Multivariate plots were utilized to create fingerprints of aromatic hydrocarbon residues in ground water. The technique allows hydrogeologists to distinguish between residues of benzene, toluene, ethyl benzene, and total xylenes originating from ground water contact with petroleum in natural deposits and refined petroleum waste products. Examples were taken from deep-well injection of refinery wastes, natural petroleum deposits, municipal and industrial landfill leachates, coal tar and creosote contaminated waters, and varnish industry contaminated ground water. The data were plotted from ASCII files generated through either Lotus 123™ or a database (The Manager™) report program, using a simple Fortran interactive program with Plot88™ subroutines.