Around 30 percent of the world's freshwater is stored underground in the form of groundwater (shallow and deep groundwater basins up to 2 000 metres, soil moisture, swamp water and permafrost). This constitutes about 97 percent of all the freshwater that is potentially available for human use.
The total volume of water on Earth is about 1.4 billion km3. The volume of freshwater resources is around 35 million km3, or about 2.5 percent of the total volume. Of these freshwater resources, about 24 million km3 or 70 percent is in the form of ice and permanent snow cover in mountainous regions, the Antarctic and Arctic regions.
In developing countries, 70 percent of industrial waste is dumped untreated into waters where they pollute the usable water supply.
The food sector contributes respectively 40 and 54 percent to the production of organic water pollutants in high-income and low-income countries.
Increases in fertilizer use for food production suggest a 10-20% global increase in river nitrogen pollution
Projected increases in fertilizer use for food production and in wastewater effluents over the next three decades suggest there will be a 10-20 percent global increase in river nitrogen flows to coastal ecosystems.
Many industries – some of them known to be heavily polluting (such as leather and chemicals) – are moving from high-income countries to emerging market economies. Despite improvements in some regions, water pollution is on the rise globally.
Up to 90 % of wastewater in developing countries flows untreated into rivers, lakes and highly productive coastal zones, threatening health, food security and access to safe drinking and bathing water.
Over 80 per cent of wastewater worldwide is not collected or treated, and urban settlements are the main source of pollution.