Wastewater Conveyance - Wastewater Operators - page 148

avoid major breakdowns, and they must be able to make needed repairs
when breakdowns do occur. A comprehensive knowledge of piping sys-
tems and accoutrements is essential to maintaining plant operations.
4.2 ConveyanCe sysTeMs
With regard to early conveyance systems, the prevailing practice in
medieval England was the use of closed pipes. This practice was contrary
to the Romans, who generally employed open channels in their long-dis-
tance aqueducts and used pipes mainly to distribute water within cities.
The English preferred to lay long runs of pipes from the water source
to the final destination. The Italians, on the other hand, whose antique
aqueduct arches are still visible, seem to have had more of a tendency to
follow the Roman tradition of long-distance channel conduits. At least
some of the channel aqueducts seem to have fed local distribution sys-
tems of lead or earthenware pipes (Magnusson, 2001).
With today's water and wastewater conveyance, not that much has
changed from the past. Our goals today remain the same: (1) Convey
water from source to treatment facility to user, and (2) convey wastewa-
ter from user to treatment to the environment. In wastewater operations,
the term conveyance or piping system refers to a complete network of
pipes, valves, and other components. For wastewater operations in par-
ticular, the piping system is all inclusive; it includes both the network of
pipes, valves, and other components that bring the flow (influent) to the
treatment facility, as well as the piping, valves, and other components
that convey treated wastewater to outfall. In short, all piping systems
are designed to perform a specific function.
Probably the best way to illustrate the importance of piping systems
is to describe many of their applications in wastewater operations. In
the modern wastewater treatment plant, piping systems are critical to
successful operation. In wastewater operations, fluids and gases (chemi-
cals and air) are used extensively in processing operations; they usually
are conveyed through pipes. Piping carries wastewater into the plant for
treatment, fuel oil to heating units, steam to steam services, lubricants to
machinery, compressed air to pneumatic service outlets for air-powered
tools, and chemicals to unit processes. In addition to wastewater influ-
ent and treated wastewater effluent, the materials conveyed through pip-
ing systems can include oils, chemicals, liquefied gases, acids, paints,
and sludge, among many others. Thus, a wastewater treatment plant has
many piping systems, not just the systems that convey wastewater. Along
with those mentioned here, keep in mind that plant piping systems also
include those that provide hot and cold water for plant personnel use.
Another system heats the plant, while still another may be used for air
conditioning.
Wastewater operators have many responsibilities and requisite basic
skills. The typical plant operator is skilled in heating, ventilating, and air
conditioning (HVAC) systems; chemical feed systems; mechanical equip-
ment operation and repair; and piping system maintenance; however, only
the fluid transfer systems themselves are important to us in this text.