Pesticide Metabolites in South Dakota's Shallow Aquifers

The Geological Survey Program of the South Dakota Department of Environment and Natural Resources has established a Statewide Ground Water Quality Monitoring Network. This network consists of 145 monitoring wells at 80 sites in 24 aquifers across the state. The monitoring wells are installed in rural, agricultural areas to avoid point source pollution, and dedicated solely for the purpose of sampling shallow ground water. The monitoring wells from this network are periodically sampled for nitrates, pesticides, VOCs, radionuclides, trace metals, cyanide, and general inorganic constituents.

A limited number of ground water samples have also been analyzed for the presence of metabolites that are produced by the breakdown of pesticides. Several metabolite species (acetochlor OA, metolachlor ESA, propachlor ESA, desethylatrazine, and desisopropylatrazine) have been identified in ground water samples from this monitoring network. The extent of these metabolites and the risks they may pose to public health are unknown at this time, and routine monitoring of all metabolites is not within the program’s current budget. This unique monitoring well network can be an excellent field laboratory for anyone interested in studying metabolite distribution and public health risk in agricultural-dominated regions of the country. For more information on the opportunities that this network can provide, contact Tom Rich (trich@usd.edu) at the Geological Survey.

Benefits to South Dakota

The information provided by studies of pesticide metabolites will help determine the distribution of pesticide metabolites in shallow ground water aquifers in South Dakota. This information may also help state agencies determine what, if any risk that pesticide metabolites pose to public health. These studies would be directed at identifying the spatial and temporal distribution of metabolite species that are present in shallow ground water. State and federal agencies can then use this database to help identify regions within South Dakota that should be examined more closely for potential health risks.