EPA Remedial Investigation updates

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Published: Monday, 02 December 2019 20:52

Over a decade has passed since EPA reached agreement with Teck in 2006 to conduct an Upper Columbia Remedial Investigation and Feasibility Study (RI/FS). EPA intends to complete the Human Health Risk Assessment in early 2020. In contrast, the Ecological Risk Assessment continues to investigate the nature and extent of contamination and assess potential risks to the environment. Risk assessment is one component of the Remedial Investigation (RI). A draft RI Report will follow completion of investigations and risk assessments. A feasibility study to consider potential cleanup alternatives then follows completion of the RI.

Each newsletter carries an update to highlight recent studies and activities that are underway. To learn about the history of the entire RI/FS and what’s been learned, visit our Public Guides at www.lrf.org/environment. Data summaries and other documents referred to below are available on the www.ucr-rifs.com/home/documents-plans/ web page.

Northern Pike Sampling
In response to increased numbers of Northern Pike catch and consumption that’s also being incentivized by a $10 per head bounty to help rid the system of this invasive predator, Lake Roosevelt fisheries co-managers worked with EPA and Teck American Incorporated (TAI) to sample and analyze Northern Pike for mercury and other metals. Sampling was completed in July 2018 and results are presented in a final data summary report. In 2019, WDOH used this data to update the Lake Roosevelt Fish Advisory to include northern pike in the healthy choice category.

Mussel and Crayfish Sampling
The purpose of this sampling is to estimate exposure from human consumption and ecological risks of chemicals concentrating in tissues of fresh-water mussel and crayfish. In the spring and fall of 2016, samples were collected at various depths throughout the river/lake system. The final data summary report was approved by EPA in March 2018 and data are currently being integrated into the human health risk assessment. In 2019, WDOH used this data to place crayfish in the healthy choice consumption category. Mussels are in the DO NOT EAT category, which is consistent with the state-wide advisory against consuming any freshwater mussels or clams.

Plant Tissue Sampling
The 2014 and 2016 Residential Soil Sampling program, residential yard soil removal actions, and the 2014 Upland Soil Sampling results document elevated levels of metals in soils sampled in these upper Columbia River Valley study areas. The Tribal Consumption and Resource Use Survey confirmed that plants may be harvested from areas where metals are elevated. Residents of the Colville Reservation consume, and otherwise utilize plants which may be contaminated with heavy metals.

Exposure to these metals in plant tissue through consumption or use, however, is unknown. As a result, EPA determined that data for the concentration of metals in berries, nuts, roots, and leaves from a variety of plants was needed for the Upper Columbia River human health risk assessment. Reconnaissance in focused locations of the study area occurred in August 2017 to identify the type and availability of plants for sampling. In 2018, the sampling plan was approved, then three rounds of sampling occurred. Samples were analyzed and results presented in a final data summary report. Data are currently being integrated into the human health risk assessment. Consumption of nuts, berries and leaves are not likely to be a health concern. However, consumption of roots, bulbs, or lichens may be a concern.

Residential Soil Sampling
In addition to sampling and residential soil cleanup activities that took place in 2014-2015, another round of soil sampling occurred in 2016. Sampling occurred at some properties within the original boundary from 2014 and extended through the river valley as far south as China Bend. 144 residential properties were sampled. Results were sent to landowners in April 2017. Data summary reports are available on the UCR web page. A time critical soil removal triggered 4 additional properties being cleaned up, bringing the total number of properties receiving cleanup since 2014 to 17. Cleanup occurred as part of voluntary agreements between EPA and TAI for TAI to fund and conduct cleanup under EPA oversight.