Drill and blast is a key excavation process in open pit mining systems. Rock fragmentation due to drilling results in the production of fine dust particles that can be detrimental to the environment. There are different methods to manage the dust make often based on some form of “wet” drilling which can cause further issues. The water separator sub is a device aimed at overcoming some of these issues. This paper outlines a study undertaken of the effect of a water separator sub on drill performance and dust suppression. The study involved collecting dust measurements through a real time dust monitor, and analysing drill performance data from a mine site, in particular drill penetration rate data and bit life.