Many sites that have had underground storage tanks or pipes that have leaked, or above ground storage tanks that have leaked and seeped into the soil, have a layer of contaminant liquid sitting either on top of the groundwater table, or at the base of the aquifer depending on the contaminant liquids density in relation to water. These contaminant liquids are called non aqueous phase liquids (NAPLs).
A light non-aqueous phase liquid (LNAPL) is a groundwater contaminant that is not immediately soluble in water and is less dense than water (like an oil sheen), in contrast to a DNAPL (dense non-aqueous phase liquid) which has higher density than water and will migrate to the bottom of the aquifer. Once a LNAPL infiltrates the ground, it will stop at the height of the water table because the LNAPL is less dense than water.
LNAPL – What it means and what you can do about it was first seen on: SESL Australia Pty Ltd
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