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...
Arsenic concentrations exceeding the U.S. Environmental Protection Agency (USEPA) current Maximum Contaminant Level (MCL) of 50 micrograms per liter are widespread in ground water in the Willamette Basin. The Oregon Water Resources Department and the U.S. Geological Survey began a cooperative study in the Willamette Basin in 1996. One goal...
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...
The report describes the results of model calibration and validation, and evaluates the extent to which runoff response to timber harvesting and increased road densities in East Fork Lobster Creek Basin can be simulated, using Precipitation-Runoff Modeling System (PRMS), a deterministic, destributed-parameter-modeling system.
"Indexed herein are references to literature pertaining to the marine waters of Oregon. References to papers, depending on the subject matter contained in the paper, are indexed under one or more of the following headings: Marine Biology, Climate, Fisheries, Geology, Hydrology, Chemical and Physical Oceanography, and Bibliographies, Literature Surveys and...
In a drought, every gallon of water saved means more crop production. There are many places in a typical irrigation operation where water is lost. Here are some prudent management practices that can conserve water and possibly make the difference between making a profit or taking a loss.
Note: These...