Occurrence of Estrogenic Endocrine Disruptors in Groundwater

Growing populations are influencing groundwater quantity and quality causing groundwaterprofessionals to continually monitor and deal with emerging issues. Increasing demands forgroundwater, resulting in infiltration of surface water into groundwater is a classic example ofone of theses issues. The drawdowns and cones of depression associated with high capacitymunicipal and agricultural wells placed near rivers have resulted in reversals in groundwaterflows. This flow reversal then sets up a potential for contaminants from the river to betransmitted to groundwater by infiltration. Additionally, the proliferation of non- conventional smallscale on site waste disposal systems in rural areas may provide another route for entrance ofcompounds of concern to groundwater. It is expected that such non-conventional systems willusually be installed in vulnerable groundwater settings, such as areas of shallow bedrock or highwater tables, where conventional on-site septic systems would not be allowed. Of growing concern related to these phenomena, is the potential for detrimental human healtheffects associated with the presence of compounds in polluted surface waters known asendocrine disrupting compounds (EDCs). Infiltration of these EDCs into the groundwater maycompromise the water quality and pose a risk to human health. The understanding of theoccurrence of these compounds in Wisconsin groundwater is necessary to aid in future decision making regarding water use. A data base needs to be created regarding the occurrence of EDC’s in groundwater, and more specifically the occurrence in vulnerable areas near rivers and rural developments which use non-conventional waste treatment systems. This data will then allow informed negotiations within the water supply community regarding decisions that willprotect the long term health of individuals who consume groundwater. The primary goal of this project is to determine the presence of estrogenic endocrine disrupting chemicals in groundwater by using the E-screen assay. Samples will be collected from high capacity municipal water supply wells located near surface waters impacted by industrial and municipal effluents. Wells from unsewered subdivisions that are likely under septic systeminfluence will also be assayed for estrogenic activity. Samples that indicate estrogenic activitywill by analysed with gas chromatography to identify which estrogenic compounds are responsible for the estrogenic activity with the E- screen. This study will help provide importantdata that could influence future decision making regarding important groundwater issues suchas land use planning, water treatment options, well placement and water use.