Lower Duwamish Waterway
Source Control Investigation

RM 4.3-4.9 East (Boeing Developmental Center)

SITE BACKGROUND

The Boeing Developmental Center (BDC) source control area (also referred to as the RM 4.3-4.9 East source control area) is located along the eastern side of the LDW Site between RM 4.3 and 4.9, as measured from the southern end of Harbor Island. The aerial photograph shows this source control area.

Boeing Developmental Center is the only facility located within this source control area.

This source control area is bordered to the north by the Slip 6 source control area and to the south by the EAA-7 source control area. Portions of the BDC property extend into these source control areas. Information on these source control areas can be found at the following links:

RM 3.9-4.3 East (Slip 6) Source Control Area: This includes the northern portion of BDC and a parcel to the north of BDC currently owned by the Museum of Flight.
EAA-7 Source Control Area: This includes the southern portion of BDC located between S. 102nd St. Bridge and the Boeing pedestrian bridge.

The upland areas near this source control area have been heavily industrialized for decades. Historical and current commercial and industrial operations in the vicinity of the BDC source control area include a commercial airport, chemical manufacturing, a military flight center, a museum, and an auto wrecking storage yard.

CONTAMINATION

Sediments in the BDC source control area have been impacted by chemical contaminants from various sources. Before reaching the LDW sediments, the contaminants are first impacted in upland media including surface water, groundwater, soil, and air.

The following chemicals are considered to be contaminants of concern in the BDC source control area because they could possibly recontaminate Lower Duwamish Waterway sediments once it has been cleaned up.

Metals	Organics
Lead	Polychlorinated biphenyls (PCBs)
	Polynuclear Aromatic Hydrocarbons (PAHs)

Source Control

Ecology is the lead for source control for the LDW Superfund site. Source control is the process of finding and then stopping or reducing as much as possible releases of pollution to the river. Ecology looks at the drainage for the BDC source control area in order to determine what source control work needs to be done. The BDC source control area drainage basin outlines the area where sources need to be controlled. The way contaminants enter Lower Duwamish Waterway sediments from this source control area include: direct discharges via piped outfalls, bank erosion from adjacent properties, surface runoff from adjacent properties, groundwater discharge, air deposition, and spills directly to the inlet.

Source Control Action Plan

Ecology developed a Source Control Action Plan for the BDC source control area which describes what source control actions are necessary. As part of the Source Control Action Plan, Ecology hired a contractor to put together a Summary of Existing Information and Data Gaps report.