Since the 1980s, GE has been evaluating the fate and transport of contamination at their Hudson Falls facility. Early investigations focused on the contamination in the overburden soils and groundwater. Extensive investigations were completed to evaluate the dense nonaqueous phase liquid (DNAPL) in the fractured shale beneath the site.
Anchor QEA personnel have been involved in many aspects of data collection at the site. Some of the more significant and informative investigative techniques used to develop the conceptual model for the site were:
- Installation of multi-level FLUTe™ monitoring systems to provide long-term groundwater level and quality monitoring in deep bedrock wells
- Rock core and FLUTe™ swab sampling to identify DNAPL bearing fractures
- Borehole video logging to identify the spatial distribution of DNAPL and bedrock fractures
- Short-term water level monitoring in the dry portion of the river using removable FLUTe™ systems
- Cross-hole hydraulic monitoring to determine preferred orientations of hydraulically-connected fractures
- DNAPL chemical fingerprint analyses
- DNAPL recovery from selected wells
- Pilot-scale polymer flood in shallow bedrock beneath the Wing Dam area
- Regional groundwater flow modeling
The New York State Department of Environmental Conservation (NYSDEC) has approved a comprehensive remedy including tunnel/drain collection system (TDCS) that will be installed at a depth of about 200 feet below the ground surface with 10- to 12-foot diameter tunnels extending to the north and south beneath the eastern edge of the river. Vertical and horizontal drain wells will be drilled from the tunnels to create an expanded region of downward hydraulic gradients beneath the river. The primary objectives of the collection system are to prevent or minimize polychlorinated biphenyl (PCB) releases to the river adjacent to the site and to contain the migration of contaminated groundwater from the site.
For more information on this project, please contact John Edwards at jedwards@anchorqea.com.