RM3.5E–Source Control Stormwater Evaluation

Client: Radius Recycling
Evaluate stormwater contributions as part of a holistic source control approach to predict and mitigate impacts to the future sediment remedy of the adjacent Superfund Site.

Overview of Floyd|Snider Contributions

Project planning around operations of an active metals recycling yard, including minimizing disruptions to operations while emphasizing field safety
Rainfall-dependent field planning requiring short-notice mobilizations and dynamic decision-making
High volume of flow meter and analytical data processing
Evaluation of results considering complex regulatory constraints and extremely stringent screening levels
Solids Sampler Installed on Ring
Sediment Trap

Project Summary

The Portland Harbor Superfund Site includes contaminated sediments along 10 miles of the Willamette River.

The U.S. Environmental Protection Agency (USEPA) has issued a Record of Decision for the Superfund Site, requiring control of sources of contamination to sediments; implementation of dredging, capping, and natural recovery remedies for sediments; and remediation of contaminated riverbank areas. The Superfund Site has been divided into multiple primary areas designated by river mile. Responsible party groups for each area are required to design and implement remedial actions, with oversight from USEPA in coordination with the Oregon Department of Environmental Quality, local Tribal governments, and key stakeholders. The 60-acre River Mile 3.5 East (RM3.5E) Project Area includes industrial waterfront properties owned by Radius Recycling (formerly Schnitzer Steel Industries, Inc.), MMGL LLC, Time Oil, and the Port of Portland.

To satisfy Project Area source control requirements, a comprehensive stormwater evaluation is required.

The Portland Harbor Superfund Site includes contaminated sediments along 10 miles of the Willamette River. The U.S. Environmental Protection Agency (USEPA) has issued a Record of Decision for the Superfund Site, requiring control of sources of contamination to sediments; implementation of dredging, capping, and natural recovery remedies for sediments; and remediation of contaminated riverbank areas. The Superfund Site has been divided into multiple primary areas designated by river mile. Responsible party groups for each area are required to design and implement remedial actions, with oversight from USEPA in coordination with the Oregon Department of Environmental Quality, local Tribal governments, and key stakeholders. The 60-acre River Mile 3.5 East (RM3.5E) Project Area includes industrial waterfront properties owned by Radius Recycling (formerly Schnitzer Steel Industries, Inc.), MMGL LLC, Time Oil, and the Port of Portland.

To satisfy Project Area source control requirements, a comprehensive stormwater evaluation is required.

Our Approach

As part of the RM3.5E Project Area stormwater investigation, potential sample locations were evaluated for the suitability of composite sampler installations.

A comprehensive work plan was developed to inform the collection of both grab and composite stormwater samples, as well as storm solids samples. Flow meters were installed at selected locations to assess flow conditions and inform appropriate sampler programming. Composite samplers and in-line solids traps were deployed in outfall pipes discharging stormwater from four upland basins into the Willamette River. Stormwater sampling was conducted over two wet seasons, with samples analyzed for contaminants associated with the Portland Harbor Superfund Site. The resulting data were compared with applicable cleanup and source control screening levels. Two years of flow meter data were evaluated and processed, and results from grab and composite samples were compared to assess the representativeness of grab samples for future monitoring. Finally, stormwater and storm solids loads were calculated to evaluate the potential for sediment recontamination and to prioritize source control measures within individual basins.

As part of the RM3.5E Project Area stormwater investigation, potential sample locations were evaluated for the suitability of composite sampler installations. A comprehensive work plan was developed to inform the collection of both grab and composite stormwater samples, as well as storm solids samples. Flow meters were installed at selected locations to assess flow conditions and inform appropriate sampler programming. Composite samplers and in-line solids traps were deployed in outfall pipes discharging stormwater from four upland basins into the Willamette River. Stormwater sampling was conducted over two wet seasons, with samples analyzed for contaminants associated with the Portland Harbor Superfund Site. The resulting data were compared with applicable cleanup and source control screening levels. Two years of flow meter data were evaluated and processed, and results from grab and composite samples were compared to assess the representativeness of grab samples for future monitoring. Finally, stormwater and storm solids loads were calculated to evaluate the potential for sediment recontamination and to prioritize source control measures within individual basins.

Project Team

Floyd|Snider
Paradise Environmental, Inc.
BACK TO Stormwater Management