WHILE WORKING ON THE LOWER LEVEL OF THE PRIMARY PLANT TO INSTALL A NEW TAIL PULLEY GUARD FOR C-1, EE NEEDED TO CLEAN THE TAIL SECTION OF THE MATERAIL THAT SPILLED OFF THE CONVEYOR BELT. WHEN HE TURNED ON THE HIGH PRESSURE WATER HOSE, THE RUBBER GROMMET ON THE HOSE WAS WORN AWAY THUS CAUSING THE WATER NOZZEL TO FLY OFF AND LACERATED HIS LEFT SHIN