FIG. 16. Entrapped (late-time) nonaqueous-phase liquid (NAPL) saturation as a function of the maximum NAPL saturation previously reached. Measurements taken in 1.18-mm sand, purple; in 0.6-mm sand, blue (homogeneous zone–empty circles, heterogeneous zone–filled); in a mixture of 0.6- and 0.3-mm sand, black; in 0.212-mm sand, green; and in 0.136-mm sand, yellow.