Deployment of Fiber Optic Networks through Underground Sewers in North America

The demand for broadband communications is exploding in North America. Two decades of cable laying has resulted in a national backbone of high-speed data network. However, a gap remains; a gap between the metropolitan area network and the prospective customer or building area network. This gap—the last mile—drives much of the fiber optic construction activity today, as broadband providers rush to provide fiber connections to millions of businesses and homes. The traditional way of accomplishing fiber-to-the-home or fiber-to-the-premises is to cut trenches into and under streets to install conduits, splice vaults, and build entrance facilities. The aftermath of this unbridled trenching has left many streets in the urban areas a collage of patches, crumbling asphalt; ultimately affecting the taxpayers who are left footing the cost of rebuilding and resurfacing. Over the past five years, dozens of towns and cities in North America have participated in this experiment of deploying fiber optic cables through underground sewerlines. The concept of “piggy-backing,” i.e., using the existing conduits to perform multiple functions, while fairly obvious from a technical and economic standpoint, has its detractors. While many have hailed the experiment “a success” others have raised legitimate concerns regarding issues related to routine maintenance of sewers, and advocated a more cautious approach.