A water well head casing adapter for attachment to a water well head casing providing a two piece body engaged within the head casing of the water well with an inner formed cavity securing a baffle comprising a plurality of flexible wafer inserts defining a linear bore, the linear bore forming a seal around an air pressure hose to introduce pressurized air into the water well casing without water or air escaping between the air hose and the linear bore, the water well head casing adapter used to reduce the time and improve the efficiency required to purge and to blow out unsanitary water in the water well casing and water lines of a newly drilled water well.