Yoshiaki Tsuzuki
In the fields of wastewater treatment planning, institutional and governance aspects are sometimes emphasised in developing and middle-developed countries. This paper summarises some important technical issues for the stakeholders of municipal wastewater treatment and water environment management. Pollutant removal efficiencies at wastewater treatment plants (WWTPs) are important but effluent water quality is sometimes emphasised. To achieve high pollutant removal efficiencies, maintaining a certain level of pollutant concentrations in the influent, or “Not Too Little” pollutant, is necessary. The second point is pollutant discharge from the river catchment should be “Not Too Much”. Excess and rapid pollutant discharge increase in the catchment results in high costs and lengthy time periods for the river water environment to recover the original water environment conditions. The third point is that developing and middle-developed countries can use a "shortcut" or technological bypass by use of existing hard and soft measures to facilitate environmental improvements. This can be done with appropriate financial mechanisms. Pollutant discharge per capita (PDC) and pollutant load per capita flowing into water body (PLCwb) are effective and efficient indicators that can be used to address these three concepts.