U.S. Rep. Dan Lipinski will meet with a senior official from Lehigh Hanson on Wednesday in Washington, D.C., to discuss the company’s role in a Nov. 4 earthquake that originated near McCook’s Federal Quarry.
The 3.2-magnitude earthquake occurred seven seconds after a scheduled blast conducted by Hanson Material Service Corporation, a subsidiary of Lehigh Hanson. Lipinski, who was at his Western Springs home when the quake triggered and said his home shook for five seconds, has requested a federal investigation into the incident and will seek answers from Hanson regarding the incident during Wednesday's meeting, a spokesperson for Lipinski said.
A two-day investigation by the Illinois Department of Natural Resources found that Hanson did not commit any violations and that the force of the blast was well under the maximum level allowed. However, scientists from the U.S. Geological Survey think the blast and earthquake were linked.
“The working hypothesis is this...event is somehow associated with the quarrying process and that it was somehow triggered by this very small explosion,” said Jim Dewey, geophysicist at the USGS’ National Earthquake Information Center in Colorado. “It’s very likely [the events were connected] just because it would be such an extraordinary coincidence otherwise.”
The USGS is considering installing its own seismographs at the quarry to collect more data that could allow quarry operators to adjust operations to prevent triggering shocks, Dewey said.
Hanson suspended blasting at the quarry after the incident and has yet to resume. Hanson spokesperson Jeff Sieg said the company would likely decide this week if and when to restart blasting, which it typically conducts every few days.