Lots of trucks and big containers have been at the former Oroweat Bakery Outlet site at the corner of NW 70th Street and Greenwood Avenue North for the last couple of weeks. Mike V sent us this photo that he took from the second floor of a building across the street.
Crews are cleaning up soil that is contaminated from when a dry cleaning chemical distribution facility operated on the site, between 1964 and 1983. Piper Roelen with Landau Associates tells us the soil is contaminated with tetrachloroethene.
Roelen says the property owner is conducting the cleanup under the Department of Ecology’s Voluntary Cleanup Program. Most of the asphalt that currently covers the entire site will remain in place, and will be repaired where crews are drilling and excavating. Roelen says the soil is contaminated as deep as 30 feet in some places.
He says TRS Group, Inc.’s cleanup involves “heating of the subsurface soil to volatilize the contamination through a process called electrical resistance heating (ERH). The contamination is then drawn to the surface as a vapor through vacuum extraction, then captured from the vapor stream with activated carbon. The carbon is then shipped to a facility where the contamination is destroyed through thermal desorption (high heat destruction).”
The cleanup is expected to last until early spring. He says the property will likely be sold after the cleanup.