For decades the Army Corps of Engineers used an island near the Bonneville Dam as a dumping ground. Toxic chemicals leaked into the Columbia River. The island is also a historic fishing site for the Yakama Nation.
The tribe is now suing the Corps to recover costs from helping clean up the contamination.
In 2003, the Corps removed electrical equipment and contaminated sediment found at the bottom of the river. In 2007, it dredged the area to remove more contaminated soil.