ASSESSING WATER PURIFICATION PROCESSES THAT HELP LOWER TOTAL COLIFORM LEVELS

Total coliforms can be a helpful indicator of biological health of water bodies in both urban and rural areas. They have also been found to cause elevated levels of gastro-intestinal diseases, such as diarrhea in children, particularly in developing countries. Water purification processes that involve the use of filtration, such as slow sand/biosand filtration, can potentially reduce total and fecal coliform levels in water bodies. These filtration systems can be adapted for use in both stormwater treatment as well as drinking water treatment. In this study, we investigated how sand can reduce total coliform concentrations in water. The total coliform and E. coli samples were collected from urban streams and stormwater retention ponds in the metropolitan Charleston area. These water samples were passed through packed columns at different flow rates to measure the efficiency of coliform removal. Finer grades of sand and slower flow rates are expected to be more effective at removing total coliforms from the samples. By utilizing porous media specifically in highly trafficked areas, total coliform contamination can be mitigated, reducing the risk of disease while integrating improved stormwater runoff management. This process will be applied as part of the establishment of a low impact development in a developing country through the Peace Corps Master’s International Program.