Greg Linder

Exposure pathways and biological receptors: baseline data for the canyon uranium mine, Coconino County, Arizona

Abstract Recent restrictions on uranium mining within the Grand Canyon watershed have drawn attention to scientific data gaps in evaluating the possible effects of ore extraction to human populations as well as wildlife communities in the area. Tissue contaminant concentrations, one of the most basic data requirements to determine exposure, are not available for biota from any historical or active uranium mines in the region. The Canyon Uranium Mine is under development, providing a unique opportunity to characterize concentrations of uranium and other trace elements, as well as radiation levels in biota, found in the vicinity of the mine before ore extraction begins. Our study objectives were to identify contaminants of potential concern and critical contaminant exposure pathways for ecological receptors; conduct biological surveys to understand the local food web and refine the list of target species (ecological receptors) for contaminant analysis; and collect target species for contaminant analysis pri...

A Geospatial Approach to Identify Water Quality Issues for National Wildlife Refuges in Oregon and Washington

Abstract Many National Wildlife Refuges (Refuges) have impaired water quality resulting from historic and current land uses, upstream sources, and aerial pollutant deposition. Competing duties limit the time available for Refuge staff to identify and evaluate potential water quality issues. As a result, water quality–related issues may not be resolved until a problem has already arisen. This study developed a geospatial approach for identifying and prioritizing water quality issues affecting natural resources (including migratory birds and federally listed species) within Refuge boundaries. We assessed the location and status of streams pursuant to the Clean Water Act in relation to individual Refuges in Oregon and Washington, United States. Although twelve Refuges in Oregon (60%) and eight Refuges in Washington (40%) were assessed under the Clean Water Act, only 12% and 3% of total Refuge stream lengths were assessed, respectively. Very few assessed Refuge streams were not designated as impaired (0% in O...

Risk and Consequence Analysis Focused on Biological Invasions Potentially Associated with Surface Water Transfers from the Missouri River to the Red River Basins

Under the auspices of the Dakota Water Resources Act (DWRA) of 2000, the Secretary of the Interior was directed to conduct a comprehensive study of the water quality and quantity needs of the Red River Valley and the options for meeting those needs. As such, the Bureau of Reclamation (Reclamation) requested technical support from the U.S. Geological Survey (USGS) Columbia Environmental Research Center (CERC) for an evaluation of the risks and economic consequences of biota transfers potentially associated with interbasin water transfers that might occur between the Upper Missouri River and the Red River of the North (Red River) basins. The technical findings of that project are summarized through a series of presentations at the Environmental and Water Resources Institute 2007 Congress in Tampa, Florida. The first paper in the series provides a brief overview of the project and the historic context for this evaluation relative to potential biota transfers, and a second presentation summarizes the technical tools applied to the analysis of risks and economic consequences. The final presentation in the series characterizes the risks and consequences potentially associated with biota transfers directly resulting from interbasin water transfers and competing pathways.