Contamination and Pollution - 15 of 27
Contamination and Pollution FAQs - 27 Found
USGS scientists have discovered that the atmosphere is a potential source of the low concentrations of methyl tert-butyl ether (MTBE) detected in shallow ground water in southern New Jersey. The scientists measured atmospheric concentrations of MTBE from November 1996 to February 1998 and determined through the use of computer simulation studies that the concentrations were high enough to cause detections in ground water, lakes, and streams. In subsequent work the scientists studied the presence of MTBE in the unsaturated zone and discovered that biodegradation of MTBE in the unsaturated zone may reduce MTBE concentrations before they can enter ground water. Variations in the properties of the unsaturated zone and the recharge of ground water need to be more fully understood, however, to determine the potential of the atmosphere as a nonpoint source of MTBE to ground water.
"Even when concentrations of volatile organic compounds in groundwater are low compared to regulatory concentration limits, it is critical to know the source. If the VOCs originate from a point source(s), concentrations in groundwater could potentially increase over time to levels of concern as groundwater plumes evolve, whereas if the atmosphere is the source, then groundwater concentrations would be expected to remain at low-level concentrations not exceeding those in equilibrium with atmospheric concentrations." (Baehr and others, 1999)
Sources of Information:
Baehr, A.L., Charles, E.G., and Baker, R.J., 2001, Methyl tert-butyl ether degradation in the unsaturated zone and the relation between MTBE in the atmosphere and shallow groundwater: Water Resources Research, v. 37, no. 2, p. 223-233, 2000WR900292, doi:10.1029/2000WR900292.
Baehr, A.L., Stackelberg, P.E., and Baker, R.J., 1999, Evaluation of the atmosphere as a source of volatile organic compounds in shallow groundwater: Water Resources Research, v. 35, no. 1, p. 127-136, 1998WR900030, doi:10.1029/1998WR900030.
Pankow, J.F., Thomson, N.R., Johnson, R.L., Baehr, A.L., and Zogorski, J.S., 1997, The urban atmosphere as a non-point source for the transport of MTBE and other volatile organic compounds (VOC's) to shallow groundwater: Environmental Science and Technology, v. 31, no. 10, p. 2821-2828, doi:10.1021/es970040b.
A National Assessment of Volatile Organic Chemicals in Major Aquifer Systems and Rivers (Methyl tert-butly ether (MTBE) is one of a group of volatile organic compounds used as solvents, fuel additives, fuels, and disinfection byproducts.)