Eli5: How does bacteria form in still water and not running water?

Question

Eli5: How does bacteria form in still water and not running water?

In: 3

Answer 1

The major thing you’re trying to avoid in water is harmful microorganisms, usually from animal waste and rotting flesh. Moving water will dilute things that fall in and the aeration will help decompose rotting materials. So if a deer shits in a river, you’ll probably be fine. If a deer shits in a pond, it might not be safe for weeks.