NAPLS

Nonaqueous phase liquids; i.e., chemical solvents such as trichloroethylene (TCE) or carbon tetrachloride – often toxic. Many of the most problematic NAPLs are DNAPLs – dense nonaqueous phase liquids.


Source: Corrosion-Doctors.org

Wikipedia:  https://en.wikipedia.org/wiki/Non-aqueous_phase_liquid