• Corporate HQ, NY
  • Melville, NY
  • Iselin, NJ
  • Ossining, NY
  • Mount Laurel, NJ

Coney Island Water Pollution Control Plant Outfall Reconstruction


HAKS served as a member of the team providing constructability review and construction management services for the $18 million reconstruction of the Coney Island Water Pollution Control Plant outfall structure. The project involved removal of existing portions of pipe, underwater excavation, placement of bedding material, pipe placement and integrity testing, and placement of marine mattresses, as well as cleaning the terminal diffuser on the 90-inch outfall and installing a new pre-cast terminal diffuser. To tie in the new terminal diffuser, stop logs were placed in the effluent channel to divert the flow through the outfall. Maintenance of outfall operations was a critical feature of the project.

Most of the construction was performed from work barges, necessitating regular underwater inspections to confirm quantities, location and placement of materials and new piping, and to ensure that pipe segments were securely sealed.

Construction activities were limited to the July-December timeframe to protect the flounder mating season. To meet this schedule, the contractor and the CM team expedited shop drawing submittal reviews and RFI responses to ensure that the contractor had enough time to purchase long-lead items and have them ready for installation prior to July 1st. During the two-week pipeline shutdown required for installation of the diversion chamber, the CM team was available on a 24-hour basis to provide oversight and inspection of the contractor’s work.