Oregon DEQ: Water Quality - Total Maximum Daily Loads (TMDLs) Program

Quick topic links: Current Topics | EPA National Strategic Plan for the Columbia River |Total Dissolved Gas TMDL | Dioxin Discharges TMDL | Basin Contact Information

DEQ works closely with local, state and federal agencies as well as the public to improve water quality in the Columbia River and its tributaries. The U.S. Environmental Protection Agency identifies the Columbia as one of the nation’s seven “great water bodies” in need of heightened protection from environmental harm.

DEQ oversees several Total Maximum Daily Load plans to help reduce pollution and toxics in the Columbia. TMDLs calculate the maximum amount of a pollutant that a water body can receive and still meet water quality standards.

Current Topics

Lower Mid-Columbia River Ecological Assessment

Columbia River Toxics Reduction Working Group

This group, formed in 2005 to share information, coordinates activities and develops strategies to identify and reduce toxics in the Columbia River Basin. It is comprised of state and federal agencies, tribes, nonprofit organizations and others with a stake in reducing toxics in the basin. The group is responsible for developing the Columbia River Toxics Reduction Action Plan. This plan in turn complements actions outlined in DEQ’s own Toxics Reduction Strategy.

Lower Mid-Columbia River Ecological Assessment

This newly released DEQ study examines habitat and water quality issues along a 150-mile stretch of the Columbia, from Bonneville Dam east to McNary Dam. The study provides data for conventional water pollutants, legacy contaminants and habitat information for the mid-Columbia and its major tributaries in Oregon and Washington.

EPA National Strategic Plan for Columbia River

Columbia River National Strategic Plan

EPA, in its 2006-11 National Strategic Plan, identified the Columbia River as one of the nation’s seven “great water bodies.” The plan’s Goal 4: Healthy Communities and Ecosystems focuses on protecting, sustaining and restoring the health of critical natural habitats and ecosystems. The plan outlines EPA’s future work and allows measurements of progress to improve the Columbia’s ecosystem.

Strategic targets for Goal 4 of 2006-11 plan:

Protect, enhance, restore 13,000 acres of wetland habitat and 3,000 acres of wetland habitat in the Lower Columbia River watershed
Clean up 150 acres of known highly contaminated sediments
Demonstrate a 10 percent reduction in mean concentration of contaminants of concern found in water and fish tissue

DEQ’s contribution toward the overall 10 percent reduction as part of the 2011 goal was the implementation of the Pesticide Stewardship Partnership for the Walla Walla Basin, with a focus on organophosphate insecticides. Current data shows that the mean concentrations of two organophosphates insecticides in Walla Walla tributaries decreased by more than 90 percent between 2006 and 2011, far exceeding the original 10 percent goal.

For the plan’s 2014 goal, DEQ will contribute to the target reduction by implementing the Pesticide Stewardship Partnership for the Walla Walla Basin and Clackamas Subbasin. DEQ added two new pesticide partnership targets to the original 2006-11 targets: acetamiprid in the Walla Walla Basin and chlorpyrifos to the Clackamas Subbasin. DEQ’s Water Quality Division believes these targets can be achieved by 2014.

Total Dissolved Gas TMDL - Lower Columbia River

EPA approved this TMDL on Nov. 18, 2002