How often do VOC mixtures occur?
Specific mixtures of volatile organic compounds (VOCs) in the 3,498 samples of ground water from aquifer studies occurred relatively infrequently at an assessment level of 0.2 microgram per liter (μg/L). The two most frequently detected VOC mixtures, perchloroethene–trichloroethene and perchloroethene–chloroform, occurred in 1.5 percent of the samples. Only one other mixture, trichloroethene–chloroform, occurred in more than 1 percent of the samples.
