CHARLESTON, W.Va.-- A blast at a surface mine near Rush Creek on Tuesday came very close to exceeding state Department of Environmental Protection sound limits, a DEP official said.
The blast was apparently amplified for miles by weather conditions and led many people across the county to fear an earthquake or another gas line explosion.
Dave Vande Linde, chief of the state Department of Environmental Protection Office of Explosives and Blasting, believes the sound came from a blast set off as part of normal mining operations at Kingston Industries LLC's Rush Creek No. 2 Mine south of Charleston.
Vande Linde said inspectors are continuing to investigate, but believe that they have narrowed the incident to a 5:08 p.m. blast at the 375-acre surface mine.
He said the blast in question did not violate any DEP standards, but was very close to exceeding the sound limit of 133 decibels measured at any buildings or structures. For instance, DEP inspectors found the blast measured 125 decibels at a monitor on a gas well about 1,000 feet away and 131 decibels on a monitor at a cemetery about 2,200 feet away, Vande Linde said.
Mine operators use explosives -- usually ammonium nitrate and diesel fuel -- to blast off hilltops, removing rock and earth to reach coal reserves underneath.
The cloudy and wet weather contributed to helping to spread noise from the "airblast," which is energy from the blasting released into the atmosphere in the form of air pressure, he said.
"It can really make a shot run down the hollow," Vande Linde said. "It was really the worst time to set off a shot."
But, Vande Linde said, DEP regulations don't take into account the potential for weather conditions to make sound carry more than it might otherwise.
"The blaster is supposed to use their best professional judgment on that," he said.
Barney Frazier looked at the Kingston Mine from his home along Mount Alpha Road on Tuesday. He said he frequently takes photos of dust rising from mine blasts nearby. Although he's sensitized to the sound and feeling, Frazier said Tuesday's blast startled him.