This report provides information on the level and effectiveness of wastewater pollution control in industrial estates in four provinces of Vietnam. It finds low levels of wastewater treatment in many industrial estates in the areas surveyed and identifies significant negative effects on many rivers. It investigates why many estates and the factories that operate inside them have not invested in wastewater treatment plants. It also looks at why many companies (even those connected to treatments plants) choose not to comply with wastewater treatment legislation. Among the reasons for this poor performance are a lack of investment capital, poor law enforcement, low penalties for non-compliance and an inappropriate fee structure for wastewater treatment.