In the capital of a country founded on the dream of a transcontinental railway, Ottawa’s Union Station has always glittered. The soaring Beaux-Arts building, opened in 1912, dominates Confederation Square opposite to the Parliament Buildings. In the decades since the city’s train traffic was re-routed to a new station, the building and its added-on structures have been used as a conference centre. But now, the complex has been given a prestigious new role – as the temporary home of Canada’s senior legislative body, the Senate.
This is needed so the Senate has a place to meet while the Centre Block building is closed for rehabilitation, which is normally the home of the Senate and the House of Commons. With the House in temporary quarters in the West Block, the Senate also needed a home. Public Services and Procurement Canada decided to renovate and modernized the former train station to serve as the interim home to the Senate.
Although the carts carrying travel trunks and suitcases are long gone, the century-old building carried some metaphorical baggage, and Golder was called in to help.
Asbestos, lead, and horsehair
Golder’s role was to help clear away some challenges and enable the rest of the project to continue. This included a wide range of services including industrial hygiene, health and safety, geotechnical engineering, as well as developing a way to manage hazardous materials, impacted groundwater and indoor air quality – with involvement that started in 2014.
With regards to health and safety, one of Golder’s first tasks was to determine where the potential hazards lay. This included making exploratory openings into walls to see what was behind them. Golder’s team worked closely with the architects and structural engineers on the project, who also needed to see what lay behind the walls, so that the two kinds of investigations could use the same openings.
Another early aspect to Golder’s involvement was to prepare health and safety protocols for all personnel working on the project, for use in situations such as dealing with any hazardous materials that were encountered on site. One of the challenges came from the early 20th century builders’ use of asbestos. This former “wonder material,” once prized for its fire-retardant abilities, but since found to be carcinogenic, was found throughout the building. This included its use in plasters and other architectural finishes and building materials. If removal was required, Golder provided specifications and carried out monitoring of the work to be sure it was done according to those specifications.
On the other hand, because materials containing asbestos are quite safe if covered and left undisturbed, part of Golder’s role was to produce a legacy document for future use, showing exactly where this historical plaster remains in the building. The information could then be used to prepare a methodology for future workers to cut into or remove that material, if needed, without potentially exposing themselves to danger. This document is necessary because the sections of new, asbestos-free plaster and other architectural finishes are blended seamlessly into the legacy sections.
Focusing on the Foundation
Golder’s environmental team also dealt with investigating the soils under the structure for contaminants. To deal with potentially contaminated groundwater under the structure, Golder assisted with re-purposing a water-treatment equipment that had been used on another legacy project nearby, 180 Wellington Street. This provided a cost-effective solution to the need to treat groundwater extracted from under the Union Station project, so it was safe to release into the city’s sewer system.
A third type of challenge had to do with geotechnical engineering, and was related to addressing the many data gaps related to missing foundation details, including the phases of detailed design, tender preparation (including the preparation of “Issued for Construction” drawings) and construction. The work included making excavations into the bedrock immediately adjacent to and below the foundations of the building — requiring rock reinforcement for pre-support and during the excavation.
The work was challenging and required numerous on-site assessments of the as-found conditions. Golder worked with Public Services and Procurement Canada and construction manager to develop solutions to the conditions encountered. The Golder team carried out the geotechnical inspections for the rock reinforcement and inspection and were on-site full time for some difficult underpinning operations, where particularly poor rock was encountered.
From 2014 to 2019, Golder coordinated with the structural engineers, architects, builders, trades, Public Services and Procurement Canada representatives and others. One of the priorities of the federal government was to provide good stewardship over the solid waste generated by the project. Golder performed waste auditing throughout the duration of the project, which demonstrated that more than 90% of construction waste from the project has been diverted from landfills.
In any transportation network, it’s the glittering planes and trains that get all the attention. But the whole system grinds to a halt if passengers’ suitcases don’t go where they’re supposed to go. On the project providing a new home for Canada’s Senate, Golder’s work dealing with the building’s historical challenges was a key part of success. In February 2019, the Senate of Canada Building formally re-opened in its current role.