Abstract: A filter module (10) including: a housing (12) extending between an opposing first (14) and second end (16) and defining an inner chamber (18), a plurality of hollow fiber membranes (20) located within the inner chamber, a tubesheet (26) including the ends (24) of the hollow fibers encased but open within a block of potting material, an end cap (30) secured to the end of the housing and including: a permeate fluid outlet (32) in fluid communication with the ends of the hollow fibers, and a concentrate fluid outlet (34) in fluid communication with the inner chamber, wherein the permeate and concentrate fluid outlets are axially aligned, and a concentrate distributor (36) including: an annular ring (38) located adjacent to the second end of the housing, at least one aperture (40) in fluid communication with the inner chamber, and an annular concentrate passageway (42) extending from the aperture and concentrically about the permeate tubesheet to the concentrate fluid outlet of the permeate end cap.