HDD: An Environmental Home Run

The Last Word
By John English | December 2010 Vol. 65 No. 12
John English

Understand the process
Those in supervisory positions need to understand the process of how the project is accomplished. To create a hole the formation must be removed. The longer and larger the line the more formation that must be moved to the surface and the drilling fluid is the conveyor belt. As the drill head moves forward the contractor pumps water, mixed with bags of powdered clay, through the inner diameter of the pipe. The small particles of drilled formation are suspended in the fluid and pumped back to the surface, around the outside of the pipe, then circulated through a cleaning system, removing the solids and the fluid is reused. If the drilled formation isn't circulated out of the hole, the pipe would become stuck or the product line may not have enough clearance to allow installation. The type of clay, mixed with the water, is called bentonite. The bentonite is organic. The fluids coming from the hole are nothing more than water, clay and whatever the makeup of the local formation may be. Farmers and ranchers like the discarded drilling fluid spread across the pastures and farms. The regulations placed on HDD contractors for the use and disposal of this material vary from state to state and area to area but are excessively restrictive.

HDD itself is used to protect the environment. The process will not be successful without removing enough formation to allow the line to be placed in the remaining hole. This cannot be accomplished without the use of drilling fluid. The inadvertent seepage of this fluid to various spots at the surface or even into the river is not an environmental catastrophe and shouldn't be treated as such. Everyone agrees the fluid should be contained and cleaned before the contractor leaves the site. In almost every case, stopping to clean, as opposed to continuing the drill and cleaning after, will increase the environmental exposure. A fact usually ignored is that once the drill is complete, the drilling fluid is allowed to remain in the hole, obviously because it creates no harm.