Effect of slanted soil design and filter media distribution on the removal of fecal bacteria and organic matter from greywater

Slanted Soil Treatment System (SSTS) was previously designed for onsite greywater treatment. In this study, several configurations were tested with granitic gravel in order to improve its efficiency. The lowest average removal efficiencies for fecal coliforms, enterococci and E. coli were 1.78, 2.15 and 2.21 log u. respectively and originated from case 3 (length 3 m, width 20 cm, grain size in second box 1-4 mm).