Lack of communication and a faulty component were among the factors that led to an ammonia leak and evacuation at a Langley industrial park last year.
Technical Safety BC recently issued a report on the cause of the leak.
At about 7 a.m. on Oct. 24, a refrigeration system at the Canature Processing dog food factory in the 5200 block of 272nd Street failed and vented ammonia.
The vapour was contained in a vacuum container on scene, but the immediate area was evacuated in case the vacuum pumps failed and the gas escaped.
Between 485 and 1,500 pounds of ammonia was released, according to the report.
About 150 people were evacuated and another 400 had to shelter in place. Roads around the site were closed, and the immediate area was under evacuation order for two days.
No one was injured, and the ammonia was slowly released into the atmosphere so it could break down naturally.
The investigation has found that multiple issues contributed to the rupture and leak of ammonia.
“In particular, Technical Safety BC’s investigation into the Langley incident noted that management did not provide proper oversight of operating, troubleshooting, or maintenance practices,” said a report posted on its website.
The immediate cause of the leak was an attempt to deal with oil building up in the system.
After an overload the morning of the leak, oil contamination was the suspected cause, according to the report.
To troubleshoot an evaporator in the system, staff on the site isolated it, but didn’t pump out the ammonia in the pipes. Ammonia trapped in a pipe above the evaporator warmed up, expanded, and burst the evaporator open at the site of a manufacturing defect.
One issue was the lack of a chief engineer to oversee the plant and its systems, said Jeff Coleman, director of risk and safety knowledge with Technical Safety BC. There were staff who had the right type of training to fit that role, Coleman noted.
Communication about the ongoing problems with the system were another issue, Coleman said.
“What we can see clearly is the oil problem is getting worse and worse, in the weeks leading up to the event,” he said.
The issue was documented in maintenance log books.
Yet that information didn’t filter up to management, Coleman said.
A standard operating procedure for dealing with oil trapped in the system did exist, and could have warned about potential hazards – but the mechanic working on the system and his managers were unaware of it prior to the incident, said the Technical Safety BC report.
Could the leak have been avoided?
“In hindsight, we learn about how failures have occurred,” Coleman said.
The important thing is to focus on what’s been learned and put that into preventative action, Coleman said.
A number of recommendations were made to the owners, management, and contractors working on the system, he said.
The incident might also serve as an opportunity to improve mainentance, signage, and training for similar systems around B.C.
Ammonia-based refrigeration systems are far from rare, Coleman noted. They’re used in ice arenas around the province, as well as in large freezers and refrigerators, in food storage and production plants.
Just days after the incident, Canature CEO John Milne said staff were already moving forward with new training last year.
The system was to be recertified, with alarms and gas detection sensors calibrated.