CASE STUDY

Teck saves native Oregon oysters in Coos Bay

Coos Bay oyster convervationWhat started as an effort to minimize future liability from former operations quickly became a biodiversity conservation initiative for Teck. In keeping with their commitment to environmental stewardship, they developed a plan for contaminant removal after the Glenbrook Nickel Operations in Coos Bay, Oregon were shut down in 1998. An environmental site investigation was conducted, which included areas where nickel ore was unloaded and conveyed across the site’s dock to storage piles and eventually to a drying and shipping facility.

Teck wanted to ensure that no contamination was left along the shore. Elevated nickel concentrations were identified in sediments between the inside face of the dock and the shore and along a portion of the shoreline on the western edge of the property. After an evaluation of remedial alternatives, the company proceeded with land-based excavation and off-site disposal of excavated sediments.

A voluntary cleanup program

The remedial work was conducted under the Oregon Department of Environmental Quality (ODEQ) Voluntary Cleanup Program, which falls outside of legal or regulatory requirement. Teck added habitat and native species restoration objectives to the project plan. Specifically, Olympia oysters (Ostrea conchaphila) were found in the areas where remediation activities were planned. This is the only oyster species native to the Pacific Northwest, and Coos Bay is known to host high densities of them. Teck worked with the Oregon Department of Fish and Wildlife (ODFW), who harvested the oysters prior to the removal of contaminated sediments.

Excavated areas were backfilled with a sand and gravel mixture, using a gradation pattern similar to the existing area, and shell hash was added to the backfill material to provide a good surface to which the oysters could attach. The objective was to save the existing oysters and provide a suitable habitat for them to “move back” to, providing they would not re-contaminate the site when clean-up activities were completed. Test results showed that the oysters would not re-contaminate, so the ODFW replanted them when Teck's remedial activities were complete.

In August, the ODEQ issued a “No Further Action” letter for the site, indicating that site clean-up objectives had been achieved. A more significant outcome for the ODFW and the National Estuary Research Reserve (a project that works to maintain the population of native Oregon oysters and understand their optimal habitats), was the ability to more fully characterize the oyster populations in Coos Bay and apply emerging restoration practices to this model site. Work performed at this site, combined with future monitoring, will provide the groundwork to guide similar work in other locations.

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CASE STUDY DETAILS

Published
30 July 2010
Company
Teck

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Mining and Biodiversity: A collection of case studies - 2010
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Seek continual improvement of our environmental performance.

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Contribute to conservation of biodiversity and integrated approaches to land use planning.

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