Specifications include, but are not limited to: Blast Hole Drilling consists of placing drilled holes for blasting as needed to excavate, break up or remove rock, construct stable rock cut slopes, and other approved reasons. Drilling for rock removal may require angled, horizontal, and vertical drilling to accomplish breaking up of rock to a manageable size. Before drilling attend a pre-blast meeting to discuss blasting and blast monitoring. Schedule this meeting after all blast plans have been submitted by the department. The County Maintenance Engineer, District Engineer, Contractor and Blaster-in-Charge (and Blasting Consultant and Blast Monitoring Consultant, if applicable) will attend this pre- blast meeting. Drill blast holes within 3" (75 mm) of plan locations, and control drilling to maintain the final cut slope angle. Accurately determine the angle at which the drill steel enters the rock. Cover blast holes after drilling to prevent unwanted backfill, and identify and mark each hole with a hole number and depth. Blast holes are required to be free of obstructions the entire depth. When rock cut heights require multiple benches or lifts, offset pre-split blast holes horizontally for each lift no more than the clearance necessary for drilling equipment. Pre-split rock cuts at locations shown on the plans and as directed. The Contractor shall include methods for maintaining blast hole alignment. When the height of a cut requires multiple lifts or benches, offset the controlled blast holes for each subsequent lift the minimum distance necessary to allow for drill equipment clearances. Adjust the alignment of controlled blast holes to account for this offset as well as any drift that occurred in the preceding lift.