- In 1988 the Tualatin River was designated 'water quality limited' by the Oregon Department of Environmental Quality. Three sources of pollution: urban point source, forestry non-point source and agricultural non-point source pollution were considered to contribute unacceptable levels of nutrients (phosphates and ammonium nitrates) to the river. Since a significant portion of this nutrient loading originated from agricultural non-point sources in the Dairy-McKay watershed, part of the Tualatin River Basin located in Washington County north and northwest of Hillsboro, Oregon, a cooperative effort to stem the tide of pollutants pouring into the river from this area was initiated. Multiple agencies (including federal, state and local community groups) defined the Dairy-McKay Hydrologic Unit Area (HUA) and designed a management plan to substantially reduce or eliminate the excess nutrient input. Foremost among the collection of contributors to this project were the Natural Resource Conservation Service (NRCS, formerly a part of the Soil Conservation Service, or SCS), the Farm Services Agency (FSA, formerly Agricultural Stabilization and Conservation Service, or ASCS) and the Oregon
State University Cooperative Extension Service (OSUCES). Each of these organizations had specific roles to play in the Dairy-McKay HUA project.
The purpose of this report is to present a generalized summary of the setting and the management plan for the Dairy-McKay Hydrologic Unit Area. Then, to proceed to an in-depth scrutiny of the Oregon State University Cooperative Extension Service's involvement in the project. This will assist in evaluating the success of that organization in meeting its goals and fulfilling its defined role as a primary collaborator.
The HUA library is housed at Oregon State University, Rangeland Resources Department, in