The diagram illustrates how the contaminate water goes to the ocean in Bristol, which is an English city, where occurs the water cycle. First, it can be notice that the water that comes of the rivers and streams, which is dirty, goes to either the reservoir or the water treatment plant. If the water goes to the reservoir, after a while it has to goes anyway to the water treatment plant, where the water is cleaned and become fresh water for the  human consume. After the humans use that water, it becomes dirty again.

The pollute water that comes of the houses and factories, can go direct to both, oceans and rivers, however one part goes the sewage treatment plants, where again pass thorough a cleaning process in order to go to the rivers and streams again. This rivers have dirty water that goes to the ocean as well.

I can see the problem is the water doesn't have being cleaning after the people's use, so all the pollution is going to the oceans, and this will be a problem for all the comunity if they are not aware of the damage that they are doing to themselves.