In the Antelope Valley, drilling deep wells for water faces myriad problems
Posted by: Aqua Blog Maven on July 13, 2008 at 11:45 amFrom the Antelope Valley Press:
Antelope Valley may be sitting on 52 million acre-feet of water, enough to cover the Valley floor 30 feet deep. Enough, some say, to quench the needs of a growing population for 300 years, maybe more. But at what cost?
Sinking wells thousands of feet deep to reach the deepest water means higher pumping costs, and also draws up water more likely to be contaminated with naturally occurring arsenic and other substances.
In addition, pumping more groundwater than is replenished by rainfall or other sources can result in subsidence: a slow compaction and sinking of the earth’s surface, which can damage buildings and roads and permanently reduce the water storage capacity in the Valley’s aquifers - underground layers of rock and sand that hold water in their pores.
“There will always be water in the aquifer,” said Adam Ariki, Los Angeles County Waterworks assistant deputy chief. “If we extract all of it … the soil’s going to crash on us and we’re all going to sink.”
However, water officials, farmers and others disagree about how much water can be safely pumped from wells without damaging the aquifers and leading to subsidence. Estimates vary from 30,000 acre-feet to as high as 120,000 acre-feet, Ariki said, but most people seem to accept a range of 70,000 to 80,000 acre-feet. (An acre-foot equals 325,851 gallons, enough to supply an average Antelope Valley household for a year.)
If water districts, farmers and other well owners collectively agree to pump about 90,000 acre-feet per year, it will be equivalent to the amount returned to the groundwater basin from rain and manmade activities, Ariki said. “Logically the amount should be equivalent to how much water is being put in the groundwater basin,” he said.
But farmer Gene Nebeker, a former water-quality official, says: “Nobody really knows how safe the yield is, until we take better data over a period of time.”
Accessing the water requires drilling deeper wells and requires more electricity to pump the water out. The deeper water in the aquifer is of poorer quality, of a higher salinity, and possibly tainted with arsenic. Read more from the Antelope Valley Press by clicking here.
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