In-Water Sediment Remediation

Client: Zidell Marine Corporation

Location: Portland, Oregon

In-water contaminants from years of barge-building activities had left the Zidell Marine Corporation (Zidell) with a major barrier to development on their Willamette River property. Zidell hired Maul Foster & Alongi, Inc. (MFA) to perform a complex series of sediment remediation efforts, including modeling the movement of contaminants within the sediments. MFA helped to design a remedy for Zidell, and the resulting sediment cap was divided into three design reaches to address variability in site conditions, topography, currents, and adjacent river uses. MFA’s design for the cap involved the use of an innovative geocomposite material called Reactive Core Mat, which consists of two layers of geotextile sandwiching a 1-cm-thick layer of granular activated carbon and an apatite mineral, providing the same protective value as two feet of sand. This solution allowed Zidell to continue their barge construction operations and begin plans for development of the newly remediated area.

With MFA’s help, the client achieved:

• Isolation of contaminants, resulting in significantly reduced risk to human and environment health
• Improvement to fish habitat
• A design that allowed Zidell to continue barge construction operations

See the trailer for 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.

Learn more about our work at Zidell.