Pre/post-closure assessment of groundwater pharmaceutical fate in a wastewater-facility-impacted stream reach.

Pharmaceutical contamination of contiguous groundwater is a substantial concern in wastewater-impacted streams, due to ubiquity in effluent, high aqueous mobility, designed bioactivity, and to effluent-driven hydraulic gradients. Wastewater treatment facility (WWTF) closures are rare environmental remediation events; offering unique insights into contaminant persistence, long-term wastewater impacts, and ecosystem recovery processes. The USGS conducted a combined pre/post-closure groundwater assessment adjacent to an effluent-impacted reach of Fourmile Creek, Ankeny, Iowa, USA.

Riverbank filtration potential of pharmaceuticals in a wastewater-impacted stream.

Pharmaceutical contamination of shallow groundwater is a substantial concern in effluent-dominated streams, due to high aqueous mobility, designed bioactivity, and effluent-driven hydraulic gradients. In October and December 2012, effluent contributed approximately 99% and 71%, respectively, to downstream flow in Fourmile Creek, Iowa, USA. Strong hydrologic connectivity was observed between surface-water and shallow-groundwater.

Human-impacted water resources: domain stratification and mapping to determine hydrologically similar units.

Geographic Information Systems (GIS) and multivariate statistical analyses were used to partition the United States into Human Influenced Water Environmental Classes (HIWECs) for the purpose of determining hydrologically similar units within the conterminous United States. Such a framework could be used to investigate various categories of watersheds throughout the country or to establish observatory sites in variant hydrologies. These HIWECs represent areas that are relatively homogeneous with respect to the human influence variables of land cover, population density, and water use; the climate variables of temperature and precipitation; and the physical variables of slope, bedrock permeability, and soil permeability.