Let's start by saying that humans are the main and only source of water pollution. If we didn't pour all our poisons and junk in the waters, it wouldn't be necessary for us to to find a way to purify them or try to minimise the consequences. However, it seems that nature knows better and some animals have been given the power do remove the harm we do, without even knowing it.
The method in question has been discovered and developed in Britain. Scientist found that the bacteria in cow and horse droppings can be used to purify high acid waters. The method was later used in Bolivia to help poor communities fight water pollution. For the certain conditions (4400m above sea level, bad weather and terrain) llama seems to be the better solution. Big cattle cannot be herd so high in the mountains and the supplying enough waste material that high up is far from cost-effective solution, so the llamas came to the rescue. The role of their droppings in the process of cleansing water is to promote the activity of sulphate-reducing bacteria. So, bravo, Llama!
Poisons and Cures
It's a fact that animals produce only natural waste, product of the physical processes in every living organism. It is also a fact that humans produce several more types of waste in addition to that one. What's more, the effect of rubbish and waste products is in some cases (in most cases to be honest) negative on both human and animal health. Human rubbish can be the primal source of pollution which causes diseases and other physical conditions. To find a relieve, cure our bodies, and minimise the negative effects, we use modern pharmaceutical products. Duuh ... But the production process of medicines and other pharmaceutical products results in more hazardous waste.
Where is the connection to animals and animal waste? It's maybe a bit surprising but ... some of them have a cure to offer us.