Posted on

EXH AR023534: Baseline Soil & Groundwater Quality Assessment — Seattle City Light Long-Term Lease Option

Document Library
Sea-Tac Airport
Third Runway
PCHB
Box 10

A 1990 environmental assessment by Roy F. Weston Inc. evaluated soil and groundwater quality on an undeveloped Seattle property along the Duwamish Waterway, where Boeing was considering a 50-year lease with Seattle City Light. The study examined areas where dredged sediment from the Duwamish Waterway had been deposited in 1968 and 1985, testing for contaminants including PCBs, pentachlorophenols, PAHs, and metals. Prior sampling had found contaminant levels generally below state-regulated thresholds, and this baseline assessment was conducted to document existing conditions before any lease agreement was finalized.

Open full document

Notes

EXH AR023534. Baseline soil and groundwater quality assessment prepared by Roy F. Weston Inc. (WESTON) for Boeing Environmental Affairs, Seattle, Washington, May 1990. Evaluates soil and groundwater quality on undeveloped property adjoining Seattle City Light (SCL) Duwamish substation at 10000 West Marginal Place South, Seattle, in connection with Boeing’s consideration of a 50-year lease agreement with SCL. Property located on the Duwamish Waterway. Assessment covers 1968 and 1985 dredge fill areas, groundwater, and SCL substation fence line area. Contaminants assessed include PCBs (polychlorinated biphenyls), PCPs (pentachlorophenols), PAHs (polycyclic aromatic hydrocarbons), halogenated hydrocarbons, and metals. Prior analyses referenced include Raven Systems & Research Inc. (30 December 1987) and Laucks Testing Laboratory (No. 90364, 18 July 1985). Dredged sediment from Duwamish Waterway placed on property in 1968 (Corps of Engineers) and 1985 (Duwamish Yacht Club marina dredging).

Sidebar On/Off
V V