Water intended for human consumption

Drinking water, also known as potable water, is water that is safe to drink or to use for food preparation. The amount of drinking water required varies. It depends on physical activity, age, health issues, and environmental conditions. Americans, on average, drink one litre of water a day and 95% drinking less than three litres per day. For those who work in a hot climate, up to 16 liters a day may be required. Water is essential for life.

Typically in developed countries, tap water meets drinking water quality standards, even though only a small proportion is actually consumed or used in food preparation. Other typical uses include washing, toilets, and irrigation. Greywater may also be used for toilets or irrigation. Its use for irrigation however may be associated with risks. Water may also be unacceptable due to levels of toxins or suspended solids.

Globally, in 2015, 89% of people had access to water from a source that is suitable for drinking - called "improved water source". Nearly 4.2 billion had access to tap water while another 2.4 billion had access to wells or public taps. 1.8 billion people still use an unsafe drinking water source which may be contaminated by feces. This can result in infectious diseases, such as gastroenteritis, cholera, and typhoid, among others. Reduction of waterborne diseases and development of safe water resources is a major public health goal in developing countries. Bottled water is sold for public consumption in most parts of the world.

The amount of drinking water required is variable. It depends on physical activity, age, health, and environmental conditions. In a temperate climate under normal conditions, adequate water intake is about 2.7 litres (95 imp fl oz; 91 US fl oz) for adult women and 3.7 litres (130 imp fl oz; 130 US fl oz) for adult men. Physical exercise and heat exposure cause loss of water and therefore may induce thirst and greater water intake. Physically active individuals in hot climates may have total daily water needs of 6 litres (210 imp fl oz; 200 US fl oz) or more. The European Food Safety Authority recommends 2.0 litres (70 imp fl oz; 68 US fl oz) per day for adult women and 2.5 litres (88 imp fl oz; 85 US fl oz) per day for adult men.

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