Rondout – West Branch Tunnel Magnetic Leak Detection Investigation

The New York City Department of Environmental Protection (NYCDEP or Department) proposes to investigate and map leakage locations in the Rondout West-Branch Tunnel ( RWB Tunnel) of the Delaware Aqueduct through the use of a patented geophysical technology called AquaTrack™ which uses controlled source- Audio Frequency Domain Magnetics (CS-AFDM) to map existing groundwater. 

The implementation of the AquaTrack™ technology would require the drilling of two wells located on industrial property near the Hudson River.  An injection electrode would be installed in direction contact with water in the RWB Tunnel through Shaft 5A of the Delaware Aqueduct and a return electrode would be placed in each of the two proposed new wells to be located to the northeast and southwest of the area under investigation.  Two small-gauge, insulated, solid copper-coated steel wires would be temporarily placed across approximately 3 miles of ground surface or vibrated approximately 6 inches below the ground surface to connect the injection electrode at Shaft 5A with each return electrode in the proposed new wells.  A signature alternating current (AC) electrical current would be applied to the electrodes which would flow along the water in the RWB Tunnel and eventually bleed off out of the Tunnel at leakage points and then flow along preferential flow paths back to the return electrodes in the new wells to complete an electrical circuit.  This signature electrical current would emit a magnetic signal that would be measured from the surface of the ground.   This investigation would take place in the Hamlet of Roseton, Town of Newburgh, Orange County, New York.

If you have any questions regarding the environmental review please contact Sangamithra Iyer at the below address.
 
Sangamithra Iyer, P.E.
Project Manager, Water Supply Infrastructure and Watershed Assessment
New York City Department of Environmental Protection
Bureau of Environmental Planning and Analysis
59-17 Junction Blvd, 11th Floor
Flushing, New York 11373