Sampling crews are drilling wells on and around University of Washington-Tacoma to monitor the spread and concentration of chemicals that were left in the soil during the more than 100 years of manufacturing and industrial activity in the area.
The work will run through the month, so area residents, students and visitors should expect periodic construction noises and detours between Tacoma and Yakima avenues from South 17th to South 21st streets.
The test wells are needed in the ongoing effort to map the locations and levels of toxins in the 46 acres of the city’s former Brewery District that is now anchored by UWT. The mapping effort is the latest step since chemicals were first found in the groundwater in 1997, as the first buildings on the campus were taking shape.
“It’s like putting pins on a map,” UWT’s Director of External Communications Mike Wark said. “Before you start cleaning up these plumes, you have to know where it is. There 100 years of industrial legacy up there.”
The studies to date have identified, but not fully characterized, the extent of contamination that likely involves areas outside of the campus footprint. The pricetag so far is $7 million as part of an agreement between the university and the Department of Ecology. The final pricetag will depend on the level and breadth of the contamination as well as the mitigation methods.
The groundwater in the area contains petroleum hydrocarbons, benzene, trichloroethene and perchloroethene, which can be harmful to people and the environment. The health risks, however, are considered to be low because of the limited contact people will have with the groundwater. But cleanup or mitigation in areas will be done to avoid the toxins from contaminating the Foss Waterway and its wildlife as well as support UW Tacoma’s potential growth and development in the area.
“There is very low cause for public concern, but the Department of Ecology want to be sure,” Wark said. “It was found on our campus so we are responsible for it.”
The source of the chemicals has so far been traced back to former gas stations, chemical disposal operations and industrial and manufacturing operations that dates back to the pioneer days of Tacoma. The campus is located along decommissioned railroad tracks as well as the terminus for the transcontinental railroad that is now commemorated by the Prairie Line Trail through the campus. Commercial and industrial uses in the area included dry cleaning, auto repair operations and various manufacturing. The tests of the water collected during this round of well drilling will help determine if there are any ongoing sources of the pollution, particularly since the campus is located on the downhill slope that is capped by a commercial strip.
As late as the 1980s, a waste management facility operated in the area, for example. The business closed and Washington State took over the site along with an adjacent property in the 1990s after toxic chemicals were found in the soil. In 1997, UWT and ecology signed an agreement to start site cleanup.
In many cases, the contaminated areas will be treated with injections of a slurry made of copper or oxygen that breaks down the solvents. The sites will then be monitored to make sure chemicals don’t leach further downhill.
“Although the contamination does not pose a public health risk on the UWT campus, the fact that evidence suggests that the groundwater contamination may be threatening the completed cleanup of the Thea Foss Waterway is very concerning,” Citizens for a Healthy Bay Director Melissa Malott wrote in her comment letter regarding the cleanup. “… The importance of remediation and monitoring to prevent the recontamination of the Thea Foss Waterway cannot be overstated. A healthy and vibrant Thea Foss Waterway and Commencement Bay is vitally important to the character and identity of our community.”