Air gap eductor with backflow deflector deflects backflowing liquid, preventing backflowing liquid from contaminating water supply by contacting water jet nozzle above air gap. Backflow deflector plate blocks 40-80% of rim area at opening at upper end of eductor discharge tube, leaving 60-20% of rim area unblocked. With bifurcated asymmetry of from 40% to 100%, blocked and unblocked rim areas deflect backflowing liquid laterally, away from water jet nozzle.