Deconstruction of the Existing Champlain Bridge
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Deconstruction of the Existing Champlain Bridge Targeted Environmental Analysis Preliminary Report Volume 1, sections 1 to 3 Description of the Project and the Environment April 2019 Contract No 62555 DECONSTRUCTION OF THE EXISTING CHAMPLAIN BRIDGE (2017-2022) Contract No. 62555 Targeted Environmental Analysis Volume 1, Sections 1 to 3 Description of the Project and the Environment Preliminary Report Targeted environmental analysis Preliminary Report Volume 1 – sections 1 to 3 April 2019 Description of the project and the environment Executive Summary The Targeted Environmental Analysis (TEA) for the deconstruction of the Existing Champlain Bridge consists of three volumes: Volume 1 contains the description of the project and environment; Volume 2, the assessment of the impacts and the mitigation measures; and Volume 3, the appendices which are referred to in Volumes 1 and 2. This study is part of the same initiative as the 2013 Environmental Assessment (EA) carried out by Transport Canada (TC) which namely pertained to both the construction of the New Champlain Bridge and the deconstruction of the Existing Champlain bridge. This TEA is being conducted in order to update the 2013 EA. The project will be carried out on a design-build delivery method. Because of this, the project description presented in this TEA is only tentative and presents the options available to the contractor for deconstruction. The impacts are assessed based on these various options and mitigation measures are proposed to limit the effects of the works. The contract that will bind the contractor will include these mitigation measures in the form of performance objectives to be met during the design and during the actual work on site. This preliminary report was prepared so that the responsible authorities (Department of Fisheries and Oceans Canada (DFO) and TC can carry out an initial assessment. Il will also serve as a tool during consultations that will be conducted in the spring of 2019. A final version of this report will be prepared taking the comments from the responsible authorities, the public and the Aboriginal communities into account. Subsequently, the responsible authorities will hold the relevant information in order to confirm that the EA completed in 2013 for the entire project including the deconstruction of the Existing Champlain Bridge is still relevant and valid considering the mitigation measures that will be proposed or modified. In 211, t Government concluded that the Existing Champlain Bridge had reached the end of its useful life and would have to be replaced. This conclusion was based on expert reports which stated that the level of deterioration of the Existing Champlain Bridge and its maintenance costs were increasing rapidly, while the inherent structural problems remained unresolved. The Government therefore decided to build a new bridge about 10 m downstream of the Existing Bridge, the latter to be deconstructed once the New bridge has been commissioned. At that time, construction of the New bridge was slated to begin in 2017 and end in 2021. In autumn of 2013, a major defect in the Existing Champlain Bridge resulted in its partial closure requiring urgent major repairs to ensure the bridge’s structural integrity and the safety of its users. New analyses also revealed that the Existing Champlain Bridge was deteriorating more quickly than anticipated and that despite the severe restrictions that were in place, the process of replacing the bridge would have to be stepped up. Given the strategic importance of the Champlain Bridge for the Montreal area, Infrastructure Canada (which had become the developer following an administrative change within the federal government) decided to accelerate the project schedule with construction starting in 2015 and delivery in 2018, three years earlier than planned. To simplify the procurement process for a fast-tracked project, the deconstruction of the Existing Champlain Bridge was withdrawn from the call for tenders. The Signature on the Saint Lawrence (SSL) consortium was awarded the contract to build, maintain and manage the New bridge. Work was started in 2015 and is anticipated to be completed in 2019. i Targeted environmental analysis Preliminary Report Volume 1 – sections 1 to 3 April 2019 Description of the project and the environment In 2018, the federal government officially mandated the Jacques Cartier and Champlain Bridges Incorporated (JCCBI), a federal state corporation, as the developer for the deconstruction of the Existing Bridge. From a legislation enforcement standpoint, the Canadian Environmental Assessment Agency (CEAA) confirmed in August 2018 that the 2013 EA, which includes the deconstruction of the