A deep well jet pump is an above-ground pump system designed for wells where the water level is greater than 25 feet, typically up to 150 feet or more. It utilizes two pipes extending into the well: one to send water down to an ejector assembly (nozzle and venturi) which creates a vacuum, and the other to draw the well water back up to the surface. This two-pipe system allows it to effectively lift water from deeper sources than shallow well jet pumps.