Western Sanitary Interceptor

Proactive risk management is the best risk management

Infrastructure is only as solid as the risk management in place to govern its use. At 28 m deep, the City of Hamilton’s Western Sanitary Sewer Interceptor channeled more than 35% of the municipality’s raw sewage through the city when we came on board to engineer its rehabilitation. It was one of only three interceptors in place. Put simply: this sewer had zero tolerance for failure, making proactive maintenance and intervention an absolute necessity. For more than two years, we worked with the City to design the best possible way of addressing significant cracking and infiltration problems within the line.

Projects with tremendous risk require unparalleled planning. What were the concerns here? Ecological sensitivities linked to nearby Hamilton Harbour. Potential cave-ins below businesses and homes. Hazardous working conditions. Scheduling limitations tied to weather patterns. Deep shafts, poor sight lines and an aging, hand-mined tunnel. We cast a wide net to understand all the possible challenges on the back end, so we could execute flawlessly with specialized contractors on the front end.

Chief among those considerations? Training, safety and communication. It wasn’t enough to engineer improvements to the sewer’s condition. We also had to build a plan that could be executed securely. That meant embedding a host of strategic safety measures and procedures into every stage of the project, and keeping the environment front and centre throughout. A properly performing sewer line serves the natural surroundings and citizens. Anything less puts greenspaces, neighbourhoods, and human health at risk.

Armed with a comprehensive design, we worked together to execute while employing new technology and creating intensive safety procedures. All the while, we were inventing a model that the City could replicate on future projects. Ground-penetrating radar allowed teams to develop a multiple array system that could be deployed in large-diameter sewers. Novel ways of working enabled the City with an important template to use in additional sewer rehabilitation projects.
Today, Hamilton continues to build on the lasting impact of this project. Successfully rehabilitating the sewer itself empowered the City to mitigate a great deal of risk. But the outcome of this project extends beyond those immediate results. Our designs have positively influenced the way the City proactively maintains infrastructure and manages related risks across its territory, year over year.