pesticides with high K oc values are more likely to run off than leach. Nonpoint sources are broad, undefined areas in which pesticide residues are present. Figure 3 .
Pesticides can enter water supplies from point sources or from nonpoint sources.
Most pesticide contamination does not come from normal, correct usage. Problems arise from misuse or careless handling. A checklist is provided to use when applying any pesticide. Use this guideline to help safeguard water sources near your nursery operation. Evaluate the location of water sources.