Blog Post #326 – Final Descent – The Best Article on Confined Space Entry

Blog Post #326 – Final Descent – The Best Article on Confined Space Entry

My point of view,

This is the second time I have used this particular article to discuss the difficult topic of ‘Confined Space Entry’. It has become my favourite course to teach and I will continue to do my part to get the word out that training, above all, must be the major step when workers are around or in a ‘Confined Space’.

Please take your time and review. The article is almost 6 years old but it is just as important today as it was then.

Daniel L. Beal
Senior Trainer at HRS Group Inc.

Article from the OH&S Canada Magazine

Good intention, an unforeseen response, a preventable accident. Four lives were lost when, one by one, the individuals entered a sump at an inactive mine in British Columbia. A reclamation project, it seems, transformed a once-safe work area into a deadly zone.

By: Jean Lian

It all seems so preventable, lives falling like a house of cards. Four people – a consultant, an employee and two would-be rescuers – dead, succumbing almost immediately upon entering an oxygen-starved space at a decommissioned mine. Circumstances, described by investigators as “unique”, were the unfortunate and unanticipated result of a reclamation project with the best of intentions: to protect the environment. Protection did not extend to those four people, their deaths revealing how a once-safe environment can be transformed into a deadly zone.

It all happened at a sampling shed, sitting atop a 1.68-metre-deep sump, at the decommissioned Sullivan Mine in Kimberley, British Columbia. The sump, at the toe of a waste rock pile, collects leachate from the rocks. It is located down-gradient from a culvert, with a drainage pipe extending into the base of the rock pile.

On May 15, 2006, a consultant with Pryzm Environmental, contracted by mine owner Teck Cominco Ltd. to do water monitoring at the closed mine, paid a routine visit to the shed to secure samples and to perform flow measures. Douglas Erickson was not heard from again.

On May 17, 2006, Teck Cominco initiated a search. Mine employee Bob Newcombe went to the shed and discovered Erickson at the bottom of the sump. Newcombe called 911, but apparently decided to attempt a rescue before responders arrived. He, too, would not emerge.

Two paramedics from the B.C. Ambulance Service (BCAS), Kim Weitzel and Shawn Currier, were dispatched to the scene, arriving at about 8:50 am.

Weitzel was escorted by a person on site to the shed. As she descended down the ladder, Weitzel asked if there was gas present. Then, there was only silence.

When Currier was informed of the situation, he decided to go down into the sump to check on his partner. But like the others before him, Currier would not emerge on his own, turning subsequent response from rescue to recovery.

What had happened? There was confusion among fellow responders, compounded by insufficient information regarding the nature of the emergency.

The accident report by British Columbia’s Ministry of Energy, Mines and Petroleum Resources (MEMPR) notes the accident location was initially described as a sampling shed. At various times thereafter, it was referred to as a shaft, a tunnel, a mine.

Responders were also working under the mistaken information that hydrogen sulphide (H2S) may be involved. The necessary precautions – had that been the case – were not followed.

The confusion only cleared later, after the Kimberley Fire Department used hand-held testers to take field samples. Oxygen deficiency – not H2S – had been the culprit. It was a surprise to all involved. “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,” Fred Hermann, then chief inspector of mines for British Columbia, said in a provincial government statement issued October 30, 2006.

The lack of oxygen was the direct result of oxidation – a process in which oxygen is consumed and carbon dioxide (CO2) created – inside the waste rock dump. The accumulation of oxygen-deficient atmosphere was “unexpectedly mobilized” from within the waste rock dump, entering the shed through a drainage pipe installed to direct water from the collection ditch to a treatment facility, says the government statement. While the sump pit was considered a confined space, the shed exacerbated things by enclosing the area, says Marshall Denhoff, director of the Canadian Registration Board of Occupational Hygienists and a member of the National Institute for Occupational Safety and Health’s Mining Sector Council.

