Perhaps you have heard about point and nonpoint source water pollution, what is the difference and why is it important? Pollution from a point source is emanating from a source which can be identified, i.e. discharging pipes, construction etc., while nonpoint sources cannot be so specifically determined. Nonpoint source water contaminants can come from varied sources originating in many possible locations. A very pointed example is industrialized farming; if heavy precipitation follows immediately after farmers fertilize their crops there is a good chance fertilizer may run off into streams and surface water.
This graphic illustrates many examples of nonpoint source pollution and the effects thereof. (Photo courtesy of the Pomperaug Watershed Coalition)
Many pollutants originate from nonpoint sources, EPA data indicates that this is the broadest contributor to poor water quality making slightly less than half of all surface water too polluted for safe swimming. Common pollutants coming from nonpoint sources include; sediment, soil erosion runoff, heavy metals and oil washing from roadways, leaks from vehicles, farm runoff and household chemicals dumped down the drain.
The dead zone in the Gulf of Mexico can be largely attributed to nonpoint source pollution. Nutrient overloaded water from the Mississippi River discharges into the Gulf, oxygen is depleted putting undue stress on aquatic life and systems. More areas like this are being found around the world now, due to excessive water contamination.
Soils can either aid in solving this problem or become partly to blame. Poorly managed soil, or soils lacking in clay may have a hard time binding phosphorus and nitrogen which will leach out into surface water. Fertilizers added to this type of soil would move through with the flow of water, and the soils themselves may erode away, so, in this instance soil is the problem. Well managed soils will mitigate damage. Farmers employing tillage practices and forest cover aids in the maintenance of soils’ integrity. Wetlands nearby areas of known runoff will help remove nutrients, sediments and pollutants from surface water and runoff.
Responsible use of fertilizers and pesticides, integrated pest management and erosion control are all methods which will help control nonpoint source pollution and improve water quality. Staying informed, researching methods and products and getting expert advice can help you make responsible choices for your landscape, community and ecosystem.
