BELLEVUE, Wash. - Preliminary results from completion of an underground water-sampling project in parts of Algona show no contamination detected at most of the water-sampling locations.
The project is part of a continuing investigation into an area of contaminated groundwater that originates from past releases of solvent chemicals on property owned by The Boeing Company (Boeing) in Auburn. The Washington Department of Ecology (Ecology) directs the investigation, conducted and paid for by Boeing.
The study in Algona is one step in determining the location and size of this underground contamination, which includes solvent chemicals, primarily trichloroethene (TCE) and vinyl chloride (VC).
Laboratory tests of samples from 34 of the 49 drilling locations in the study showed no detection of the solvent chemicals of main concern for health risk (TCE and VC). Ecology and the Washington State Department of Health have begun a thorough review of the information. Boeing is preparing to submit a scientific assessment of the study results to Ecology.
Boeing contractors collected most of the water samples in a 12-block area bounded by Boundary Boulevard on the north, 8th Avenue on the south, State Route 167 on the west and Chicago Avenue on the east. Crews also gathered samples at sites to the south of this area. They collected water samples between five and 25 feet below ground.
Samples collected at 14 sites in the seven northeastern blocks of the study area did contain TCE and VC. This area is bounded by Boundary Boulevard, Chicago Avenue, Ninth Avenue and Algona Boulevard N. One other location – along Junction Boulevard, south of 9th Avenue – showed the chemicals to be present 25 feet below the ground, too deep to impact indoor air.
“These are encouraging findings, that suggest the contamination occurs under a limited part of the study area,” said Robin Harrover, Ecology’s site manager. “Concentrations at the water table are lower than those at deeper depths, and this suggests that the risk to people of exposure in indoor air is less than we originally thought it might be. However, we believe it is critical to continue to evaluate this information, conduct follow-up studies, and keep the community informed.”
Ecology has directed Boeing to move forward with studies to determine:
- Whether contaminants in high water table areas may be present in surface water, such as street ditches or ponds that form on private property.
- Whether vapors may be released from solvents in the groundwater that could enter homes, and, if so, whether these reach levels that require corrective actions.
The studies, to begin in the next few weeks, will concentrate on the seven-block area where the investigation detected groundwater contamination closest to the water table. Ecology will inform the public when these studies occur, and will contact property owners and occupants in the study areas to request permission to gather samples and related information in homes and yards.
The groundwater contamination does not affect public drinking water systems in the vicinity because the supply wells are located safe distances away from the contamination. Also, the area’s groundwater flow carries the contamination away from the supply wells.
Ecology will continue to provide updates on the investigation as information becomes available.
Ecology maintains updated information on the investigation at: https://fortress.wa.gov/ecy/gsp/Sitepage.aspx?csid=5049.
People with questions or comments about the investigation may contact Ecology at firstname.lastname@example.org.