Washington State Department of Ecology - October 24, 2013
The effort is part of a continuing investigation, directed by the Washington Department of Ecology (Ecology) and carried out and paid for by Boeing.
The consultants, from Boeing’s environmental contractor, Landau Associates, will first collect water samples from city stormwater ditches in the residential area.
Later this fall or winter, owners and occupants of about 32 homes and lots will receive letters from the contractor to ask whether water collects in ponds on their property. If so, the company will ask permission to take samples of that water.
The water table in Algona can be very high in the fall and winter. When this happens, groundwater can enter low-lying areas and mix with rainwater. The ditch-and-yard study will help determine whether groundwater contaminants may be present in surface water during the wet season, and, if so, at what concentrations.
Groundwater studies in Auburn and Algona have detected trichloroethene (TCE), a solvent formerly used by Boeing, and related compounds that form as TCE degrades. These include cis-1,2-dichloroethene (cis-1,2-DCE), and vinyl chloride. Groundwater studies in areas outside the Boeing property have detected these compounds at low levels.
The stormwater ditch study will include streets bounded by 7th Avenue North, Boundary Boulevard, State Route 167 and Chicago Avenue. Boeing took groundwater samples in this area earlier this year and did not detect contamination in most locations. The 32 homes and lots are located in the northeastern portion of this area, where groundwater sampling did detect low levels of groundwater contamination.
The city of Algona has aided the study with arrangements for the street-ditch sampling and other technical assistance.
This surface water study is one step in determining the potential effects from contaminated groundwater under parts of Auburn and Algona. Ecology may direct additional surface water sampling, depending on the results of this study.
A water sample previously collected from the Chicago Avenue ditch, in the planned study area, contained the chemicals TCE, cis-1,2-DCE, vinyl chloride and tetrachloroethylene (PCE). The Washington State Department of Health completed an assessment to see if the ditch water would have an impact to children or city workers. The Department of Health found the levels were not likely to cause health problems for people who come into contact with it.
Ecology will request a further assessment from the Department of Health once the upcoming sampling is completed.
Ecology is mailing information about the project to addresses in and near the study areas. When results of the surface water sampling are available, Ecology will post the information online at https://fortress.wa.gov/ecy/gsp/Sitepage.aspx?csid=5049.
Ecology continues to direct other parts of the investigation:
Vapor intrusion: Boeing received permission to sample indoor air in 15 homes (and one garage) in the area where the groundwater study detected low levels of contamination in Algona. Because the chemicals can release vapors, and because of the high water table, Boeing is assessing whether vapors may be entering homes. Ecology plans to post more information online about these sample results in December.
More surface water studies: Boeing will install a device in the Chicago Avenue ditch to monitor and record the rise and fall of surface water. Comparing the water levels in the ditch with water level data from the nearby groundwater monitoring wells will help in understanding the interconnection of groundwater and surface water. Boeing also will collect water samples from stormwater ponds north of Algona, test them for the chemicals of concern, and install a water level monitor in one of them.
Website improvement: Ecology plans to launch an updated website later this fall to make it easier to track information about the overall investigation into the groundwater contamination from the Boeing property.
Drinking water is safe
The groundwater and surface water contamination does not affect the municipal drinking water supply from Auburn, which also supplies Algona, because the supply wells are located safe distances away from the contamination. Also, the area’s groundwater flow carries the contamination from the Boeing facility away from the supply wells.
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Larry Altose, 425-649-7009, firstname.lastname@example.org
Robin Harrover, Ecology site manager, 425-649-7232, email@example.com
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