Location
Construction & Engineering Hall, Oregon State University
Start Date
25-6-2013 3:30 PM
End Date
25-6-2013 3:50 PM
Description
A Natural Resource Damages (NRD) Settlement Agreement between the New Jersey Department of Environmental Protection (NJDEP) and El Paso Corporation specified the removal of three lowhead dams (Calco Dam, Nevius Street Dam, and Robert Street Dam) that were preventing anadromous fish passage on the main stem of the Raritan River, New Jersey’s largest watershed and longest interior river system. The most downriver dam (Calco Dam) was successfully removed in July -August 2011. The July 23 -August 24, 2012 removal of the Robert Street Dam, the largest of the three dams, posed the most significant technical challenges. For example, there was no suitable road access to the dam, requiring the 40-ton demolition equipment to be mobilized into the river far upstream and carefully maneuvered downriver over a meticulously delineated route of shallow sand bars to reach the dam site. The dam was comprised of a 1964 reconstructed sheet-piled supported structure that encased a deteriorated circa 1915 concrete gravity dam. That unique configuration required developing a deconstruction sequence that involved initially removing the concrete capping the tops of two parallel rows of sheet piles, which were spaced17.5-ft apart, then removing the rock fill and the buried circa 1915 dam lodged between the sheet piles. An excavator-supported vibratory sheet pile driver/extractor was then employed to remove the 300 individual sheet piles that had been driven into bedrock. Restoration activities included reconnecting the thalweg and stabilizing the embankments that had been formerly supported by the dam. Over 700 tons of concrete and 70 tons of steel were removed from the river and sent off-site for recycling. The finalphase of the project will be the July 2013 breaching of the Nevius Street Dam, thus satisfying the NRD Settlement terms and completing the Raritan River’s most significant river restoration project to date.
Concurrent Sessions A: Dam Removal II - Robert Street Dam Removal - Continuing the Restoration of the Raritan River Watershed, New Jersey
Construction & Engineering Hall, Oregon State University
A Natural Resource Damages (NRD) Settlement Agreement between the New Jersey Department of Environmental Protection (NJDEP) and El Paso Corporation specified the removal of three lowhead dams (Calco Dam, Nevius Street Dam, and Robert Street Dam) that were preventing anadromous fish passage on the main stem of the Raritan River, New Jersey’s largest watershed and longest interior river system. The most downriver dam (Calco Dam) was successfully removed in July -August 2011. The July 23 -August 24, 2012 removal of the Robert Street Dam, the largest of the three dams, posed the most significant technical challenges. For example, there was no suitable road access to the dam, requiring the 40-ton demolition equipment to be mobilized into the river far upstream and carefully maneuvered downriver over a meticulously delineated route of shallow sand bars to reach the dam site. The dam was comprised of a 1964 reconstructed sheet-piled supported structure that encased a deteriorated circa 1915 concrete gravity dam. That unique configuration required developing a deconstruction sequence that involved initially removing the concrete capping the tops of two parallel rows of sheet piles, which were spaced17.5-ft apart, then removing the rock fill and the buried circa 1915 dam lodged between the sheet piles. An excavator-supported vibratory sheet pile driver/extractor was then employed to remove the 300 individual sheet piles that had been driven into bedrock. Restoration activities included reconnecting the thalweg and stabilizing the embankments that had been formerly supported by the dam. Over 700 tons of concrete and 70 tons of steel were removed from the river and sent off-site for recycling. The finalphase of the project will be the July 2013 breaching of the Nevius Street Dam, thus satisfying the NRD Settlement terms and completing the Raritan River’s most significant river restoration project to date.
Comments
John W. Jengo, PG, a licensed Professional Geologist in several Northeastern states and a Licensed Site Remediation Professional in New Jersey, works as a Principal Hydrogeologist in an environmental consulting firm in southeastern Pennsylvania. He has degrees in geolgy from Rutgers University (1980) and the University of Delaware (1982). Over the last 20 years, he has lead the characterization and remediation of large, complex contaminated industrial sites throughout New Jersey, Pennsylvania, and Delaware. He is the technical Project Manager and Project Agent for a series of dam removal projects specifically designed to restore historically significant anadromous fish passage up the Raritan River in central New Jersey, the state’s largest watershed and longest interiorriver system. As part of this on-going effort, he has successfully planned, permitted, and executed the removal of the Calco Dam in July-August 2011 and the Robert Street Dam in July-August 2012.