2015-03-11_REPORT - M1974004

• Permit No: M1974004
• IBM Index Class Name: REPORT
• Doc Date: 3/11/2015
• Doc Name: Annual Report Fee Map
• From: Martin Marietta Materials, Inc.
• To: DRMS
• Email Name: MAC
• Media Type: D
• Archive: No

Martin Marietta Materials
Spec -Agg 2015 Annual Report
4.0 MINING PLAN AND PROGRESS
Mining activities have been focused in two distinct areas: the Main Pit and the Southern Expansion Area
(Figure 2). Minimal mining activity except groundwater pumping appears to have occurred in the Main Pit
since the last report. The sump location appears similar to the 2013 -2014 investigation. Plant operation
records indicate that the daily pumping durations from the Main Pit are usually three to four hours under
normal weather conditions with increased durations during rainfall events. Under normal weather
conditions approximately 80,000 to 100,000 gallons of water are discharged per day (mainly from
groundwater).
Significant mining activity has taken place in the Southern Expansion Area since our last annual report
and between our June and December 2014 site visits (Photos 1 to 3). The current temporary benches
are being advanced to approximately the 6,701 to 6,707 -ft elevation (Figure 2) with reclamation occurring
in stages following excavation along permanent benches. Three temporary benches were actively being
mined during our site visits, including an upper bench near the western margin of the Southern Expansion
Area (see stations 15 -01 and 15 -04 in Figure 2). The next lower bench is being mined starting from the
eastern side approximately 30 feet lower than the upper bench and working to the west (see stations 15-
02 and 15 -05 in Figure 2). An additional area of recent mining was observed in the southeastern portion
of the Southern Expansion Area (see stations 15 -03 and 15 -06 in Figure 2). This area may represent the
start of a new lower bench of the Southern Expansion Area.
Based on the current mine plan developed by Martin Marietta (formerly Lafarge West, Inc.) in December,
2003, and the current Colorado Division of Minerals and Geology mine plan, we understand that the mine
will eventually be excavated to the topographic configuration shown in Figure 2, with an approximate final
mine floor elevation of 6,200 feet. The orientations of the final planned highwalls are the basis for our
rock structural discontinuity assessment, as discussed in Section 6.0.
February 25, 2015 Page 5 Lachel & Associates, Inc.
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