Light Non-Aqueous Phase Liquids (LNAPLs)

Light non-aqueous phase liquids are liquids that are sparingly soluble in water and less dense than water. For example, oil is an LNAPL because it "floats" on top of water and does not mix with water. Hydrocarbons, such as oil and gasoline, are examples of LNAPLs. At LNAPL contamination sites LNAPL can form a pool of LNAPL in the subsurface on top of the water table. The following diagram is a cross sectional view of a hypothetical LNAPL spill.

Figure has been adapted from Delin and others, 1998, USGS Fact Sheet FS-084-98.

Related Definitions

• Non-Aqueous Phase Liquids (NAPLs)
• Dense Aqueous Phase Liquids (DNAPLs)

Toxics Program Investigations on the Fate of LNAPLs

• Crude Oil Contamination in the Shallow Subsurface, Bemidji, Minnesota
• Natural Attenuation Fuel Oxygenates in Ground Water, Laurel Bay, South Carolina
• Natural Attenuation Gasoline in Ground Water, Galloway Township, New Jersey
• Osage-Skiatook Petroleum Environmental Research Project, Oklahoma

Other Information on LNAPLs

• Software Provides Estimates of How Long it Will Take for Remediation Efforts to Achieve Their Goals
• Using Oxygen to Clean Up Ground-Water Contamination
• MTBE Can Degrade Naturally Without Oxygen
• MTBE Biodegrades Naturally in Stream Sediments
• Natural Attenuation of MTBE at Laurel Bay, South Carolina
• How Do You Clean Up Gasoline Spills Naturally?

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