Evaluating Well Data Provided by Engineers and Determine if Well Site is Suitable
for Military Operations. When surface water supplies are inadequate or unusable, develop ground
water supplies. Subsurface or ground water is water existing below the earth's surface. In most regions
the ground is saturated with water to a depth that depends largely on the type of rocks and soil, the
amount of rainwater, and the topography of the land. This is the water table. The water table is not a
level surface, but it is irregular and reflects the surface features, rising high under the hills and falling back
low under flat areas.
Wells are classified into five types, according to their method of construction: dug, bored, driven, jetted,
and drilled. Before a well is pumped, the depth from the ground surface to the water level is called the
static level. After several hours of pumping at a constant rate, the water level stabilizes itself at a lower
level than the static level. This is called the pumping level or the dynamic water level for this rate of
pumping. The distance that the water is lowered by pumping is called drawdown. When operating a well
along coastal areas and on islands, there is the danger of saltwater intrusion into ground water sources.
Pumping tests are made on wells to determine their capacity and other hydraulic characteristics and to
secure information so that permanent pumping equipment can be skillfully selected and used.
Preliminary tests of wells drilled as test holes are sometimes made to compare the yielding ability of
different water-bearing formations or different locations in the same formation. Use this information as a
basis for selecting the best site for a supply well and the aquifer in which it should be completed.
Engineer well drilling units conduct these tests. Review well data with engineer personnel and determine
suitability of the well.
1-22
QM 4924
Previous Page
