U.S. EPA Contaminated Site Cleanup Information (CLU-IN)

U.S. Environmental Protection Agency
U.S. EPA Technology Innovation and Field Services Division

Dense Nonaqueous Phase Liquids (DNAPLs)

Environmental Occurrence

Halogenated Alkanes

Three classes of halogenated alkanes are considered in this section: methanes, ethanes, and propanes. The 17 chemicals profiled are the ones commonly found at Superfund sites and do not represent the universe of DNAPL alkanes.

Many of the ethanes and methanes have found use as degreasers and solvents. While their production levels have fallen, some still qualify as large production chemicals. Most of the contaminating ethanes and methanes are found in groundwater aquifers and domestic and public supply wells, generally at low levels. One ethane and four methanes were refrigerants or feedstocks in their manufacture, and their current production has been restricted by the Montreal Protocol's ban on ozone-depleting chemicals.

Ethylene dibromide and 1,2-dichloropropane were used in leaded gasoline formulations, and they are likely to be found at leaking underground storage tanks where leaded gasoline was stored. These two chemicals, as well as 1,2-dibromo-3-chloropropane, were used as pesticides and fumigants and are commonly found in the groundwater in areas where they were applied.

For Further Information

Adobe PDF Logo The Quality of Our Nation's Waters: Volatile Organic Compounds in the Nation's Ground Water and Drinking-Water Supply Wells
Zogorski, J., J.M. Carter, T. Ivahnenko, W.W. Lapham, M.J. Moran, B.L. Rowe, P.J. Squillace, and P.L. Toccalino. U.S. Geological Survey Circular 1292, 112 pp, 2006

This report summarizes the findings of an investigation of aquifers that supply drinking water to the public. The investigation was conducted to determine the presence or absence of 55 volatile organic chemicals.