“The shed is [meant] to prevent people from falling into the sump pit and prevent water in the pit from freezing up or becoming diluted by rain or snow,” explains Denhoff, who testified at the recent provincial inquest as a confined space expert.

There had been no previous indication of a problem at the sampling shed, possibly contributing to Erickson and Newcombe entering the structure without apparent concern. Subsequent analysis of air samples collected by Rescan Environmental Services on May 20, 2006 showed that the oxygen level near the bottom of the sump was just two per cent. “That’s indicative of a depletion of oxygen occurring somewhere in the system. In this case, it was occurring inside the dump,” says John Meech, professor of mining engineering at the University of British Columbia (UBC). Although it’s known oxygen levels inside dumps “are low, the connection wasn’t made to that until well after the accident.”

Eric Partridge, assistant deputy minister for the Mining and Minerals Division at MEMPR, notes the lack of oxygen was down in the sump. Air quality test results (right) from the Government of British Columbia indicated there were varying levels of oxygen in the shed.

The normal concentration of oxygen in air is about 21 per cent, says Dr. Francis Green, professor of pathology and laboratory medicine at the University of Calgary.

Oxygen levels below 19.5 per cent can have adverse physiological effects, says information posted on constructionwork.com. At 15 to 19.5 per cent oxygen, it notes, a person’s coordination may be impaired; at eight to 10 per cent, fainting and nausea may occur; and at four to six per cent, consciousness can be lost in as little as 40 seconds, with death by asphyxiation following within minutes.

At two per cent oxygen, the four victims didn’t stand a chance.

O2 to CO2

Samples taken by Rescan Environmental further showed that CO2 concentrations – at seven per cent – were 200 times higher than ambient concentrations, and the nitrogen level was 11 per cent above. The samples mirror those collected by Teck Cominco and MEMPR on May 18, 2006.

Dr. Green reports that “low oxygen is more dangerous than high carbon dioxide.” In low-oxygen conditions, he explains, the body reacts by increasing the speed of respiration and the depth of individual breaths to augment the amount of oxygen being carried in the blood cells. As the oxygen level decreases, effects on the brain become more pronounced, resulting in disorientation, poor judgement and loss of consciousness.

“It’s similar to climbing the mountain when the oxygen level goes down,” says Dr. Green. The difference is climbers are aware they’re heading into a dangerous situation, he says. “If you get into a situation where the oxygen level is low, like in a mine, you may not register until it’s too late.”

The response to high CO2 levels, like having a plastic bag tied over one’s head, is dramatic, says Dr. Green. But with low oxygen, “you don’t notice that it’s getting very unpleasant, at least not in a horrible way as if you [held] your breath.”

Good to bad

So how did things go so horribly wrong? The MEMPR notes in its accident investigation report that the shed had been erected at least four years earlier. Mine personnel regularly assessed it, with no safety concerns being raised, and the shed was checked as recently as a week before the accident.

The “unique” and deadly atmosphere was the result of two developments related to the reclamation project, Meech says. The environmentally conscious act of covering a waste dump with a layer of glacial till to curb acid rock drainage (ARD) – an oxygen-depleting process that produces sulphuric acid when sulphide-bearing rocks are exposed to air and water – significantly heightened hazards, he contends. The till, a protective guard against surface water flowing into the dump and being contaminated, is typically done to limit the oxidation reaction triggered by air and water.

The second development revolved around extending the rock drain at the toe of the dump over the surface of the drainage ditch. The drain had been designed to direct water flows from within the dump to a collection pipe and into the sampling shed, which is connected to a downstream treatment facility.

Together, these developments “basically created a situation where the dump kind of acts like a tea-bag,” says Meech, who visited the site May 24, 2006 and was an independent member of the Technical Advisory Committee that reviewed the incident.

Before the till was applied and the toe extended, Meech explains, “there was no direct connection between the sump and the air in the dump.” Water flowing into the shed was open to the air, he notes, adding that as it flowed out of the oxygen-depleted waste dump, it travelled along the open channel and picked up oxygen.

