Difference Between Point Source and Nonpoint Source Pollution

The main difference between point source and nonpoint source pollution is that the point source pollution occurs through a specific, identifiable source whereas the nonpoint source pollution occurs through a combination of pollutants from a large area. 

Point source and nonpoint source pollution are two mechanisms of pollution. Discharge pipes from factories, sewage treatment plants, and various organizations are responsible for point source pollution while the runoff of the contaminants of gardens and construction sites through water bodies is responsible for nonpoint source pollution. 

Key Areas Covered 

1. What is Point Source Pollution
     – Definition, Sources, Effect
2. What is Nonpoint Source Pollution
     – Definition, Sources, Effect
3. What are the Similarities Between Point Source and Nonpoint Source Pollution
     – Outline of Common Features
4. What is the Difference Between Point Source and Nonpoint Source Pollution
     – Comparison of Key Difference

Key Terms 

Diffusible Pollution, Effect, Localized Pollution, Nonpoint Source Pollution, Point Source Pollution

What is Point Source Pollution 

Point source pollution is a pollution which occurs through a single identifiable source. Therefore, the effect of this type of pollution is local to the point of discharge. The size of the pollution can vary from a small pollution to a large. As an example, the discharge of an electric battery to a water source is a small-scale point source pollution while the emission of smoke from a factory is a large-scale point source pollution. 

Figure 1: A Discharge Pipe

Since point source pollution is a localized type of pollution, the pollutants enter in the environment in a high concentration and then, are slowly diluted into the ecosystem. Hence, a severe damage to the ecosystem can be observed at the point of discharge. On the other hand, it is easy to prevent and control point source pollution by stopping the source or installing a treatment plant. 

What is Nonpoint Source Pollution 

Nonpoint source pollution is the other type of pollution in which the source of the effluent cannot be traced to a single point. This means it is a more diffused type of pollution. Effects of this type of pollution can be identified in the atmosphere, water bodies or on the land. As an example, the high carbon dioxide concentration in the atmosphere is a result of the emission of carbon dioxide from various factories worldwide, vehicles, and so on. The emitting carbon dioxide moves across the globe through diffusion. 

Figure 2: Runoff of Soil and Fertilizer 

Since nonpoint source pollution is diffusible, it cannot be controlled by a quick solution.  

Similarities Between Point Source and Nonpoint Source Pollution 

• Point source and nonpoint source pollution are two types of mechanisms of pollution. 
• Pollution can be water pollution, air pollution, land pollution, noise pollution, etc.  

Difference Between Point Source and Nonpoint Source Pollution 

Definition 

Point source pollution refers to the pollution that occurs from a single identifiable source while nonpoint source pollution refers to the pollution that occurs via many diffuse sources.  

Source 

The discharge of effluents occurs at one point in point source pollution while the discharge of effluents over a wide area leads nonpoint source pollution. This is the main difference between point source and nonpoint source pollution. 

Effect 

The effect of point source pollution is high while the effect of nonpoint source pollution is less. 

Treatment Plant 

A treatment plant can be installed in the area of discharge in point source pollution while a treatment plant is less effective for nonpoint source pollution because of the source of pollution. This ia another important difference between point source and nonpoint source pollution. 

Examples 

Some examples of point source pollution include faulty treatment plants, oil tank spills, combined sewer outfalls, etc. while some  examples of nonpoint source pollution are farming fertilizers, road salt runoff, etc. 

Conclusion 

Point source pollution is a type of pollution that occurs via an identifiable source while nonpoint source pollution is a type of more diffusible pollution. The effect of point source pollution is high in the affected area while the effect of nonpoint source pollution is more global. The main difference between point source and nonpoint source pollution is their source. 

Reference:

1. “Sources of Pollution.” UF Clean Water Campaign, University of Florida, Available Here

Image Courtesy:

1. “Discharge pipe” (Public Domain) via Commons Wikimedia 
2. “Runoff of soil & fertilizer” By Lynn Betts, photographer – U.S. Department of Agriculture, Natural Resources Conservation Service.Filename:NRCSIA99129.tif (Public Domain) via Commons Wikimedia