EPA Remedial Investigation Focusing on Baseline Ecological Risk Assessment

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Published: Monday, 11 January 2021 20:14

A Baseline Ecological Risk Assessment (BERA) is the next big milestone for the Upper Columbia River Remedial Investigation and Feasibility Study (RI/FS). The BERA and Human Health Risk Assessment (HHRA) are required to complete the Remedial Investigation (RI). The purpose of the RI is to fully assess the site and inform next steps to protect human health and the environment.

Development of the UCR RI/FS Site Baseline Ecological Risk Assessment (BERA)

The BERA evaluates risk (i.e., the potential for adverse effects) to wildlife on land and in water.  

As shown in Figure A, this requires examining exposure pathways for chemicals of potential concern (COPCs) that might result in plants and animals being adversely affected. COPCs found to be the cause of unacceptable ecological risks will be identified in the Remedial Investigation, then further evaluated in the Feasibility Study for possible cleanup or other remedial actions.

Although done under EPA oversight, Teck American Incorporated (TAI) is responsible for completing the BERA. Per the settlement agreement guiding this process, TAI’s work is reviewed by EPA, who also works with other government parties (“participating parties”) to consider their review comments. Participating parties include the Colville Confederated Tribes, Spokane Tribe of Indians, State of Washington (represented by the Washington Department of Ecology), and U.S. Department of the Interior. Interior agencies include the Bureau of Reclamation, the National Park Service, Bureau of Indian Affairs, the U.S. Fish and Wildlife Service, and the U.S. Geological Survey.

The draft BERA is not expected to be completed until sometime in 2022.

BERA Status Report

All field and laboratory studies have been performed for the BERA, including river associated surface water, beach sediment, fish tissue, mussel and crayfish, fish, sediment and porewater (water between the grains of sediment) sampling. It also includes upland soil sampling in a 100-square-mile Upper Columbia Valley area.

The river sampling is quite complex and has occurred in three phases. Essentially, investigators are continuing to evaluate how and to what extent metals and other chemicals present unacceptable risks to the benthic invertebrate community (aquatic sediment-dwelling bugs such as mayflies, mussels, and crayfish). In addition to sediment and porewater chemistry analysis, bioassays are used to evaluate risks to organisms from exposure to contaminants in sediment or porewater. Risks in these communities can harm the benthic life directly.  These risks also may negatively affect fish and wildlife as they work their way through the food web and up the food chain.

A Phase 3 Sediment Study was the final BERA field study. This included sediment facies mapping in the entire northern section of the UCR Site (a 40-mile river reach) and additional sediment and porewater sampling in three generally representative areas of interest (AOIs): Deadman’s Eddy, China Bend and Evans.

Two main objectives are to better characterize 1) sediment bed attributes (done through sediment facies mapping), and 2) sediment and porewater conditions in the three AOIs to help assess the risks to benthic organisms and the nature and extent of contamination in this portion of the Site. To help with this, a survey also was conducted to consider the composition and diversity of the benthic community more fully.

TAI completed a data summary report, approved by EPA, for the sediment facies mapping study in September 2020 and TAI will submit the draft data summary report for the sediment and porewater sampling at the beginning of January.

Next Steps

TAI will develop a draft BERA report for terrestrial (upland) and river associated investigations in 2021. After EPA provides comments, including those they integrate from participating parties, TAI will complete a revised draft. EPA will then initiate release of the draft BERA for public comment (most likely in 2022).  

Due to this timeline, the Forum does not expect the feasibility study (which requires the remedial investigation be complete) to begin before 2023. The feasibility study will evaluate potential cleanup or other alternatives to address human or ecological risks the remedial investigation identified as a possible concern.