All that changed when the till cover acted like a bag and the pipe at the bottom of the dump “like a straw,” with air flowing in and out of that shed through the pipe, notes Meech. “What was originally a very safe site became a dangerous one.”

Carbon dioxide was being created and had “nowhere to go because the waste rock was capped,” Denhoff explains. Its exit point was out of the sampling pipe into the pit, filling the shed.

With the amount of CO2 being produced and pumped into the area, Denhoff says it’s difficult to say how much, if any, openings in the shed would have helped to improve the atmosphere.

Fair to foul

Changing weather, too, seems to have had a hand in creating hazardous conditions. May, marking the transition from cooler to warmer temperatures, altered air flow within the waste rock dump, the inside temperature of which remains at about 10 degrees Celsius year-round.

“When the temperature outside in the atmosphere is below 10 degrees, then the flow of air would be [from the shed] into the dump and there’s no danger inside the shed,” Meech explains. But once ambient temperature rises above 10 C, “the air would reverse itself and flow down the pipe and into the shed, and you’ve got bad air entering the bottom of the shed.”

The MEMPR report indicates there were “extremely hot” temperatures, hovering at the 30 C mark, for several days before the accident. Similar to findings in the MEMPR report, then mines inspector Hermann pointed to density and temperature, or pressure-driven advection, as likely mechanisms for the cooler, denser oxygen-depleted air inside the waste rock pile to flow down the culvert to the sump and into the shed.

“When that happens,” Meech says, “you’ve got an extremely dangerous situation that hadn’t been recognized.”

Hourly records of barometric pressure at the Cranbrook Airport, located 30 kilometres southeast of Kimberley, indicated that between May 14 and 19, 2006, the trend was decreasing pressure and increasing temperature. The combination would not have been a problem prior to the reclamation project. But “once they covered up the channel and put a pipe to carry the flow into the shed, they created a confined space,” Meech says.

A space that claimed four lives.

Intent to result

Oxygen depletion requires two factors to produce a hazardous condition, notes the Saskatchewan Mine Emergency Response Program manual. First, oxidation must consume oxygen from the surrounding air; second, there must be a limitation on incoming fresh air to replace consumed oxygen. The covered waste rock dump met both criteria.

“The tragic accident that took place is of considerable interest to those of us involved in the field of waste dump management and reclamation, as the situation in question could certainly exist in other mine sites undertaking covering as a method to reduce ARD,” Meech wrote in a letter to Teck Cominco, dated June 5, 2006.

The mine deaths further unearth how procedural error can cost workplace safety. The investigation report by MEMPR states that Erickson’s employer, Pryzm Environmental, did not follow comprehensive call-in procedures, which resulted in the employee being unaccounted for and out of contact for two days.

Nor did Teck Cominco adopt a formal tallying sheet to track the movements of workers coming on and off the site, as required by the Health, Safety and Reclamation Code for Mines in British Columbia. The code obliges employers to ensure a means exists for checking on the well-being of lone workers at mine sites, and that checks be carried out no more than 2.5 hours apart.

As is often the case with safety matters, a compromised exchange of information contributed to conditions from which workers had no means of escape.

The MEMPR reports that paramedic Weitzel, based on information received from the BCAS dispatch centre, believed that she and her partner were responding to a drowning incident. This, together with the misunderstanding that H2S was involved, contributed to creating layers of confusion and a life-ending response.

A transcript of Newcombe’s call to the dispatch centre indicated that he had identified the site as a “confined area”. The word, however, was apparently missed by the dispatch operator who answered the call.

Testimony before last summer’s inquest into the deadly accident revealed that dispatchers work under poor and highly stressful conditions, New Democrat labour critic Chuck Puchmayr charged in July, 2007. “The centre is understaffed, dispatchers are expected to work 12-and-a-half-hour shifts, often without a break.”

