Sewage will continue to be a problem, as long as there is a human population to produce it. In the coming years, the total amount of sewage discharged into the rivers and coastal waters in tropical Asian countries will progressively increase and add to the pollution already affecting parts of the region. Clearly in view of the current data and evidence of the implications of sewage pollution, this paper highlights the necessity of the continuation of water treatment system improvement.Continuous assessment of the extent of sewage pollution in rivers and coastal waters can indicate the level of improvement brought about by the upgraded sewage systems. Therefore, further research concerning sewage and other anthropogenic pollutants is critical to reduction of health risks in tropical Asia.