34 upward 34 and the distribution pipe subassembly 148 pointing 34 downward 34 this provides the benefit that the distribution pipe subassembly 148 can be placed in the trench 502 in any orientation then either of the two distribution pipes 20 in the top row 142 is connected to the source of effluent subembodiment 14 is preferably dimensioned as follows although these measurements are not intended to be limiting pipe diameter 150 4 625 in width 152 22 125 in height 154 9 25 in and backfill cover 156 10 in a second subembodiment 16 of this drain field assembly shown in fig1 contains a total of thirteen pipes the top row 162 comprises two void pipes 30 on either side of two distribution pipes 20 the primary distribution pipe 21 is for receiving effluent as before and the secondary distribution pipe 22 serves the same function as a void pipe the bottom row 164 comprises two void pipes 30 on either side of a third distribution pipe 23 that is not connected to the source of effluent and also serves the same function as a void pipe the purpose for this arrangement is likewise for ease of installation two subassemblies are prebundled for shipping see fig1 a first type of subassembly 166 comprises five void pipes 30 a second three distribution pipes 20 in both types the pipes are bundled in a close.