Airlift Pump

A improved method of operating an air lift pump for repeated subterranean insertion into and removal from sampling wells useful in groundwater monitoring, the airlift pump comprising:

• inserting an airlift pump with a bottom end into a monitoring well with the bottom end below a water surface in the monitoring well, the pump comprising a hollow, cylindrical main body having a top end, a bottom end, and a cylindrical wall between the top end and bottom end, the cylindrical wall having an inside surface and an outside surface, and an injection hole bored through a wall of the cylindrical main body near said bottom end, and a channel beginning at the injection hole and extending continuously along an outside surface of the main body to said top end, the channel milled into the wall of the main body such that no portion of the channel displaces the inside surface of the main body, the channel having:
• (a) a base and two sidewalls, the base and sidewalls disposed at a substantially square orientation;
• (b) a break point located proximate to the injection hole;
• (c) a first mill beginning at the break point and extending continuously to the top end, the first mill having a base oriented substantially parallel to the inside surface of the body;
• and
• (d) a second mill beginning at the break point and extending to the injection hole, the second mill having a base oriented at taper with respect to the inside surface of the main body such that the wall of the body is thinner at the second mill than it is at the first mill;
• seating an air tube in the channel;
• connecting the air tube to the main body via a bond between the air tube and the main body along a length of the channel forming a streamlined section to the body of the air lift pump beginning at the injection hole and extending along the length of the body to the top end of the main body;
• forcing air into an air tube having a receiving end and an injection end;
• said injection end in fluid communication with the injection hole;
• injecting air into an interior portion of the main body at an angle based upon an injection angle formed by a bend in the air tube;
• causing a column of material in the interior portion of the main body to become buoyant with the air injected into the interior portion of the main body;
• move the column of material upward towards a discharge tube;
• and
• discharging the column of material from the discharge tube.