Sullivan deaths ruled unprecedented

The circumstances that led to four deaths in a water sampling shed at the Sullivan mine in southeastern British Columbia May 15-17, resulted from an unprecedented incident caused by an oxygen-deficient atmosphere, according to the province's chief inspector of mines.

After producing lead, silver and zinc in vast quantities for nearly 70 years, the Sullivan Mine near the resort community of Kimberley had been decommissioned. Reclamation by mine operator Teck Cominco Ltd. was nearly complete when the fatalities occurred last spring during ongoing monitoring activities.

"The incident was caused by an oxygen-deficient atmosphere. However, previous to this incident, there was no indication of a problem at the sampling shed or anywhere on the mine site," Chief Inspector Fred Hermann said Oct. 30. "We have clearly established the cause of death of the four victims, but this accident is unprecedented in the history of mining, and the process that led to the oxygen-depleted atmosphere has not, to our knowledge, occurred anywhere else in the world."

The incident claimed the lives of Doug Erickson, a Pryzm Environmental consultant working for Teck Cominco, Bob Newcombe, an employee of Teck Cominco, and BC Ambulance Service Paramedics Kim Weitzel and Shawn Currier.

Province, Teck Cominco accept recommendations

The province's chief inspector of mines presented his conclusions as well as recommendations to further ensure the safety of workers and rescue personnel at all mines in British Columbia.

"I accept the chief inspector of mines' report and its findings and support his recommendations to ensure the safety of workers and first responders at mine sites," said Minister of State for Mining Bill Bennett, who expressed condolences to the families and friends of the victims.

Teck Cominco said it also reviewed the report and has already implemented many of the chief inspector of mines' recommendations.

"The report has been provided to all of our operations, and we are committed to working closely with the appropriate agencies to ensure the recommendations are implemented so that this type of accident will never happen again," said Don Lindsay, president and CEO of Teck Cominco.

Tragic chain of events

In the report, Hermann concluded that the accident was caused by the accumulation of oxygen-deprived atmosphere in a sampling shed (and in particular in the sub-level excavation in the shed). This air mixture was transported through a drainage pipe feeding into the shed from the covered ditch surrounding the toe of a nearby dump. The ditch, part of the completed reclamation of the mine, had been designed and constructed to direct water flowing through the dump into a collection system for treatment.

Hermann said Erickson and Newcombe entered the shed without concern for a potentially hazardous environment because there was no prior indication of a hazard.

He said paramedic Weitzel entered the shed with the understanding that she was responding to a medical emergency. On her way down the ladder she noticed the second victim. This raised concern in her mind such that she asked if gas was present. By the time she asked that question, it was too late for her to escape the oxygen-deprived atmosphere.

Currier entered the shed to assist his partner after Weitzel was overcome. A lack of basic hazard recognition training and experience contributed to his death, Hermann said.

Among factors contributing to the accident:

• The shed had been in use for several years and had been accessed safely as recently as one week before the incident. This uneventful history led to the belief that the site was safe and that no atmospheric degradation would be suspected.

• The atmosphere within the dump was altered through oxidation of a layer of rock 2.5 meters thick and 15 meters wide in the drain area at the toe of the dump. The process consumed oxygen in the air and created carbon dioxide as a by-product. The resulting gaseous mixture is heavier than air and would naturally accumulate lower in the dump. But this process would continue until all available oxygen was depleted or no rock was left to oxidize.

• In 2005, workers covered the dump with a 1-meter-thick layer of glacial till, which contained a lot of clay. This cover was relatively impermeable. However, a week before the accident, workers scarified the till layer in preparation for seeding.

• How the oxygen-deprived atmosphere that accumulated in the dump migrated to the sampling shed has not been conclusively determined. But very hot temperatures (plus-30 degrees Celsius) for several days before the accident, coupled with presumed cold temperatures within the dump may have resulted in air flowing from the dump out to the rock drain and through the pipe into the shed.

"We are doing additional research and tests to determine what caused the oxygen-depleted air to be in the shed," Hermann said.

More answers in fall 2007

The chief inspector of mines has determined that the accident was caused by the accumulation of oxygen-deprived atmosphere in the sampling shed. This air mixture was transported through a drainage pipe feeding into the shed from the covered ditch surrounding the toe of the dump. The ditch was designed to direct water flowing through the dump into a collection system for treatment.

Research and modeling as to why the shed had an oxygen-depleted atmosphere will be conducted, including simulating the conditions (including temperature and atmospheric conditions) present during the incident in the sampling shed in May 2006. Results will be released in fall 2007, according to the report.

Safety measures ordered for all B.C. mines

Following the incident, the chief inspector of mines ordered interim measures in May to ensure that a similar event could not happen at any other mine site in the province. Those directives will remain in place, and more have been added, Hermann said.

They include monitoring and sampling the atmosphere of all enclosures located downstream of mine waste dumps and controlling access to the enclosures. The chief inspector also directed all B.C. mines to equip such enclosures with positive ventilation systems to provide forced ventilation to the lowest point with maximum air exchange of 10 minutes. In addition, enclosed sampling stations must be equipped with air quality monitoring systems that can be accessed from outside where interior building conditions can be gauged from a safe location. Handheld monitors also must continue to be used after installation of the ventilation and air quality monitoring systems.

Additional safety measures include requiring all independent emergency personnel who respond to a mine incident to be accompanied by a qualified representative of the mine appointed by the mine's manager. Emergency responders also must become familiar with potential hazards at a mine site and where these hazards might be encountered. They must be trained to recognize and safeguard against such hazards.

Jake Jacobs, a spokesman for the British Columbia Ministry of Energy, Mines and Petroleum Resources, said the cost of implementing the safety measures is nominal when compared with the resulting improvement in mine worker safety.

Moreover, B.C. mines that do not comply with the chief inspector of mines' directives will be subject to either a fine of up to $100,000 or one year in prison or both penalties, according to the British Columbia Mines Act.

The chief inspector of mines' report is available on the British Columbia Ministry of Energy, Mines and Petroleum Resources Web site at http://www.gov.bc.ca/empr.