In all distillation/
Site technical requirements. Site technical
a. Equipment downtime.
requirements are specific to each particular process.
storage will be determined by equipment downtime
Generalized recommendations can be made regarding
when equipment downtime is more than 1 day. To
location, space, and access requirements. A typical
determine the necessary storage, establish the longest
desalination system flowsheet is shown in figure 2-1. A
period of time that could be required for planned or
typical desalination system layout, using reverse
Calculate the storage by
osmosis as a sample process, is shown in figure 2-2.
multiplying this time period by the water demand rate.
a. Location. Desalination facilities will be located
as close to the raw water source as possible in order to
b. Peak daily demands.
equipment downtime is less than 1 day, the peak daily
avoid excessive pipeline or pumping costs and to
demands may set a larger storage demand. When
minimize operation and maintenance costs for pumping
these peak demands set the storage requirements, refer
raw water (high saline content). The placement of
to water storage in the TM 5-813 series.
desalination facilities within the perimeter of a military
c. Fire water storage. On a facility served by a
reservation will provide facility security. Topography
desalination system, fire water may be saline water or
should be considered in the siting of a desalination
potable water depending on economic analysis. Dual
facility, and gravity flow should be used where possible.
water distribution system will be required if saline water
b. Space requirements. The space required for
is used. Hence, part of the fire protection water can be
desalination facilities is determined by the process.
either saline or potable water due to piping and pumping
Membrane desalination equipment needs less space
Economic evaluation of various design
alternatives is usually needed to assure the optimal
In general, space requirements are less for the
design to be adopted.
desalination equipment than for a conventional surface
d. System redundancy and modularization. One
water treatment plant of the same capacity.
complete and functional desalination module in excess
exception is solar desalination systems. These systems
of that required to supply the design flow will be
employ solar collectors that require an area several
provided as redundant capacity, and all desalination
times greater than other types of desalination equipment
systems will have a minimum of three independently
in order to achieve equal capacity.
functioning desalination modules where practicable.
c. Access. Access to systems must be provided to
permit routine maintenance, sludge and brine removal,
and delivery of desalination equipment and supplies.
The access requirements for desalination facilities are
similar to those for conventional water treatment
Water storage and system modularization.