By Rita Legault
Sherbrooke, Quebec
It appears faulty seals on the electrical conduit between the control room and the compressor station were behind the explosion that destroyed the Trans- Qu?bec Maritime Pipeline instrument control building in East Hereford last week.
"The seals failed and allowed high pressure gas to migrate from the compressor into the control room and when the electric furnace came on it exploded," explained Transportation Safety Board of Canada spokesman Jim Harris. "That was the spark that set the gas off." The conduit brought electrical wires and computer cables from the control building to the compressor station some 50 feet away. There is no direct link between the natural gas pipeline and the building that blew.
While the cause of the explosion is now known, Harris said the safety board still has a lot of work to do - both at the site, perhaps in the laboratory, and in documentary research. Harris said the board will now take a closer look at the seals to see why they failed.
"If we can find where the deficiencies are, we can point them out to those who can do something about it," he said, adding that recommendations may be directed at manufacturers, pipeline operators and/or regulators.
Harris said that over the next weeks and months the board will look at construction plans, maintenance reports, computer data and other records to see how the equipment was installed and maintained. Laboratory tests may be needed on some equipment to see if it there was a problem with the product or with the installation, he added.
Harris said the board will also examine the regulatory process overseen by the National Energy Board. "We don't just look at the operator, but also at the regulator to ensure the approval process was adequate and proper testing was ensured," he said. "We will look at the rules and regulations to see if they are sufficient."
Harris said it will take many months to complete the final report, but in the meantime the board has the option of establishing interim safety regulations to ensure a problem does not recur. "But most companies take quick action on things like this because they don't want this sort of thing to happen again," he said, adding that accidents like these are expensive and the safety of workers is endangered.
"This is the sort of accident that is very rare," Harris said, adding that the pipeline industry - both companies and the National Energy Board - have done much to improve the safety of lines in recent years. The Transportation Safety Board is the independent agency that investigates accidents in the maritime, pipeline, rail and air transport industries. The goal is to identify safety deficiencies to prevent accidents and reduce risks to people, property and the environment. While safety inspectors continue their investigation, the worker who was injured in the explosion at the Trans-Qu?bec Maritime Pipeline station between Christmas and New Year's is slowly recovering from his injuries.
Denis Lalibert?, who was in the control room beside the furnace room when the blast occurred, is still at the Centre hospitalier universitaire de Sherbrooke in Fleurimont where he remains hooked up to a respirator because his larynx was damaged in the blast, reported TQM vice-president Robert Heider. Lalibert?'s burned hands and face are healing well and he will not need any skin grafts. Heider said it will take months before the control building is rebuilt. He said TQM must wait until safety board inspectors are finished their on-site inspection before cleaning up and preparing to rebuild. "It will be a matter of months, not weeks," he said, adding experts will look at the plans to ensure a design flaw did not lead to the holiday blast. "We will have to understand the problem before we get started again."
In the meantime, pressure on the pipeline is reduced and TQM can only supply 70 to 80 per cent of the demand to the Portland Natural Gas Transmission System - especially during the winter when demand for natural gas is greater.
"We must depend on added pressure from our Trans-Canada Pipeline partners and our compression station in Lachenaie," he said. However, there are limits to how much the line can be pressurized. Heider said TQM has compensated local businesses affected by the blast, including a nearby sawmill which he said was slightly damaged by the reverberations of the blast.