Seaward Marine Services, LLC mobilized from Norfolk Virginia to Arthur Kill Power Station in Staten Island New York to conduct underwater repairs to the concrete discharge tunnel damage discovered during previous 2017 and 2021 underwater inspections.
 
  The 350-foot-long discharge tunnel walls were cleaned of marine growth prior to repairs utilizing Seawards Submersible Cleaning and Maintenance Platform (SCAMP) to allow identification of damaged areas, proper surface preparation, and execution of the repair plan. Repairs performed on the underwater portions of the North, East, and West walls of the discharge tunnel and support columns included areas of concrete spalling, cracks, and exposed reinforcement bar. All loose concrete material was removed from areas of spalled concrete by use of pneumatic and hydraulic powered chipping hammers. Exposed areas of reinforcement bar with corrosion were surface prepped using underwater grit blasting process prior to coating with Hycote 461 underwater fairing compound and capped with Splash Zone Underwater Epoxy Compound. There were old steel seal plates installed over some voids that had large areas of bare meatal with corrosion and pitting which were surface prepped and coated with Hycote 151 and 461.

Work was completed by Seaward Marine Services Mobile Diving Unit 2 from October 1 through 8, 2021.