An interesting quirk of TCE is that it's a "dense non-aqueous phase liquid" (https://en.wikipedia.org/wiki/Dense_non-aqueous_phase_liquid https://en.wikipedia.o

An interesting quirk of TCE is that it's a "dense non-aqueous phase liquid" (https://en.wikipedia.org/wiki/Dense_non-aqueous_phase_liquid https://en.wikipedia.org/wiki/Dense_non-aqueous_phase_liquid), which means that it sinks in water generally and groundwater specifically, making it hard to remediate.