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 CHAPTER 3. BRIEF DESCRIPTION OF UTILITY SYSTEMS
1. WATER UTILITY SYSTEM
a. Description. The base water distribution system is normally fed by a main water line
ranging from 12 inches to 24 inches in diameter. The water source may be provided by the base
or by local utility companies. A water treatment plant is normally located near the source, and
is used to treat the raw water before distribution.
The water distribution systems may include pipe sizes that range from l-1/2 inches to 24
inches in diameter. Pipe materials may consist of PVC rigid plastic pipe, steel, asbestos cement,
cast iron, and ductile iron. Components of the water distribution systems are hydrants, valves,
meters, storage tanks, reservoirs, pumps, water purification systems, piping, and thrust blocks.
Water pressures in the distribution system range from 60 to 120 psi.
b. Nonrepairable Components. Water distribution system components, such as water
storage tanks, pumps, and purification units, are considered nonrepairable because normal
repairs exceed the 4-hour time limitation for repair. On a temporary basis, these components
may be replaced individually with stand-alone systems (see chapter 4).
c. Repairable Components. Most water distribution lines are considered repairable
because they can generally be repaired within a 4-hour period.
2. SEWER UTILITY SYSTEM
a. Description. A typical sewage system consists of relatively large trunk lines as the
main, and smaller service lines, which branch off the trunk lines to service the base facilities.
Trunk lines can vary from 8 inches to 24 inches in diameter. Service lines are usually 4 inches
to 6 inches in diameter. Pipe materials may consist of asbestos cement, cast iron, ductile iron,
concrete, PVC, and vitrified clay. Wastes are carried primarily by gravity flow to sewage
treatment plants for treatment before final discharge into selected medians. Lift stations, with
associated pumps, are often employed in sewage systems.
b. Nonrepairable Components. Sewage treatment components, such as sewage
treatment plants are considered nonrepairable because of the 4-hour time limitation for repair.
Well and sump pumps can be replaced if damaged.
c. Repairable Components. Sewer trunk and service lines are considered repairable
because they can generally be repaired within a 4-hour period.
3. PETROLEUM, OIL, AND LUBRICANTS (POL) UTILITY SYSTEMS
a. Description. The typical POL system consists of loading pipe lines from ship tanker
to shore terminal POL. The shore terminal POL consists of booster pumping stations, storage
tanks, manifolds, transfer pumps, flood pumps, pipeline pumping stations, main pipelines,
reserve storage tanks, dispensing tanks, filtering devices, bulk distribution lines, and loading and
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