National Grid – Dangman Park Former MGP Site

Coney Island, NY

National Grid

Contract Value:

Project Dates:

  • Steel Sheet Piling
  • Stone, Sand, Clean Fill
  • Thermal Disorption and Recycling of Petroleum Contaminated Soils
  • Thorough on-site Sampling; Testing and Analysis of Soils
  • Transportation and Disposal of Contaminated Soils
  • Remediation


The scope of this project was to remediate contamination of a former National Grid MGP site to allow for future site development. This included the demolition of a concrete slab, the installation of steel sheet piles as temporary support of excavation, the installation of dewatering sumps and of a water treatment system, the erection of a temporary tent enclosure with carbon air filtration system and the excavation and disposal of 1,500 tons of MGP source materials. To complete the project, Posillico backfilled the excavated area, removed the temporary SOE and restored the site with 3/4-inch stone.


The complexity of this project lay in the location of the site. The former MGP site is in a heavily used pedestrian area, on the corner lot of a building. It is also located in very close proximity to residential apartment buildings. The deep excavation drew a heightened awareness, involvement, and scrutiny from the community. The concentration and high volatility of the contaminants required the use of a tent, with a filtration system, as well as level C PPE. Lastly, the limited space within the temporary enclosure made it challenging to maneuver heavy equipment and maintain a fast workflow.


To mitigate these challenges, Posillico supported community outreach led by National Grid and diligently coordinated the work with the New York City agencies to facilitate their communication with the public. Daily safety huddles, full time health and safety oversight and work zone air monitoring were in effect for the duration of the project. For added layers of protection all remedial work was preformed within a temporary enclosure and crews used foam to neutralize potential airborne contaminants. Lastly, Posillico used zero-swing equipment, as well as spotters to facilitate maneuvering the equipment working within and around the enclosure.