Evaluating Benefits of Horizontal Directional Drilling Compared to Open-Cut: Case Study in the City of Enid, OK

The process of installing and maintaining buried pipelines can be disruptive to the local traffic along with other undesirable impacts such as airborne emissions from the construction equipment used and workers’ safety concerns. City engineers have the option of using traditional open-cut installation or trenchless technology methods known as horizontal directional drilling (HDD) at their disposal. A waterline relocation project by the City of Enid in Oklahoma to relocate and replace more than 1,100 ft of an existing waterline is used in this study to build empirical evidence of the benefits of HDD over open-cut method based on production rate, airborne equipment emissions, traffic disruption, and workers’ safety features. Field data using human observers and wireless sensors on production, airborne emissions of equipment used, traffic disruption, and workers’ safety from the two separate installations were collected and analyzed. The airborne emissions of the equipment used in the HDD and open-cut installations were comparable, with a lower carbon-monoxide level in the HDD installation accompanied by a sudden spike during the last hour of work. There was no evidence in favor of HDD having less traffic disruption with comparable traffic flow rates and average vehicle speeds at the intersections of the neighboring streets. There were no accidents or incidents recorded during the period of observation.