Evaluation of Watershed Susceptibility to Contaminants of Emerging Concern

Contaminants of emerging concern (CECs) are raising public awareness because of their potential effect on aquatic ecosystems and public health. For this study, the authors applied spatial analyses to four selected US watersheds to identify critical areas susceptible to CECs and used watershed characteristics (i.e., potential source distribution, land use, climatic and hydrologic conditions) to prioritize the types of CECs. The results identified sub-basins where major wastewater treatment plants are located as critical areas for potential CEC point source pollution in general. Sub-basins containing intensive agricultural activities with high precipitation greatly contributed to CEC pollution, especially during wet-weather periods. The rank of prioritized prescribed pharmaceutical groups was similar for most watersheds because of the association between pharmaceutical groups and population demographics. Prioritized pesticide types were dependent on the type and areas of crops and urban yards in each watershed. This study demonstrates the utility of using spatial analysis for effectively assessing CECs in watersheds, which is important for the implementation of monitoring and management strategies.