Remedial Investigation Feasibility Study Update

CCC Information Sheet – September, 2022

Final reports are on Teck’s public UCR-RIFS website:

Human Health Risk Assessment (HHRA)

The HHRA combines the studies outlined below to establish nature, extent and possible human health risks of metals and other contaminants found in the Upper Columbia River (UCR). The findings are primarily driven by lead in soil and affect between 12 and 389 residential decision units (DU) of 588 tested depending on the calculated blood lead level (3-8 ug/dL) chosen for remediation. For residents and recreational visitors, no results exceeded EPA’s cancer benchmark of 1/10,000 increased risk. For non-cancer endpoints, risk to resident children living on properties with beaches and exposed to non-lead chemicals or lead were marginally exceeded for developmental and nervous systems, and skin/hair/nails systems. The number of exceedances differed by fish species consumed, but were present for all fish tested for children; adult risk was exceeded only for consumption of suckers. The HHRA was finalized in 2021 and is available at: ( EPA is drafting preliminary remedial management action objectives for human health risks, proposing a 5 ug/dL blood lead level target.

Baseline Ecological Risk Assessment (BERA)

The BERA is in progress. The purpose is to evaluate potential risks to terrestrial and aquatic species at the Site under current and future conditions and identify which chemical(s) of potential concern, exposure pathways, and ecological receptors (specific ecological communities or species) may be associated with unacceptable risks. The BERA includes Upland Habitat and Riverine Habitat portions composed of studies on sediment (background and from sampling), soil, benthic organisms, plants, animals and sediment transport.

Partial Remedial Investigation (RI) Report

The partial RI is in progress. This document will summarize activities conducted to characterize the study area, sources of contamination, nature and extent of contamination, and the transport and fate of focus metals within the Upland Study Area. The report also summarizes results from the HHRA and ongoing BERA. The findings will be combined with the upcoming Draft Interim Partial Riverine RI into a Draft Site-wide RI for the UCR. Considered are: aerial deposition area, relict floodplain deposition areas, and windblown sediment deposition areas.

Beach Sediment

Bottom line: All beaches are considered safe for recreational use except Bossburg Flats, which is closed pending EPA/National Park Service action. Contaminants above ecosystem screening levels were found at most DUs at Bossburg including antimony, cadmium, lead, manganese, vanadium, and zinc. Human health screening levels were exceeded in 2 soil DU’s for lead. Status: Final

Fish Tissue

Bottom line: Contaminants in fish tissue were largely unchanged from 2005 (arsenic in suckers; mercury, selenium, zinc, and PCBs in multiple species). Some contaminant levels were lower (arsenic in walleye; copper levels in walleye and suckers; lead in walleye) and some were higher (cadmium in suckers and walleye, lead in suckers). Additional study performed on hatchery white sturgeon (2016) and northern pike (2018) showed acceptable levels of contaminants for consumption except for northern pike, based on mercury content, for which consumption of large fish (>450 mm) is restricted to 8 meals/month. Status: Final

Plant Tissue Study

This study examines potential contamination of plants identified in the Tribal Use Survey; data will be used in the tribal portion of the HHRA. Field sampling work has been completed. The study sampling and analysis plan and data summary report are available on the website.

Recreational Use

Bottom line: EPA is able to get fish consumption and exposure information from these data on 2,109 people (response rate 82%). Estimated mean fish consumption for adults was 6.3 g/day; most frequently walleye and rainbow trout. Beach trips, with swimming, were estimated at a mean of 6.8 days/year and camping mean range 2.7 to 7 days. Status: Final.

Recreational Soil

First wave 2014 sample collection on 74 properties: 24 had lead levels above the national screening level (400 ppm) and 18 were above screening level (20 ppm) for arsenic. Time critical removal was completed on 14 properties in August 2015. Second wave 2016 sample collection on 144 properties: 26 had arsenic levels above the screening level (20 ppm), 6 had lead levels above the national screening level (400 ppm), 3 had thallium levels above the screening level (0.78 ppm) and 1 had cobalt levels above the screening level (23.4 ppm). Removal actions on 4 properties were completed. EPA initiated a non-RI/FS removal assessment in 2019 which identified 16 properties in Northport with lead levels above 700 ppm and additional soil removals were completed; 14 residential properties and one common-use area were cleaned up in 2022.

Sediment Toxicity Study

Primary objective was to evaluate unacceptable risks to benthic invertebrates from exposure to metals and other chemicals in UCR sediments. Porewater collection was of poor quality. Sediment and porewater chemistry were assessed and survival, weight, biomass, and reproduction were the biologic endpoints. Status: Final

  • Sediment toxicity study phase III: A five-part study examined potential sediment toxicity in more detail at Deadman’s Eddy, China Bend, and Evans. Sites were identified via sediment bed (facies) maps from the 2018 sediment facies mapping program. 106 sites were successfully field sampled and showed elevated levels of arsenic (mean 14.6; range 1.11 to 80.5) and lead (mean 367 ppm; range 12.1 to 5520) compared to reference samples. Survival data showed lower survival for H. azteca especially at Deadman’s Eddy followed by Evans compared to reference populations; low survival also occurred in one of the reference populations. Toxicity reference values were established for fish and wildlife. Status: Final

Sediment Transport

Plans are underway for this study that will provide information for monitoring and evaluating sediment transport, loading, and remobilization


Bottom line: Analytes exceeding screening levels for freshwater mussels included arsenic, cadmium, manganese, and total PBC congeners. Exceedances were also noted in the reference samples. Crayfish contained similar analytes that exceeded SLs including arsenic and total PCB congeners. Status: Final; a consumption advisory is available from the WA State Dept. of Health. They recommend not consuming freshwater mussels and clams but placed no restriction on crayfish except for high-volume consumers.

Soil Amendment Technology Evaluation Study (SATES)

  • Evaluating noninvasive techniques to decrease lead and arsenic bioavailability in soils on three tribal allotments that were offered but declined remediation from the 2014 residential soil study. Test plot characterization confirmed lead contamination above screening level (range 419-1587 ppm). Bench testing of amendments resulted in three (compost, soluble liquid phosphate and soluble phosphate plus biochar) being chosen for application in Fall 2020. After one year, the amendments have not reduced lead bioavailability.

Sturgeon Study 2010 (also see fish tissue above

Reports of study results were unacceptable except for water-only copper exposure data. CCC urged EPA to write a report on study findings to inform future efforts to understand risks to the sturgeon population. Study results for the USGS study were published. Copies are available on the CCC website.

Surface Water

Bottom line: There are no concerns with contaminants in surface water, absent a spill; CCC is concerned that disturbed water, is not well assessed. Status: Final

Tribal Use Survey

Bottom line: EPA will be able to get fish consumption and exposure information from these data on 1700 individuals from the Colville Confederated Tribes. The tribe released their own report (Fish consumption was 400 g/day). Status: Final

Upload Soil

215 composite samples were collected. Concentrations above screening levels were found for antimony, cadmium, lead, vanadium, and zinc in aerial deposition areas. Status: Final