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MIL-HDBK-419A
1.2.1.2 Geological Effects.
Identify the significant geological features of the site. Specifically, attempt to establish:
a.
(1) the distribution of major soil types (see Volume 1, Section 2.3.2) to include the locations of
sand and gravel deposits,
major rock formations,
(2)
(3)
the presence of water sources to include underground streams, and
(4)
the depth of the water table.
Utilize test borings, on site inspections, studies of local maps, and interviews with local construction
companies, well drillers, and other local personnel to obtain the desired information.
Evaluate the information provided by these sources for indications of particularly troublesome (or
b.
particularly helpful) characteristics that may influence the design or installation of the earth electrode
subsystem of the facility.
1.2.1.3 Physical Features. Locate and identify those other physical features that will influence the general
placement of the earth electrode subsystem, the location of test and access points, physical protection
requirements, and the cost of materials and installation. For example, indicate on the general site plan :
the planned physical layout of the building or structure,
a.
b.
locations of paved roads and parking lots,
drainage, both natural and man-made, and
c.
the location of buried metal objects such as pipes and tanks.
d.
1.2.1.4 Local Climate.
Review local climatic conditions and determine the annual amount and seasonal distribution of
a.
rainfall, the relative incidence of lightning, and the depth of freezing (frost line) typical of the area. Obtain
the rainfall and frost line information from the local weather service; project the relative lightning incidence
from the isokeraunic maps given in Volume I, Section 3.4, Figures 3-2 and 3-3.
Record the data and make it a part of the facility files for the site. Immediately, however, use this
b.
information to aid in the design of the earth electrode subsystem for the facility to be constructed at the site.
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