Portland Harbor Superfund Site – Willamette Cove

Project Completed: 2020-2023

GSI Water Solutions

The Environmental Protection Agency (EPA) identified a 10-mile stretch of the lower Willamette River as a Superfund Site in 2000. The classification resulted from hazardous substances and pollutants threatening the surrounding environment and public health. In 2017, the EPA issued its final cleanup plan, and now the site is undergoing remedial design. The cleanup process will involve a combination of dredging, capping, and other technologies to manage the cleanup for years to come. 

Since 2020, our team has provided a range of services to support the remedial design and monitoring activities at several smaller sites within Portland Harbor. One of these sites is at Willamette Cove, where tasks have included full-bottom coverage high-resolution multibeam echo sounder (MBES) surveying paired with simultaneous measurements of acoustic backscatter intensity; mobile (vessel-mounted) lidar of the shoreline and low-lying topography; aerial lidar of the upland elevations; multiple episodic hydrodynamic data collection efforts (current speeds and directions) with acoustic Doppler Current Profilers; and conventional land survey tasks (e.g. boundary locating).  


Using a high-resolution multibeam echo sounder (MBES), our hydrographic team collected full-bottom coverage bathymetry and acoustic backscatter intensity data. Data were of fine enough resolution to identify logs, debris, and sunken recreational vessels on the riverbed. In addition, acoustic backscatter (ABS) intensity indicated areas of softer (silt/mud/unconsolidated material) sediment versus harder (sand/rock/consolidated material) to support coring operations, site conceptual understanding, and remedial design. 


Our land surveying team used a vessel-mounted lidar and collected aerial lidar measurements to supplement the bathymetric elevations. In 2023, we completed a property line and boundary survey at the Willamette Cove site to delineate the Willamette Cove property (owned by the Port of Portland) from the adjacent BNSF railroad property. Our team extensively researched property boundary monuments and used conventional surveying to locate and delineate the property line.