What is a real case scenario of water pollution on Earth that is point source? What caused it? When did this happen? What effects did it have on the environment? How was it managed? What management techniques and mitigation techniques were involved?

Two years ago, there was a chemical spill in the Elk river in Charleston WV.....that happened to be just above the American Water company's water intake for this entire area.....needless to say our water smelled like licorice and we couldn't use it for anything for a really long time. So one chemical spill affected this entire areas population, not to mention the wildlife that utilizes these waters. Grrrr....