Project at a Glance

• Client: Prismatic Development Corporation
• Owner: New York City Transit Authority
• Location: 845 Bay St., Staten Island, NY
• Tri-State Scope:
  • Dewatering (Deep Wells)
  • Groundwater Treatment (Filtration)
• Year Completed: 2020

Project Summary

NYCTA Contract C-82004 was issued to construct a new vehicle maintenance shop in Staten Island.

Tri-State Work Summary

Over the course of 2 years, despite seasonal adjustments and continual onsite logistic challenges, Tri-State was successful in the installation of nine Deep Wells at the project site, in addition to the management of a groundwater filtration system. Additionally, the project required a large amount of sumping for trench and deep pits concrete work alongside deep well operation to keep the site dry.

Due to a large portion of the deep well installation and water treatment process being completed during cold weather months, extra precautions were required to successfully complete the job at hand. A continuous issue that presented itself was the potential for low flow of water within the pipes, and the high levels of Iron Bacteria. Low flow created frequent freezing of water within pipes in addition to blockage produced by the Iron Bacteria deposits. To counter this issue, water was recirculated into the well via a sump pump from the tank, wells are capped to reduce iron bacteria contact with air. Further challenges, such as the collapsing of boreholes around the site. Tri-State utilized Urethane Grout, to ensure a safe, environmentally sound solution.