This quest is no longer available within the game.
Kill 30 Hive'Regal Burrowers and report back to Commander Mar'alith at Cenarion Hold in Silithus. You must also bring Combat Task Briefing XI in order to complete this quest.
As the war effort mounts, the silithid presence in the area presents an ever increasing threat to our operations. You've been selected to partake on an assault on Hive'Regal where your primary target will consist of Hive'Regal burrowers.
Report back to Commander Mar'alith after your task is completed.