A method for aerating water in a treatment basin includes positioning at least one bridge above an upper surface of the water in the basin; providing a retrievable mounting frame assembly; securing a guide rail assembly to the bridge; transporting the mounting frame assembly on a transport device to a selected position on the walkway near the guide rail assembly; securing a transfer crane to the walkway proximate the guide rail assembly; transferring the mounting frame assembly from the transport device for connection to the a one guide rail assembly; connecting the mounting frame assembly to the guide rail assembly to provide a supply of air to the first air distribution conduit; moving the retrievable mounting frame assembly from a first position above the upper surface of the water to a second position below the water; and initiating a flow of air to the first air distribution conduit.