skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Ground-water contamination at an inactive coal and oil gasification plant site, Gas Works Park, Seattle, Washington

Book ·
OSTI ID:5893454

Gas Works Park is located in Seattle, WA on the site of a coal and oil gasification plant that ceased operation in 1956. During operation, many types of wastes, including coal, tar, and oil, accumulated on site. The soil at the park presently is contaminated with compounds such as polynuclear aromatic hydrocarbons, volatile organic compounds, trace metals, and cyanide. Analyses of water samples from a network of observation wells in the park indicate that these compounds also are present in the groundwater. Polynuclear aromatic hydrocarbons and volatile organic compounds were identified in water samples in concentrations as large as 200 mg/L. Concentrations of organic compound were largest where groundwater was in contact with a nonaqueous phase liquid in the soil, and were lowest where nonaqueous phase liquids were absent, even if the groundwater was in contact with contaminated soils. This condition results from weathering processes at the site, in which soluble, volatile, low-molecular-weight organic compounds are preferentially dissolved from the nonaqueous phase liquid into the groundwater. Where nonaqueous phase liquids are absent, only stained soils containing relatively insoluble, high-molecular-weight compounds remain; therefore organic compound concentrations in the groundwater are much lower. Specific conductance values in water samples were as large as 5,280 microsiemens/centimeter, well above a background of 242 microsiemens/centimeter; this indicates the presence of large concentrations of minerals in the groundwater. Trace metal concentrations, however, generally were less than 0.010 mg/L. Cyanide was present in groundwater samples collected from throughout the park, ranging in concentration from 0.01 to 8.6 mg/L. 25 refs., 7 figs., 6 tabs.

OSTI ID:
5893454
Resource Relation:
Related Information: USGS Water-Resources Investigations Report 88-4224
Country of Publication:
United States
Language:
English