Ways that water pollution occurs is that people dumb their garbage into the ocean or an oil spill occurs, killing many wildlife mammals and affects our food source. we cannot eat the fish that are contaminated with diseases from the oil or waste. We have to put our trash somewhere and that is in a landfill. In the landfill the waste and all the nasty things in the landfill seep into the ground and affect our natural ground water system. Little things such as CO2 that are put into the air from cars and big trucks can affect the water, CO2 gets into the air leaving back a smog that can kill fish and other animals that live in the water. Just like landfills we have a waste treatment plant where all of our feces go. If the treatment center isn't careful, the feces and the dirty water can go into the ground or near by river if it over flows. No one can drink or use this water, its disgusting and leaves so much bacteria behind. A point source of pollution is not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged. A non point source is results from land runoff, precipitation, atmospheric deposition, drainage, seepage or hydrologic modification. ways to prevent water pollution is to recycle and to clean up your community. you could start a group that helps clean up trash around the roadside or the riverside to prevent more water pollution. water pollution first affects the animals living in the water then affects us because we cannot eat contaminated fish or sea food and we cannot drink contaminated water or else we can get very sick. we do not realize what we are doing is so bad for us in the long run.