Earlier this week, the Village participated in a meeting between municipal leaders and officials from Hanson Material Service. The meeting was attended by several mayors, including Village President Livingston, and Congressman Lipinski.
Hanson provided a presentation of quarry operations and staging specifics leading up to the blast. About one and one-half years ago, Hanson out-sourced its blasting operations to a private firm for several reasons among them being to take advantage of broader based knowledge and evolving technologies in mining practices. Hanson used a digital blast technique generating a 0.35 peak particle velocity (PPV) between levels 8-9 of the quarry (there are nine levels in total and each level ranges between 40-60 feet in height) in the southwest corner of the quarry. The August 2010 blast was on level 4 along the southern wall of the quarry. To see aerial map depicting the location of the 2010 and 2013 blasts, please click on this link: aerial map. The maximum allowable PPV is 1.0. This maximum blasting standard is set by the State of Illinois. Over 420 blasts have been detonated between August 31, 2010 and November 4, 2013.
The following day, officials from Hanson and the U.S. Department of Interior/Geological Survey (USGS) met to exchange information. As a result of that meeting, the USGS concluded that the quarry blast itself was too small to account for the measurement recorded by seismic equipment and that the tremor which the region experienced on Monday, November 4, 2013, was in essence an earthquake at a shallow level which occurred at or very near to the quarry within seconds of the quarry blast. See attached link to USGS: USGS.
This finding, along with several other action items discussed between Hanson and the USGS, are expected to be discussed at a subsequent meeting between municipal leaders and Hanson.
The Village has confirmed that as of today, Hanson does not intend to resume blasting for the time being. They are continuing to assess the situation. Hanson has committed that they will notify municipal leadership of their plans before blasting operations resume.