SAFE DRINKING WATER

Clean drinking water is a basic human need. Unfortunately, more than one in six people still lack reliable access to this precious resource. The problem is particularly acute in the developing world.
Water is a fundamental human need. Each person on Earth requires at least 20 to 50 liters of clean, safe water a day for drinking, cooking, and simply keeping themselves clean.
Polluted water isn’t just dirty—it’s deadly. Some 1.8 million people die every year of diarrheal diseases like cholera. Tens of millions of others are seriously sickened by a host of water-related ailments—many of which are easily preventable.
The United Nations considers universal access to clean water a basic human right, and an essential step towards improving living standards worldwide. Water-poor communities are typically economically poor as well, their residents trapped in an ongoing cycle of poverty.
Education suffers when sick children miss school. Economic opportunities are routinely lost to the impacts of rampant illness and the time-consuming processes of acquiring water where it is not readily available. Children and women bear the brunt of these burdens.
Water is obviously essential for hydration and for food production—but sanitation is an equally important, and complementary, use of water. A lack of proper sanitation services not only breeds disease, it can rob people of their basic human dignity.
The state of drinking water supplies can be quantified by four important characteristics: quality, quantity, reliability, and cost.
The World Health Organization (WHO) and various national agencies have drinking water quality standards that specify the acceptable microbial, chemical, and radiological characteristics of safe drinking water.
Excessive amounts of microbes or chemicals derived from human and animal wastes, agricultural runoff, industrial chemicals, and even natural pollutants, make some water unsafe to drink and cause water-related diseases. If water sources are not protected, or are unexpectedly contaminated for any reason, the quality of drinking water suffers.
Contamination can occur at the source of the water both at the surface and in the ground. Once the water is in the distribution system, there are additional opportunities for drinking water to be contaminated. If pipes are not successfully protected from contaminants, the quality of drinking water suffers. Improper storage can also result in unsafe drinking water.
Water sources may be variable and unreliable. Water reliability may vary by season, by year, and by location. In some areas, the rains fall mainly during the monsoon seasons, leaving dry conditions at other times of the year. Large scale climate variability such as the influence of El Niño and La Niña may mean that one year is wet while the next is dry.
The quantity of water in rivers and lakes can also be unreliable. Some rivers only flow during part of the year, leaving a dry riverbed and no local source of water. Rivers and lakes can also dry up from overuse.
At the household level, the reliability of the distribution system that provides water to the people is critical to maintaining quantity. If pipes are broken or only intermittent service is available, the quantity of drinking water suffers.
Often the unreliability of surface water can be off set by the use of groundwater. However, if ground water sources are depleted too rapidly, or are not being successfully recharged by either natural or man-made processes, the quantity of drinking water suffers.