Upland Riverbank Sediment Remediation

Client: Zidell Marine Corporation

Location: Portland, Oregon

To remediate their 30-acre waterfront Superfund site in Portland, Oregon, which had been the location of a ship building and dismantling facility, Zidell Marine Corporation (Zidell) needed to consider how best to address the site’s issues. With its geotechnically unstable riverbank, historical contamination, and changing fluvial environments, Zidell’s overarching goal for the remediation was to protect human and environmental health. The company’s longer term plan to redevelop the former brownfield for mixed-use residences and businesses would complement other new development on Portland’s burgeoning South Waterfront.

Due to the scale of the remediation, effective supervision of all related construction and permitting activities was paramount to the project’s success. Providing civil and environmental construction oversight, MFA worked in a lead role as part of a multidisciplinary team, and coordinated elaborate construction efforts with subcontractors. MFA tightly tracked all units of construction and managed issues by providing efficient resolutions with a direct understanding of the complex issues.

As work was approaching the final stages of completion, TriMet announced its new Portland to Milwaukie light rail and pedestrian bridge span would cross directly over the sediment cap and land on the Zidell property. MFA supported communications between Zidell, DEQ, and TriMet to design and construct a 12,000 cubic yard repository of contaminated soil within the new bridge landing and behind the clean retaining wall structures, eliminating the need for TriMet to import the same volume of fill for the bridge approach. Design and construction success has been demonstrated by reduced concentrations of PCBs in the vicinity of the sediment cap. The shoreline area is starting to reflect Zidell’s vision: planting of native shrubs and trees has transformed the site into a vegetated shoreline with significant potential for redevelopment.

This effort was the largest privately-funded cleanup of industrial land along the Willamette River to date. The property is now poised for its next stages of use as Zidell Yards, a mixed-use complex Zidell plans to develop for valuable office, retail, and residential use. The Yards will be a continuation of the adjacent South Waterfront neighborhood.

MFA assisted the client in achieving:

  • Effective soil cap remedy for 30-acre parcel of brownfield land along the Willamette River
  • Permitting and communications with government entities to ensure smooth transitions between cleanup, remediation, and construction activities
  • Removal of contaminated soils to reduce risk to human and environmental health
  • Development-ready shoreline property with risk removed, making it attractive to potential developers

See the trailer below about our movie describing remediation at Zidell. Then, watch the full 30-minute film for an understanding of the investigation and remediation work at the site, its past use, and its potential for future development.

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Erik Bakkom, PE

Principal Engineer

(503) 312-0094