Sediment Contamination Delineation

Client: Confidential Client

Location: Portland, OR

Because of the complexity of the legacy impacts affecting sediments at the site of a silicon wafer production facility in Portland, Oregon, the client, who operates the facility, had major contamination issues to contend with.

Unaware of the full extent of the damage caused by historical uses of the property—including as a holding area for manufactured gas plant waste in the 1950s—the client reached out to MFA to prepare a groundwater investigation. Once the sources of the plumes were identified, MFA followed up with a remedial investigation including an analysis of the nearby Willamette River’s surface water. Using fate and transport modeling to predict the movement of contaminated sediment, it was confirmed that natural attenuation would be an efficient and cost-effective remedy for managing the in-water portion of the plume. Once implemented, MFA’s remedy took less than one year to reach the set remedial action objective, allowing the client to continue their operations.

As an outcome of MFA’s assistance, the client:

• Received comprehensive knowledge of their responsibilities regarding contamination present at the site
• Was able to move forward with implementation of a fast and cost-effective remedy
• Is able to continue their operations today