The University of Michigan needed to upgrade its historic Ingalls Mall area of campus to modernize existing electrical and pedestrian lighting infrastructure, improve fire safety apparatus and expand its storm water management capabilities.
Because the Ingalls Mall area is a major pedestrian throughway for students, faculty and visitors, construction activities had to be strictly confined to a small footprint and completed as efficiently as possible.
Further, the university needed to retain more of the mall area’s storm water on site, with less outflow to the city of Ann Arbor’s storm sewer system. Because of the limited area available, the plan required a robust underground system with adequate storage capacity.
Project managers opted for Triton Stormwater Solutions’ underground chambers due to their ability to deliver the required storage in a small footprint with easy installation and maintenance. The system also allowed the project team to accommodate a high-voltage duct bank that ran through the storm water field.
A 70-by-150-ft trench was dug and lined with geofabric in preparation for the project. Next, a layer of stone was laid down and leveled. The installation of the chambers was done in a configuration that included a main header row and two banks of distribution chambers, one bank on each side of the high-voltage duct. The chambers then were topped with crushed stone and finished with topsoil to re-establish the mall’s courtyard.
After the initial excavation of the storm water field, the entire project was completed in two days, including installation of the chamber system. Today, the Ingalls Mall area serves the university community better than before, with improved lighting, fire safety and storm water management.
“I had worked with the Triton system on another project (the Ann Arbor Skate Park) and was impressed by the ease of installation,” said Jeff Leadbetter, lead contractor for Krull Construction. “Given the setting of this project, the ease of working with the chambers and the fact that they are delivered stacked to save space made the Triton chambers a natural choice. When you look at the cost savings and the ease of installation, it makes it a win-win.”
