Point Source and Nonpoint Source Pollution.
What is point source pollution? Point source pollution means pollution that comes from a single, identifiable source or point. The effects of this type of pollution usually remain relatively local to the point from which the pollution is emanating.
Key examples of point source pollution include sewage pipes releasing sewage into a ditch, smokestack style factory chimneys and oil spills. As these two examples show, point source pollution can be deliberate or accidental.
A point source of pollution can be almost any size. For example, a battery from a discarded mobile phone leaking into a lake can be said to be a form of point source pollution. However, a huge factory with chimneys emitting smoke into the neighboring town is also a type of point source pollution – but a much larger one.
What is nonpoint source pollution? Nonpoint source pollution means pollution whose source cannot be traced back to a single thing. Nonpoint source pollution is pollution that is more diffuse. It is not concentrated around a particular point or source. This type of pollution and its effects can be seen in the atmosphere, the earth or the sea and other bodies of water.
The fact that nonpoint source pollution cannot be traced to a single point can be due to several factors. It may be because nonpoint source pollution has multiple sources (for instance, the high CO2 levels in the atmosphere are caused by many sources, such as factory smoke, people’s cars and so on). Or, it could be because the movement of the air and the water has caused the pollution to move right across the globe and diffuse very widely. Very often, both factors are at work in the case of nonpoint source pollution.
Differences between point source and nonpoint source pollution.
- Definite single source vs no definite single source: The most obvious difference between these two types of pollution is that point source pollution emanates from a definite, individual source. On the other hand, nonpoint source pollution cannot be traced back to one single source. This can be said to be the definitive difference between the two types of pollution – indeed, this difference is reflected in the two names that are given to these two types of pollution: ‘point source’ and ‘nonpoint source’.
- Local vs widely diffused: Point source pollution is more of a localized pollution (for instance, it comes from a single leaking sewage pipe). Nonpoint source pollution is widely diffused whilst point source pollution will often remain concentrated close to the source of the pollution. This is another very important difference between the two types of pollution, and it is right at the heart of the other differences that are listed below.
- Ease of preventing and controlling the pollution: It is often argued that point source pollution is easier to control than nonpoint source pollution. This is because point source pollution can be traced back to a single point. That way, the pollution can be stopped at source. For example, if a pipe is leaking chemicals into a river, the pipe can be located and the leak stopped. With nonpoint source pollution, however, there is no single source of the pollution that can be tackled. This can make it much harder to control by means of a single ‘quick fix’ solution. Better waste disposal systems can quickly prevent point source pollution, but not point source pollution is harder to prevent.
- Levels of dilution: Nonpoint source pollution tends to be more diluted than point source pollution. This is due to the fact that point source pollution is concentrated around the source of the pollution. Nonpoint source pollution, however, moves more widely from its multiple origins. For instance, an oil spill from a tanker in the sea will tend to concentrate around the tanker and it will be very thick and concentrated: this is a type of point source pollution. However, the fumes from aerosols sprayed throughout the world will rise up into the air and dilute more thoroughly with the molecules in the air as they spread throughout the globe.
- Scale of measures needed to address the pollution: Action within a single community is usually enough to stop point source pollution. It is because point source pollution has an identifiable source it can be said to be easier to tackle than nonpoint source pollution. Nonpoint source pollution tends to diffuse very widely. For this reason, nonpoint source pollution is often tackled through global action – for instance, by asking factories throughout the world to reduce their CO2 emissions and by asking private individuals throughout the globe to stop using their cars so often and to take global action. For nonpoint source pollution, smaller scale measures are usually needed. These might include fixing the chimney on a particular factory so that it emits less soot and smoke and plugging up leaks in pipes carrying sewage or chemicals.
Conclusion.
Pollution is a very big problem in the world today. It affects plant, animal and human life and contributes to world-changing phenomena such as climate change. Knowing whether a particular type of pollution is point source pollution or nonpoint source pollution can help us to fix it. This is because there are different measures that need to be taken in order to deal with nonpoint source pollution as compared to point source pollution – for example, more global measures are needed to tackle nonpoint source pollution, and more local measures tend to suffice when dealing with point source pollution.
One key question that can be asked, however, is whether a pollutant can produce both point source and nonpoint source pollution. For example, if there is a car driving around an enclosed valley, then its fumes may well get trapped in the valley and pollute the air there. In this way, the car can be described as producing point source pollution. However, some of the car’s fumes are likely to escape into the atmosphere, and to be carried by the wind far across the globe where they mingle with polluting molecules from other vehicles. In this way, the car can also be described as producing non point source pollution. So, it is certainly not a contradiction to say that a single source can produce point source pollution, but can also contribute to non point source solution.
Thus, we conclude that both point source and non point source pollution are undesirable, but the former may be easier to control and prevent than the latter.
What about your own life and your own environment? What types of pollution can you think of? Are they point source or non point source pollution? Are there any ways in which you could cut down on both of these types of pollution through your own actions.
