Variable-density groundwater flow and contaminant transport, Operable Unit 1, Naval Base Kitsap, Keyport, Washington

• DOI: 10.3133/sir20205066
• Publication Date: 2020-10-22T01:42:55Z
• Authors: Richard M. Yager; Wendy B. Welch; Alexander Headman; Richard S. Dinicola
• Keywords: Physiographic province; Peninsula

First posted October 21, 2020 For additional information, contact: Director, Washington Water Science CenterU.S. Geological Survey934 Broadway, Suite 300Tacoma, 98402 Chlorinated volatile organic compounds (CVOCs) have migrated to groundwater beneath a former 9-acre landfill at Operable Unit 1 (OU-1) on Naval Base Kitsap, which was active from the 1930s through 1973 Keyport Peninsula, in Kitsap County, Washington. Biodegradation of CVOCs OU-1 limits mass dissolved-phase that discharges surface water, but contaminant concentrations up 630 milligrams per liter persist localized areas, likely dissolution residual, non-aqueous phase liquids. Variable-density groundwater-flow and contaminant-transport models were developed using SEAWAT-Version 4 computer program simulate direction rate flow 5.9 square-mile (mi2) - area surrounding estimate CVOC loading, assess possible remedial activities OU-1.The study is underlain by Quaternary deposits consisting alternating glacial interglacial sediments ranging 500 1,500 feet (ft) thick. A hydrogeologic model delineated sequence 10 units including relatively thin package (less than 100 ft) recent (Vashon Stade younger) Peninsula are much thicker (more 300 Clover Park Aquitard, overlies confined, sea-level aquifer.