We seek the highest level of integrity throughout the pipeline lifecycle by:
- Proper design and construction.
- Monitoring and leak detection.
- Inspections and maintenance of our pipelines.
Coating and Cathodic Protection
An external coating is designed to protect the pipeline against corrosion from water, bacteria and other external environmental factors. A secondary safeguard of applying a small electrical current to protect against external environmental factors is performed.
Maintenance and cleaning pigs are run inside the pipeline to clean debris, bacteria and other corrosive agents to avoid internal corrosion.
Chemicals are used to mitigate internal corrosion by forming a film inside the pipeline wall and minimizing the contact area of corrosive agents.
PMC conducts internal inspections of pipelines that allow us to understand, track and monitor the conditions of steel from inside the pipeline.
- In-Line Inspection (ILI) tools, also known as “smart pigs,” travel inside the pipeline using sensors to identify inconsistencies or anomalies inside the pipe.
- Regular ILIs allow us to track and monitor the conditions of our pipelines for both internal and external defects such as detecting metal loss, cracks or dents.In addition to regulatory requirements, the frequency of ILIs is determined by other factors such as history, age and condition of the pipeline. ILIs are conducted on a maximum four-year frequency for all PMC pipelines.
PMC spends $20 to $45 million per year conducting roughly 400 integrity digs along our 7,100 km of pipeline.
When an ILI detects inconsistencies that meet certain criteria, an integrity dig is performed. The following simplified steps are taken:
- Earth above a pipeline is removed and the line is exposed for inspection.
- The exposed pipeline is cleaned and examined for defects or weaknesses such as dents or corrosion.
- If repairs are required, options include installation of a metal sleeve over the damaged area, or in some cases, we may cut out the impacted section and replace it with new pipe.
Watercourse Management & Geotechnical Program
Watercourse crossings and slopes along our pipelines have been assessed by qualified third party geotechnical engineering experts to identify the unique characteristics of each site.
Watercourse crossing assessments include the current depth of cover over the pipeline, flow rate of the water, flood patterns and return periods, river bank width, stream bed, etc. Slope assessment includes length of slope, angle of slope and soil characteristics.
Inspection results are used to determine if existing pipe needs replacement, mitigation or additional protections using engineered solutions at vulnerable sites.
PMC monitors watercourse crossings through a flood monitoring program that uses Environment Canada’s streamflow gauges providing real-time continuous monitoring of streamflow.
We have identified specific streamflow criteria for each watercourse crossing that, if exceeded, triggers specific actions by our employees to safely shut-in and isolate the pipeline.