In most cases, groundwater is the safest source of quality water than surface or reservoir water because it may not require any treatment before distribution to the public. Besides naturally occurring water pollutants such as arsenic or radon contamination which pollutes groundwater or surface water, human activities such as industrial wastes, runoffs, pesticides applications etc increases the risks of groundwater and surface water pollution (Moeller, 2011). In all cases of public water supply, water treatment is required before surface water is distributed to the public. In contrast, groundwater is a very clean water source, and in many cases are distributed to the public without treatment, unless if there is known contamination problem in the area in question. In fact, in the US, there are about 160, 000 public water supply, half is surface water, and the other half is groundwater, and about half of the groundwater are distributed to the public without treatment (Moeller, 2011).

Improving water quality started thousands of years ago. First recorded event of improving water supply was in fifteen century B.C.E in Egypt before the Common Era (Moeller, 2011). Hippocrates, the father of modern medicine facilitated the essential links between water, air and the environment to individualism (Moeller, 2011). The Romans used the Greek’s public health policies to design the first aqueduct system and established policies/regulations prohibiting malicious water pollution (Moeller, 2011). In each recorded cases, there is a clear understanding of the consequences of poor water quality or water contamination.

Unfortunately, each generation or Era had limited understanding of the best way to purify water yet each consequent generation had improved methods on water purification systems. There are many steps involved in water purification or at least an attempt for a better water purification system. The fact that water is filtered, heated, chlorination and fluoridated does not make the water safe for drinking, and some of the additional improved methods of water purification were not applied by prior Era.

Over the years, chlorination has been the common end process in water treatment. Fortunately, scientists and epidemiologists discovered that chlorination reacts with hydrocarbons or organic compounds in water, and thus producing chlorinated hydrocarbons and phenols, compounds known as carcinogens (Moeller, 2011). In addition, scientists also found that groundwater with high concentrations of fluoride causes dental fluorosis (Moeller, 2011). Based on these facts, improving the water treatment methods are required to avoid residual byproducts or toxic components resulting from water treatments.

Ozone and ultraviolet radiation (UV-radiation) were implemented to remove or inactivate viruses or organic compounds (Moeller, 2011). However, this additional steps deserve continuous epidemiological surveillance to ensure their safety. The challenge with water treatment is that thousands of chemicals with unknown health impacts dissolves in water. Therefore, the process of water purification continuously needs active and ongoing improvement in water treatment methods as scientists discover molecules or by-products with negative health impacts either as a result of water-treatment processes or other water contaminants.

On a global scale, one out of eight people, which is about 1 billion people lack access to clean and safe water and more than 3 million, mostly children die annually for lack of clean water or water related health problems, and about 2.5 billion are without adequate sanitary facilities (Moeller, 2011). Consequently, lack of clean water provides a medium for unsanitary environments, which leads to the spread of communicable and infectious diseases. In the US alone, about 350 billion gallons of water are used on a daily basis, and the cost of maintaining public water facilities in the US is about $3.5 billion annually (Moeller, 2011). In the continent of Africa, about 80% of water borne diseases are associated with the use of unclean water.

Most global water supply facilities follow similar guidelines for water purification and treatment. However, the current methods do not remove all contaminants or pollutants. In the US, the environmental protection agency (EPA) required that water treatment distributed to the public must have zero microbial organisms, but other pollutants or known chemical contaminants have different allowable concentrations (Moeller, 2011). In general, water treatment process produces about 250 cubic feet sludge (3 large trucks loads) per millions of gallons of water produced (Moeller, 2011).

As stated earlier, organic chlorination and residual chlorine in drinking water is a problem. One of the ways to avoid this by-product contamination from water treatment is the use membrane filtration methods after chlorination. Additional filtration of chlorinated water with membrane filtration system will remove chlorinated hydrocarbons. Alternatively, water plants can implement ozone and UV radiation treatments instead of chlorination. However, science innovations or methodologies are not immune from blind-spots in all areas. Hence, there are possibilities that ozone or UV-radiation inactivation process may produce inert toxic by-products not yet known to scientists. Prion presence in food, and its potency in causing disease is an example of evolution in science, and changes in the characteristics of pathogens. The most important aspect of all good effort is being cautious and anticipating the unanticipated. Most importantly, implementation of active surveillance programs is essential in addressing problems when problem arises, quickly recognized and timely fixed.

Reference

Moeller, D.  W. (2011). Environmental health (4th ed.). Harvard university press, Cambridge  Massachusetts