The most economical system, after the fosse septique and decolloideur
( optional - secondary filter ) are 3 or more drain channels, minimum of 60 meters, usually 3 x 20 meters, The maximum length for a trench is 30 meters.
The trenches are either 50 cm or 70 cm wide and up to 1 meter deep, filled with approx 25 tons of stone from size 10 to 40 WASHED. The bigger the septic tank the bigger the drains or trenches.
The stone is put into the channels first, to a minimum degree of slope, then eppandage pipes are laid, again to a minimum of slope, leading from a regard or manhole. The pipes are all connected at the far end to form a circuit in the shape of a rectangle. These are then covered with stone, and covered with geotextile ( a material to prevent the earth from clogging up the drains and to prevent roots searching out the waste water. The drains are of a FAIBLE PROFONDEUR shallow and must not be driven on by motor vehicles after, mowers being the exception!!!
