Hazen & Sawyer / CDM under contract with the New York City Department of Environmental Protection selected the J. F. White Diving Division to acquire condition assessment data from the underground and submerged structure at Shaft 19. This critical information was required for the subsequent design of an Ultraviolet Disinfection Facility.
Our site work included removal of soil overburden to gain access to the top of the structure, providing sediment controls, and installing a perimeter drain to avoid ponding during heavy rain. Inspections within the underground Confined Space occurred above and below water during overnight flow shutdowns. Tasks included extracting core specimens, abrading concrete to expose and evaluate reinforcing steel, and extensive video and still photography. An ROV (Remotely Operated Vehicle) was deployed to investigate submerged shaft conditions at depths exceeding 500 feet.
Work was performed by a combined crew consisting of local union divers, laborers, operators and J. F. White supervisory personnel.