Spectra performed a geophysical investigation along the northbound lane of the Major Deegan Expressway in the Bronx, near the intersection of 167th Street and Sedgewick Avenue. The purpose of the investigation was to confirm the location of an existing underground NYCDEP chamber and to assess whether there were geophysical anomalies or other underground features present in the area.
The investigation was completed using a 400 MHz single-channel ground penetrating radar (GPR) antenna and a 200 MHz single-channel GPR antenna.
The investigation revealed areas of reinforcement beneath the highway and within a concrete slab that surrounds a metal hatchway. The location of the NYCDEP vault could not be definitively determined, but it was assumed that the vault was at least 5-6 feet below the surface. All features were mapped and presented in a final report to the client.