Elevated groundwater nitrate (NO3
-) concentrations in the Southern Willamette
Valley (SWV) caused the Oregon Department of Environmental Quality (ODEQ) to
declare a Groundwater Management Area (GWMA) in Spring, 2004. To better
understand direction of groundwater flow, groundwater age, and nitrate transport
pathways of the SWV we developed a steady-state...
Groundwater nitrate contamination is a well-documented issue in the Southern Willamette Valley (SWV) of Oregon, as a Groundwater Management Area (GWMA) has recently been declared. As a GWMA, groundwater nitrate monitoring must occur until regional concentrations are below 7 mg/L NO3-N. However, the presence of temporal variability can make it...
The region’s high winter rainfall provides aquifers
that are often within 50 feet of the land surface. In
many parts of the United States and in other countries
where groundwater is this close to the surface, pesticide
contamination has been observed. Thus, with our
high population, significant applications of pesticides,...
Low-permeability geologic units may offer significant chemical and hydraulic protection of adjacent aquifers, and are important for managing groundwater quality, especially in areas with significant non-point source contamination. Nitrate in the Willamette Valley is attenuated across the Willamette Silt, a semi-confining unit overlying a regionally important aquifer. To quantify the...
Hydrologic processes within mineral flat wetlands, along with their
connections to groundwater and downstream surface water in lowland agricultural
catchments are poorly understood, particularly under different land uses. In the three
field studies included in this thesis, we examined infiltration, wetland hydroperiod,
groundwater recharge dynamics, surface runoff generation, and water...
A relatively stable, persistent and historical problem with elevated NO₃⁻ concentrations in rural drinking wells in the southern Willamette Valley, Oregon is evident. What is the origin of NO₃⁻ in rural drinking water wells in this area? The answer to the question is not simple. Many non-point sources contribute to...
Published February 1966. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Growing urbanization, shifting water uses, and a focus on ecosystem health in the Deschutes River Basin in Central Oregon led to experimentation with new voluntary market-based approaches to water management in the last decade. To meet groundwater demands while maintaining instream flows and upholding prior water allocations, the Oregon Water...