The U.S. Geological Survey (USGS) has worked cooperative with the Unified Sewerage Agency of Washington County (USA) since 1990 to assess water quality in the Tualatin River Basin. The objectives of this study were to: assess the occurrence and magnitude of trace element and selected organic contaminants in streams of...
This report presents the concentrations of major ions, nutrients, and trace elements in water and bottom sediments collected in the four-tributaries during the low-flow condition of September 9-13, 1996. Stream-water chemistry results are contrasted, and trace-element concentrations compared with U.S. Environmental Protection Agency chronic aquatic life toxicity criteria. Bottom -sediment...
This report presents results of an investigation of water and streambed-sediment quality in selected tributaries of the South Umpqua River. Concentrations of inorganic constituents in water (major and minor ions, nutrients, and trace elements) and streambed sediment (primarily trace elements), along with standard field parameters, are tabulated for samples collected...
This report reviews and summarizes available information on aquatic biological communities in the Willamette Basin through 1995. Specifically, the report describes (1) the distribution, abndance, and trends of three taxonomic groups--algae, macroinvertebrates, and fish--and, to a lesser degree, other selected semi-aquatic taxa (i.e., taxa frequenting but not living wholly in...
The purposes of this report are to describe the quality of shallow ground water in alluvial aquifers of the Willamette Basin and to identify relationships between shallow ground-water quality and various natural and anthropogenic factors. Several natural and anthropogenic factors (soil characteristics, cumulative thickness of clay above open interval of...