The cooperative Water-Resources Research Program of the U.S. Geological Survey and the Massachusetts Department of Environmental Management,1995
Nitrate and pesticides in ground water of the Ozark Plateaus region in Arkansas, Kansas, Missouri, and Oklahoma
The climactic June 1991 eruption of Mount Pinatubo, Philippines, was the largest volcanic eruption in this century to affect a heavily populated area. Because it was forecast by scientists from the Philippine Institute of Volcanology and Seismology and the U.S. Geological Survey, civil and military leaders were able to order massive evacuations and take measures to protect property before the eruption. Thousands of lives were saved and hundreds of millions of dollars in property losses averted. The savings in property alone were many times the total costs of the forecasting and evacuations.
Nitrogen-based fertilizers are used extensively in the White River Basin. Water samples were collected for nitrate analysis from 103 monitoring wells in four networks in the basin. Ninety-four "shallow" wells were screened near the top of the uppermost aquifer encountered; the remaining 9 wells were paired with shallow wells but screened 18 to 45 feet deeper. Samples from 6.4 percent of the shallow wells exceeded the U.S. Environmental Protection Agency's Maximum Contaminant Level of 10 mg/L (milligrams per liter). Elevated nitrate concentrations (higher than 3 mg/L) were common in unconfined, permeable deposits underlying agricultural areas; nitrate concentrations decreased with depth in these deposits. Low nitrate...