The History of Filtration

How filtration trickled into civilization

Since ancient times, civilizations have understood the importance of having a sufficient water supply. It was often regarded as more important than having food. Back then, however, the only way to determine water quality was through aesthetics - the water’s turbidity (cloudiness), taste or smell. Most treatment processes only addressed these.

Over time, a greater understanding of contaminants emerged, and filtration systems became more advanced.

Purifying History:

4,000 B.C. The earliest methods of water treatment are recorded. Water is filtered through charcoal, exposed to sunlight, or strained.

1,500 B.C. The ancient Egyptians use the chemical alum to settle suspended particles out of water. This method, known as flocculation, is still commonly used today.

1700s. Filtration is introduced as an effective way of removing particulates.

Early 1800s. Slow sand filtration becomes common in Europe.

1855. Dr. John Snow, an English epidemiologist, proves that an outbreak of cholera in London was caused by a sewage-contaminated public well, and was thereby a waterborne disease. A greater understanding of water contaminants emerges, particularly of contaminants not visible to the naked eye.

Early 1900s. Scientists discover that disease-causing pathogens in public water supplies are often accompanied by high turbidity. Reducing turbidity becomes a priority, and some U.S. cities begin using slow sand filtration.

1908. Disinfectants, including chlorine, are used for the first time in Jersey City, New Jersey. These offer the greatest reduction in waterborne disease outbreaks. Other disinfectants, such as ozone, are used in Europe, but not in the U.S. until decades later.

1914. The Federal Government begins regulating drinking water. The U.S. Public Health Service sets standards for the bacteriological quality of drinking water. The standards only apply to contaminants capable of causing disease, and only to water systems for interstate carriers such as ships, buses, and trains.

1962. The Public Health Service begins regulating 28 substances in drinking water.

1969. A Public Health Service study shows that no more than 60% of the water systems comply with the Health Services standards. Major deficiencies exist in more than 50% of the small Water Districts; especially those with fewer than 500 customers, they are the worst.

1974. Congress enacts the Safe Drinking Water Act (SDWA). Revisions to the Act are made in 1986 and 1996.