The World's Water

Among the many resources that we need on Earth, water is one of the most important. Most of the Earth's freshwater is stored in lakes, rivers, and streams or below ground in aquifers. As water moves both on the surface and under the ground, suspended particles or dissolved substances such as pesticides can move with it. Because surface and groundwater are interconnected, they can easily contaminate each other.

For information on the continuous movement of water on, above, and below the surface of the Earth see:  watercycle.html

To learn where Earth's water is located see:
http://ga.water.usgs.gov/edu/earthwherewater.html

Surface Water

Water collecting on the ground or in a stream, river, lake, sea or ocean, is called "surface water." Surface waters are an integral part of most watersheds, and, because they are exposed, they can be contaminated very easily.

Groundwater

Groundwater is below the soil surface and develops from the seepage or infiltration of water into the ground. Gravity draws the water down, causing it to move through the cracks and pores in soil, subsoil, rock, and gravel.

For more information on groundwater and surface water and their interactions see:
http://www.conservationinformation.org/?action=learningcenter_kyw_groundsurfacewater

How often are pesticides found in water?

Pesticides are frequently found in surface and ground water. That statement although true, does not by itself give a complete picture of the situation. After decades of sampling and testing water for the presence of pesticides, very few samples have been found to contain enough pesticide to be a human health concern. More often the concentrations are found to be at levels that could affect small aquatic organisms or animals that live primarily by eating fish. The National Water Quality Assessment Program (NAWQA) has been monitoring water on a national-scale. They have published a comprehensive analysis of pesticides in streams and ground water. To read this report click on the link below.

 http://pubs.usgs.gov/fs/2006/3028/

United States Geological Survey (USGS) has publish a current study of pesticides in rivers and streams. USGS scientists studied 11 herbicides and insecticides frequently detected in the Corn Belt region, which generally includes Illinois, Indiana, Iowa, Nebraska and Ohio, as well as parts of adjoining states.

To read the results of this study click on the following link: Pesticide Levels Decline in Corn Belt Rivers

Authored by Ronald D. Gardner