The global desalination market is expected to
keep companies supplying those systems extremely busy not just
in the near term, but for the next 20, 30 or even 50 years as
fresh water scarcity worsens while technological solutions to
address the problem become better and more affordable.
Cedella Beazley, global marketing manager of
Filmtec reverse osmosis membranes for Dow Water Solutions,
Minneapolis, said there are currently 75 major desalination
plants in various stages of development worldwide, including
facilities for the treatment of not just saltwater but also
brackish water and in some cases wastewater.
She estimated that desalination plant
capacity, especially facilities using reverse osmosis
technology, will continue to be quite strong, possibly
exhibiting low double-digit percentage growth year on year,
although the annual growth rate will bounce around a bit based
on what big plants are installing one year vs. the next.
It also varies by the kind of water being
treated, according to Randolph L. Truby, chief executive
officer of Toray Membrane USA Inc., San Diego, who placed the
annual growth of seawater desalination at as much as 20 percent
while brackish water desalination grows at a "calmer" 3 to 5
percent a year and wastewater treatment at about 10 to 12
And these growth rates are likely to
continue. "You hear about new projects all the time under
development. We are seeing it especially in the Middle East,
China, India, Australia and Singapore," Truby said. "It is
Beazley agrees, noting that one push has been
coming from countries that are becoming more industrialized,
such as China and India. But there also is increased demand
from other countries that are already industrialized, such as
Spain and Australia, which are experiencing droughts that have
significantly reduced water availability.
Growing populations and rising demand are
stretching water supplies worldwide, according to GE Water
Process Technologies, Minnetonka, Minn. "Today, about one-third
of the world's population lives in countries with moderate to
high water stress," the company said. "If the present
consumption patterns continue, two of every three people on
Earth will live in water-stressed conditions by 2025."
The problem is that all the easy-to-reach
water sources are drying up at the same time that the world's
population is booming, said Chuck Martz, Dow Water Solutions'
global marketing director. "Only about 3 percent of the world's
fresh water is accessible. About 2 percent is tied up in the
polar ice caps, so only about 1 percent of fresh water is truly
accessible," he said.
While many other areas of the world are even
more water stressed than the United States, some parts of the
country are starting to suffer from water scarcity as well.
Jorge Arroyo, engineer for water science and conservation at
the Texas Water Development Board, said that in the next 50
years Texas' existing fresh water supply is expected to decline
about 17 percent at the same time that the state's population
is expected to double.
Texas already has about 80 million gallons
per day of brackish water desalination capacity, Arroyo said,
and a number of new facilities-both seawater and brackish water
plants-will be built in the state in the next 50 years,
including several smaller ones in the next 10 years.
While most desalination plants were
traditionally based on thermal desalination, or distillation,
in the past 10 years or so demand for reverse osmosis systems
has been growing and is beginning to overtake thermal, Beazley
said, largely because both the capital costs and operating
costs of reverse osmosis have come down considerably. Reverse
osmosis uses a lot less energy than thermal desalination, she
said, and the fact that it uses less metal also provides a
savings, especially given recent rising commodity prices.
"The reverse-osmosis module is almost all
polymer-based and its pressure vessels are fiberglass," Martz
said. "It is primarily the racks, the pumps and the pipe that
are metal. Any parts that come into contact with the water are
stainless steel. Others are not necessarily stainless."
Reverse-osmosis plants, however, do use pipes
to transport the water, Truby said, adding that pipe,
especially in seawater systems, needs to be made from
high-grade stainless steels, as do certain valves and
By comparison, pretty much the whole thermal
desalination unit is stainless steel or other
corrosion-resistant alloys, Martz said.
"People are feeling the volatility of the
price of stainless," Truby acknowledged. "It is something that
contractors need to be aware of when bidding on projects. As
the price goes up, so does the price of the plant."
That has not had much of a dampening effect,
however. "If you need water, you have to build a desalination
plant no matter what the commodity costs," Arroyo said.