What is a point source of pollution apes?

Almost everything humans do, from growing food to manufacturing products to generating electricity, has the potential to release pollution into the environment. Regulatory agencies charged with protecting the environment identify two main categories of pollution: point-source and nonpoint-source pollution.

Point-source pollution is easy to identify. As the name suggests, it comes from a single place. Nonpoint-source pollution is harder to identify and harder to address. It is pollution that comes from many places, all at once.

The United States Environmental Protection Agency (EPA) defines point source pollution as any contaminant that enters the environment from an easily identified and confined place. Examples include smokestacks, discharge pipes, and drainage ditches.

Factories and power plants can be a source of point-source pollution, affecting both air and water. Smokestacks may spew carbon monoxide, heavy metal, sulfur dioxide, nitrogen dioxide, or “particulate matter” (small particles) into the air. Oil refineries, paper mills, and auto plants that use water as part of their manufacturing processes can discharge effluent—wastewater containing harmful chemical pollutants—into rivers, lakes, or the ocean.

Municipal wastewater treatment plants are another common source of point-source pollution. Effluent from a treatment plant can introduce nutrients and harmful microbes into waterways. Nutrients can cause a rampant growth of algae in water.

Nonpoint-source pollution is the opposite of point-source pollution, with pollutants released in a wide area. As an example, picture a city street during a thunderstorm. As rainwater flows over asphalt, it washes away drops of oil that leaked from car engines, particles of tire rubber, dog waste, and trash. The runoff goes into a storm sewer and ends up in a nearby river. Runoff is a major cause of nonpoint-source pollution. It is a big problem in cities because of all the hard surfaces, including streets and roofs. The amount of pollutants washed from a single city block might be small, but when you add up the miles and miles of pavement in a big city you get a big problem.

In rural areas, runoff can wash sediment from the roads in a logged-over forest tract. It can also carry acid from abandoned mines and flush pesticides and fertilizer from farm fields. All of this pollution is likely to wind up in streams, rivers, and lakes.

Airborne pollutants are major contributors to acid rain. It forms in the atmosphere when sulfur dioxide and nitrogen oxides combine with water. Because acid rain results from the long-range movement of those pollutants from many factories and power plants, it is considered nonpoint-source pollution.

In the United States, the Clean Air Act and the Clean Water Act have helped to limit both point-source and nonpoint-source pollution. Thanks to these two legislative initiatives, in effect for some 50 years now, America’s air and water are cleaner today than they were for most of the 20th century.

8.1 Sources of Pollution

Every human activity impacts the environment, and one 1️⃣ of the most major of those impacts is pollution. In APES, we can define pollution as anything that is present or introduced to the environment with harmful effects.

In this section, we will begin by classifying pollutants into two main categories, Point Source and Nonpoint Source.  When you look at the images below, your first thought might be that they are the same when in fact they are very different. Can you identify which one is a Point Source and which is a Nonpoint Source?

Images from Pixabay Smoke Stack and Water Runoff

Point Source Pollution

Pollutants that are emitted from a single 1️⃣, identifiable 🔍 source are known as point source pollutants. Examples of point source pollution include smoke from a smokestack of a factory 🏭, untreated sewage coming out of a pipe into a river 💩, and vehicle exhaust coming out of a car 🚗 tailpipe. Point sources of pollution are easy to identify and much easier to regulate pollution coming from these sources.

A major characteristic of point source pollution is a plume which is where the pollutant is most concentrated. Here’s an example:

Image from National Geographic

Pipe drains dirty water into river

📜 Legislation Connection - Clean Water Act

This act makes it unlawful 👮 for anyone to discharge any point source pollution without permits.

1. The act requires that we use “Best Practicable Technology” (BPT) to clean point sources and “Best Available Technology” (BAT) be used to clean up toxins ⚠️

2. This act funds construction of several important facilities such as sewage treatment plants and includes provisions for protecting wetlands 🌴

3. The main goal of this act is to get to the point where all water is “fishable and swimmable” 🏊‍♀️

Resources:

Nonpoint Source Pollution

Nonpoint source pollutants come from a non-identifiable location📍, and are often spread out over a large area. Nonpoint source pollution transported by moving water, or going into water, is commonly referred to as "runoff" ⛈️

Image from New York State Government Graphic displaying the non-point sources of pollution in a watershed

Be careful 🚨 using this graphic to define nonpoint sources of pollution! While everything on the image is true, be aware that sometimes you can identify sources of pollution from Industry, like in the pipe shown in the image above.

Examples of nonpoint source pollution can include excess fertilizer 🧺 washing off all the lawns in a neighborhood during a rain storm and into a local creek, as well as smoke from a wildfire 🚒. Since nonpoint source pollution is diffuse in its location 📌, it is very difficult to regulate and thus is usually the largest source of surface water pollution.

Check Your Understanding 🚯

Go back to the image of the smokestack and water runoff.  Although they both look similar in that they are a pipe emitting pollution, the smokestack is a point source because it is coming from one identifiable factory, and, if needed, it would be ‘simple’ to create regulations to prevent that factory from polluting.  The water runoff, however, is a collection of alllll the potential pollutants found on the street.  If something toxic was found in that water it would be very difficult to track down and regulate the original source. 

Environmental Hazards ☣️  

Practice MCQ (Multiple Choice Question) Time 🎉

Which of the following in the chart correctly gives examples of Point and Non-Point Source Pollution?

✅ Correct Answer Choice

🅱️! Remember that with point source pollution, you can point 👉👆👇👈 to a direct source. With nonpoint source, you will have a combination ➕ of pollutants from different sources.

Need more practice with Source of Pollution? Check out a trivia game 🎮

Resources:

Which is a point source of pollution?

What are 3 sources of point pollution?

What is an example of point source pollution quizlet?