MIL-HDBK-1005/7A
waters are likely to be highly mineralized. Select from other
types with due consideration of yield, quality, and other
factors.
4.4.2.2
Collection Works.
Select suitable types of collection
works as follows:
a)
Collection chamber, for all gravitational springs
b)
Open trenches, for depression and contact springs
c)
Buried pipes, for depression and contact springs
d)
Wells, for artesian springs
4.4.2.3
Sanitary Protection. Provide protection against
pollution of spring water in accordance with EPA-570/9 -75-001.
4.4.3
Infiltration Galleries . For collateral readings,
refer to Infiltration Galleries in Water and Wastewater
Engineering, by Fair, Geyer, and Okun. These collectors,
generally placed horizontally at right angles to the direction
of flow, are served by gravity flow. Consider the applications
and limitations of the following types.
4.4.3.1
Open Trench. Do not use open trenches; they are
subject to problems of algae, erosion, clogging by vegetation,
and surface contamination.
4.4.3.2
Buried Pipes . For diameters up to 2 ft, perforated
vitrified clay, concrete, cast iron, or tile drains laid with
open joints, may be used. Bury the pipes in a trench and pack
gravel around them. Trenches more than 20 ft deep are usually
uneconomical.
a) For the design of perforations, joint opening, and
gravel packing, use the same criteria as for wells.
b) The design velocity in collecting pipes should not
exceed 2 fps.
c) Collect the water in a covered sump and pump it.
d) Provide manholes spaced at 100 to 300 ft to
facilitate inspection and maintenance.
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