Boeing Isaacson Thompson Site

SITE LOCATION

This site is located at 8625-8811 E. Marginal Way S. in Tukwila, Washington on the east bank of the LDW. The site includes 2 adjacent properties owned by The Boeing Company, the Isaacson (Boeing Isaacson) property on the north and the Thompson (Boeing Thompson) property on the south. The site is bordered by other cleanup sites: to the north by the Jorgensen Forge site, to the south by the former Kenworth Truck (former PACCAR, aka, 8801 E. Marginal Way S.) site, and to the west by the Lower Duwamish Waterway site. The Lower Duwamish Waterway is controlled by the Port of Seattle (Port), and includes a strip of uplands along the west side of the Boeing Isaacson property(see Figure) The final site boundaries will be defined by the extent of contamination determined during the Remedial Investigation (RI).

SITE BACKGROUND

Ecology and The Boeing Company are negotiating a draft Agreed Order to conduct an RI/FS and prepare a draft cleanup action plan.

Boeing Isaacson Property

The Boeing Isaacson property is located along the east side of the LDW at approximately river mile (RM) 3.7 to 3.8, as measured from the southern tip of Harbor Island. The property is rectangular shaped, long in the east-west direction, and is situated between the Port’s LDW property on the west and the East Marginal Way S road on the east. The property is bordered on the south by the Boeing Thompson property and on the north by the Jorgensen Forge property. The western Boeing Isaacson property boundary does not extend all the way to the water; a strip of land consisting of the shoreline bulkhead and approximately 20 to 30 feet inshore of the bulkhead is identified in King County parcel ownership records as part of the waterway and therefore is under Port control.

The Boeing Company purchased this property from the Isaacson Steel Company on March 14, 1984. The parcel was originally 12.29 acres in size; however, a property boundary adjustment was recorded on November 8, 2001, which moved the southern Isaacson property line north to its current location, reducing this parcel by 2.45 acres to its present size of about 9.8 acres. The topography is relatively flat.

Boeing Thompson Property

The Boeing Thompson property is adjacent to the south of Boeing Isaacson property, along the east side of the LDW at approximately RM 3.8 to 3.9, as measured from the southern tip of Harbor Island. The property is approximately 19.35 acres in size, and is situated between the LDW on the west, East Marginal Way S. road on the east, and the 8801 Site (former Kenworth Truck/Paccar property) on the south.

The Boeing Company purchased this property from the Parr Seattle Company in January 1957. The topography is relatively flat, with a steep, armored LDW shore.

Both properties are located in an area of extensive fill placed as part of the re-channelization of the Duwamish River. The thickest filling is within the area of the former Slip 5 that was filled in the 1960’s.

CONTAMINANTS OF CONCERN

Contamination at this site is due to industrial operations and facility development.

soil

Arsenic, Cadmium, Chromium, Lead, Mercury, Nickel, PCBs, Petroleum Hydrocarbons, Zinc

groundwater

Arsenic, Barium, Chromium, Lead

stormwater

Antimony, Arsenic, Lead, Petroleum Hydrocarbons

The chemicals of concern in sediments resulting from exceedances above Sediment Management Standards, Chapter 173-204 WAC, Sediment Quality Standards (SQS) and Cleanup Screening Levels (CSL) are:

Chart of sediment contaminants of concern.

PREVIOUS CLEANUP WORK

Environmental investigations and remedial actions of the Isaacson property, of soils in Building 14-05 storage bays and for moving a 48” stormwater line, were conducted from 1983 through 1991. Incomplete independent cleanup actions were conducted on the Isaacson property to address elevated metals concentrations in soil and groundwater. Much of the excavated contaminated soil was treated on-site by stabilization and contained by capping. In 2008, The Boeing Company independently removed some of those soils to level the terrain and revise the stormwater system. Some of the investigations were also conducted on the Thompson property.

CURRENT ACTIVITY