Construction noise control program and mitigation strategy at the Central Artery/Tunnel Project

Abstract

One of the biggest challenges facing urban roadway and tunneling construction projects today is the need to mitigate associated environmental noise impacts. This article presents an overview of the Central Artery/Tunnel (CA/T) Project’s noise control program and strategy to control this politically-charged issue. It has been demonstrated that failing to adequately control a project’s “physical noise” can lead to the generation of more “political noise” than project managers may be able to handle. The CA/T Project, otherwise known as the “Big Dig”, is the most ambitious and grandest-scale urban construction project ever undertaken in the United States. Construction in close proximity to thousands of residences and businesses may take 12 years to complete and cost upwards of $13.6 billion. Broadly stated, the challenge facing the project’s noise control program is to successfully control construction noise to avoid posing a hardship on abutting communities, while supporting construction milestones and ensuring environmental noise commitments contained in the Project’s Environmental Impact Report are fulfilled. In general, the solution is a willingness to use any and all reasonable and feasible noise control methods to mitigate construction noise at the source, along the intervening pathway, or at the receptor locations. While cost estimates for the entire 18-year noise control program (design and construction) approach $17 million, this figure is only 0.13% of the CA/T Project’s total construction cost. The CA/T Project’s noise control success to date starts with unambiguous “command support” from project managers. The project has made it publicly clear that noise control is highly regarded. Fair noise-related policies and specifications have been developed which balance the community’s needs for peace and quiet with the project’s needs to advance the work. The cornerstone of the project’s noise control program is the Construction Noise Control Specification 721.560; the most comprehensive specification of its kind in the United States. The Noise Spec sets noise limits for the contractor, describes required submittals, contains contract-specific noise mitigation commitments, and provides guidance on source, pathway, and receptor noise control options. The Noise Spec’s intent is to address noise pro-actively whenever possible; to anticipate and avoid creating undue noisy conditions, but also to allow proper reaction to control noisy conditions without sustaining costly claims from the contractors. With these available noise control measures, established policies and specifications, support from project officials, open dialog with the affected community, and due diligence, noise from this and other large-scale urban construction projects can be managed successfully. The lessons learned from this precedent setting construction noise control effort should be useful to many other future projects. © 2000 Institute of Noise Control Engineering.