MULTI-MEDIA FLUX METERS TO EVALUATE CONTAMINANT MIGRATION THROUGH GROUNDWATER-SURFACE WATER INTERFACE
The flux meters were designed to collect the data necessary to limit the potential for ebullition, groundwater or expressed pore water from the underlying sediment to impact the cap due to the potential contamination migration pathway through the groundwater-surface water interface. Five flux meters were installed in Stryker Bay; three in locations within the cap area where higher groundwater flow was expected based on sediment temperature profiles, and two outside the cap area to complete aerial coverage of the bay and provide data from locations with typical sediment temperature profiles. Vibrating wire piezometers installed at depths of 5 and 20 feet below the mudline at each flux meter location were synchronized with the site water level meter to evaluate temporal and spatial variations in groundwater gradient, flow direction, and head distribution. Each flux meter captured all gas and water entering the base of the 3.14-square-foot flux meter. A dome was welded to the inside wall of the flux meter to capture gas and water in a flexible bag, and glass wool mesh was suspended just below the dome to capture sediment or NAPL. Temperature probes were installed in the sediment and the water column to allow for gas volume standardization.
Data, results and conclusions from deployment of these multi-media flux meters will be presented.