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Environmental Health - Toxic Substances




DNAPL (Dense Nonaqueous Phase Liquid) - "A DNAPL is one of a group of organic substances that are relatively insoluble in water and more dense than water. DNAPLs tend to sink vertically through sand and gravel aquifers to the underlying layer." - U.S. Environmental Protection Agency, 2010

DNAPL - "An acronym for denser-than-water nonaqueous-phase liquid -- an organic liquid, composed of one or more contaminants, that does not mix with water and is denser than water. The most common DNAPL contaminants in ground water are chlorinated solvents." - National Research Council, 1994

DNAPL - "Chlorinated solvents are more dense than water and are thus called dense NAPLs, or DNAPLs. Other DNAPLs include coal tars, which contain PAHs [polycyclic aromatic hydrocarbons], and transformer oil, which may include mixtures of PCBs [polychlorinated biphenyls]." - National Research Council, 1994

DNAPL - "Many of the halogenated hydrocarbons are characterized as dense nonaqueous-phase liquids (DNAPLs). Their densities exceed that of water, but they have lower viscosities. Their solubility in water is in the range of 100-500 mg/L." - Lesage and Jackson, 1992

Text in brackets ("[text]") are additions by the editor

Related Definitions

NAPLs (Non-Aqueous Phase Liquids)

LNAPLs (Light Non-Aqueous Phase Liquids)

PAHs (Polycyclic Aromatic Hydrocarbons)

USGS Information on DNAPLs

Related Headlines

Other Information on DNAPLs


Lesage, S., and Jackson, R.E., 1992, Groundwater contamination and analysis at hazardous waste sites: Marcel Dekker, Inc., 552 p.

National Research Council, 1994, Alternatives for ground water cleanup: Washington, D.C., National Academy Press, 315 p.

U.S. Environmental Protection Agency, 2010, Waste and cleanup risk assessment glossary: U.S. Environmental Protection Agency, access date July, 27, 2010.


Disclaimer: The definitions on this page are provided for information purposes only, and do not indicate endorment by the U.S. Geological Survey.

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