Abstract: An in-line accessory faucet having a separable plastic air gap module for use with an activated carbon purification unit bypassing thereby dishwasher waste water conduits. An improved air gap module prevents contaminated effluent dishwasher water from backing up into the dishwasher while providing a source of purified water to pass therethrough to an accessory faucet. A molded plastic outer body defines a contaminated water inlet conduit adjoining a contaminated water outlet conduit in which a removable splash plate is positioned on top of the outer body having a slotted air gap cover defining an air gap chamber coupling said waste water inlet to said waste water outlet placed overall, wherein the improvement comprises a third conduit disposed within the outer body for allowing passage of purified water without contamination therethrough from a water purification system. Said third conduit is molded as an integral portion of the outer body adjacent to a wall separating the inlet and outlet conduits.