EP 1110-1-27
27 Jan 00
may be had from allowing samples to settle in a bucket, and a quantitative record may be available if
water samples were collected using an Imhoff cone or Rossum sampler. These and other methods are
discussed in Driscoll (1986).
(3) Well acceptance tests. Finally, data from well acceptance tests, usually a step-drawdown test
(Section 2-2), is helpful to document the effectiveness of the development. (As described in the
discussion on step-drawdown testing, the resulting efficiency of the well can be estimated from the
analysis of the test.)
2-5. Well Construction Diagram
"As constructed" well construction records are used in well maintenance to provide a basis for
comparison of past and present conditions, and for use in other calculations. At a minimum, diagrams
shall contain an accurate geographic location and precise designation used by the project, accurate depth,
diameter (including different components), casing and screen material type, screen slot size and screen
length, filter pack type, particle size and dimension, grout type and dimensions, and well equipment
descriptions and dates drilled and developed. ER 1110-345-700 provides general guidance for plan
components. EM 1110-1-4000 provides general guidance on well construction documentation. Plate 2-3
is an example well construction diagram.
2-6. Construction Boring Log
Boring logs include precise geographic location and boring identification (with cross reference to
subsequent well designations), accurate formation descriptions (including sediment and rock descriptions
provided according to uniform accepted standards with accurate depths), and particle size descriptions of
water-producing/accepting zones.
a. Lithologic log. The lithologic log is a record of the character, depths, and thickness of geologic
materials encountered by the drill as the borehole is advanced, with emphasis given to hydraulic
properties of the materials. Lithologic logs should be recorded and maintained by qualified oversight
personnel, using standard engineering or geologic terminology. EM 1110-1-4000 provides guidance on
sample logging, the data to be recorded, and examples of forms used to record the data.
(1) The lithologic/boring log should contain as a minimum.
(a) The depth at which geologic changes occur and at which samples are collected and described.
(b) A description of cutting samples collected at every change of geologic materials and at 1- to
1 -m (3.28- to 5-ft) intervals, and 100 percent logging for the screened interval in either the pilot or the
final boring.
(c) Changes in drilling action, that is, penetration rate, fluid loss, drilling noise, etc.
(2) Descriptions of unconsolidated sediments should note dominant grain size, sorting, and
estimates of relative percentages of sizes according to the Unified Soil Classification System (USCS)
procedures and those described in ASTM 421 and 422. Grain shape and rounding are useful for
estimating hydraulic properties. Color related to degree of weathering and oxidation-reduction is useful in
determining degree of saturation. Descriptions of consolidated bedrock should note degree of
cementation, induration, and fracturing. The depth at which saturated conditions occur should be noted.
Changes in drilling fluid properties (gains or losses of fluids, changing specific gravity, etc.) should be
noted, as they provide information on water-bearing zones.
2-9
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