Water distribution network study on fate and transport of contaminant and its decontamination by Pilot-Scale Tests

Population growth due to migration is causing tremendous pressure on city infrastructure. Providing safe drinking water to the residents still remains a challenge in the cities of developing the world. To meet the ever-increasing demand for drinking water, government agencies employ intermittent water supply schemes. Under this scheme, water is distributed to the residents intermittently for few hours in a week. Due to the intermittent water supply, most of the time the pipelines in the distribution network are either empty or partially filled. These conditions make the water in pipelines vulnerable to cross-contamination via sewage and contaminated groundwater. Maintaining free chlorine of 0.2 mg/l in piped water till consumers end is supposed to address the issue of cross-contamination. But as water travels within the pipelines drops, most of the free chlorine is lost due to reaction with biofilms and bulk organic carbon. Thus, it becomes very important to study the kinetics of chlorine disinfection in the distribution network. Various factors that impact the chlorine decay rate have been well studied and investigated in the developed world. However, there are very few studies that reflect the conditions pertaining to water distribution networks in the developing world. The objective of this project is to study the chlorine disinfection rate for different types of water, pipe material under different flow conditions (laminar and turbulent flow). The results of the study would help government agencies to control and monitor free chlorine in pipe water and eventually provide safe drinking water to consumers.