Natural gas subject of LEPC meeting

Friday, June 23, 2017

Gary Tolle from Southern Star Central Gas Pipeline Inc. briefed the Local Emergency Planning Committee on Southern Star’s distribution network and natural gas safety Wednesday.

“Pipeline ruptures are very rare,” Tolle said. “It’s much more common to have damage by someone that didn’t call 811, damage by an excavator or boring company …”

Southern Star Central Gas Pipeline’s 550 psi pipeline enters western Vernon County where their line connects with an 8-inch 165 psi pipeline owned by Empire District Gas. Once the natural gas reaches residential customers, the pressure is measured in mere ounces.

In speaking on safety, Tolle said, “550 psi in a steel line … is a hazard for sure if it’s hit or ruptured. It’s kind of a bomb in a steel casing — it has a lot of pressure in there.”

Tolle explained the conditions in which natural gas will explode. There must be between 5-15 percent of natural gas in an area for it to explode. Too little or too much and natural gas will not explode.

He showed a video further explaining the lower and upper explosive limits and possible ignitions sources.

If an explosive mixture of natural gas exists in an area, a room, or a building; a number of things can trigger an explosion: a light switch being turned on, someone walking by with a cigarette, a ringing mobile phone or even a flashlight.

“On a gas leak, we always encourage you to immediately leave the residence. Don’t turn on any switches. Cell phones could possibly give off enough spark to set off a natural gas explosion. This first call you want to make is 911 … and the second call will be to the local distribution company, Empire …”

In addressing the first responders in the room, Tolle said, if the pipeline feeding Fort Scott were to rupture, it would be a serious event because the line is not on a loop, the one line is the only source of natural gas for Fort Scott and Nevada.

“Hopefully we have enough line pack to run for several hours, maybe a couple days, if we can shut that in real quick,” Tolle said, referring to the residential pressure in the pipeline after the supply is turned off.

Heating requirements during winter weather would hamper Southern Star’s ability to keep up with demand in the event of a rupture.

Tolle said the primary cause of pipeline breaks was due to excavation around a pipeline that had not been properly located and marked.

Anyone planning an excavation project needs to call the Missouri One Call System at 1-800-344-7483 or 811 or visit their website at https://www.mo1call.com/ to request the location of utility lines on their property be marked. This is a free service.

“How you recognize a pipeline leak, three major ways: sight, sound and smell,” Tolle said. “Natural gas is colorless but a vapor or ground frosting may be visible at high pressure. A gas leak may also be indicated by bubbles in a wet or flood area …”

Tolle said areas with dead vegetation can also indicate a gas leak because the natural gas will put too much nitrogen in the soil killing the vegetation.

“Another way is sound. Volume can range from quiet hissing to a loud roar depending on the size of the leak.”

The larger the leak, the louder the sound. Tolle said a large leak often creates enough static electricity to ignite the leaking gas.

Tolle explained natural gas is colorless, tasteless and odorless unless an odorant is added. Mercaptan is frequently added to natural gas and is often described as smelling like rotten eggs, cabbage or even smelly socks.

“One hundred percent of odor calls get responded to,” Tolle said.

Empire District Gas adds an odorant at the connection to Southern Star’s pipeline.

Again, if you suspect you are in a building or area where there is a gas leak, leave the area before calling 911.

“You always want to respect natural gas,” Tolle said.

In other business,

• Doug Hundley was unanimously elected chairperson.

• Melissa Keating was unanimously elected as secretary.

• Mike Ast was unanimously elected as vice-chairperson.

• Paula Messner said Vernon County’s new online mapping system is available on the county website or at vernon.integritygis.com

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