The world is in the midst of a boom in groundwater use. The rate of extraction from aquifers more than doubled in the 40 years to 2000. It has continued to soar since then.
Professor Craig Simmons, who directs Australia's National Center for Groundwater Research and Training, says as much as 40 percent of humanity's total water supply now comes from underground. It is not only used for drinking, but is also needed to grow food and support many industries.
Yet international water scientists are warning of a growing threat to groundwater supplies from over-extraction and from pollution by farm fertilizers, pesticides and mining residues. They say that major aquifers in some countries will start to run low by 2030 unless immediate steps are taken to better manage the resource.