The Oregon Department of Environmental Quality may designate a Groundwater Management Area when DEQ monitoring and assessment shows widespread groundwater contamination resulting from suspected nonpoint source activities (ORS 468B.175-188).
DEQ has designated three Groundwater Management Areas, or GWMAs, because of elevated nitrate concentrations in groundwater. These include the Lower Umatilla Basin GWMA, the Northern Malheur County GWMA, and the Southern Willamette Valley GWMA. Each one has an action plan to reduce nitrate concentrations in groundwater.
Nitrate contamination is a problem for rural communities across Oregon and the nation. The most common sources of nitrate contamination are agricultural fertilizer, manure, septic systems, and wastewater that travels through soil and into groundwater. DEQ may designate GWMAs for other contaminants, but all three areas in Oregon have been designated due to nitrate.
The Northern Malheur County Groundwater Management Area was declared in 1989 after widespread groundwater nitrate contamination was identified that had resulted primarily from nonpoint source activities. Oregon DEQ and a citizen’s advisory committee created an Action Plan for restoring the groundwater nitrate concentrations to acceptable levels. The Action Plan identifies specific "measures" to gauge the success of groundwater restoration activities in the area.
Action plan
Reports
The Southern Willamette Valley is one of Oregon’s fastest growing regions and depends heavily on groundwater for both private and public drinking water, irrigation water, and other uses. The Groundwater Management Area is the result of many years of studies and analyses of the shallow groundwater in the lowlands of the Southern Willamette Valley. Studies beginning in the 1990s show that shallow groundwater contains nitrate above levels that are a concern.
On May 10, 2004, following a public comment period on the final Southern Willamette Valley groundwater report and proposal for declaring a Groundwater Management Area, DEQ director Stephanie Hallock signed the official Declaration, creating the Southern Willamette Valley Groundwater Management Area. By declaring a Groundwater Management Area for portions of the Southern Willamette Valley, DEQ, Department of Agriculture, Water Resource Department, Department of Human Services and other state agencies are required to focus efforts on the development of an Action Plan to restore the groundwater quality.
Proposed Action Plan