Initial assessment of industrial structure and wastewater characteristics is important for successful environmental management in an industrial district. This is particularly important for the cases where highly polluting industries such leather tanners are of concern. In this study, Biga Leather Tanners District was evaluated. The process characteristics, wastewater amounts, wastewater quality and their variations with time were defined. The district housed 46 tanning plants, processing mainly sheepskins with a total capacity of 66.5 tons skin per day. Process profile was prepared and checked With experimental data. Chemical treatability experiments were conducted to assess the pretreatment alternatives. Chemical precipitation preceded by catalytic air oxidation of sulfide was found to be an optimum pretreatment system providing COD and TKN removals up to 80% together with complete chromium removal, Results of the study were evaluated and discussed. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved.