Our subsurface investigative work program
Before a pipeline can cross a river, we need to know what kind of rock lies below the surface and whether it is stable enough to support the drilling needed to pass a pipeline under the river. Subsurface testing is not new, and is not specific to the pipeline industry. If you have a water well on your property, then it was drilled using the same techniques. The holes drilled are some six inches in diameter, which is large enough to retrieve a sample to confirm the makeup of the rock.
Such techniques near rivers are used to confirm that the subsurface rock is stable enough to support horizontal directional drilling, or HDD. HDD is a process that allows a large diameter pipe to pass under a river without affecting the stream or riverbanks in any way.
The B.C. Oil & Gas Commission grants investigative permits to conduct this type of work. It should be emphasized that there is no negative impact on the rivers during the testing.
The procedure involves a crew of 10 to 12 workers, who typically drill vertical, six inch holes at each site to obtain samples for further testing. This process takes between 20 and 30 days at each site. The holes are typically drilled 75 to 100 metres vertically into the ground.
We have consistently worked with B.C. regulatory authorities to ensure we have the legal right to proceed with environmental and technical testing and studies. Permits from the BC Oil & Gas Commission give us the legal right to conduct the testing.
Those who oppose our pipeline project – or any such development – insinuate that we are putting the rivers at risk. This is completely false.
We are fully in compliance with all applicable BC Ministry of Environment regulations and at no time are rivers or riverbanks at risk. We have conducted such subsurface investigations many times in other areas, including along the Kispiox and Skeena Rivers without harm to the environment.
Taking extra care near wildlife
The protection of our workers, wildlife and habitat is important to all of us. We will maintain appropriate distances from wildlife during the survey and other investigative work. We will ensure that local wildlife is identified and maintained at safe distances to protect them and our crews.
After the drilling is complete
To comply with B.C.’s Groundwater Protection Regulations, the holes are backfilled with grout after completion to seal them and ensure no surface water flows into the groundwater systems. Garbage is removed daily and all equipment removed at the completion of the work.
Any sediments or cuttings resulting from the drilling process will be spread around the adjacent area or removed and disposed of in a certified facility as needed. The material is spread thin so that it doesn’t impede future vegetation growth.
Any felled trees will be cut into pieces smaller than two metres in length and will be placed in contact with the ground so they don’t create a hazard to workers or barriers to wildlife movement through the site. Felled trees and vegetation will not obstruct drainage patterns.