‘Unprecedented’: Natural gas expert says ‘over-pressurization’ may be to blame

LAWRENCE, MASS. (WHDH) - An expert in natural gas distribution says “over-pressurization” may be to blame for the 60-80 gas-related fires and explosions in Lawrence, Andover, and North Andover Thursday night.

Mark McDonald, president of the New England Gas Workers Association (NEGWA), says that a failure in the primary and secondary pressure regulators along the gas distribution lines may have caused the explosions that ignited as many as 80 homes across those three towns.

“This is unprecedented in my history,” McDonald said. “It’s quite catastrophic.”

Transmission lines carrying gas across the country withstand hundreds of thousands of pounds of pressure.

As gas travels down the pipeline from the transmission lines to the gas company, to homes, the pressure steadily decreases, McDonald said.

This lowering of pressure is done for safety reasons.

There are primary and secondary regulators which are in place to ensure that this happens.

However, in this case, McDonald said it seems that there may have been a breakdown in this ever-important chain.

“Once that failure happens gas can fill a home quite quickly,” he said.

Following the explosions, National Grid cut off power to Lawrence, Andover and North Andover in an attempt to stave off any more destruction.

“You need a perfect combination of too much gas and an ignition source,” McDonald said.

Anything from lighting a candle, to turning on a light switch to receiving a telephone call can cause a fire with that much gas in the air.

So far the cause of this apparent “over-pressurization” remains under investigation.

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