The earthworms move progressively from the older layers of fully processed
organic waste into the fresh material at the wedge surface that is added daily so that the
entire earthworm population is always concentrated in the top 15-20 cm below the
leading surface. At convenient intervals (e.g., 1 to 2 months), the removable barrier is
taken away and replaced about 60 cm behind the leading face of the wedge, so that no
earthworms are removed when the waste is collected. All of the processed waste behind
this barrier can be removed with front loader machinery and collected free of earthworms
for subsequent drying to 35 to 45% moisture, sieving, and packaging. Processing of
wastes in a wedge system takes about 3 to 4 months.