Columbia Slough Sediment Project

The Columbia Slough runs parallel to the Columbia River and includes about 31 miles of waterway from the Willamette River to Fairview Lake. Industrial, agricultural and urban development along the Columbia Slough has resulted in contamination accumulating in the bottom of the slough. Some contaminants, including polychlorinated biphenyls (PCBs) and pesticides bioaccumulate in fish that live in the slough year-round. These fish are now unsafe to eat. In 2005, DEQ issued a cleanup plan that established a program to clean up the slough. This program includes addressing individual sites that released contamination into the slough, controlling any ongoing sources of contamination, and monitoring conditions over the long term to make sure conditions were improving.

DEQ is working with many partners to address Columbia Slough contamination including:

• City of Portland to prevent elevated stormwater discharges associated with City Outfalls and city properties to the Columbia Slough.
• Private parties at many individual sites to prevent further pollution releases to the Columbia Slough and Columbia Slough sediment cleanup.

• Multnomah County Drainage District's dredging operations achieve concurrent flood conveyance and remediation of sediment contamination where project objectives overlap.

• DEQ conducts investigations/sediment cleanups in various Slough segments using settlement funds obtained from private parties in exchange for a liability release for their site's contribution to contamination in Slough sediments.
  

More information

• Moore & Wright Islands Natural Area Sediments Cleanup Story Map
  
• Columbia Slough Annual Report
  
• Columbia Slough Sediment Project Story Map
  
• Fish advisory updates
  
• Get involved at Columbia Slough.org
  
• Fact sheet: Columbia Slough Sediment Update
  
• Fact sheet: Columbia Slough Cleanup near Moore and Wright Islands
  
• City of Portland Columbia Slough Sediment Program