Agricultural Runoff is water sent from farm fields due to irrigation, rain, or melted snow. This runoff water can contain fertilizers, pesticides, animal waste, or soil particles, which can enter and contaminate sources of drinking water.
Agricultural Runoff has been a growing issue for lakes and rivers. As pollutants run off farm fields, they find their way into rivers and streams that eventually end up in drinking water. Water treatment centers have to spend millions in purchasing chemicals to remove runoff from farms, so it is safe for human consumption.
Swanson, Abbie Fentress. “What is Farm Runoff Doing to the Water? Scientists Wade in.” NPR. http://www.npr.org/sections/thesalt/2013/07/09/199095108/Whats-In-The-Water-Searching-Midwest-Streams-For-Crop-Runoff. July 5, 2016.
U. S. National Library of Medicine. “Agricultural Runoff.” Tox Town. https://toxtown.nlm.nih.gov/text_version/locations.php?id=1. Accessed July 5, 2015.