Gentry, J.L., A. Salter-Blanc, K. Sheets, B. Sharma, L. Tochko, and S. Martin.
Remediation 30(2):5-14(2020)

Releases of petroleum LNAPL related to upland impacts caused occasional sheens on a portion of the Willamette River in the Portland Harbor Superfund site., OR. The frequency and volume of sheens decreased following the installation of an upland sheet pile barrier wall, but occasional sheens related to LNAPL stranded downgradient of the wall continued, prompting the design of a shoreline remedy. To mitigate the LNAPL and dissolved-phase groundwater constituents, a novel, multilayered shoreline cap was designed and installed. The cap was designed to mitigate sheen and to meet the objectives specified in the Portland Harbor Record of Decision including limiting the discharge of certain dissolved-phase constituents of interest. The cap design was the first instance of combining an oleophilic bio-barrier to mitigate sheen and an activated carbon layer to capture dissolved-phase constituents. No sheens have been visually observed since cap installation. More information https://www.deq.state.or.us/Webdocs/Controls/Output/PdfHandler.ashx?p=0da006fb-a778-45aa-a491-b2b982bbe3aepdf