A major chlorine dioxide leak left Weyerhaeuser and the community of Dryden in reactionary mode, sabotaging the company’s good intentions to spend millions on upgrades on the plant this year.
According to Jayne Murray, Weyerhaeuser’s public affairs manager, a chlorine dioxide leak was noted at 8:40 p.m. on July 30. The local fire department called the emergency operations control team to evacuate residents living within an 800-metre radius of the plant southeast of the mill. By 9:11 p.m. approximately 300 employees at the mill were evacuated once an emergency shutdown had been completed.
Maintenance crews went into the chemical plant to assess the situation and found a tank had imploded. It had damaged a pipe that was coming off that tank and the chlorine dioxide was being released via the damaged pipe.
The pump that fed into the pipe was shut down, which stopped the leak.
Although there is no definite figure on the amount of chlorine dioxide released, Murray says in excess of 6,300 litres likely leaked, with 30,000 litres being the worse case scenario. She says it is hard to quantify it since there are a number of ways to calculate it.
“We will probably never know how much has leaked out,” Murray says.
“When the pump was shut down there was still water being pumped into the tanks so it changed the level somewhat. Because there are three storage tanks that are all connected, the levels equalized so we will never know.”
Some of the released chemical converted to gas, but most of it became a solution that went into the mill effluent system, breaking down the chemical within a short period of time, she says.
Weyerhaeuser administration, in conjunction with fire department, local police, Ministry of Environment and Energy (MOEE) and mill employees who were trained in gas testing, went to sites both on and off the Weyerhaeuser property to begin air testing at about 10:50 p.m. Testing continued until early morning the next day.
“All the readings in the town and on the Weyerhaeuser property came back zero,” Murray says.
A reading of one part per million can cause respiratory irritation.
As daylight approached the Weyerhaeuser team recommended all the solution be drained into another tank in the bleach plant, and both the MOEE and the plant crew advised a cleanup on the tanks as a precautionary measure before bringing the people back to their homes.
Murray could not comment on the cost the company will incur as a result of the accident, but they are waiting for calls from the manufacturer that made the tank and the chemical company who provides the chlorine dioxide to the plant.
The incident happened on the heels of a media release stating Weyerhaeuser was going to spend $200 million on upgrades to the plant.
The main piece of equipment being replaced is the recovery boiler. That alone costs between $80 million and $100 million.
“(The boiler) is the heart of the pulp and paper mill,” Murray says. “By replacing this piece of equipment, it renews the life of the mill significantly and maintains the sustainability and viability for the long-term.”
The other portion of the money will be going toward the air-emission upgrade. Since the government has become more stringent on emission regulations, Weyerhaeuser deemed it necessary to not only comply, but exceed government standards.
“This is all part of a long-term strategy to not only meet the current standards, but to anticipate what the standards may be 15 to 20 years from now,” Murray says.
The upgrades indicate a commitment on behalf of the company to continue its operations in Dryden.
“It is a part of Weyerhaeuser’s plan for this mill to be an industry leader, not just in the next 10 or 15 years, but for the next 50 years,” says Norm Bush, Weyerhaeuser’s vice-president for Ontario operations.
Preparations for the site started in April. The steel structure, which will contain much of the capital improvements, is taking form. K.C.I general contractors are overseeing the whole project from construction and installation to the hiring of 500 employees.