As a public health nurse, I learned that modern Public Health began in London when Dr. John Snow discovered in 1854, that sewage dumped into the Thames caused folks downstream to get cholera. When there were few people on Earth, dumping waste into water sources didn't have much effect, since it all got washed downstream. But as populations grew, the issues of providing food and clean water, and exporting waste from highly dense population centers became a critical issue. As such, governments arose to organize food and water transport in, and waste disposal out. Pigs became a valuable cog in this great wheel because you could keep a pig in a small pen in the backyard and feed it all of your kitchen wastes and night soil. In turn, the pig would produce juicy little piglets for you to eat or sell. Ancient governments created aqueducts and underground pipes for municipal water supplies, as well as engineers to maintain them. Of course, the ancient Romans used lead for their water pipes which then caused a great deal of mental retardation and some bizarre imperial behavior.
Here in California, water is a huge political issue. As the most populous state, as well as the fruit and vegetable basket of America, water is in great demand. Although water is considered by some to be a basic human right, and by others as part of the Commons, private corporations are buying up water rights in order to sell it to the people at cutthroat prices. Case in point: the cities of Boulder Creek and Stockton. As the environment declines, I foresee water filling stations to rival gasoline stations.
Even the popularity of plastic bottles of water is based on the suspicion that our tap water is not safe to drink. Considering that taxes paid to governments are used to build water and sewage treatment plants, and when taxes are severely cut, then governments no can longer afford to clean our tap water or treat the sewage before dumping it into the water source. Now it turns out that the plastic of the water bottles contains BPA which feminizes everyone that is exposed to significant quantities of it. I filter tap water at home for drinking and cooking.
In the popular fiction series, Dune, the indigenous people of the desert planet Arakis wore water recycling suits in which they drank their own sweat and urine. When a member of the tribe died, they would render all the water from the corpse, and pour it into their sacred underground lake from which they drew all their village water needs.
Although the Ganges River is turbid with pollution, the popular belief is that it purifies everything it touches. The elderly of India wait to die on the banks of the Ganges so their ashes can be thrown into the river after cremation. I swam in the Ganges.
Considering the purification qualities of water, I find it quite amazing to consider that water, a fluid mineral countless millenia old, actually does clean and purify everything it touches. Water is precious and amazing. Even in the Holy Bible, water is mentioned in the second sentence of Genesis.