Occurrence of Antibiotics in Wastewater Effluents and their Mobility in Soils: A Case Study for Wisconsin

Background/Need: Recent reports on the detection of pharmaceuticals in water bodies and waste streams in Europe and the United States have raised some environmental concerns. Sulfonamides have been detected in leachate from a Danish landfill, in Berlin drinking water wells for which 80% of the groundwater was bank-filtered surface water, and in groundwater in Germany. Studies in the U.S. have identified antibiotics (sulfonamides and trimethoprim) in groundwater down gradient from a landfill containing hospital waste, in water supply wells in a Nebraska bank filtration site and in groundwater from Washington. There is an increasing interest among scientists, policy makers and industry personnel in the U.S. to survey the nation’s water resources for human and veterinary pharmaceuticals, steroidal hormones, etc. The United States Geological Survey (USGS) is leading the efforts by collecting stream samples from several locations across the country to obtain baseline information regarding these emerging organic contaminants. Their efforts need to be augmented at the local level by systematically screening potential sources (e.g., wastewater treatment effluent, on-site wastewater systems, animal waste lagoons) to obtain a better understanding of the transport pathways and environmental fate of pharmaceuticals. Compared to conventional organic contaminants (e.g., pesticides, PAHs, PCBs), little information is available on the environmental fate and transport of antibiotics. The molecular properties of the antibiotics would favor sorption to soil components and interaction with metal ions in soils. However, our ability to predict mobility and fate of antibiotics in surface and subsurface systems is hampered by a lack of understanding of the fundamental processes governing their environmental reactivity.