By ROBERT WHALE
rwhale@auburn-reporter.com
Starting Wednesday, people in certain sections of Algona may see men and women in safety vests lugging gear around, surveying here and there, marking places where workers will later drill probes.
All part of an ongoing investigation of a plume of contaminated groundwater that started on The Boeing Co. property in Auburn.
Larry Altose, a spokesman for the Washington State Department of Ecology, which is overseeing the investigation, said groundwater data collected so far shows that the contamination does not affect public drinking water sources.
“Possibly as early as April 1, there’ll be temporary fencing off of each site where they will spend about two to three hours per location, probing and drawing up water samples,” Altose said. “We’re not talking about a big drill rig like someone uses to drill a water well. These fit on the back of a small truck.”
Most of the holes, Altose added, will be 5 feet deep, though there are a few that will be 15 or 25 feet. Combined, the bores will give technicians a bit of a 3D view of what’s happening with the groundwater.”
Geologists consider these depths to be shallow groundwater.
In the north-to-northwest direction that technicians have concentrated their search, they have not yet found the end of the plume, and the work will continue until they do, Altose said.
“There is some lateral movement (of the contamination). That’s how they plot it out because the groundwater moves slowly. When they find a concentration, they can project out based on their hydrogeological information,” Altose said. “So there’s a combination of things used. There’s the data collected from processes like this, and the existing information about groundwater movement in the area. Then there’s models they can use to combine the knowledge they have about groundwater movement and the data that they are finding to estimate where the contamination might be. That’s how they are able to plan each round of sampling.”
Algona Mayor Dave Hill said much of the City’s worry centers on the possibility of vapor contamination, which could rise through homes.
The study is one step toward determining the locations and size of the underground contamination, which includes solvent chemicals, primarily trichloroethene (TCE), a known carcinogen, and vinyl chloride (VC), in South King County. Boeing used the chemicals up to the 1980s to degrease airplane parts.
Information from the study will help planners decide on the cleanup of the groundwater contamination and determine whether more sampling is needed. Boeing is conducting the investigation and paying for it.
Crews will work in streets and public right-of-ways in three general areas:
• A 12-block area bounded by Boundary Boulevard on the north, Eighth Avenue on the south, State Route 167 on the west and Chicago Avenue on the east.
• Between Celery and Chicago avenues, crews will gather one sample mid-block on Fifth, Sixth and Seventh avenues north and Broadway Boulevard.
• Farther south, one sample will be taken at each end of Junction Boulevard and on Washington Boulevard near Second and Third avenues south.
The City of Algona has helped with arrangements for the sampling and in the selection of sampling locations.
All planned activities are subject to the City’s street-use approval process.
Workers first will conduct surveys and utility-location work. As early as April 1, truck-mounted drilling machines will begin to bore approximately 50 small holes to collect groundwater samples. Most of these will be 5 feet deep, with 15 and 25 foot borings planned at some locations.
Safety signs, barricades and fencing will guide vehicles and pedestrians away from active work sites. Crews will patch the small bore holes immediately after collecting each sample. Each groundwater sampling location requires one to three hours for preparation and drilling. The project will take approximately two weeks to complete.
The groundwater samples will be tested in a laboratory to detect the presence and concentrations of specific solvent-related chemicals. Ecology review of that data will provide information for the next steps in the investigation of the affected area and assessment of potential health risks associated with the contamination.
Ecology is mailing information about the project to addresses in and near the study areas. Project information also will be updated online during the project at fortress.wa.gov/ecy/gsp/Sitepage.aspx?csid=5049.
When results of the groundwater sampling are available, Ecology will post the information on line at https://fortress.wa.gov/ecy/gsp/Sitepage.aspx?csid=5049 and arrange a community meeting to explain the results and answer questions.
“This work is taking place a little bit later than we had initially thought it would be because we took some time to sit down with the City to map out our plans. Actually there are sites that have been added to the project at the City’s request,” Altose said.
