Where does the human excrement flow in the city? Actually all the human excrement flow into rivers in china city. Can the depostion pool(septic tank) save excrement?

In china's every residence, the excrement and the waste water flow into the depostion pool(septic tank) beside house through the household drainage pipe. The exits of depostion pools connect with the public larger drainage pipe in city. The exits of city public big drainage pipe lead to rivers. This is the common style of dealing with excrement, urine, and waste water in china city.

The only installation in dealing with excrement and waste water is the depostion pool beside residence in china city. Can it collect excrement or prevent excrement from going into river? If we count according to the volume of the depostion pool, we would found the depostion pool will be filled up with excrement in one or two monthes. But, in fact, most of the depostion pools are never dealt with during ten years or twenty years.

Now. I will dissect the use of the depostion pools. Every day there is much waste water and excrement flowing into the depostion pool. On flowing into the depostion pool, most of excrement quickly resolves from lumps to wadding, and is suspended in the pool. Then the excrement and waste water flowing into the city public big drainage pipe.(the washing water scour them out,or say:the washing water bring most of the excrement into the the public larger drainage pipe from the tank.) At last they flow into river. The use of the depostion pool is only changing the excrement from lumps to wadding, so that they don't block up the city's public big drainage pipe. It doesn't work for collecting excrement. And it is just the midway station when the excrement flows into river.

There are 500 million people in china's cities, and there is much excrement in the cities everyday. If all the excrement is provided to farmers as fertilizer at least it can be used for 100 million mil farmland. Because of lacking fertilizer, many farmers still buy it. Now the excrement is wasted and flows into rivers to pollutes our drinking water.

So, I advise that the relevant departments of the city goverment should forbid that the depostion pools connect with the public drainage pipe in city. We shouldn't lead the excrement to rivers, we should collect the excrement in depostion pools regularly and send them to farmers as fertilizer. The works of collecting the excrement would make many new jobs for people out of job too.