Drain field system

A drain field for use with a sewage disposal system comprising:

• a generally rectangular trench having a depth beneath ground level, a width, and a length;
• a drain field assembly having a top, a bottom, two sides, a width, and a height, the assembly positioned within the trench with the bottom facing downward and comprising:
• a generally cylindrical distribution pipe for receiving liquid effluent from the sewage disposal system, the distribution pipe having an inlet at a first end, a capped second end for preventing liquid effluent from escaping out from the second end, a central axis, a cylindrical cross section, a bottom half defined by an imaginary plane bisecting the distribution pipe along the central axis and through the cylindrical cross section, a wall, and a plurality of holes through the wall, the holes distributed along the bottom half;
• a plurality of generally cylindrical void pipes for receiving effluent from the distribution pipe, retaining the effluent for a time, and distributing the effluent to an area of soil, each void pipe having a central axis, a wall, and a plurality of holes through the wall;
• a protective soil-impervious, liquid-permeable sheeting surrounding the top and the two sides of the assembly for protecting the holes in the distribution pipe and the void pipes from intrusion by soil;
• wherein:
• the length and the width of the assembly are dimensioned to reside within the trench;
• the distribution pipe is positioned along the top of the assembly with the bottom half facing the bottom of the assembly;
• and
• the distribution pipe and the void pipes are situated in a plurality of adjacent rows, the central axes of the distribution pipe and the void pipes generally parallel to each other and to the sides of the drain field assembly, with one row of void pipes along the bottom of the assembly;
• and backfill material sufficient to cover the drain field assembly.