Comment: 01:39 - 02:47 (01:08)
Source: Annenberg/CPB Resources - Earth Revealed - 21. Groundwater
Keywords: "James Sadd", groundwater, water, irrigation, agriculture, industry, lake, river, "Earth's surface", pollution, geologist, soil, "surface water", replenishment, infiltration
Our transcription: Most people tend to take groundwater for granted, but, in fact, it's a tremendously valuable resource upon which most of us depend.
Over one half of the U.S. population relies on it for its drinking water supply.
Even more groundwater is used for irrigating agriculture, and its industrial use is growing every day.
Groundwater is valuable because it's plentiful and clean.
There's about 50 times more water underground, than in all the lakes and rivers on the Earth's surface combined.
And in many areas, especially those with dry climates, groundwater is the most abundant and economical source of water available.
And because it's filtered as it passes through the soil, groundwater tends to be less polluted than surface water.
But this valuable resource is now being threatened.
In some places, groundwater has been contaminated by industrial or agricultural pollution; in others, wells are extracting groundwater faster than it can be replenished.
Already this has caused severe economic and health problems in several areas of the world.
Consequently, there's an increasingly important role for the geologist to study the movement of water beneath the ground, and who can accurately predict the location and quantity of groundwater.
Geology School Keywords