The Great Depression, the recession, I don't know the other one.
Many companies make other goals a priority over profit maximization. Additionally, some aspects of running a business that meets social and environmental obligations take away from the sole focus of profit maximization.
Water pollution is caused by us, humans. One example is that everyday we pollute the water with toxic wastes containing hazardous chemicals that harm the natural inhabitants and contaminate the pristine waters making it unsafe for us to use.