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Bradford Island

Aerial image of Bradford Island

Bradford Island is an island in the Columbia River at Bonneville Dam between the spillway and the first powerhouse. The island has hosted a variety of activities since dam construction including project maintenance, housing, equipment storage, chemical storage, and waste disposal.

The Corps began investigating the potential for contamination from these activities in 1998. In 2000, when electrical equipment was discovered submerged in the river adjacent to the landfill, the study was expanded to include the north shore of Bradford Island and potential impacts from that equipment. In 2002 the Corps removed the electrical equipment from the river bottom and in 2007 dredged sediment from approximately one acre of river bottom to remove PCB contamination from the environment. The impacts to the upland areas and to the river were evaluated in a Remedial Investigation completed in 2012. Further evaluation was conducted in the subsequent Baseline Human Health and Ecological Risk Assessments completed in 2016.

Studies and Results

The impacts to the upland areas and to the river were evaluated in a Remedial Investigation completed in 2012. Further evaluation was conducted in the subsequent Baseline Human Health and Ecological Risk Assessments completed in 2016.

Four areas on the island were identified for study and evaluation of risks to humans and the environment.

  • Landfill Area. From the 1940s until about 1982, a small landfill on Bradford Island was used to dispose of project waste materials. It is on the northeastern portion of Bradford Island, and is not in a public area. The landfill contains discarded materials such as oil, grease, paint, solvents, scrap metals, mercury-vapor lamps, cables, and sandblast grit. Some electrical transmission components like switchgear, insulators, and possibly light ballasts were also in the landfill. Some household waste came from a small community of homes used by construction workers and later project personnel until 1976. The total landfill area is approximately a half-acre in size (about one-third of a football field), and is estimated to hold about 8,800 cubic yards of material, including soil used to fill and cover the landfill.
  • Pistol Range Area. The Pistol Range is located on the south side of Bradford Island. It was used for small arms target practice from approximately 1950 through 1970. Surface soils became contaminated with low concentrations of lead and zinc. The highest lead concentrations in soil are likely associated with bullet fragments that remain in the soil. The Pistol Range is now well vegetated and does not show evidence of soil erosion.
  • Sandblast Area. The sandblast building was used for sandblasting and painting from about 1958 to 1995. Sandblast grit contains metals, and it primarily affected an area east of the sandblast building. The Sandblast Area also includes a place where transformer oil was released onto the ground in 1995, a former hazardous material storage area, a burn pit to the southeast of the sandblast building, and an out of service septic system northwest of the building. An investigation in 2006 concluded there is an estimated 1500 cubic yards of soil in the area with concentrations of metals and other industrial constituents.
  • Bulb Slope Area. The Bulb Slope consists of a fan-shaped accumulation of glass and electrical light bulb debris that extends across approximately 1,900 square feet of a steep slope between the Columbia River and the Landfill access road. There is a thin layer of soil, up to 1 foot thick, that overlies bedrock and has low concentrations of PCBs, mercury, and lead from discarded light bulbs and other debris.

The Corps has completed the process of evaluating alternatives for the upland areas. It has been determined that the Landfill Area and the Pistol Range Area may pose risks to human health or the environment. However, it has been determined that there are no concerns at the Sandblast Area or the Bulb Slope Area. The Corps is currently in the process of evaluating alternatives for the portions of the site in the adjacent Columbia River.

The Corps continues to work with state and tribal health agencies to inform area subsistence fishers and recreational anglers about the danger of eating fish that may be contaminated.

Portland District released the final Remedial Investigation Report in 2012 that documents our investigation of upland and in-river contamination; identifies the sources, nature, and extent of the remaining contamination; and identifies potential concerns to human health and the environment.

The report concludes that contaminants both on land and in the water exceed risk screening levels and proposes that we perform a feasibility study of the in-water area to identify remedial actions that will lower concentrations to an acceptable risk level. It also proposes that we perform either a feasibility study of the land areas or a site-specific baseline Human Health Risk Assessment or Level III Ecological Risk Assessment to determine if risks to human health or ecological receptors are unacceptable. Ultimately, a baseline risk assessment was completed for both the in-river area and the upland sites in 2016. A Feasibility Study for the land areas was also completed in 2017, and a Feasibility Study for the in-water area will be completed in 2018.

In 2012 the Corps published results of samples collected in the river in 2011 of sediment, clams, and fish tissue. The report was produced to determine whether contaminant levels had changed in the river area since the dredging project in 2007. The results showed that contaminant levels were not reduced by the dredging project.

Timeline of Events

2018

Planned. River area feasibility study.

2017

Upland area feasibility study completed.

2016

Risk assessments for upland and river areas completed.

2012

Remedial investigation report summarizing all work to date published.

2011

Collected sediment and clams in the area dredged in 2007 and additional fish to compare with the fish collected in 2006. Results published in 2012 show the contaminant levels had not been reduced by the dredging.

2007

Removed 65 tons of sediment from a 0.83-acre area along the shoreline of Bradford Island. 2.2 million gallons of water and sediment were suctioned from the river bottom and filtered to remove contaminants. The water returned to the river was non-detectable for PCBs at five parts per trillion. The captured sediment, taken to a licensed landfill, was non-detectable for PCBs at 80 parts per billion. Sediment results indicate that the average contamination level in the river was far lower than originally estimated.

2006

Additional sampling was conducted in 2006. Clams, small mouth bass, sediment, and surface water samples were collected during this time.

2005

Completed draft engineering evaluation and cost analysis for landfill and in-water areas.

2004

Completed ecological and human health risk assessment.

2003

Collected samples of in-water sediments and clams.

2002

Previously discovered equipment containing PCBs removed from river.

2000

Underwater dive survey discovered equipment containing PCBs.

1998

Conducted a landfill site investigation.

1996

Contaminants confirmed in the landfill and the Environmental Protection Agency and the Oregon Department of Environmental Quality were notified of a CERCLA release.

1992

First internal ERGO audit of the Bonneville project held.

1980s
1990s

The Corps began efforts to bring Bonneville Lock and Dam into compliance with new hazardous waste regulations. During that time the Corps was also developing the Environmental Review Guide for the Operations program. ERGO is a comprehensive self-evaluation and program management system for achieving, maintaining, and monitoring compliance with environmental laws and regulations at Corps of Engineers projects and facilities..