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Nonpoint Source Water Pollution*


What is Non-point Source Water Pollution?

The Environmental Protection Agency (EPA) defines non-point source water pollution as "[pollution that] 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 then into lakes, rivers, wetlands, coastal waters, and even our underground sources of drinking water" (Pollution Runoff).  This type of pollution is so pervasive that "states report that non-point source water pollution is the leading remaining cause of water quality problems" (Pollution Runoff).  Major sources of this type of pollution include construction sites, automobile waste from road runoff, businesses, homes and agricultural practices (Pollution Non-point).  In particular, agricultural pollutants are common, and are often referenced as examples in non-point water pollution discussions.      

This, just like point source, can mean big problems for people if the polluted water or its inhabitants are ingested.  This pollution is considered a market failure because it negativly affects people who were not involved in the decision to pollute - a negative externality.  These negative affects are not incorporated into the decision-making criteria of the polluting entity.  

The economic response to this type of pollution usually comes in one of two forms: targeting management practices or targeting estimated emissions (Hanley, 246).  An agricultural example would be if the EPA sets strict limits for the number of livestock or the type of fertilizer to use, the Agency would be targeting the management practices of the farm.  On the other hand, if the EPA decides to set a limit of nitrates that are allowed in the water body, this would be an example of targeting the estimated emissions.  Since livestock and certain types of fertilizers are directly responsible for the nitrate waste that is carried to water bodies, these examples explain two ways to target this type of pollution problem.

Information Sources:

"Pollution Runoff (Non-point Source Pollution)." U.S. Environmental Protection Agency. 29 Nov. 2006. April 2007.

"Pollution: Non-point Source Pollution" Protecting Water. 2002. U.S. EPA The Hawaii State Department of Health Clean Water Branch and the City of Honolulu Department of Environmental Services. April 2007.

*Unless otherwise noted, the information in this section was summarized during a study of the following text: Hanley, Nick, and Jason F. Shogren and Ben White. Introduction to Environmental Economics. New York: Oxford University Press, 2001.

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