We waste billions of litres of water washing away our excreta, fouling all that perfectly clean water with vast numbers of bacteria and with organic matter that burns up the oxygen supply in the water. Every town or city has millions of dollars invested in dams, pumps, pipes and filtration plants and a significant proportion of this financial outlay and ecological damage is merely to dispose of our excreta politely. Once we have polluted all that water we have to spend billions of dollars on sewage works to clean up the waste once more before we put it back into the natural aquatic environment. Even worse, we pump this polluted water out into the ocean, breaking the cycle of nutrients that starts with the soil and should return to the soil. This is a clear example how the human race is diverting resources away from the balanced cycles of nature and causing problems as they deal with substances in a linear fashion.
Ocean outfalls reflect our attitude towards excreta.
We regard it as something to be thrown away. We do not regard it as a resource to be utilized. When any resource is thrown away it becomes pollution and does some harm to the ecosystem. It will be a giant step for mankind when we recognise sewage as a valuable resource worth utilizing as a source of plant nutrients and a source of energy. The excreta of all animals are a valuable part in the cycle of nutrients and energy in the ecosystem.