Hydro cut power after gas leak to avert disaster in busy area

Gas leaks, explosions not uncommon

On Feb. 26, Winnipeg police cadets blocked off Molson Street at Grassie Boulevard because of a gas leak, while Manitoba Hydro crews and private contractors worked to repair the problem. It was repaired without incident.

On Jan. 25, 2014, there was a massive explosion near Otterburne (50 kilometres south of Winnipeg) when a TransCanada Corp. natural gas pipeline ruptured and caught fire.

The explosion left behind a 30-metre crater and 3,600 Manitoba Hydro natural gas customers in the Ritchot, Tache, De Salaberry and other southeastern municipalities without heat during bitterly cold temperatures that dipped to -40 C with the wind chill.

Five homes were evacuated in the area. No injuries were reported.

Brookdale, April 14, 2002

A TransCanada Pipelines gas line ruptured, exploded and caught fire two km west of the village of Brookdale, northeast of Brandon. The explosion created two craters — one at each end of the ruptured section of pipe — and burned for nearly four hours.

About 100 people were evacuated within a four-km radius of the blast, but there were no injuries.

The investigation found, similar to the Rapid City blast in 1995, stress-corrosion cracking was found to have caused the explosion. It was unusual in this case as the affected pipe was coated with asphalt and buried in non-corrosive soil. It was discovered a combination of the pipe’s coating separating from the surface, a fluctuating water table, the presence of anaerobic bacteria and other factors created a corrosive environment.

St. Norbert, April 15, 1996

At a spot where a TransCanada pipeline crosses the La Salle River, gas escaped from a crack, caught fire, and an explosion destroyed a nearby home. The explosion also left a 13.5-metre-wide crater on the bottom of the river and damaged hydro lines and trees on both sides of the river. No one was injured.

The investigation found “environmental-assisted cracking” to be the cause. A shift in the river slope led the pipe to move and stress out a crack that may have been present since the pipeline was laid in 1962.

Rapid City, July 29, 1995

A TransCanada gas line ruptured and caught fire near Rapid City, north of Brandon. An adjacent gas pipe also ruptured and caught fire which damaged a third line.

The incident left a 51-metre-wide crater, five metres deep. One TransCanada employee suffered minor cuts and bruises.

The investigation found the first rupture was caused by stress corrosion cracking, the slow growth of small cracks in an environment capable of corroding a pipe. The second rupture was partly the result of a delay in shutting down the flow of gas to the first pipe.

Power outage tips

Keep an emergency box stored someplace easy to find in the dark that contains: candles and matches, flashlight and extra batteries, portable radio and extra batteries, bottled water, food that doesn’t require cooking, a manual can-opener, blankets, spare fuses, and backup battery pack for charging cellphones.

If you want to cook during an outage, never barbecue indoors or in an enclosed space. Fuel-burning equipment not connected to a chimney or vent should not be used indoors. Many appliances generate dangerous levels of carbon monoxide very quickly.

If you have a natural gas fireplace, make sure it is serviced and working properly. Many natural gas fireplaces will continue to work without electricity.

Having a properly-sized and well-maintained standby generator can restore electricity within minutes.

A full freezer will keep food frozen for about 48 hours. A half-full freezer will keep food frozen for about 24 hours.

An unopened refrigerator will keep food cold for about four hours. If available, add ice to the refrigerator to keep the food at a safe temperature should the power be out for a long time.

A house will remain warm for several hours. Avoid opening doors. If you have an alternate heat source, use it before the house cools. Maintain adequate ventilation.

A power outage may mean the furnace won’t work. Most natural gas furnaces need electricity to operate but may operate the burner without a power source. Refer to the appliance manufacturer instructions.

Turn off all electrical appliances. Pay special attention to those being used when the power went out (i.e. stove/oven).

Unplug electronic equipment to protect it from a voltage surge when power is restored.

Keep one light plugged in and turned on, so you will know when the electricity is back on.

— source: Manitoba Hydro