The third international workshop of the Project BEST was arranged in Toila, Estonia. The workshop concentrated on hazardous substances in waste water and their effects on treatment efficiency in municipal sewage treatment plants, and utilization of sludge. Current recommendations and legislation regarding industrial waste water treatment were also covered. The workshop presented good examples of cooperation methods and technical solutions used to manage and pre-treat industrial waste waters. The panel discussion in the workshop brought up suggestions on regional targets, priorities and measures in industrial waste water management sector for updating of the BSAP segment on hazardous substances.