Tributaries of the Tualatin River cascade down high gradient slopes for relatively short distances, then flow into the low gradient mainstem which meanders for much of its length. The gentle, east-facing slopes of Oregon's Coast Range provide the geomorphic and climatic template for the watershed's patterns of discharge, water quality,...
The Tualatin River Basin in Washington County, Oregon has been identified by the Oregon Department of Environmental Quality (DEQ) as "Water Quality Limited." Algal blooms have become commonplace in the lower , reaches of. the river during summer months. Phosphorus has been identified as the nutrient upon which to base...
The goal of this phase of the study was to develop a model of the Tualatin River incorporating Scoggins Creek and Hagg Lake. This tool will be used in conjunction with a hydrologic model, the EPA HSPF model (Johnson, Imhoff, and Kittle, 1984), to analyze management strategies to improve water...
In July of 2001, the Environmental Protection Agency (EPA)
activated the Total Maximum Daily Load (TMDLs) provisions of the
Clean Water Act. As the first river in Oregon to implement TMDL
regulations, people and agencies in the Tualatin basin face many
challenges. Non-point source pollution affects water quality in the...
The pages which follow contain the authors responses to a series of comments that were received in response to "A Project to Collect Scientific Data and Provide Evaluation and Recommendations for Alternative Pollution Control Strategies for the Tualatin River Basin, 11 submitted to the Oregon Department of Environmental Quality (DEQ)...
In response to Oregon House Bill 3338, the Oregon Department of Environmental Quality requested proposals in 1991 to assemble available information on Tualatin River Basin conditions to provide a scientific basis for improving river water quality. An interdisciplinary team of researchers from Oregon State University and Portland State University was...
The Tualatin River is a major water resource for Washington County. In its course, the river drains forest lands, farmlands, and urban areas receiving toxic materials from non-point source runoff: Wastewater treatment plant effluents from municipalities and industries also contribute toxic materials to the river. Many materials discharged into the...
This report summarizes the conclusions reached in "A Project to Collect Scientific Data and Provide Evaluation and Recommendations for Alternative Pollution Control Strategies for the Tualatin River Basin."
This study was funded by the Oregon Department of Environmental Quality as a grant to the Oregon Water Resources Research Institute on...
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...