An airlift pump comprising a hollow, cylindrical main body having an injection hole near the bottom end, a channel routed in the outside surface of the main body and extending continuously from the injection hole to the top end, and an air tube seated in the channel and bonded to the main body. The air tube comprises an injection end having an elbow forming an injection angle such that the air is injection into the main body in a downward direction toward the bottom end. The air tube further comprises a receiving end extending past the top end of the main body and connecting to air supply tubing. The pump has a restricted lateral width enabling the pump to fit inside the narrow monitoring wells typical in the groundwater monitoring industry.