Desalination: Is It Worth
Its Salt? describes
desalination as "one tool in the toolbox for meeting water supply needs" but points out that the brine disposal, impingement and entrainment of aquatic and marine life, and increased electrical needs are issues of concern with desalination that need to be addressed in deciding whether to undertake a desalination project.
In addition the Sierra Club notes that if desalination is pursued it should be "part of a comprehensive water supply program that also includes advanced water conservation and effective drought management measures."
For Immediate Release: Wednesday, March
11, 2009
Contact: Tyson Broad, 325-248-3137 or Ken Kramer, 512-626-4204 or 476-6962
Sierra Club Releases Report on Desalination
Publication Covers the Pros and Cons of Water Desalination
(Austin) - The Lone Star Chapter of the Sierra Club has released
a report on brackish and seawater desalination to help
decision-makers and the public evaluate the possible role
of desalination in addressing future water demands in Texas
and elsewhere.
Desalination: Is It Worth
Its Salt? describes
desalination as "one tool in the toolbox for meeting water supply needs" but points out that the brine disposal, impingement and entrainment of aquatic and marine life, and increased electrical needs are issues of concern with desalination that need to be addressed in deciding whether to undertake a desalination project. In addition the Sierra Club notes that if desalination is pursued it should be "part of a comprehensive water supply program that also includes advanced water conservation and effective drought management measures."
Desalination is discussed in the Sierra Club report in a series of questions and answers that highlights how the desalination process works, the environmental concerns about desalination, the dollar costs of desalination, and the status of desalination projects in Texas. The report also includes a number of sources and links for further information about desalination.
One of the major environmental concerns about desalination that must be addressed, according to the Sierra Club report, is the disposal of brine and other concentrated material that is left over from the desalination process.
The most common brine disposal method used for desalination facilities along the coast is direct discharge to coastal waters. "Depending
upon where the brine is discharged from a seawater desalination
plant, the discharge could increase water salinities by as
much as 100%," notes Ken Kramer, Director of the Lone Star Chapter. "These
increased salinities can have impacts on local marine populations,
especially for non-migratory species such as oysters. It
is certainly preferable to dispose of the brine into the
open ocean than into a bay or estuary although there could
be problems with ocean disposal of brine in localized situations."
Another economic as well as environmental consideration
regarding desalination is the increased electrical demand
required by the process. The report estimates that producing
enough desalinated water for a person on an annual basis
can require a corresponding 20% increase in per capita energy
usage. Because electrical costs may comprise up to one half
of the total cost of a desalination project, volatility in
electrical rates can have a significant impact on the overall
project price tag. For example, the report estimates that
a 50% increase in electrical rates could increase the cost
of water from a desalination facility by at least 25%.
"The large amounts of electricity required
for desalination make the process vulnerable to changes in
electrical rates," notes Kramer. "These
high costs underscore the need for a water supplier to implement
much more cost-effective water conservation and drought management
strategies prior to pursuing desalination projects."
