Project Profile: Managing Stormwater at the Pan American Games

July 24, 2015

The Pan American (Pan Am) Games are the world’s third-largest international multi-sport games and are surpassed in size and scope only by the Olympic Summer Games and the Asian Games.

The first Pan American Games were held in Buenos Aires, Argentina, in 1951, and the inaugural Parapan American (Parapan Am) Games were held in Mexico City in 1999. Both the Pan Am and Parapan Am Games are held every four years for the athletes of the 41 Pan American Sports Organization member nations, in the year preceding the Olympic and Paralympic Summer Games.

Although the Pan Am Games have been hosted in a dozen countries throughout the Americas, Canada has had the honor of hosting them twice: in 1967 and 1999, both times in Winnipeg, MB. In 2015, Canada will again have the pleasure of hosting the 17th annual Pan Am Games. Nearly 7,000 athletes from across Latin America, South America, the Caribbean, and North America will compete in 36 Pan Am sports from July 10 to 26, and in 15 Parapan Am sports from August 7 to 15, in Toronto, ON.

To prepare Toronto for the Games, a number of projects were undertaken, including the construction of an Athletes’ Village; Tim Hortons Field in Hamilton, ON; and York University Track and Field Stadium in Toronto, ON. The planning and development for these project sites commenced in mid 2012 and included the demolition of several existing buildings and stadiums. In addition to the construction of the new housing and stadiums, each site would require its own stormwater management system to effectively detain water. A project consultant and a general contractor determined that all three locations would use Cultec Inc.’s subsurface stormwater management chambers, as they were found to be the most efficient.

As a method of pretreating runoff, a Cultec Separator Row is included with each system at all three sites. The Separator Row acts as a water-quality row, preventing suspended solids from intruding into the chamber bed and stone, and is also included in the storage volume provided by the overall system. The Separator Row captures silts and fine particles before the stormwater overflows into the rest of the basin and sump. To help maintain the stormwater system, any debris can be easily flushed using high-pressure water to an upstream manhole and removed with a vacuum truck.

The newly constructed Athletes’ Village is located on an 80-acre site next to the Don River in Toronto’s waterfront district. In several five- and six-story buildings, the Village will house 10,000 athletes, coaches, and team officials and will incorporate a full range of conveniences and amenities. After the Games, the Village will become a mixed-use neighborhood with affordable housing, new condominiums, a YMCA, and a dormitory for George Brown College students.

The stormwater management system for the Athletes’ Village is the most complex of the three and consists of four separate beds of chambers, two of which use Cultec’s Recharger V8HD and two with the company’s Recharger 900HD. (The 900HD has since been upgraded to the model 902HD.) In total, the project required 76 Recharger 900HD chambers, which provided 16,067 cubic feet of storage.

Cultec’s Recharger V8HD subsurface plastic chamber was selected for the job, as it maximized the storage volume while using a small footprint, best satisfying the requirements of the Athletes’ Village site. Each chamber measures 32 inches high and 60 inches wide with a bare chamber capacity of 8.68 cubic feet per linear foot. When installed, each unit provides a minimum of approximately 100 cubic feet of water storage.

Two Recharger V8HD beds were installed—one system with 42 chambers and one system with 80 chambers. In total, 122 Recharger V8HD chambers were installed in the two beds to provide 11,879 cubic feet of storage.

Both the York University Track and Field Stadium and Tim Hortons Field soccer stadium were design-build projects, a method to deliver a project in which the design and construction services are contracted by a single entity. The design–build method relies on a single point of responsibility and is used to minimize risks for the project owner and to reduce the delivery schedule by overlapping the design phase and construction phase of a project.

Contractors from Rafat (York University Stadium), London Paving (Hamilton Stadium) and Ontario Sports Solutions collaborated on the joint venture between Bouygues Building Canada and Kenaidan Contracting Ltd., the general contractors for the York University Stadium and Hamilton Stadium, respectively, to develop a general design. Each party worked to keep the design phase one step ahead of what was currently being built. Morrison Hershfield served as the consultant for the design of the system. Kent Frame from GeoStorm Inc. also assisted with the design and was onsite during installations.

