(WESTERVILLE, OH — January 20, 2012) As drought or near-drought conditions stress southern states from coast to coast, people dependent on water wells may need to assess or address the impact on their water supplies, the National Ground Water Association said today.
“There are some simple diagnostic steps well owners can take if they experience problems with the productivity of their well,” said Cliff Treyens, NGWA director of public awareness. “An accurate diagnosis of a problem is key to an effective solution.”
Here is a brief assessment of drought conditions as of mid-January in the southern United States (moving west to east) from the National Integrated Drought Information System:
Following is some guidance from NGWA for well owners in areas of water scarcity.
When a well goes “dry” due to drought, it means the water table drops below the level of the pump in the well, or may drop below the bottom of the well. It’s like putting a straw into the top of a glass of water. If you drink and don’t lower the straw toward the glass bottom, you will end up sucking air. There is still water in the glass, but the straw is sitting above it.
The type of aquifer from which you are drawing water also can make a difference. Aquifers are water-bearing geologic formations underground.
Some aquifers are continually replenished by rainwater that infiltrates the ground. Depending on the severity of drought, it can take multiple soaking rains over a period of time to replenish an aquifer that has experienced a significant lowering of the water table.
Wells typically do not go dry all at once. Rather, they slowly get worse due to lack of recharge. Often older wells that were drilled only into the top of an aquifer and did not penetrate the full thickness of the aquifer are the wells most likely to fail first.
However, some aquifers are sealed off from surface water replenishment due to an impermeable layer of rock. A well drilled into such an aquifer is drawing from a limited source of water which, when depleted, will not be replenished in the near future. In some cases, such aquifers may take hundreds, or even thousands of years to replenish, and in these cases the groundwater is considered being “mined”.
Even though you may be in an area of water scarcity, your well’s loss of productivity may be due to reasons other than a lowering of the water table. A qualified water well system contractor can determine the cause.
When the problem is not a lowered water table, a well sometimes can be rehabilitated to yield substantially more water. Often various techniques can be applied to the well screen or surrounding geology to enable water to flow more freely into the well.
Other times, when the problem is a lowered water table, the well can be drilled deeper to extend its depth back below the water table. Deepening a well, however, does not guarantee that you will get more water. The size and condition of the well casing will dictate if a well can be drilled deeper. Have a reputable contractor inspect your well for its condition and viability to be drilled deeper.
In some cases, a new well drilled in a different location may be necessary to provide a more reliable water supply. A qualified water well system contractor can determine which option is best and explain why.
One aspect of using water wisely is not wasting it. Many people in drought areas are resourceful in cutting back on water use, recycling water, or harvesting water to meet certain needs. Well owners can learn more by going to NGWA’s Web site especially for well owners, www.wellowner.org.
Another aspect of using water wisely involves having a sufficiently sized tank (or tanks) so that stored water can be delivered while the well is refilling. Even a low-producing well can be adequate if there is sufficient storage. Another way to modify a well system so marginal wells can continue to provide sufficient water is to install transducers in the well. These monitor water levels and signal the pump to activate when adequate water is available.
Another strategy is to schedule water intensive activities such as clothes washing, dishwashing, and showers across the day so they are not occurring simultaneously. This allows the well and/or storage tanks to refill in order to meet the next need.
Learn more about all aspects of water well ownership at www.wellowner.org.
NGWA, a nonprofit organization composed of U.S. and international groundwater professionals — contractors, equipment manufacturers, suppliers, scientists, and engineers — is dedicated to advancing groundwater knowledge. NGWA’s vision is to be the leading groundwater association that advocates the responsible development, management, and use of water.
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National Ground Water Association
601 Dempsey Rd.
Westerville, OH 43081
(614 898.7791 outside the US)
fax 614 898.7786