Fig. 5. Relation between volatile organic compounds (VOCs) (below and above the water table) in multilayer sampler 2 (MLS-2): (a) TCE (trichloroethylene) vs. PCE (tetrachloroethylene); (b) 1,1-DCE (1,1-dichloroethylene) vs. cis-1,2-DCE (cis-1,2-dichloroethylene); (c) TCE vs. cis-1,2-DCE.