Humber Sanitary Trunk Sewer Rehabilitation

Completed in 2021 by Southland Contracting, the Humber Sanitary Trunk Sewer (STS) Rehabilitation Project consisted of the installation of approximately 7,972 linear feet section of 60-inch to 64-inch diameter Humber sanitary trunk sewer and a 220 linear feet section of 28-inch diameter Chapman sanitary trunk sewer using a Hobas glass-fiber reinforced plastic (GRP) pipe, the rehabilitation of associated maintenance holes using chemical grout to seal active infiltration, and the application of sprayed interior corrosion resistant coating. Confined space entries consisted of three existing manhole structures on the Humber STS project that required new cementitious structural liner and corrosion-resistant epoxy coating. Eight new manhole structures also required the application of corrosion-resistant epoxy coating. There were also seven existing wet tie-ins that had to be reinstated once the proposed FRP was installed (sliplined) through the host pipe. The project was completed exclusively in live flow conditions, often peaking at a velocity of over 9.8 feet per second. Over 7,875 linear feet of fiberglass reinforced pipe (FRP) liner was installed ranging in size from 54 inches to 57 inches. A 219-foot section of 27-inch FRP was installed through an existing 30-inch reinforced concrete lateral. This particular section had a much slower velocity, peaking at around 4.3 feet per second. There was a 43-foot section of 30-inch reinforced concrete pipe that required replacement. Due to the curve sliplining was not an option. This section was open cut and required a bypass system to control a flow rate of approximately 300 liters per second while the final connection was made between two of the new manhole structures. Asphalt and concrete paving was primarily for rehabilitation and included 4,527 square feet of full-depth structural section asphalt paving as well as 18,044 square feet of asphalt for a multi-use trail. Concrete was used to construct a 295 linear feet concrete barrier curb, 295 linear feet of standard curb and gutter, and a standard sidewalk of 131 linear feet.