Safety Performance Portal - Glossary of Terms



As defined in the OPR, “incident” means an occurrence that results in

  • (a) the death or serious injury to a person;
  • (b) a significant adverse effect on the environment;
  • (c) an unintended fire or explosion;
  • (d) an unintended or uncontained release of low vapour pressure (LVP)Footnote 1 hydrocarbons in excess of 1.5 m³;
  • (e) an unintended or uncontrolled release of gas or high vapour pressure (HVP)Footnote 2 hydrocarbons;
  • (f) the operation of a pipeline beyond its design limits as determined under CSA Z662 or CSA Z276 or any operating limits imposed by the Board.

As defined in the PPR, “Incident” is defined as an occurrence that results or could result in a significant adverse effect on property, the environment, or the safety of persons.

For the purposes of incident reporting in the PPR, events that fall under this definition include, but are not limited to:

  • the death of or serious injury to a person;
  • a significant adverse effect on the environment;
  • an unintended fire or explosion that results in or has the potential to result in  damage to company, public/crown or personal property;
  • an unintended or uncontained release of LVP liquids in excess of 1.5 m³;
  • an unintended or uncontrolled release of gas, HVP hydrocarbons, hydrogen sulfide or other poisonous gas; or
  • the operation of a plant beyond its design limits or any limits imposed by the Board.

Significant Incident

A significant incident is an acute event that results in:

  • death;
  • a serious injury (as defined in the OPR);
  • a fire or explosion that causes a pipeline or facility to be inoperative;
  • a LVP hydrocarbon release in excess of 1.5 m³ that leaves company property or the right-of-way;
  • a rupture; or
  • a toxic plume (as defined in CSA Z662).

Serious Injury

As defined in the OPR, “serious injury” includes an injury that results in

  • (a) the fracture of a major bone;
  • (b) the amputation of a body part;
  • (c) the loss of sight in one or both eyes;
  • (d) internal hemorrhage;
  • (e) third degree burns;
  • (f) unconsciousness; or
  • (g) the loss of a body part or function of a body part.

Significant Adverse Effect on the Environment

A significant adverse effect on the environment occurs when any chemical substance is released at a concentration or volume that has the potential to change the ambient environment in a manner that would cause harm to human life, wildlife or vegetation (e.g., glycol, potassium carbonate, methanol, methanol mix from hydrostatic testing, etc.).

Operation Beyond Design Limits

This incident occurrence includes situations such as:

  • over pressures;
  • vibration beyond design limits;
  • slope movements causing movement in the pipeline beyond design limits;
  • pipe exposures in rivers or streams; and
  • introduction of an inappropriate product (e.g., sour gas in excess of CSA limits).

Operation beyond design limit is typically linked to an over-pressure of the product in the pipe; however, if a pipe was exposed to excessive vibration and was not designed for this, this could be considered operation beyond design limits. Operation beyond design limits does not include equipment contacting the pipe, or corrosion pits, etc.

Incident Causes

Incident causes are the circumstances and factors that lead to the occurrence of an incident.  Incidents have immediate and basic causes.  These causes have been grouped into categories to for ease of reference and for presentation purposes.

Immediate Causes

The immediate cause(s) of an incident are the circumstances that directly lead to the occurrence of the incident.  An incident may have more than one immediate cause.  The immediate cause categories are:

  • Material Defect: A construction or manufacturing defect in the pipe body, welds or components that leads to an incident.  This does not include material loss or material degradation.
  • Internal Corrosion: A reduction in internal wall thickness, typically caused by corrosion.
  • External Corrosion: A reduction in external wall thickness, typically caused by corrosion.  This incident type may include coating and cathodic protection factors that contribute to external corrosion.
  • Material Degradation: The deterioration of the structural properties of the pipe or pipe components, assisted by exposure to mechanical or environmental elements.
  • Equipment Failure: A failure of the equipment components of the pipeline. Examples of equipment include valves, electrical power systems or control systems.
  • Cracking: Cracking of the pipe or component, including from corrosion, stress, fatigue or other factors.
  • Incorrect Operation: Incorrect operation by personnel, for example, by failing to follow procedures or using equipment improperly.
  • Operating Conditions: Substandard conditions that contribute to an accident. Some examples are inadequate ventilation, adverse weather, or presence of harmful materials.
  • External Interference: External activities that cause damage to the pipeline or components. Some examples are excavation damage and vandalism.
  • Natural Force Damage: Damage caused by natural forces, including earthquakes, landslides, wash-outs and other forces.
  • Other Causes: Used for all other causes, or when the immediate cause of an incident could not be determined.

