EP 1110-1-27
27 Jan 00
b. Borehole camera survey. High-resolution borehole camera (still or video) surveys provide a
means of recording lithology and fracture features in open boreholes, in addition to construction features.
The camera provides depth-specific images for interpretation of lithologic features; for example,
noticeable changes in formation color and texture, water cascading into the hole through fractures, and
fracture orientations.
2-7 Pump, Flow Meter, Pressure, Electrical, and other Monitoring
a. Equipment and material choice importance in data gathering.
(1) Purpose. Meeting data-gathering goals requires apparatus that will provide the most accurate
possible measurements. The equipment should be reliable and not distort measurements. To achieve these
goals, the equipment should be well matched to the data-gathering needs and well operational
environment.
(2) Material choices. The choice of materials to be used in devices for pumping and injection well
performance is important to well system life and quality of service. For example, in most situations,
where metals are specified, they should be stainless steel or other materials resistant to corrosion in the
water being extracted. Materials should be specified based on analysis and experience under the
environmental conditions to be found in the system. This requires analysis of the geochemistry of the
fluid (Section 2-8) and comparison to the reactivity of materials proposed for use. This analysis should
consider biological fouling and corrosion predictions (Section 2-9) because biofouling routinely
introduces clogging and corrosive conditions where they might not occur in sterile fluids. Discussions of
the material choice decision-making process are provided in numerous references (e.g., EM 1110-2-1914,
EM 1110-1-4000, EM 1110-1-4008, and Powers, 1992; Borch, Smith, and Noble 1993; Smith 1995; and
McLaughlan 1996 in the open literature specific to well maintenance).
(3) System component capacity. Pumps should be sized to closely match the well capacity and
match the flow requirements and pressure head conditions in the system being supplied.
(a) Poor sizing affects performance adversely. Pumping well capacity can be established by step
testing (Section 2-2). Flow and head conditions may be calculated, allowing for any likely fluctuations.
Should as-built conditions differ from design conditions, pump selection should be reviewed to ensure
that it matches the as-built hydraulics.
(b) EM 1110-1-4008 provides guidance in pump discharge head calculations. Pump sizing then
can commence using standard ground water industry well pump sizing procedures. TI 814-1 provides
sizing calculation procedures for submersible and vertical turbine pumps typical of remediation extraction
wells. Powers (1992) provides design sizing methods for vacuum and ejector pump systems often
employed.
(c) Once hydraulic head and flow conditions are used to design an ideal pump, comparisons can
be made to pump capacity charts or pump curves generated by manufacturers and provided in the
Contract Submittals (TM 5 813-9). See also discussion in Chapter 9 concerning material choices.
(d) An important feature is the location of the low water-level (lwl) shut-off, as specified by
CEGS 11212. Manual override of the pump controls should not bypass the lwl shut-off.
b. Monitoring measurement systems. To obtain necessary baseline data, reliable methods of
monitoring system parameters are needed.
2-10
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