PROJECT: Portland Harbor Superfund

Portland, Oregon

The City of Portland operates multiple stormwater conveyance systems that discharge into the Lower Willamette River. A 7-mile-long reach of the river has been designated by the U.S. Environmental Protection Agency (EPA) as the Portland Harbor Superfund Site. GSI has assisted the City in developing project approaches and regulatory strategy to guide its participation as a potentially responsible party on this project. GSI managed the data compilation task where the objective was to gather pertinent City of Portland data and literature data to estimate the significance of stormwater loading to the Willamette River. GSI staff members also managed the evaluation and proposed sediment sampling of the downtown reach of the Willamette River. This involved delineating the outfall basins, identifying potential upland sources within the outfall basins, and using the data quality objective process to propose additional sediment sampling locations. Subsequently, the GSI team used the data compilation results to estimate loading from stormwater to the downtown reach of the Willamette. This CERCLA project requires routine interaction with state and federal agency staffs to help develop source control measures on these upland properties.