USG Interiors Inc Puyallup

Ecology held a public comment period for the USG Interiors, LLC Puyallup site between January 7 and February 5, 2019. The following documents were available for public comment:

• Remedial Investigation (RI) and Feasibility Study (FS) that describe the contamination and compares cleanup options.
• Cleanup Action Plan (CAP) that outlines the cleanup action selected by Ecology.
• Agreed Order DE#11098 that requires USG to implement and maintain the recommended cleanup actions.
• State Environmental Policy Act (SEPA) Checklist and Determination of Non-Significance (DNS) that describe the potential environmental impacts of the cleanup work.

Ecology responded to the two comments we received.

The site is located at 1005 River Road East between River Road and the Puyallup River. It is 1.58 acres and consists of four USG-owned tax parcels that include portions of the Bonney Lake Used Cars property to the west, Market Place Auto property to the east, and Pierce County’s Inter-County River Improvement Right-of-Way along the Puyallup River to the north. The Riverwalk Trail, a paved path at the top of the river bank, is used for biking and walking. Currently, there are no plans for future land use at the site.

Prior to 1971, the USG facility used slag from the former Tacoma Asarco copper smelter as a raw material to produce rock wool. Rock wool is an insulating and fire-proofing material. It is made by heating rock until it is molten, and blowing or spinning it into fine fibers. The manufacturing waste that consisted of “baghouse dust” and “shot”, was used as fill on the site to raise the grade.  In the 1980s, USG learned that the slag and waste contained high concentrations of arsenic, and had contaminated soil, sediments in the Puyallup River, and groundwater. 

In 1984, USG entered into an Agreed Order to assess groundwater contamination on the site.  Between 1984 and 1985, USG removed contaminated soil and disposed of it at a hazardous materials landfill.  Ecology required USG to monitor the groundwater after the cleanup. 

In 2006, USG conducted a site assessment and found soil and groundwater with arsenic concentrations above the state Model Toxics Control Act (MTCA) cleanup levels.  In 2007, USG conducted a Remedial Investigation (RI) and Feasibility Study (FS). Now, Ecology and USG are proposing to implement the Cleanup Action Plan (CAP) to address the remaining contamination.