Anion-exchange liquid chromatography with detection via both particle beam mass spectrometry (electron impact and negative chemical ionization) and UV absorption spectrophotometry is used to characterize target and nontarget compounds in lyophilizates from three Stringfellow hazardous waste leachates-upstream, downstream, and a charcoal-treated mixture. Lyophilization retains essentially all the organic carbon, which is 513, 46.8, and 453 ppm, respectively. Charcoal treatment removes priority pollutants but not most the total organic carbon (TOC), which is primarily highly polar, nonextractable, and nonpurgeable material. Besides 4-chlorobenzenesulfonic acid (from 53 to 69% of the TOC), seven additional major aromatic sulfonic acids are tentatively identified. All are sulfonated and chlorinated aromatic byproducts probably from DDT manufacture. Relative ratios of the aromatic sulfonic acids are not significantly altered by the charcoal treatment. The potential impact upon human health of these highly polar halogenated organic compounds is unknown. © 1990, American Chemical Society. All rights reserved.