A lack of field measurements was the main cause of a pipeline puncture and leak at Sherwood Park's Enbridge site.
On February 17, 2017, crews were using a horizontal directional boring technique to install a new pipeline in an area where pipelines were already in place.
During the installation, a 24-inch Line 2 pipeline was struck and punctured.
No one was injured, but around 1,000 cubic metres of petroleum crude oil condensate was leaked. Most of the oil condensate released was recovered.
In a release on Monday (Jul.23), the Transportation Safety Board (TSB) of Canada said the incident took place without a field-measured confirmation of the exact location and depth of cover for the Line 2 pipeline at the crossing of the new pipeline being installed. Instead, measurements were taken from an adjacent pipeline.
The TSB also added a ground disturbance checklist incorrectly indicated that visual depth confirmation had been completed for all pipelines to be crossing during the operation.
After the leak, Enbridge reviewed internal communications, including clarifying technical terminology related to pipeline crossings.