Monitoring Ground Water for Pesticides

Abstract

At least 17 pesticides have been found in ground water in a total of 23 states as a result of agricultural practice. These results have been obtained through three different types of monitoring studies: (1) large-scale retrospective, (2) smallscale retrospective, and (3) small-scale prospective. The first two types of studies survey areas where the pesticide(s) in question has already been used. The third type of study is an intensive field study where the pesticide is applied and monitoring begins at time zero. Often, soil core data are at least as important as ground-water data. The ability to draw meaningful conclusions from large-scale studies is greatly diminished unless the studies have a statistical, stratified design. The purpose of this paper is threefold: to describe the three study types; suggest guidelines for ground-water sampling, soil sampling and well construction; and update the data summary of pesticides in ground water from agricultural practice.In 1984, Cohen et al. reviewed leaching and monitoring data on 12 different pesticides found in ground water in a total of 18 different states as a result of agricultural practice (V) · They also established criteria for predicting whether certain pesticides could leach to ground water as a result of normal use.In the less than 2 years since that paper was published, the numbers of pesticides found in ground water have increased significantly as have the number of states found to have pesticides in ground water. Seventeen pesticides have now been found in the ground water of 23 states as a result of agricultural practice (Figure 1, Table I). (As described in the "Occurrence" section at the end of this paper, many additional findings can be attributed to poor disposal practices, mixing-loading operations, etc. and are not included in this count.) This significant increase is more likely due to an increase in the quality and quantity of studies rather than an increase in This chapter not subject to U.S.

Detection of Oxamyl and Imidacloprid Pesticide residues in Some Iraqi Vegetables

“…Due to the high ability of bacteria for decompose oxamyl, it is found rarely in surface water and frequently in ground water [71]. Oxamyl residual duration life in plants are 1-2 weeks.…”

Potential contamination of ground water by pesticides

“…The basis of large scale retrospective studies is probability sampling (7). This means that every well In the study area which meets the criteria of the study objective must have a finite probability of being sampled in a random selection process.…”

“…In small-scale prospective studies, a pesticide is applied to a field along with a tracer such as chloride ion and the movement and dissipation of the pesticide is followed through soil and ground water for a period of, typically, one to two years (7). The primary objective of this study type is to characterize the subsurface fate of a particular pesticide, i.e.…”

“…The final study type is a small-scale retrospective study (7). It is analogous to the previous type of study, but is mainly used for existing pesticides when concerns for potential health hazard require study results more quickly.…”

Herbicide and Nitrate in Surface and Ground Water: Results from the Iowa Management Systems Evaluation Area

“…The MSEA program was initiated in response to previous studies indicating that pesticides were widespread in both surface water and groundwater at levels that possibly were significant to public health (2,3). Several MSEA programs included multiple sites and the Minnesota MSEA included sites in South Dakota, North Dakota and Wisconsin.…”