A Bayesian method to estimate proportional payments of users in a wastewater treatment plant

A simple Bayesian method to estimate proportional payments for using or constructing a wastewater treatment plant is presented. The method addresses the usually unknown individual participation in global pollution, of municipal and industrial wastewaters that are normally discharged into the same collecting pond. The individual contributions are calculated from the discharged volume of each source and its pollution percentage in the wastewater volume previous to the disposal. According to the method presented here, the costs in building and/or running the plant can be covered by proportional individual payments based on the individual contributions, in a more even way. The simplicity of the model allows to assess different strategies for the participants in a wastewater treatment system. A real case study in the Izta-Popo National Park, located in the Mexican States of Puebla, Mexico and Morelos, is analyzed.