The Sullivan Mine incident, however, may be an unfortunate example of a more general problem: a lack of agreement on just what makes – or can make – a confined space. “The fact is that right across Canada, there are varying definitions, depending on which province you’re in,” says Denhoff.

“In some cases, even in the same province, such as is happening in B.C., one branch, one regulator, would define it differently than another regulator,” he adds.

Definition to awareness

While there is agreement on many of the broad strokes, such as an enclosed area with restricted access and egress is not meant for human occupancy, different takes on a few important points remain, Denhoff says.

“What safety professionals recognize now is that in assessing confined spaces, in many cases the potential for a harmful atmosphere developing is not well-understood,” he says. That is why some definitions “do not refer to harmful atmosphere at all. Rather, they focus on the enclosed nature of the space and access restrictions,” he adds.

Under WorkSafeBC’s definition, says Al Johnson, director for construction, a space can be considered a “confined space,” but present no problems with dangerous gases, or atmospheres or concentrations of concern.

For comparison, Denhoff cites the Health, Safety and Reclamation Code for Mines in British Columbia. The code notes “the manager shall ensure that written procedures are developed and implemented for work in confined spaces where irrespirable, toxic or flammable atmospheres might be encountered.”

One problem when “toxic or flammable atmospheres may be encountered,” Denhoff contends, “is that unless you have a qualified person doing a thorough assessment of potential atmosphere hazards, you may arrive at the wrong conclusion that there is no potential for a harmful atmosphere.”

And if that conclusion is reached, he adds, no testing would be done. Pointing to the Sullivan Mine deaths, “in my opinion, it’s quite likely that a poor atmosphere existed long before the fatalities occurred, but at a level that may not have seriously impaired a person,” Denhoff says. “We will never know, because no air testing was ever conducted.”

Meech says that is “not an unreasonable assumption,” adding that “it’s quite likely” oxygen-depleted water flowing in at the bottom of the shed would establish a slightly lower oxygen level in the shed’s inside air. This air would be quickly replaced with outside air upon entering the shed, although it likely would remain at a low level down at the bottom of the sump.

Jim McNaught, occupational health and safety chair for Local 7619 of the United Steelworkers, says it can be tough to understand what a confined space is. And, sometimes, “the work you do within a space changes it into a confined space,” McNaught says.

A sump will “most definitely” be considered a confined space by most, he suggests, but in the Sullivan Mine case, the confined space was below a shed in an open field. The debate over what makes a confined space is what the Health, Safety and Reclamation Code Committee is trying to iron out, says the MEMPR’s Partridge. The tripartite committee is tasked with examining all aspects of the code to make improvements. “The question is whether that definition of what’s a confined space is as current as it might be, and our assessment is that it’s not,” notes Partridge, who says the committee report is to be completed in the near future.

McNaught, a member on the committee, says members are categorizing and identifying all confined spaces at mine sites to serve as a guide for miners.

While rethinking the “confined space” definition may be a step forward, the root of the problem may lie deeper still. Andy King, national health and safety coordinator for the Steelworkers in Canada, says there needs to be a “serious look” into the current practice of separating the regulation of mining from other industries.

“Miners in B.C. are protected by completely separate legislation,” says King, pointing out that mining regulation procedures – particularly with regard to confined spaces – are far less protective than those under the oh&s laws.

“B.C. is the only jurisdiction left in Canada where the mines’ health and safety is regulated by the same ministry that is responsible for promoting mining,” King reports. “I argue it’s a conflict of interest.”

Present to future

The Sullivan Mine deaths, clearly, were preventable. But actions already taken or planned to improve safety may serve as the most fitting legacy for the loss of four lives.

A final report from British Columbia’s Office of the Chief Coroner is being written and may provide additional direction on how to enhance safety in confined spaces. The preliminary report of the five-day inquest in July yielded 16 recommendations. These run the gamut from improving working conditions in the BCAS dispatch communications centre to amending mining regulations to meet or exceed provisions within the provincial oh&s regulation, and identifying all confined spaces in the province with signage.

