A leaching chamber, particularly a chamber which lacks ribs and is therefore flexible along its length, has a length in the range 4 to 5 ft, a length to width aspect ratio of between 1.2 and 1.6 and a weight of less than 3 pounds per foot, preferably about 12 pounds for a 4 ft chamber. Since the chamber length is less and the mass is more favorably concentrated, handling of chambers, and installing chambers in trenches is improved. The ability of a string of interconnected chambers to curve is increased.