EP 1110-1-27
27 Jan 00
3-4. Water-Level Data
a. General use of water-level data. Water-level data, combined with flow data, can be used to chart
changes in well specific capacity (and aquifer and well loss) over time. The longer and more
representative the water-level history, the more reliable the trends that can be drawn from the data.
b. Internal pumping/recharge well levels. Except when static, these levels only reliably reflect the
dynamics inside the well itself. Pumping output flow divided by the pumping (or injection) dynamic level
provides specific capacity (Section 2-2). This calculation should also be made over time. As with the
source data, the longer and more representative (seasonal, site pumping pattern) the specific capacity
history, the more likely that valid trends can be drawn.
c. Comparisons of water levels. Pumping/injection water levels in wells typically differ
(sometimes dramatically) from levels outside the casing. For direct comparison with aquifer loss and well
loss calculations (Section 2-2) and routine monitoring, these differences can be used to narrow down
Whether a change in pumping water level reflects a "regional" (site) trend.
Where clogs are occurring.
(1) Pumping or injection dynamic level to filter pack piezometer comparisons are used to
determine whether or not clogging is in the screen and filter pack. Installation of in-screen and satellite
rehabilitation wells facilitates this monitoring (Section 5.4 and Alford and Cullimore 1999).
(2) Pumping or injection dynamic level to area monitoring well comparisons are used to
determine if clogging is occurring in the screen and filter pack vicinity, or whether a change in pumping
water reflects change at the "regional" scale.
(3) Unit-specific piezometer levels are used to determine what changes are occurring in the
contributions by multiple units to a well.
3-5. Piezometric Data
Piezometric data provide water levels outside the immediate casing and pumping influence of a well.
Piezometers (water-level monitoring wells) offer information on the response of a producing or accepting
unit to change induced by site activities in addition to larger scale effects (e.g., changes in water table). As
with pumping and recharge wells, the reliability of water-level response in monitoring wells depends on
the wells' original design, development, and maintenance. A Standard Guide to procedures for this
purpose has been published by ASTM (D 5978).
3-6. Electrical (Power) Data
Power component (V, A, φ) data (Section 2-7) charted over time provide a history of motor and power
system changes. Historically, power problems may be the most common source of well problems. Power
supply consistency is sometimes suspect, especially with φ imbalance. A history of φ imbalance data can
provide the evidence needed to take well system power source problems to the power supply for
correction.
of the quality of power supplied and can provide ideas on what changes may be necessary.
3-2
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