Throughout North America, the infrastructure for commercial and residential utility lines has gone underground – literally. Over the last 20 years, civil engineers have realized the benefit if running power and data transfer cables below the surface, in many cases right alongside water and sewer lines. In newer subdivisions where this work has taken place from the development’s startup, it means that residents can live in neighborhood free of overhead utility lines – an aesthetic touch whose value cannot be underestimated; ask any developer.
In Ontario, Canada, underground utility placement faces a different set of challenges due to the region’s unique geological situation. In the last Ice Age, glaciers scraped most of Canada on their way down into parts of Michigan, Ohio, Indiana and Wisconsin. As they receded, glacial till was deposited in those Midwestern states, but the Canadian landscape remains as the glaciers last rendered it – scraped down to bedrock with very little topsoil to be found. This makes underground utility placement in Ontario a more difficult proposition than it would be in areas to the South.
Taking Place in a Vacuum
While this presents greater difficulty in initially digging utility trenches, once they are back-filled, utility companies use vacuum excavation techniques – using powerful jets of air or water for “pot-holing” down to the areas in need of line repair or replacement. This technique, particularly the method utilizing air, eliminated the need for mud removal and all but eliminates damage to road structures. The excavated native material can thus be easily put back into the places from whence it came.
Such technological advancements have all but relegated the overhead line methods to the history books. Indeed, a 2005 cost-benefit analysis determined that the average return-on-investment for major underground infrastructure projects to be $3.41 for every $1 spent. Such economic factors make underground utilities an easy and practical decision for those who are spending the money and doing the work.