Directional Boring is generally accomplished in three principal phases. First, a small diameter pilot hole is drilled along a directional path from one surface point to another. Next, the bore created during pilot hole drilling is enlarged to a diameter that will facilitate installation of the desired pipeline. Lastly, the pipeline is pulled into the enlarged hole, thus creating a continuous segment of pipe underground exposed only at the two initial endpoints. Directional Boring/HDD can be utilized to cross any number of surface obstacles including roadways, railroads, wetlands, and water bodies of varying sizes/depths.

The process is suitable for a variety of soil conditions including clay, silt, sand, and rock. Problematic soil conditions include large grain content in the form of coarse gravel, cobbles, and boulders. Other subsurface conditions which can impact the feasibility of Directional Boring/HDD include excessive rock strength and abrasivity, poor rock quality, and rock exhibiting karst features.