Blasting operations are scheduled to resume March 17 at the Hanson Material Co. quarry in McCook, following a voluntary suspension since a 3.2 magnitude seismic event Nov. 4.
Two additional seismographs have been installed at the quarry, southeast of 47th Street and East Avenue, and researchers from Northwestern University have joined in monitoring seismic activity.
La Grange officials issued a statement March 13 saying the resumption of quarry blasting may assist in gauging any seismic impacts of blasting. Results of the analysis will be shared when available.
“After working with representatives from Northwestern University, the U.S. Geological Survey and the Illinois Department of Natural Resources, we do not currently have data that confirms any correlation between blasting by the quarry and the seismic event that occurred on Nov. 4,” wrote Michael Stanczak, Hanson vice president and general manager, in a statement dated March 12.
Initially, the U.S. Geological Survey said Hanson’s quarry blast caused the 3.2 magnitude tremor at 12:35 p.m. Nov. 4. But further analysis showed two separate events seven seconds apart and didn’t determine a causal relationship between the blast and tremor.
Hanson’s statement also said an independent consulting firm is nearing its analysis of the Nov. 4 event and so far, has determined none of the damage claims reviewed “can be attributed to the seismic impact of the blast.”
The village’s statement said residents who filed a claim relating to the Nov. 4 event should have received an inspection already and will be issued a written report on their claim.
Residents should continue to use the Lyons Township Quarry council hotline at 1-866-934-3278 to report unusual or disruptive quarry blasting. For more information, visit the council’s website at www.ltqc.org.