Groundwater and Aquifers - 6 of 20

Groundwater and Aquifers FAQs - 20 Found

How frequently are volatile organic compounds (VOCs) detected in groundwater?

Volatile organic compounds (VOCs), which are widely used in the manufacture of many products including refrigerants, plastics, adhesives, paints, and petroleum products, have been detected in about one-third of the wells sampled by the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS). Chloroform and other trihalomethanes, the most commonly detected compounds, were found in about 9 percent of the sampled wells. Solvents, particularly chlorinated solvents, were found in about 8 percent of sampled wells. VOCs predominantly occur in urban areas, often in mixtures; specifically, 2 or more compounds were found in about one quarter of the sampled urban wells.

A commonly detected VOC is methyl tert-butyl ether (MTBE), which is a gasoline oxygenate designed to add oxygen to decrease vehicular carbon monoxide emissions and ozone levels in the atmosphere. MTBE has the highest production volume of all fuel oxygenates.

Graphic showing the most commonly detected VOCs in ambient ground water

Trihalomethanes, solvents, and gasoline oxygenates are the most commonly detected volatile organic compounds in ambient groundwater.