An excavation head (26), mounted on one end of a telescoping hollow boom (28), has nozzles (162) for directing jets of high speed air at an excavation face to loosen soil. A vacuum transport pipe (28) extends from the excavation head (26) through the hollow of the boom to a spherical joint (30). The spherical joint (30) movably joins the other end of the boom (28) to a primary separator (32). The primary separator (32) is a chamber for disentraining loosened soil (64) from air flowing through the primary separator (32). A primary air lock (34) is fixed to the lower portion of the primary separator (32) for expelling soil (66) from the primary separator (32). A secondary separator (38) is joined to the primary separator (32) by way of a separator connector pipe (36). A positive displacement vacuum pump (44) has its vacuum side pneumatically connected to the secondary separator (38). A conveyor (48) is located under both the air locks (34, 40) to receive soil (66) that is expelled.
