2002-07-31_PERMIT FILE - M2002004

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Blasting Impacts Assessment for the Proposed GCC Rio Grande, Inc. Quarry in Pueblo County, Colorado 1.0 INTRODUCTION GCC Rio Grande, Inc. (GCC) currently owns or leases land located in Pueblo County, Colorado. This property, south of the City of Pueblo, Colorado, is bounded to the north by the St Charles River and roughly to the west by Denver Rio Grande Rail Road (DRGRR) tracks. With the intent to develop a cement plant and limestone feed quarry at this site, GCC has applied to the Colorado Department of Natural Resources, Division of Minerals and Geology (CO- DNR -DMG) for a mining permit. In the geotechnical stability section (6.5) of the permit request, the applicant is required to demonstrate, through appropriate blasting, vibration, geotechnical and structural engineering analyses, that off -site areas will not be adversely affected by blasting. GCC has retained Gordon F. Revey, Principal consultant of REVEY Associates, Inc. (RAI), to perform the required blasting impacts analyses. RAI is a company that specifically focuses on rock blasting design, controls and environmental impacts work. On July 5, 2002, Gordon F. Revey (author) inspected the proposed quarry site. James D. Gill, P.E., representing Contour Consulting Engineering, LLC, accompanied the author during this visit. The locations of residential properties, waterways, wells, roadways, bridges, utilities and other facilities in the area, along with the topography of the site, were studied during this site visit. The author has also reviewed the mining permit application for the Red Rock Plant and Mine, No. M- 2002 -004. The primary focus of this report is to develop a listing of all potential blasting issues and damage concerns and to evaluate their impacts or validity. The report was created to address concerns raised by written comments submitted to the Division of Minerals and Geology during the public comment period on the Red Rock Plant and Mine, issues designated in the Pre - Hearing Order of June 7, 2002, and to provide additional information to the Mined Land Reclamation Board and the Division of Minerals and Geology on the lack of blasting impacts at the Red Rock Plant and Mine. In order to acquaint the reader with the physical science of seemingly complex effects, e.g. ground vibration and air - overpressure (blast noise), a brief technical review of blasting effects and technical terms is included in the body of this report. The technical sections also include reviews of applicable regulatory limits, which are followed by a specific evaluation of typical blasting issues and potential physical impacts of blasting at the proposed Red Rock Project. A map showing the location of the site is shown in Figure 1.1. All identified issues and findings expressed in this report are based on the author's observations made at the site, prior experience, industry- standard technical calculations, and maps, reports and information provided by other engineers and professionals representing GCC and public comments. REVEY Associates, Inc. Page 1 July 2002