Initially, Tim Hortons Field, a multi-purpose stadium, was to serve as the principal Pan American Stadium for both soccer and track and field/athletics events, but organizers of the 2015 Games ultimately chose to propose another stadium on the campus of York University to host the track and field events.

Tim Hortons Field is located approximately 50 miles outside of Toronto in Hamilton, ON. It used to be known as the Ivor Wynne Stadium and served as the home of the professional football team the Hamilton Tiger Cats. Demolition of the Ivor Wynne Stadium took place in winter 2012, and the new stadium was built over the course of 2013 and 2014. The resulting stadium will seat approximately 24,000 spectators for Canadian football.

“The site was very tight, so we needed to figure out a way to install the underground stormwater system while leaving access to the back corner of the site to place the stone, particularly with the larger of the two beds we installed there,” says site supervisor Garreth Barkey, general contractor with Bouygues-Kenaidan. “Since we certainly could not drive on top of a partially completed system, our best option was to build the system in concentric Ls, getting closer to the back corner in order to always have access to place the stone.”

The stormwater system at Tim Hortons Field includes two separate single-layer beds, one using Cultec’s Recharger 330XLHD, an efficient, large-capacity chamber that has a high volume capacity and low velocity at the early stages of a storm, and the other using the company’s Recharger 900HD. Two systems were needed to provide two separate discharge points into the Hamilton stormwater management system. The entire site consists of hard surface, turf, or building structures, resulting in a significant amount of flow during rain events.

The Recharger 330XLHD has a bare chamber capacity of more than 400 gallons, making it one of the larger Cultec chambers available. The unit itself is 52 inches wide by 30.5 inches high and has an installed length of 7 feet with a bare chamber capacity of 7.5 cubic feet per linear foot. The field required 253 chambers to be installed. In all, the Cultec system provided 26,653 cubic feet of storage, which maximized storage capacity within a small footprint to best satisfy the requirements of the site.

The second system at the field includes 53 Recharger 900HD chambers, which provide 10,551 cubic feet of storage to the site.

York University, with approximately 55,000 students, is Ontario’s second-largest graduate school and Canada’s third-largest university. To make room for the track and field stadium during the Games, five one-story buildings that were built on slab grade were removed. One challenge that contractors faced during the construction of the York University stadium was the weather. Toronto experienced one of the heaviest rainfalls in the city’s history during this time, causing extensive flooding around the city. More than 12 feet of water filled the excavation site during the installation of the Cultec stormwater chambers. Before the installation could continue, contractors had to dewater by pumping water out of the excavation site.

Following the Games, the York University Stadium will be converted into a soccer field for international, top-level play. As such, the field had to be constructed in accordance with specific regulations. The major concern during construction was how the field would be drained and whether the compaction of the fill above the Cultec chambers would meet the specified design. Because the chambers are present under only half the field, engineers were concerned that one side of the field would settle differently than the other. To ensure that there would be no differential settlement, native fill was placed over the Cultec system in 18-inch layers, each of which was compacted to a minimum requirement of 98% modified proctor dry density.

Two separate beds make up the subsurface stormwater system at York University, one of which uses Cultec’s Recharger 330XLHD units and the other Recharger 900HD units. A total of 570 Recharger 330XLHD chambers provided 52,617 cubic feet of storage and 28 Recharger 900HD chambers installed in a single row provided 6,123 cubic feet of storage to the site.

The Pan Am Games take place July 10–26, 2015, and the Parapan Am Games August 7–14. For more information about the games, please visit www.toronto2015.org.

Since the time of these installations, the Recharger 900HD chamber model has been upgraded to the Recharger 902HD—released in early 2015. The Recharger 902HD is an ultra-high-capacity chamber with an installed size of 3.67 feet long, 78 inches wide, and 48 inches tall. The bare chamber storage capacity of

the Recharger 902HD is 17.66 ft3/ft.—more than 20% greater storage per foot than the closest competitor chamber size. The chamber has a minimum installed storage of

27.27 ft³/ft. when installed with stone. The Recharger 902HD is designed to withstand AASHTO HS-25 defined loads when installed according to Cultec’s recommended installation instructions.