GSI was selected to conduct a supplemental remedial investigation and feasibility study (RI/FS) in 2013 under an Administrative Settlement Agreement and Order on Consent (2013 AOC) between the U.S. Environmental Protection Agency (EPA) and six potentially responsible parties known as the RM11E Group. The project is located along the east bank of the Willamette River near the upriver end of the Portland Harbor Superfund Site.
GSI helped the RM11E Group meet the obligations of the 2013 AOC by preparing all planning documents and implementing sediment, soil, groundwater, and porewater investigations to fill data gaps and facilitate the selection and design of a sediment remedy. All work products and the final report prepared by GSI were approved by EPA.
Following completion of the supplemental RI/FS, GSI conducted an assessment of the potential for recontamination of remediated river sediments from both upland and in-river sources. The Recontamination Assessment Report was approved by EPA in 2018—the first approved under the 2017 Portland Harbor Record of Decision (ROD). Meeting this milestone allowed the project to advance to the remedial design phase.
GSI’s work on the recontamination assessment involved:
In 2006, GSI and our teaming partner began managing the technical elements of the project as a subcontractor to the Oregon Department of Environmental Quality (DEQ). Since then, we have implemented several complex research and monitoring projects including:
GSI is now supporting development of the Basis of Design Report and will continue to provide technical and facilitation support to the RM11E Group throughout the design.
GSI staff member logging power-grab surface sediment sample
GSI staff members conducting groundwater monitoring at nearshore wells
Passive porewater and surface water sampler after removal
Collecting water depth measurement
Diver preparing to retrieve passive porewater sampler