Potential for soils to transfer pesticides to water systems in Southern Ontario
The purpose of this study was to determine where, in the Southern Ontario Great Lakes basin, high amounts of pesticides were being used on soils which can readily transport pollutants to water systems. The potential for soils to transport pesticides was assessed for 263 townships. Six potential problem categories were developed, each of which described a different combination of pesticide use (High, Moderate or Low) and soil potential for pollutant transfer to surface or ground water systems. Generally, the areas where pesticide transfer to surface water is most likely are located in Southwestern Ontario (townships in Lambton, Kent, Elgin, Oxford, Brant, Haldimand-Norfolk and Niagara Counties). Potential problems with ground water pollution are also concentrated in the same area, although ground water pesticide contamination was not predicted to be as widespread as that of surface water. Townships which were ranked highly for both surface and ground water potential problems were Dover, Raleigh and Tilbury East (Kent County), Dawn, Enniskillen, Moore, Plympton and Sombra (Lambton County) and Niagara-on-the-Lake (Regional Municipality of Niagara). Townships that might be expected to have fewer problems with pesticide pollution were those in south-central and eastern Ontario. It is hoped that the information from this study can be used in general, regional- level exercises to identify, prioritize and target "Potential Problem" areas for further investigations.