An adequate freshwater supply is a basic necessity for the development of civilization. For thousands of years development has occurred in towns and villages along a rivers edge. These communities grew from the need for water for hygiene, consumption, live stock and transportation. Only in the past 200 years have there been major developments in water treatment.
Prior to 500 BC
In ancient times, clean water meant clear water. Visual observation of water’s clarity was the only indicator of how untainted a water source was. Early treatment included the addition of chemicals to improve the taste and appearance of the water. In Egypt, the use of alum to remove suspended solids in the water was first documented. Mayan civilizations developed remarkably elaborate hydraulic systems for water distribution. Ancient Hindu writings, almost 4,000 years old, directed the people to “heat foul water by boiling and exposing to sunlight and by dipping seven times into a piece of hot copper, then to filter and cool in an earthen vessel.”
500 BC – 1000A.D.
The Greek physician Hypocrites stated that “water contributes much to health.” His recommendations were to select the healthiest water source, rather than purifying inferior sources. The Romans utilized extensive aqueduct systems to transport in the purest water from far away. These open aqueducts benefited from the sun's rays acting as a mild disinfectant on the water. No other treatment was provided. In the 8th century, Arabian alchemist Geber distilled water for purification. Avicenna, a Persian physician recommended travelers to strain water through a cloth or boil their water.
1000 – 1500 AD
Little advancement was made during the Middle Ages toward an understanding of water treatment and its importance to public welfare.
The British philosopher and scientist Sir Francis Bacon applied the ‘scientific method,’ in his approach toward water purification. Empirical observations and conclusions were produced in his 1627 publication which detailed thousands of experiments detailing water purification methods, such as percolation, filtration, boiling, distillation and coagulation. In 1684, Dutch scientist Antony van Leeuwenhoek published sketches of common forms of bacteria that was observed under his simple microscope.
With the Age of Enlightenment came many new discoveries with practical applications to benefit mankind. In 1703, a Parisian scientist Phillippe La Hire presented a plan to provide a sand filter and rain water cistern for every household. In addition, he observed that groundwater was rarely contaminated. In 1746, Frenchman Joseph Amy was granted the first patent for a filter design. James Peacock, a British architect received the patent for a three-tank, upward-flow backwash filter in 1791.
In 1804, Paisley, Scotland became the site of the first filter facility to deliver water to an entire town. Two years later in Paris, a large water treatment plant using the Seine River as source water opened. This plant treated water by settling for 12 hours, sponge prefilters and main filters. The filters consisted of coarse river sand, clean sand, Fountainebleau sand and pounded charcoal. Pumps were driven by horses that worked in three shifts to move the water through the system. This plant was in service for 50 years. Customers in Glasgow, Scotland received the first filtered water piped directly to customers. The first sand filtration plant in the US was built in Richmond Virginia in 1832.
A London typhoid epidemic in 1850 is believed to have been caused by bad water. The 1855 cholera outbreak in London was found to be caused by sewage contamination of a pump well, known as the Broad Street Pump Affair.
In the United States, the construction of new waterworks facilities increased significantly after the Civil War ended. Slow sand filters were introduced in Massachusetts in the mid-1870s. Major developments in bacteriology provided further advancements in water treatment technology. Robert Koch, a German physician and microbiologist proposed the “Germ Theory of Disease, ” which postulated that some microorganisms were responsible for disease. Joseph Lister, a Scottish surgeon gave further advancements in the understanding of disinfecting.
By the 1890s water filtration had gained recognition; those communities whose water purification included this step had fewer outbreaks of typhoid than other communities. Technology improvements included the development of rapid sand filter that were mechanically driven and could produce higher volumes of treated water, as well as the breakthroughs in disinfection with chlorine and ozone. The Louisville Kentucky Water Company combined coagulation with rapid sand filtration, reducing both turbidity and bacteria.
In 1894, Water works engineer George Warren Fuller suggested the standardization of bacteriological testing, to enable the comparison of results. The result was an 1897 report that has now evolved into the Standard Methods text used today.
In 1914, the US Department of Treasury promulgated the country’s first drinking water bacteriological standard, a maximum level of 2 coliforms per 100ml. This regulation was created under the 1893 Interstate Quarantine Act and was limited to only interstate systems in an effort to prevent the spread of disease from one state to another. Chloramination, a disinfection technique, was first used in 1917. Abel Wolman and L.H. Enslow demonstrated that chlorine consumption varied dramatically depending on the characteristics of the water. The 1920s and 1930s substantially eliminated epidemics of major waterborne disease.
In 1942, the US Public Health Service adopted drinking water standards that included bacteriological sampling in the distribution system and maximum permissible concentrations for lead, fluoride, arsenic, and selenium. Hexavalent chromium was added four years later. These standards (except for the interstate coliform rule) were unenforceable until the Safe Drinking Water Act of 1974. This regulation provided for the process currently used to set health based maximum contaminant levels (MCLs) and the aesthetically related secondary MCLs.
2000 and Beyond
Today the process of filtration and disinfection are still in use, but are continually being refined with breakthroughs in new technology and knowledge.