ANDOVER — Nine months after the Merrimack Valley was rocked by the gas explosions of Sept. 13, Mark Kempic, newly appointed president of Columbia Gas of Massachusetts, said he is “confident that it will never happen again.”

The disaster, caused by over-pressurized gas lines, resulted in the death of an 18-year-old man from Lawrence and displaced thousands of others. However, standing in the gymnasium of Greater Lawrence Technical School at a STEM event for young girls initiated by Columbia Gas, Kempic said he is confident about the future safety of Merrimack Valley residents.

He credits his confidence to two features the utility has been including in their restoration work. The first is a regulator at each house that shuts off gas, preventing over-pressurization. 

The second is an excess-flow valve on the service lines. Kempic said the valve shuts off gas automatically if a line is unintentionally struck by digging equipment.

Kempic said these two safety features are on the new Merrimack Valley system installed last fall, which is considered a medium-pressure system. Eventually, he said, they will be put on every Columbia Gas system throughout the state.

“Those two safety features really give me that confidence that this isn’t going to happen again,” he said.

On the low-pressure systems not impacted by the disasters, Kempic said the utility is putting the over-pressurization regulators at stations that provide service to hundreds of residents’ homes, rather than at each individual home.

Kempic said the work being done now on the low-pressure lines is protecting people in the “short-term,” and will be complete later this year for the next heating season.

He said over the next 10 years, all of those low-pressure systems are going to be replaced for long-term safety.

All of the pipe will be made of high-density polyethylene plastic, which Kempic said is “extremely safe.” The excess flow valves and regulators will also be at each customer’s home.

The cost of the piping over those 10 years is expected to be as much as $1 billion, Kempic said.