A selection of the remaining recommendations follow:

– BCAS – dispatch should have access to mine rescue telephone numbers 24 hours a day for advice on rescue protocol at abandoned mine sites; one oxygen sensor should be issued to each ambulance and steps taken to ensure it is worn by the senior person at all times while on shift; and all BCAS staff should be required to take confined space courses annually.
– Teck Cominco – the company should take responsibility for the safety training of all contractors on its sites; and continue to support the technical panel in developing direction and information on preventing such incidents in future.
– MEMPR – the effectiveness of the ministry’s enforcement strategy should be reviewed to establish a minimum number of site visits per mine per year; and all decommissioned mines should be required to contact local fire/rescue personnel to notify them of the hazards.

Teck Cominco has implemented several safety procedures as per Hermann’s earlier recommendations, David Parker, the company’s director of corporate affairs and sustainability, said in a statement last July. These recommendations are meant to ensure workers entering confined space environments downstream of waste dump sites are qualified in air sampling or accompanied by someone so qualified; to adopt procedures to check on the well-being of workers who may be working alone; and to determine the mechanism of mobilizing the atmosphere from within the dump out to the shed.

“Our objective has been to ensure the unprecedented and unforeseen events of May, 2006 never happen again,” Don Lindsay, president and CEO of Teck Cominco Ltd., said in a press statement issued last July.

To prevent similar loss, Meech says risk assessment should be ongoing. “It’s tragic a requirement doesn’t exist to redo a risk assessment whenever there’s a change in the environment or a change in the design of something that might lead to a confined space or any type of accident.”

Adds King, “You can’t prevent [similar accidents] if you keep the woefully inadequate rules that are in the mines regulations.”

For Joan Kuyek, national coordinator for Mining Watch Canada, it is an employer’s responsibility to ensure employees “have the equipment and any information they need to protect themselves.” As well, employers “should be making sure that there’s enough backup that workers aren’t on their own,” Kuyek argues.

“We certainly work in areas that most of the general public doesn’t understand,” says McNaught, who likens mine sites to “a private no-man’s land,” what with their sometimes inaccessible nature. “I think the Sullivan inquest kind of highlighted on that, because outside agencies that may need to render assistance on the mine site weren’t trained in hazards,” he says.

And the toll for a lack of understanding can be very high.

Jean Lian is assistant editor of ohs canada.

**********

Deadly Countdown

May 15, 2006:
Morning, time unknown: The first victim, Douglas Erickson, arrives to conduct routine water sampling.

1:45 to 2:00 pm: Erickson enters the sampling shed.

May 16, 2006:
11:50 am: Erickson’s cell notes a missed call from Pryzm Environmental.

May 17, 2006:
7:00 to 7:46 am: Erickson’s cell misses two calls.

8:00 am: Search for Erickson begins.

8:43 am: Newcombe locates Erickson’s truck.

8:45 am: Newcombe calls 911 after finding Erickson’s body in the sump.

8:48 am: Newcombe calls the mine owner, Teck Cominco, to respond to the site. Second victim Newcombe attempts a rescue before the ambulance crew arrives.

8:48 to 8:58 am: Paramedics Kim Weitzel and Shawn Currier arrive. Third victim Weitzel descends into the sump, followed by Currier.

8:59 am: 911 is informed that four people are down.

9:22 to 9:33 am: Weitzel, Currier and then Newcombe are removed from the sump and taken to triage.

9:37 am: Erickson’s body is removed from the area.

10:07 am: The RCMP arrive at the site.

10:20 am: Then chief mines inspector, Fred Hermann, is notified.

10:40 am: The site is secured and access controlled.

11:09 am: Teck Cominco calls in the Emergency Response Team (ERT).

14:25 pm: A safety perimeter is established, and air testing begins.

20:35 pm: ERT members stand down for the day.

21:30 pm: The shed is locked, the site secured, and security established.

Dan
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