Posted by: Vicki Burns | April 21, 2014

The ABCs of Point Source Versus Nonpoint Source Pollution, What’s the Difference?

One of the goals I have in writing this blog is to take what I hear from scientists and other environmental professionals, and turn it into information that the general public can understand. It is so easy for professionals to use the language and jargon that is common in their field and not alter it when speaking to others. Although it is understandable why this happens, it can impede getting the correct information and message out to the public, to policy-makers and to our elected officials.
In water and lake protection work, understanding where the problem elements and pollutants are coming from is key to being able to stop them getting into the water. In particular, with the challenge of blue-green algae blooms (some of which contain dangerous toxins) the problem elements are phosphorus and to a lesser extent , nitrogen. Amongst the science and conservation professionals, we often hear the terms point source and nonpoint source phosphorus used but most of the general public are not familiar with those terms. If we are to gain support for investments in decreasing phosphorus and nitrogen getting into our lakes, we need to broaden the understanding of the point source vs. nonpoint source terms. Why – because the methods for intervening are very different and although, both sources need to be decreased it is much easier to start with the point sources.

Point Source & Nonpoint Source  image courtesy of t4-1contaminants blogspot

Point Source & Nonpoint Source
image courtesy of t4-1contaminants blogspot

The U.S. Environmental Protection Agency (EPA)” defines point source pollution as any single identifiable source of pollution from which pollutants are discharged, such as a pipe, ditch, ship or factory smokestack. Factories and sewage treatment plants are two common types of point sources” when we are discussing water pollution and blue-green algae blooms.
The U.S. EPA defines nonpoint source (NPS)as “coming  from many diffuse sources. NPS pollution is caused by rainfall or snowmelt moving over and through the ground. As the runoff moves, it picks up and carries away natural and human-made pollutants, finally depositing them into lakes, rivers, wetlands, coastal waters, and even our underground sources of drinking water.”
In future blogs, I’ll discuss why and how we should be decreasing impacts from our point sources of phosphorus more effectively and then, get working  on the nonpoint sources.


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