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How We Manage Materials Around the Tunnel Reconstruction Sites: Asbestos, Dust and Silica




Three Things to Know


  1. Asbestos is removed before any construction is done: We did a survey to identify any areas with asbestos-containing materials, and prior to doing construction, that asbestos will be removed from the materials.
  2. Materials containing asbestos will not be near you: It is removed using a controlled process, so any materials you see above ground do not contain asbestos.
  3. Our process follows regulations and guidelines from relevant federal, state and city government agencies: MTA New York City Transit (NYCT) follows requirements for removing and disposing of asbestos from USEPA, NYSDOL, NYSDEC, NYSDEP, federal/state/local DOT and our own policy.

NYCT has long-standing processes and procedures in place for managing asbestos, and lots of experience using them. For the L tunnel project, we have taken the following steps:


Before the project


  • Prior to the start of construction, areas potentially impacted by the project were surveyed to determine if any “asbestos containing materials” or “ACM” were present. This is part of the procedure as required by NYCT policy, USEPA and NYSDOL regulations. 
  • As a result of these inspections, typical applications of ACM was confirmed and asbestos abatement design drawings were prepared and included in the contract documents to ensure that the general contractors, sub-contractors and NYCT personnel are aware of ACM on the project site. NYCT and its abatement contractors have extensive experience in safely handling these materials.


During the project


  • NYCT maintains a dialogue with the contractor throughout the project to ensure that locations that have been identified to contain ACM are not disturbed until licensed asbestos abatement contractors are brought in to remove the ACM.
  • All asbestos activities are performed within a regulated area. These areas are isolated and labeled with asbestos warning signs. Only trained workers and inspectors are allowed to enter this area. These workers are contractors who must be licensed and certified to remove ACM in accordance with New York State law, as regulated by the Department of Labor.
  • NYCT follows strict specifications and procedures to ensure appropriate removal and disposal of all ACM, including additional NYCT onsite inspections and random safety inspections.
  • Air monitoring by an independent licensed consultant, in accordance with Department of Labor Code Rule 56, is performed during all phases of ACM removal and disposal.


Disposal process


  • Asbestos is packaged in a 6-mil polyethylene disposal bag, sealed airtight and then placed in a second plastic bag which is also sealed airtight.
  • Following packaging, the waste is transported to a licensed and EPA-approved landfill in accordance with applicable federal, state and local Departments of Transportation and New York State Department of Environmental Conservation regulations. 


All components above comply with the standard regulations for asbestos abatement (New York State Department of Labor Code Rule 56) – and go beyond it. For more than 25 years, NYCT has included its own set of stringent rules for oversight of asbestos, including:


  • NYCT approves all asbestos contractors in advance of the removal and disposal of asbestos containing materials. The process includes review and approval of all abatement contractors’ licenses, permits and procedures by the construction manager, environmental engineering team and the Office of System Safety (who will issue the final approval document to start removal called an asbestos placard). 
  • On-site inspection includes mandated project monitoring of contractors, by an independently hired and NYS licensed environmental consultation firm. The environmental consultant will provide on-site inspection as well as required air monitoring.
  • Over and above the level of inspection required by law, NYCT provides full time on-site oversight during the abatement process, and is responsible for the overall project management of the abatement
  • NYCT’s Office of System Safety ensures all procedures and activities are being complied with by conducting random unannounced inspections of abatement activities. 
  • NYSDOL also has the authority to perform inspections during abatement activities.


Dust and Silica


Three Things to Know


  1. We have a process for measuring dust and silica: Every construction site has a dust control protocol, which is measured by PM10 monitoring instruments.
  2. We also have a process for mitigating dust and silica: To mitigate dust and silica, a custom filtration system is used underground, and water is used above ground.
  3. Our process follows regulations and guidelines from relevant state and city government agencies: MTA New York City Transit (NYCT) follows OSHA requirements for dust and silica and NYSDOH Community Air Monitoring Protocol (CAMP) for particulates.


NYCT has as dust control protocol for all construction jobs, which requires the contractor to formally submit a dust control plan. The protocol includes the requirement to eliminate visible emissions. The contractor’s current plan follows the NYSDOH CAMP for particulates and is using PM10 direct reading instruments to ensure compliance. 


Silica, which is found in concrete and sand, can be made airborne during demolition and construction activities – for example, a construction worker using a jackhammer to demolish concrete.


Measuring silica
To protect workers, OSHA, the Occupational Safety and Health Administration, has set a standard for exposure based on an 8 hour TWA (time-weighted average) in its regulations found in 29 CFR 1926.1153. Although there is no regulatory standard for ambient silica levels, we are performing PM10 monitoring to ensure our control measures are effective. We will also continue performing regular visual inspections.


Mitigating silica
The best way to keep silica levels to a minimum is to control concrete dust. We have set up several mechanisms to do this including:


  • When NYCT does work in the tunnel, there will be a custom-made filtration system set up to capture silica dust. This system will not only protect workers but will keep dust from leaving the tunnel. Air monitoring will also be in place to ensure the system is working properly.
  • The contractor also will use various methods, including containment and water, so that visible dust is eliminated wherever work is taking place.
  • Engineering controls will be established for demolition activities, as well as debris removal and disposal, with the goal of eliminating worker and public exposure to dust and silica.


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