GROUND WATER CONTAMINATION CONCERNS IN HORTICULTURAL PRODUCTION SYSTEMS

The focus of this review article is on pesticide contamination of ground waters from horticultural crop production systems. In the past, agriculture was mainly concerned with "on-site" measures to enhance production. But now we have become increasingly aware of "off-site" impacts of farming operations, including the "out-of-sight" contamination of ground water. The issue of ground water contamination by pesticides is a far more complex problem than nitrate contamination simply because of the vast number and types of chemicals used to control pests. This paper describes the fate and transport of pesticides; the factors contributing to the vulnerability of leaching of pesticides, such as pesticide properties, soil properties, site conditions and management practices; and threshold values for determining pesticides that are "leachers". Two central themes are emphasized: "everything has to go somewhere" and "an ounce of prevention is worth a pound of cure." The article concludes with recommendations to implement source controls and alternative pest management practices. The likelihood of increased regulations on pesticide usage and banning of hazardous chemicals are anticipated.