Answers:
- Groundwater is the water held in the interconnected openings of saturated rock beneath land surface. (Hydrogeologic Menu Section)
- 1% of the earth's water is available fresh water; 2/3 is groundwater
- 9 out of 10 public water systems use wells
- Public Water System
- 4.2 trillion gallons of water falls on the US each day
- No, the volume of water is constant on the earth, it just changes form or moves
- The water budget is the amount of water received annually for an area. The US water budget would cover the entire country in 30 inches of water
- Only 0.1 of an inch goes back into the groundwater. We should keep this in mind when we are thinking about irrigation, well use, etc.
- 450 billion gallons of water are withdrawn each day. It takes less than 10 days to use the annual amount of precipitation. About ¾ of this water is returned.
- 28% of the population lives in the west and they use 80% of the nation's water
- The saturated zone is the term
- An aquifer is a rock unit that will yield water in usable quantities to wells or springs
- Unlike fast moving surface water, groundwater will flow several inches to several feet a year. (Water Movement in Aquifer Section)
- Recharge can be affected by: characteristics of soil, plant cover, slope, water on the surface, amount of rainfall, presence of confining layers and aquifers (How Aquifers are Replenished Section)
- Downdraw is the vertical drop in height between water level in a well before pumping and the level during pumping. It helps ensure continuous supply of water, helps identify overlying land for management purposes, and could show change in a water source (Groundwater and Wells Section)
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Groundwater