Hanson Quarry to Review Monday Blast, Denies Responsibility for Tremor

Written by Joe O'Donnell

Updated at 5:59 p.m.

There was quarry blasting going on at the Hanson Material Service site in McCook Monday, according to the Village of La Grange, but the company denies it was out of the ordinary and behind the tremor that shook the western suburbs Monday afternoon. 

"Hanson Material Service quarry has stated that they were preforming routine blasting operations at 12:35 p.m. today and that the blast was consistent with their typical operations. The quarry reports that the recorded seismic readings related to the blast were below regulatory limits," according to a message posted on the village website.

"Further, the quarry states that approximately seven seconds after the blast, a separate seismic event was recorded. Hanson is in the process of reviewing the seismic readings in order to better understand what may have occurred, but at this time they are denying any correlation between their blast and the seismic event."

The Illinois Department of Natural Resources is investigating Monday's event, which the U.S. Geographic Survey (USGS) attributed to quarry blasting.

Claims for damage should be directed to the Hanson Material Service quarry by calling the Lyons Township Quarry Complaint line at 1-866-WE-HEAR-U (1-866-934-3278).

Updated at 4:43 p.m.

The U.S. Geological Survey (USGS) says the magnitude of Monday afternoon's ground-shaking quarry blast in the western suburbs registered at 3.2, down from an initial estimate of 3.7 earlier in the day.

The Chicago Tribune talked to a USGS geophysicist who said the wave patterns from Monday's event do not match those of an earthquake, and that the USGS is "pretty sure" it's from a blast. 

The Tribune reports that a representative of McCook's Vulcan Materials said there was no blasting going on in their quarry Monday, and that a representative of a second McCook quarry, operated by Hanson Material Service, would not comment on whether there was blasting going on Monday.

Read the full Tribune story here.

The McCook Police Department has not been able to confirm to Patch that the blast came from one of the village's quarries. 

Original story:

A tremor felt in Chicago's western suburbs Monday afternoon was caused by a quarry blast in the Countryside area about 12:35 p.m., according to the U.S. Geological Survey.

The USGS had previously reported the tremor as magnitude-3.7 earthquake. The epicenter of the quake, the USGS reports, was in Indian Head Park.

Patch spoke with Countryside police, who said they are relying on information from the USGS and could not confirm any details of the quarry blast.

The Hinsdale Police Department has been providing updates on its Facebook page. "We had just felt a tremor and although it remains unconfirmed, but preliminary indication received is that this was a quarry blast that was felt fairly strong in the Hinsdale community," Hinsdale Deputy Police Chief Mark Wodka said in an email Monday at 12:40 p.m.

The National Weather Service tweeted at 12:44 p.m. that it had received reports of the tremor:

"We received a call from our Oak Brook observer about what appeared to be a minor earthquake at 1236 PM CST. Shaking lasted ~5 sec."

Did you feel the tremor? Tell us about it in the comments below.