Gentry, J., S. Martin, T. Sale, K. Sheets, and J. Gentry.
10th International Conference on the Remediation and Management of Contaminated Sediments, 11-14 February, New Orleans, Louisiana, poster, 2019

Despite a 216-ft sheet pile wall, hydraulic control, and LNAPL recovery system to prevent LNAPL migration from at the Portland Harbor Superfund Site, occasional petroleum sheening was observed on the Willamette River. Additional investigation to augment the conceptual site model determined that the sheens occurred when the river levels inundated a 2- to 4-ft-thick lens of LNAPL located riverside of the wall. A 65-ft oleophilic biobarrier cap was constructed from October-November 2017 on the riverbank to contain and treat contamination and prevent sheening. The cap included activated carbon and armoring layers and a top cover of fish-friendly beach habitat mix. No sheen has been observed since biobarrier construction. Longer abstract: https://www.battelle.org/docs/default-source/conference-proceedings/2019-sediments-conference-proceedings/c6.-napl-and-mgp-sites/463.pdf?sfvrsn=9f0e3706_2 Poster: https://www.battelle.org/docs/default-source/conference-proceedings/2019-sediments-conference-proceedings/c6.-napl-and-mgp-sites/c6_-463_poster_gentry.pdf?sfvrsn=d47cd173_2 See the cap construction completion report for more information: https://www.deq.state.or.us/Webdocs/Controls/Output/PdfHandler.ashx?p=0da006fb-a778-45aa-a491-b2b982bbe3aepdf Also see the 2017 EPA ROD: https://semspub.epa.gov/work/10/100036257.pdf