Existing Champlain Bridge, would be sufficient to proceed with the deconstruction of the Existing Bridge. It should be recalled that the EA of the New Champlain Bridge project began under the previous Canadian Environmental Assessment Act. Under the transitional provisions of the Canadian Environmental Assessment Act 2012 and confirmed by ministerial order, the construction project for the New Champlain Bridge and the deconstruction component of the Existing Champlain Bridge continued under the previous Canadian Environmental Assessment Act. In 2018, the CEAA also recommended that steps be undertaken with the responsible authorities to obtain confirmation that the EA completed in 2013 was still relevant and valid. This was done by JCCBI in August 2018. Although different methods could be used for deconstruction, the mitigation measures and environmental objectives to be met and presented in the 2013 EA are valid and applicable for these different methods. Considering this information, and in continuity with the 2015 TEA conducted by Infrastructure Canada, a TEA of the deconstruction project was undertaken by JCCBI. This TEA assesses the effects of the other possible deconstruction methods and determining whether the mitigation measures and the objectives stated in the 2013 EA are still appropriate. It also suggests new measures and objectives, as well as improvements to the current ones, (if required), based on best practices in 2019 and the lessons learned from the construction of the New Bridge. The project components remain the same (deconstruction) and therefore, only coordination with DFO and TC to assess the impact on fish habitat, navigation, wetlands and migratory birds will be required. However, JCCBI broadened the reviewed environmental components to add enhanced and updated mitigation measures for all the elements likely to be affected, where applicable. There are several possible methods for the deconstruction of the various parts of the Existing Bridge. The 2013 EA stated that the concrete spans and piers would be sawed, and the steel spans dismantled. These elements would then be recovered using barges, transported to land, then cut into smaller pieces that can be transported by trucks, and taken to landfills, recovery or reuse sites. In 2017, Parsons, Tetra Tech and Amec Foster Wheeler Consortium (PTA) studied the various possible deconstruction methods based on the different types of bridge structures and access options (by land, jetty, by water using barges). These methods have been reviewed in this TEA. For the deconstruction of the concrete deck a “launcher” could be used, but conventional options (hydraulic and pneumatic hammers, shear-type concrete breaker (jaws)) or the use of a crane are also possible. For the steel deck, the cantilever or de-hoisting methods are an option, depending on the deck section, but the reverse construction method could also be used. For the pier caps and pier shafts, conventional methods using cofferdams and sawing are feasible options, depending on the bridge sections involved. Controlled blasting will not be permitted. Four mobilization sites could be used for deconstruction: one situated in Nuns’ Island, one on the Seaway dike, and two on the Brossard side. ii Targeted environmental analysis Preliminary Report Volume 1 – sections 1 to 3 April 2019 Description of the project and the environment Lastly, the size of the temporary jetties located on Nuns’ Island, the Seaway dike and Brossard side, where the water is not deep enough for the barges, was established. These jetties constitute the maximum encroachment in the aquatic environment. Other options such as access via a temporary bridge on piles could also be considered. Regarding the description of the physical environment, contaminated soil, sediment and groundwater could be present in the work area. Surface water meets provincial and federal criteria for maintaining aquatic life. Some contaminants are present on the structure of the Existing Bridge, and a detailed characterization is under way to confirm and locate the contaminated areas and propose adequate management methods. Air quality is an issue due to the emissions expected during deconstruction. With respect to the biological environment, there are several at risk wildlife and plant species, including the Brown Snake and Peregrine Falcon. The Cliff Swallow colony nesting on the Existing Bridge is an issue that will involve compensatory measures aimed at favoring their relocation along with a monitoring program. There is also the Couvée Islands migratory bird sanctuary, which will have to be protected during the work. Lastly, sensitive fish habitats are present and temporary encroachments associated with the presence of jetties will have to be compensated by one or more compensation projects. Regarding