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Bonneville To McNary: Fish Samples Show High Levels of Toxic Pollutants, Degraded Riparian Areas by Staff Columbia Basin Bulletin, November 30, 2012

The little-studied lower-middle section of the Columbia River, a 150-mile stretch between Cascade Locks and Bonneville Dam on the west and Umatilla and McNary Dam on the east, has "generally good" water quality for recreational use but suffers from fish habitat degradation.

Fish samples from the area show potentially harmful levels of toxic pollutants, according to a recently released Oregon Department of Environmental Quality study.

DEQ's Lower Mid-Columbia Ecological Assessment www.deq.state.or.us/lab/wqm/docs/2009%20columbia%20REMAP%20final%20report_DEQ_complete.pdf summarizes the results of nearly five years of scientific planning, research and analysis.

It fills data gaps for conventional water quality pollutants such as bacteria, temperature, nutrients and dissolved oxygen. It examines other contaminants including PCBs, mercury, flame retardants and banned pesticides such as DDT.

The study also assesses habitat conditions on the lower mid-Columbia and its major tributaries in Oregon and Washington.

"This study is the first of its kind for this section of the river. It helps us better understand general water quality conditions in the Columbia and the extent of contamination in fish in the river," says Aaron Borisenko, manager of the DEQ Laboratory's water quality monitoring program, which produced the study.

The U.S. Environmental Protection Agency listed the Columbia River as one of seven

"Great Water Bodies" deserving of special attention and protection from environmental harm, Borisenko noted.

The study involved collecting water and fish tissue samples at 31 locations along the lower-middle Columbia. Most of the study's field work took place in 2009, followed by chemical analysis, data reviews and development of the final report.

The study's main findings:

• Legacy contaminants that are no longer manufactured but persist in the environment were evident in fish tissue samples -- some at excessively high levels. Concentrations of the banned pesticide DDT and other banned pesticides exceeded DEQ's human health criteria for the safe consumption of fish at a 175 gram-per-day rate -- both in smallmouth bass and largescale suckers.

• Every fish tissue sample failed to meet DEQ's standard for mercury - some by as much as 10 times or 20 times over the acceptable limit. Likely sources of mercury in this section of the Columbia are from burning fossil fuels, waste incineration, mining, and soil and rock erosion.

• Water quality samples from the study area were generally good, with all water samples meeting DEQ's recreation contact criteria for E. coli bacteria. On the negative side, the entire river segment had temperature levels above the state's temperature criterion for salmon species protection.

• The river's habitat generally suffers from degraded streamside (riparian) areas. While the river's banks are relatively stable due to riprap and natural basalt, other elements of a healthy river habitat are declining or absent. Large and small woody debris useful for aquatic habitat was absent or sparse in 90 percent of the area. Some areas were nearly barren of vegetation. Habitat loss is attributed mainly to increased land-use intensity from urban activity, forestry, farming and range use. Good riparian conditions lead to reduced erosion and improved wildlife habitat.

An EPA grant largely funded the project. DEQ directly funded 25 percent of the field work as well as provided project management, planning, sample analysis, data compilation and final reporting.

For more information about toxic pollutants in Oregon waters see, CBB, Oct. 21, 2011, "EPA Approves Toughened Oregon Water Quality Standards Based On Higher 'Fish Consumption Rate' www.cbbulletin.com/413443.aspx

Related Pages:
Estuary Report: Columbia River Salmon Show High Levels of Toxic Contaminants, Monitoring Inadequate by Staff, Columbia Basin Bulletin, 6/11/10