There are a lot of given signs that will show whether or not a river is safe to swim in. They are telltale, and you can usually tell by merely seeing the river or lake whether or not the specified body of water is safe to swim in. However, there is another sense which will tell you, such as sound and more importantly smells. If you can detect any of the inverse and negative signs that tell whether or not the river is safe to swim in, you can end up saving yourself and your friends and family from becoming dangerously sick or further polluting the water.
If you drive by a body of water or smell it before you see it, then it is very clearly unsafe. There are multiple different reasons that can attribute to a foul smell of a river or other body of water, some of which we will begin to go over now. The first would be a dead animal or carcass. If an animal lies rotting and decomposing in any body of water, then bits and pieces of the flesh and rotting meat will be carried down the said body of water and therefore dispersed into the water supply.
If you see a stream that has a dead deer in it, all of the water (and I mean ALL of it) near it and below it as well as further down the stream will be thoroughly polluted. However, water that is even two inches above the animal will be completely pure and fresh because it has not yet made contact with the said animal. It is possible that another dead animal is farther up in the body of water, although it is unusual for more than one animal, or even one animal for that matter, to be dead and lying in the same stream.
2. Is The Water Still Or Moving?
This is one of the easiest ways to tell whether or not a river is safe to swim in. If it has a current, it is most likely fine. However you should never drink the water, no matter how clear, crisp, and fresh it looks feels or smells. If the body of water is still, it provides bacteria and germs with the chance to grow in the water and therefore pollute and infect the water with sickness-inducing bacteria or viruses.
However, if it is a moving body of water, then because it is not still it does not provide bacteria nor viruses with the chance to germinate, meaning that it cannot grow and therefore cannot survive, which means that the water will be fine.
One thing that you will want to keep in mind if you are planning to swim in a river or body of water is that you could always get sick. If you swallow even a teaspoon of water by accident, you are liable to procure a disease or sickness. In my case, I swallowed about a tablespoon and a half or so on one or two different days, back to back, and was sick almost immediately. I then got strep throat and had a terrible fever, so I do not particularly recommend being careless when it comes to swimming in a river or more importantly a still body of water. In addition to this post, check out what Prevention magazine has to say about signs to look for of unsafe waters.