(over)Exploitation of fresh water?

Many factories in third world countries pump waste material into lakes & streams, the waste causes toxins to build up in the freshwaters and essentially contaminates them. The contaminated water kills off fresh water species as well as harnessing the quality of people's drinking water. Many governments in developed countries have laws that prevent factories from pumping their waste material into lakes & rivers, there are not a lot of ways to fix the already contaminated water, as many toxins don't decompose easily. I suppose all that an average citizen can do is not disposing rubbish near lakes & rivers.