The role of filtration in preventing waterborne disease

Filtration is an important treatment process in the removal of pathogenic microorganisms and in the prevention of waterborne disease. Historical records indicate that filtration was responsible for reducing death and illness from waterborne disease in 1871 in Germany and for reducing morbidity and mortality from typhoid fever in the United States in the late 1800s‐early 1900s. After studying recent outbreaks of waterborne disease, the authors attribute the causes of these outbreaks to the lack of filtration or to faulty operation and maintenance of the process. Pilot‐plant data and results from full‐scale operation are presented to illustrate the effectiveness of various forms of filtration in reducing microbial populations to concentrations that are easily controlled by disinfection.