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1.0 Introduction and Background LACHEL & Associates, Inc. (L&A), Golden, Colorado has prepared this annual 2002 independent structural geology evaluation for Specification Aggregates (Spec-Agg) Quarry in Golden, Colorado. This study was conducted at the request of Lafarge West, Inc., owner of the quarry, as a requirement for State Colorado Permit M-74-004. The structural evaluation includes observations and measurements that have been obtained at the quarry in an effort to monitor the impact of structural geologic features on the pit wall stability as mining progresses, and in an effort to add to the baseline structural data collected for previous reports. The measurements, observations, and structural analyses have been performed by L&A geologists and engineers and are applicable to the quarry at the time of the data was obtained (March 2002). More specifically, the goals of this study are as follows: • Review and characterize the existing stability conditions at the quarry relative to the current mine plan; • Locate and document any obvious slope instabilities; • Locate and document changes in groundwater conditions; • Monitor overall pit stability; • Map and photograph geologic discontinuities along each quarry wall and utilize the new data in validating and updating the existing database; • Analyze new data relative to the existing data in order to verify or modify existing conclusions, and to evaluate possible emerging trends. The Spec-Agg Quarry is located to the north of Interstate 70 near Jackson's ' Gulch on the east flank of the Rocky Mountain foothills, approximately 3 miles south of downtown Golden. The natural topography of the property increases ' significantly in elevation to the west, with elevations varying from approximately 6,250 feet along the eastern boundary to 6,970 feet on the western boundary. ' 2002 Spec-Agg Annual Report Page 3