University of Washington Tacoma cleanup site

After historic contamination left chemicals from commercial degreasers, oil, and fuel in soil and groundwater, cleanup is underway at the University of Washington Tacoma  (UW Taccoma) cleanup site. UW Tacoma is in the early stages of cleanup. Under our oversight, they are working to find the extent and types of contamination, and to complete a smaller, partial cleanup in one part of the site.

Site background

The University of Washington Tacoma site is on about 50 acres in south downtown. The site includes a mix of old and new buildings, ranging from new construction to structures over a century old.

This part of downtown has a long legacy of industrial activity. Many of those activities contaminated the soil and groundwater with chemicals from solvents, oil, and fuel including:

We’re motivated to clean up this contamination because each of these chemicals can be harmful to the environment and to peoples' health. We are working to prevent release into Commencement Bay and people's exposure through direct contact or vapors entering buildings.

Cleanup management

In the 1980s, a facility that stored and managed dangerous waste called Arrcom Inc. operated at the site. When they closed, Washington state took over the site along with an adjacent property in the 1990s. In 1997, we signed a legal agreement called an agreed order with UW Tacoma to start site cleanup.

As the property owner, UW Tacoma accepted responsibility as the potentially liable party and agreed to work on cleaning up soil and groundwater at the site.

Under this agreed order, groundwater treatment began in 2013 on a part of the UW Tacoma cleanup site called the Howe Parcel. The Howe Parcel is at the northeast corner of the UW Tacoma site, and extends south down Pacific Avenue.

In 2016, we finalized a new agreed order for the entire cleanup site that requires UW Tacoma to:

  • Conduct a remedial investigation to describe the nature and extent of the contamination on the site.
  • Conduct a feasibility study to evaluate cleanup options for the site.
  • Submit a draft cleanup action plan to outline proposed cleanup actions for the site.

We are now the lead for the cleanup. The 2016 agreed order includes an expanded site footprint to focus on area-wide groundwater contamination, which is now considered the principal environmental issue.

Public participation

At milestones throughout the cleanup process, we encourage public participation by inviting your comments on key cleanup documents. If you’d like to be included on our outreach list for these comment periods, contact Site Manager Tom Middleton at 360-407-7263 or

In spring 2016, we invited public comment on a public participation plan and draft agreed order for the UW Tacoma Cleanup.

Our basic cleanup process

The basic stages of cleanup under Washington State's Model Toxics Cleanup Act. See Ecology's cleanup process web page for more information.

What’s next in cleanup?  

The next step toward cleanup at the UW Tacoma site is completing a remedial investigation. This investigation will help us understand what types of contamination are on the site, where the contamination is, and the potential risks contamination poses to people and the environment.

Partial site cleanups called interim actions are also allowed under the current agreement and may take place at any point in the process. If we take an interim action, your comments will be invited before the work plan is final.