RESUMO
A tariff system has been set up for the largest wastewater treatment plant in South-East Asia, the Samut Prakarn Wastewater Treatment Plant south of Bangkok, which is currently under completion. Fully functional the plant will have a design capacity for 500,000 m3 per day and will service a combined residential and industrial area with approximately 600,000 residents and 2,300 factories. The tariff system, which includes a tariff model, is based on water consumption and BOD load. As background for setting the tariffs a comprehensive monitoring system including an industrial permitting system has been developed. The paper presents the background and rationale for setting up the system as well as the objective, scope and content of the tariff system and the industrial permit system. Further, the feasibility of introducing cost recovery systems, which is widely accepted in developing economies on the conceptual level and to some extent implemented at the legal and regulatory level, but has yet to be implemented at large, is discussed.