The purpose of the study was to develop and utilize sampling, analytical and predictive methods to assess the fate of selected chemicals in a full-scale wastewater treatment facility by monitoring a wastewater treatment facility which received wastewater from a large petrochemical plant. The treatment facility consisted of (1) neutralization, (2) equalization, (3) aerated stabilization and (4) UNOX treatment. Eight chemicals were monitored. These included four volatile chemicals (benzene, toluene, 1,2 dichloroethane, and ethyl benzene) and four semi-volatile chemicals (tetralin, 2-ethyl hexanol, 2-ethyhexylacrylate, and naphthalene). Extensive sampling of the air, water and sludge streams around each of the wastewater treatment unit operations was conducted for a three-week period during August 1983. (Copyright (c) Chemical Engineering Progress 83(11): 46-54, November 1987.)