Horizontal Directional Drilling (HDD), also called Directional Boring and Directional Drilling, is a method of installing underground pipes and conduits from the surface along a prescribed bore path. Installation lengths up to 6500' have been completed and diameters up to 48" have been installed in shorter runs. However, most installations are considerably shorter and of smaller diameter. The process is used for installing telecommunications, power cable conduits, water lines, sewer lines, gas lines, oil lines, product pipelines, and casings used for environmental remediation. It is used for crossing waterways, roadways, congested areas, environmentally sensitive areas, and any area where other methods are more expensive or not feasible. Use of HDD is growing rapidly and is expected to continue to increase for the foreseeable future.
HDD is used for the following reasons