'Mystery boom' explained
CHARLESTON, W.Va. -- The mysterious boom heard around Kanawha County on Tuesday evening is a mystery no more.
The Keystone surface mine, which is in the Rush Creek area east of Charleston, apparently caused the boom when it used a controlled explosion, referred to in the industry as a "mine shot," to extract coal, a state Department of Environmental Protection official said.
Dave Vande Linde, chief of the DEP's Office of Explosives and Blasting Inspectors, said inspectors traveled to the mine Wednesday to check blast logs. Pikeville, Ky.-based Revelation Energy LLC, owns the mine.
The log showed there was a blast at 5:08 p.m., the same time the boom was heard around the county, he said.
The explosion was within the legal decibel limit prescribed by state law, Vande Linde said.
But wind and weather could have caused the sound to stay closer to the ground, allowing it to be heard over a larger area, he said.
The procedure for setting off the explosion could have also caused it to be heard over a wide region, Vande Linde said.
Mine workers used a technique called presplitting to mine the coal, he said. Presplitting is when a smaller charge is set off to make a hole for the larger charge, Vande Linde said.
Presplitting produces a crack to keep the high wall "nice and smooth," he said.
Although the explosion was within legal limits, officials from the state office will be speaking with company officials about complaints related to the "boom."
"We always talk to the companies when we have any kind of complaint," Vande Linde said.
Calls to the company's headquarters in Pikeville were not returned.
Speculation abounded on social media sites Twitter and Facebook Tuesday night about what caused the boom. Some thought it was a sonic boom from an airplane. Others thought it was mining activity. Some even suggested it was aliens.
Kanawha County Commission President Kent Carper praised the DEP for unraveling the mystery in such a "prompt" fashion.
"The state was right on top of this," Carper said.
And although the shot did not violate law, Carper hopes the mine owners reevaluate their procedures.
Not only did the explosion cause rampant speculation as to the cause of the boom; it also raised a large amount of dust around houses in the Mount Alpha area.
"People deserve better than this," Carper said. "Even if they didn't violate the law, they need to reconsider their activity a bit."
Vande Linde also said his office had received complaints about the excessive amount of dust caused by the explosion.
Carper also believes low clouds and an unusual weather pattern could have caused the sound of the explosion to stay closer to the ground, thus making it heard over a large area.
"At any rate it was a pretty big explosion," Carper said.
Emergency dispatchers began receiving calls about the boom immediately.
People in the Ariel Heights and Falling Run Road areas, both near Oakridge Drive, told dispatchers they heard a loud booming noise and felt their homes shake.
Callers reported hearing the sound on Garrison Avenue and feeling it in Fort Hill. Dispatchers said calls came in from all over the county but no one had been able to pinpoint where the noise came from or what caused it.
Carper, who was in the county courthouse at the time of the explosion, did not hear the boom. But his wife, Debbie, who was home at the time, did.
"She thought a tree had fallen on the house," Carper said. "She was outside looking for damage."
The boom did cause concern among county emergency personnel, said Dale Petry, director of the county office of Homeland Security and Emergency Management.
Dispatchers at the 911 Center called chemical and gas companies in the region to see if an accident had caused an explosion, he said.
Carper also assigned county personnel to investigate the cause.