Organic Contamination of Ground Water at Gas Works Park, Seattle, Washington


  • G.L. Turney,

    1. Gary L. Turney is a hydrologist with the U.S. Geological Survey (1201 Pacific Ave., Ste. 600, Tacoma, WA 98402) where he has worked since 1977. His interests are in water chemistry and his experience includes ground water chemistry and contamination studies. He received his B.S. in chemistry from Washington State University in 1977.
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  • D.F. Goerlitz

    1. D.F. Goerlitz (U.S. Geological Survey, 345 Middle-field Rd, Menlo Park, CA 94025) joined the U.S. Geological Survey in 1961 and is employed as a chemist. He received both his B.S. and M.S. degrees from the Agricultural College, University of Missouri.
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Gas Works Park, in Seattle, Washington, is located 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 park soil is currently (1986) 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 are also present in the ground water.

Polynuclear aromatic hydrocarbons and volatile organic compounds were identified in ground water samples in concentrations as large as 200 mg/L. Concentrations of organic compounds were largest where ground water was in contact with a non-aqueous phase liquid in the soil. Where no non-aqueous phase liquid was present, concentrations were much smaller, even if the ground water was in contact with contaminated soils. This condition is attributed to weathering processes in which soluble, low-molecular-weight organic compounds are preferentially dissolved from the non-aqueous phase liquid into the ground water. Where no non-aqueous phase liquid is present, only stained soils containing relatively insoluble, high-molecular-weight compounds remain. Concentrations of organic contaminants in the soils may still remain large.