Recent precipitation and elevated water levels across Alberta have increased risks to pipeline integrity and leak detection. Proactive measures and mitigation of these risks can help prevent incidents and minimize impacts to the public, the environment, and infrastructure. The AER reminds licensees to identify, assess, and manage environmental and geotechnical hazards through their integrity management programs and ensure that these remain appropriate for current conditions. This includes consideration of slope instability, watercourse hazards, and the potential impact of standing water on leak detection and surveillance capabilities.
The Pipeline Act and Pipeline Rules require licensees to follow the requirements contained in Canadian Standards Association (CSA) Z662: Oil and Gas Pipeline Systems. In particular, clauses 3.1.2, 3.2, and 3.3 require licensees to have a safety and loss management system, manage risks, have integrity management programs that monitor for conditions that can lead to pipeline failure (including slope movement), and act to eliminate or mitigate such conditions. As well, Annex N outlines in more detail activities that must be conducted by all licensees to identify and control hazards through proper risk management of their entire pipeline inventory. Failure to comply with these requirements may be a contravention under the Pipeline Act and Pipeline Rules.
Slope Movement
Significant rainfall accumulation and elevated soil moisture can result in slope instability, increasing the potential for pipeline strain, deformation, or failure. Many pipelines in Alberta traverse terrain susceptible to slope movement, and historical stability does not necessarily indicate future stability when environmental conditions change.
Licensees should evaluate geohazard inventories and risk assessments, increase surveillance in affected areas, assess drainage and erosion conditions, and implement monitoring, mitigation and remediation measures where necessary. Consideration should also be given to leak detection capabilities and emergency response readiness in areas affected by slope instability.
Resource: Relative Landslide Susceptibility Model of the Alberta Plains and Shield Regions [AGS map]
Water Crossings and Flood-Related Hazards
High streamflow, flooding, and runoff events can rapidly alter watercourse conditions or generate new water flow paths, exposing pipelines or reducing depth of cover. High water levels may also result in debris impacts, increase load on pipelines, or cause vortex-induced vibration of the pipeline, which can lead to a rupture.
Changes can occur rapidly during high-water events and may not be readily apparent while water levels remain elevated, potentially delaying detection until significant damage has already occurred or water levels have subsided.
Licensees should review crossings potentially affected by current or forecasted high-water conditions, conduct inspections where warranted, monitor streamflow and flood advisories, and take appropriate mitigation measures and timely actions which may include purging and shutting in pipelines where risks are elevated.
Reduced Leak Detectability During Wet Conditions
Standing water, saturated soils, and flooded areas may reduce the visibility of leak indicators such as stressed vegetation or soil discolouration and delay detection of releases.
Licensees should confirm that leak detection systems remain effective under current conditions, increase surveillance where appropriate, investigate unusual pooling water at lease sites and along rights-of-way, and ensure that personnel are prepared to identify and respond to potential leak indicators.
Delayed detection can increase release volumes, environmental impacts, cleanup complexity and cost, and overall consequences of failure.
Consistent with CSA Z662, clause 10.3.2.1, licensees who become aware of conditions that may lead to pipeline failures should conduct an engineering assessment to determine which portions of their pipeline systems may be susceptible to failure and whether they remain suitable for continued service
If you have any questions, contact our Customer Contact Centre by phone at 1-855-297-8311 or by email at inquiries@aer.ca.
