A trench or bed more than 36 inches (0.91 meter) wide containing at least 12 inches (30.5 centimeters) of clean, coarse aggregate and a system of distribution piping through which treated sewage may seep into the surrounding soil.
SEEPAGE BED
Meaning of SEEPAGE BED in English
Environmental engineering English vocabulary. Английский словарь экологического инжиниринга. 2012