Increased gas leaks linked to construction boom

A third of ruptures caused by improper excavation

Doctors performed surgery with flashlights, a house caught fire in the east end and the métro’s Yellow Line was shut down for nearly an hour.

All three of these events were caused by separate ruptures in underground gas lines in the last six months. A rupture also caused 12,000 customers to go without power in the Côte- St-Luc area last month, and last year, left a portion of the Metropolitan Expressway’s service road closed to traffic for several hours.

As Montreal is experiencing a construction boom, there also appears to be a sharp increase in the number of gas lines that are being broken. Figures provided by Montreal’s fire department show that as of Aug. 7, there were 92 reports of gas line breaks from the beginning of the year, up 15 per cent from 80 over the same period last year and the highest figure by far since 2011. Overall, ruptures have gone from 113 in 2013 to 185 last year.

David Laureti, a spokesperson for the natural gas utility Énergir, formerly Gaz Métro, said the increase in breaks is likely due to the greater number of crews doing work around the city.

Laureti said about 57 per cent of all gas line breaks occur because of imprudent or improper excavation. In one third of all ruptures, those who broke the line had not communicated with the InfoExcavation service to determine — before digging — where the gas lines were located.

“Obviously we would like to cut down on the number of breaks,” Laureti said.

As disruptive as they can be, ruptures of gas lines are usually minor events, with few injuries — the fire in the east end resulted in minor injuries to the occupants of a home. Rarely, gas line breaks have serious consequences. In Montreal, an explosion at Acceuil Bonneau in 1998 destroyed the building and killed three people, while a 1965 explosion in LaSalle caused the deaths of 28 people.

Because of the risk, responders don’t take any chances when a gas leak is reported. They will shut off power to the affected area, cordon it off to pedestrians and motorists, and evacuate the area.

Laureti explained that natural gas can erupt if it makes up between five and 15 per cent of the volume of air in an area, and can be set off by a static electricity shock, or the spark from an electrical appliance. If a break occurs outdoors, there is very little risk, because gas is lighter than air, so it floats away.

“The gas is odourless, but we add the smell of rotting eggs so that people can identify when there is a leak,” he said, adding that anyone who smells the odour of a gas leak should call 911. If the smell occurs indoors, Laureti suggests opening the windows, refraining from turning on any lights or appliances, and then leaving the premises before calling 911.

Firefighters will usually be the first to arrive to a report of a gas leak and they are the ones who often request for Hydro- Québec to shut off the power to an affected area. Énergir crews must respond within 25 minutes of a reported gas leak, and they usually fix the break within a few hours.

Laureti said the utility is encouraged by new rules the city outlined in June that require contractors doing work for the city to have an underground map of infrastructure. The city is also working to review procedures for anyone doing private work on the city ’s territory, said Marilyne Laroche Corbeil, a spokesperson for the city.

Énergir also has what Laureti called “sniffer trucks” that travel around the city and check for the odour of leaking gas to find the source of a leak and repair it.