Final Plan to Clean Up Contaminated Moss Bay Site Open for Comment

The state Department of Ecology (DOE) is seeking public comment on a plan to clean up a former industrial site in the Moss Bay neighborhood that has contaminated area groundwater with vinyl chloride, a known carcinogen.

The DOE specifically wants public comment on a legal agreement with the ULTRA Corp. that outlines a final plan to clean up the contaminated groundwater.

The now-vacant site is at 500 7th Avenue South, across the abandoned Burlington Northern railroad tracks from the Google Kirkland campus, and was used by commercial and industrial occupants since the early 1960s. Pace National mixed and packaged chemicals at the site for some 20 years beginning in the early 1970s, storing various substances in 14 underground tanks.

ULTRA has already cleaned soil at the site of petroleum hydrocarbons, semi-volatile organic compounds and chlorinated solvents. But vinyl chloride remains present in groundwater, and the possibility exists that over time it could seep into nearby bodies of water, including Lake Washington, potentially endangering ecological and human health, according to the DOE.

DOE Site Manager Maura O’Brien said the soil cleanup markedly reduced the levels of vinyl chloride in the groundwater, but that sampling shows levels of the substance at five locations remain above the state action level of 0.2 micrograms per liter.

The highest tested at 9.7 micrograms per liter in January of 2011 -- which was down from a level of 30 micrograms per liter in February of 2009.

Public comment on the plan will be taken through Feb. 27. You can send comments or questions to Site Manager Maura O’Brien at 3190 160th Ave. SE, Bellevue, Wa.; 425-649-7249; maura.obrien@ecy.wa.gov.

For details, see this DOE fact sheet about the site (also attached to this story). More depth, including legal decrees, site investigation reports, and relevant State Environmental Policy Act documents, can be found at the DOE web pages here.