Frederickson Industrial Park

The Columbia Powder Company first developed the site in 1935 to produce explosives. Since then, property ownership changed many times. Despite changes in ownership, explosives continued to be produced on site until 1976. Between 1976 and 1986, the site was used for timber cutting, lumber milling, and log storage. In 1987, a new owner bought the site and developed it as an industrial park.  In 1990, the property was sold again to the current site owner, Boeing, who developed the site to make aircraft parts.

Site groundwater is contaminated with carbon tetrachloride (CTC). In the past, CTC was used as a cleaning solvent or in fire control. Cleanup is important because CTC can be harmful to human health and the environment.

In 1995, Ecology identified former property owners Mallinckrodt US, LLC (Mallinckrodt) and Olin Corporation (Olin) as the potentially liable persons (PLPs) responsible for cleaning up the site. The PLPs and other owners conducted many studies and partial cleanup actions during the past 25 years. These included:

• Studying soil, groundwater, and soil vapor.
• Removing soil, waste, and debris.
• Treating groundwater.
• Monitoring groundwater. In 1999, samples showed that CTC levels around the site were low enough that there was no risk to human health through vapor intrusion. Vapor intrusion is when chemicals move from soil and groundwater into air in buildings.

In 2000, more studies showed the contaminant plume reaching well water supplies for nearby homes and businesses. By 2007, public water service was brought into the area near the plume and properties with private wells were connected to the public supply.

As a result, there is very little risk of human exposure to the contamination.

Following earlier cleanup efforts, groundwater tests showed:

• The contaminated area (plume) was shrinking.
• Contamination levels were decreasing.

Because the site was improving naturally, Ecology proposed allowing the remaining CTC to break down through a process called natural attenuation. This method uses natural physical, chemical, and biological processes to reduce contamination over time.

We selected natural attenuation as the final cleanup approach because:

• Studies confirmed that CTC levels were steadily decreasing.
• The risk of human exposure to contaminated groundwater was minimal.
• Other cleanup methods would have a larger environmental impact and higher costs.

Ecology held a public comment period from January 23 to February 24, 2014, to gather feedback on the proposed cleanup plan. Documents up for review included:

• An Agreed Order (download 6.6MB) — a legal agreement that requires the potentially liable parties (Olin and Mallinckrodt) to clean up the site. Exhibits to the Agreed Order include:
  • The Cleanup Action Plan (CAP)-- outlines the cleanup.
  • A Compliance Monitoring Work Plan -- tells how, where, and when groundwater sampling will be done.
• A Remedial Investigation/Feasibility Study (RI/FS) (download 10.1MB) — describes the nature and extent of contamination and compares cleanup options.
• A Public Participation Plan (download 1,719KB) — describes the tools Ecology will use to inform the public and gather feedback.

No public comments were received during the review period. After finalizing the documents, cleanup efforts moved forward.