An excavation system employing a high-pressure pulsed air jet in combination with a low-pressure high velocity blower for excavating improvised explosive devices or other buried objects. The excavation system may also be employed to operate a pneumatic tool such as a cut-off tool or a chisel. The high velocity blower may incorporate a bifurcated fan duct having two air outlets. The system may include a pressure control module for regulating the from a high-pressure air source to an evacuation valve. The evacuation valve employs first and second valves where the second valve controls the operation of the first valve.