The separate system,most commonly used these days,provides two sewers,one taking domestic sewage,trade effluent etc. and the other, rainwater from roads,yards,roofs,etc.

• 目前最常用的分流式。分流式使用两条管道,一条用来排放生活污水和工业废水,另一条用排放道路、庭院和层顶的雨水。