History of drinking water treatment

History of drinking water treatment Humans have been storing and distributing water for centuries. Before, when people lived as hunters/ collectors, river water was applied for drinking water purposes. When people permanently stayed in one place for a long period of time, this was usually near a river or lake. When there were no rivers or lakes in an area, people used groundwater for drinking water purposes. This was pumped up through wells. When the human population started growing extensively, the water supply was no longer sufficient. Drinking water needed to be extracted from a different source. About 7000 years ago, Jericho (Israël, figure 1) stored water in wells that were used as sources. People also started to develop drinking water transport systems. The transport took place through simple channels, dug in the sand or in rocks. Later on one also started using hollow tubes. Egypt used hollow palm trees and China and Japan used bamboo strunks. Eventually one started using clay, wood and even metal. In Perzia people searched for underground rivers and lakes. The water went through holes in rocks into the wells on the plains. Around 3000 B.C., the city of Mohenjo-Daro (Pakistan) used a very extensive water supply. In this city there were public bathing facilities with water boiler installations and bathrooms. In ancient Greece spring water, well water, and rainwater were used very early on. Because of a fast increase in urban population, Greece was forced to store water in wells and transport it to the people through a distribution network. The water that was used was carried away through sewers, along with the rainwater. When valleys were reached, the water was lead through hills under pressure. The Greek where among the first to gain an interest in water quality. They used aeration basins for water purification. Figure 1: bathing residence in Mohenjo-Daro, Pakistan The Romans were the greatest architects and constuctors of water distribution networks in history. They used river, spring or groundwater for provisioning. The Romans built dams in rivers, causing lakes to form. The lake water was aerated and than supplied. Mountain water was the most popular type of water, because of its quality. For water transport the aquaducts where built. Through these aquaducts water was transported for tens of miles. Plumming in the city was made of concrete, rock, bronze, silver, wood or lead. Water winnings were protected from foreign pollutants. Figure 2: a Roman aquaduct After the fall of the Roman empire, the aquaducts were no longer used. From 500 to 1500 A.D. there was little development in the water treatment area. In the Middle Ages countless cities were manifested. In these cities wooden plumming was used. The water was extracted from rivers or wells, or from outside the city. Soon, circumstances became highly unhygenic, because waste and excrements were discharged into the water. People that drank this water fell ill and often died. To solve the problem people started drinking water from outside the city, where rivers where unpolluted. This water was carried to the city by so-called water-bearers. The first drinking water supply that supplied an entire city was built in Paisley, Scotland in 1804 by John Gibb, in order to supply his bleachery and the entire city with water. Within three years, filtered water was transported to Glasgow. In 1806 Paris operated a large water treatment plant. The water settled for 12 hours, before it was filtered. Filters consisted of sand and charcoal and where replaced every six hours. In 1827, the Englishman James Simpson built a sand filter for drinking water purification. Today, we still call this the number one tribute to public health.