October 29, 2007

Rail failure named as cause of 2005 derailment, spill at Lake Wabamun

The Transportation Safety Board of Canada (TSB) has concluded that the August 2005 derailment of a westbound Canadian National freight train near Wabamun, Alberta was caused by a defective rail that broke under the weight of the train passing over it.

Forty-three cars went off the track, spilling approximately 700,000 litres of Bunker C and 88,000 litres of pole treating oil. Although there were no injuries, the derailment forced the evacuation of about 20 people from the immediate area and caused extensive property, environmental, and biological damage.

The findings of an investigation of the incident by the TSB are outlined in its final report (R05E0059), released October 25. It makes two recommendations with respect to testing and replacing worn rail, and reiterates a third dating back to 1993.

Specifically, the Board says Transport Canada should set minimum standards for the quality and strength of maintenance rails, and should establish standards requiring the replacement of rails approaching their fatigue limit. These recommendations build on a 1993 recommendation by the Board calling for Transport Canada to reassess the adequacy of current equipment and procedures for main-track rail testing.

The report also says that given the limitations of ultrasonic inspection technology and methods, effective, complementary defect management strategies need to be developed continually in order to reduce the risk of defects going undetected, growing to critical size and eventually causing rail failure.

Based on its investigation of the incident, the TSB includes extensive observations concerning emergency response and management of the derailment's environmental impacts. It points out, for example, that the hazardous properties of Bunker C and pole treating oil were not understood and effectively communicated to enable preventive mitigation of the associated risks to residents, workers, and the environment.

The Board concluded that management of the spill would have been more efficient if CN's dangerous goods emergency response plan (DGERP) and its environmental emergency response plan (EMP3) been activated under a unified command system. However, says the report, the Bunker C was not classified as a dangerous good because it was never at a temperature greater than or equal to its flashpoint at any time while in transport.

In the first few days after the Lake Wabamun spill, the Board found that there was considerable confusion among first responders, due in part to the lack of a unified command structure and the resultant miscommunications and delays in decision-making.

As part of the effort to mitigate the spill, booms were immediately deployed to contain the spread of the oil on the lake. However, the local supply was inadequate, and additional equipment had to be brought in from across Canada and the U.S. to contain the rapidly expanding plume. The investigation revealed that, to guard against the possibility of having to deal with other environmental spills, not all emergency equipment available in Alberta was deployed to the Lake Wabamun accident site.

Emergency response plans developed by both of Canada's major railways include detailed, comprehensive measures for mitigating the risk of environmental contamination of adjacent lands and waterways as a result of railway operations. This is all well and good, but railway companies clearly need to work with provincial environmental departments to establish a system that allows access to sufficient emergency equipment in the event of a major environmental disaster, says the Board.

In addition, even though Alberta established a spill reporting and response protocol in 2002 under its Dangerous Goods Incident Support Plan (and updated it in March 2005), sufficient resources were not in place to support the response protocol at the time of the derailment.

In a province with an extensive petrochemical industry and where large volumes of product are transported by rail, pipeline and highway, an effective provincial emergency plan to respond to spills of this magnitude could have mitigated its effects. Instead, says the report, without sufficient resources in place, the volume of spilled product quickly overwhelmed containment efforts.

In the aftermath of most derailments, there is a need for co-ordination between federal and provincial environment officials. Environment Canada has jurisdiction over railway rights-of-way on federally regulated railways and the provinces have jurisdiction over materials that end up on lands under provincial jurisdiction.

The TSB also expresses concern that Environment Canada has not established environmental response protocols with its provincial counterparts to ensure an adequate and comprehensive early response to environmental damage as a result of rail transportation accidents.

The TSB is an independent agency that investigates marine, pipeline, railway and aviation transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.

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