Humans largely influence the factors that determine water quality, as they depose off their waste in water and add all kinds of substances and contaminants that are not naturally present. We now know more than 70.000 water pollutants.

About 450 cubic kilometres of wastewater are carried into coastal areas by rivers and streams every year. These pollution loads require an additional 6,000 cubic kilometres of freshwater to dilute the pollution. This amount equals to two-thirds of the world's total stable run-off.

Public water supplies must meet or exceed certain standards. The kind of standards that are used differ for each country. Many public water supplies consistently supply water that is much better than the minimum standards.

Four litres (1 gallon) of gasoline can contaminate approximately 2.8 million litres (750,000 gallons) of water.

Groundwater supplies serve about 80% of the population, whereas up to 4% of usable groundwater is already polluted.

There are 12,000 different toxic chemical compounds in industrial use today, and more than 500 new chemicals are developed each year.

Over 70,000 different water contaminants have been identified.

Each day almost 10,000 children under the age of 5 in Third World countries die as a result of illnesses contracted by use of impure water.

Today, drinking water meets over a hundred different standards for drinking water quality.

The principal sources of contamination are associated with the post World War II chemical age.

If all new sources of contamination could be eliminated, in 10 years, 98% of all available groundwater would then be free of pollution.

Most of the world's people must walk at least 3 hours to fetch water.

Freshwater animals are disappearing five times faster than land animals.