Basic Causes

The basic cause(s) of an incident are the underlying reasons behind the immediate cause that explain why the immediate circumstances existed. An incident may have more than one basic cause. The basic cause categories are:

  • Engineering and Planning: Failures of assessment, planning or monitoring that may be related to inadequate specifications or design criteria, evaluation of change, or implementation of controls.
  • Maintenance: Inadequate preventive or reparative maintenance, and excessive wear and tear.
  • Purchasing: Failures in the purchasing, handling, transport and storage of materials.
  • Tools and Equipment: Tools and equipment that are inadequate for their purpose.
  • Standards and Procedures: Inadequate development, communication, maintenance or monitoring of standards and procedures.
  • Leadership and Communication: Failures in communications, or inadequate leadership and/or supervision.
  • Individual Factors: Factors relating to individual conduct, capability, or physical and psychological factors.
  • Natural or Environmental Forces:  External natural or environmental conditions.

Toxic Plume

A toxic plume is typically used in reference to a gas release but it also may be a liquid release into water or soil. A toxic plume is defined in CSA Z662 as a toxic or asphyxiating column or band of service fluid moving from a point of release through the air, soil or water.

Unauthorized Activities

Unauthorized Activity

An unauthorized activity is any activity required to be reported by a regulated pipeline company to the NEB under subsection 11(1) of the National Energy Board Pipeline Damage Prevention Regulations – Obligations of Pipeline Companies, and includes:

  • every contravention of the National Energy Board Pipeline Damage Prevention Regulations – Authorizations;
  • all damage to its pipe caused or identified during the construction of a facility across, on, along or under a pipeline, the operation, maintenance or removal of a facility, an activity that caused a ground disturbance within the prescribed area or the operation of vehicles or mobile equipment across the pipeline; and
  • any activity related to the construction of a facility across, on, along or under a pipeline, an activity that caused a ground disturbance within the prescribed area or the operation of vehicles or mobile equipment across a pipeline that the pipeline company considers could impair the safety or security of the pipe.

Ground Disturbance

Ground disturbance refers to an activity that moves or penetrates the ground. However, under section 2 of the NEB Act, ground disturbance does not include:

  • cultivation to a depth of less than 45 cm below the surface of the ground
  • any activity to a depth of less than 30 cm and that does not result in reduction of the earth cover over the pipeline to a depth that is less than the cover provided when the pipeline was constructed

Activities causing ground disturbance can include, but are not limited to, the following:

  • digging
  • excavation
  • trenching
  • ditching
  • tunneling
  • plowing to install underground infrastructure
  • tree planting
  • blasting/use of explosives

Prescribed Area or Safety Zone

The prescribed area, as defined in the National Energy Board Pipeline Damage Prevention Regulations – Authorizations (DPR – Authorizations) is a strip of land measured 30 metres perpendicularly on each side from the centreline of a pipe.
This is the safety zone where the regulations apply and that safety measures must be met for activities causing a ground disturbance.

Right of Way (ROW)

The strip of land acquired for which a pipeline company has obtained the rights for the construction and operation of the pipeline.


Excavation includes any operation using equipment, explosives or other means to move earth, rock or other material below the existing grade.  

Constructing a Facility

Constructing a facility refers to the placement of a facility across, on, along or under the pipeline. This includes, but is not limited to, placing or storing equipment (mobile or otherwise), outbuildings, skating rinks, swimming pools, sheds, gazebos, woodpiles, berms or any other structure on the ROW.

Vehicle Crossing

Vehicle crossing is the operation a vehicle or mobile equipment across, or on a right-of-way. Occurrences that fall into this category include operation of heavy equipment or trucks across the right-of-way, with the exception of any vehicle operating across the right-of-way on the travelled portion of a highway or a public road.


The sub-type for the unauthorized activity has not yet been determined.

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