Contaminated Soil - If it's not the Airport's contaminated soil, the Duwamish soil brought in before it was declared a Superfund site, it's ASARCO contminated soils
The DOE published another Tacoma Smelter Plume report on the web April 4, 2002. It covers mainland King County contamination data. It includes unsafe soil contamination levels in Burien, Normandy Park, Des Moines, etc.
Maximum Lead concentrations map - 250 ppm is WA's toxic clean up level
Not only are their issues with proposed sources of fill at the airport being contaminated, so are other possible sources such as Maury Island.
Below link does not work but thier site is being worked on
Where will the fill com from for the 3rd runway come from? How many aquifers are endangered? Will it come by double haul truck or barges or both? How contaminated will it be? Thanks to Washington Legislature overuling thier own pollution experts, it can be very toxic. See Table