SUN EDITORIAL:

All washed up

A desalination plant is not the immediate answer to Southern Nevada’s water needs

Tue, Mar 25, 2008 (2:06 a.m.)

Opponents of the Southern Nevada Water Authority’s plan to draw water from rural Nevada to supply Clark County — including Gov. Jim Gibbons — have pointed to desalination as the answer.

They say that instead of building a pipeline to pull water out of rural Nevada, a desalination plant could be built in California or Mexico. Nevada could swap the water the plant produces for a larger draw of water from Lake Mead.

Problem solved? Not exactly.

The situation is much more complex than the Water Authority’s opponents make it out to be.

As Phoebe Sweet reported in Friday’s Las Vegas Sun, the Water Authority has been pursuing desalination as part of a broader plan for the long term. But desalination is certainly not a short-term option, given the expense of building and operating a plant, not to mention the environmental issues associated with desalination.

For now, the cost of water produced by desalination is prohibitive. The process requires a tremendous amount of money, and environmentalists note that the demand for more electricity means more power plants, which come with their own set of costs and environmental issues.

Desalination plants also produce brine and disposing of that can be an environmental problem. Trying to build a plant in California would be a difficult — and expensive — task. In California, environmental issues receive considerable scrutiny, particularly by the powerful Coastal Commission, which holds a tight rein on development along the Pacific Ocean.

Desalination certainly is something the Water Authority should be pursuing, but building a desalination plant would not ease Southern Nevada’s reliance on Lake Mead. The current drought threatens to curtail extra water supplies Nevada might otherwise use. As the lake level continues to drop, it is clear the region needs other sources of water that can be tapped more quickly and realistically than desalination.

Discussion: 1 comment so far…

By WDI

3/25/08 at 10:17 a.m.

Suggest removal

Several news articles on seawater desalination reveal
that desalination technology is little understood by
most journalists, local water managers, politicians
and environmental groups. In searching for
renewable potable water or supplementing current
sources few are aware that there is more than one
desalination technology.

When evaluating a desalination project Reverse Osmosis
is typically the process considered. Yet, there is a
viable and proven alternative in distillation. The
Advanced Vapor Compression Desalination
Process is an advanced and highly environmentally
friendly desalination process, an alternative, single
performance, and lower maintenance process compared to
Reverse Osmosis. The system is based on proven
flash distilling principles but features an innovative,
highly efficient, and compact design. Additionally,
it offers a unique advantage in the treatment of salt byproducts.
The system produces outputs of either valuable crystalline
Salt or concentrated brine. The process is optimized for
the desalination of seawater drawn from wells below the
sea floor and not returning the brine to the sea.

The process has modular abilities and can be expanded
to meet future requirements in water demand or
designed and built at the start for higher volume. A
basic plant design can operate on solar, thermal,
nuclear or traditional energy sources. Each unit is
optimized from an initial engineering site study to
account for different environmental and structural
needs. A basic stand-alone unit of 1 acre-foot per day
has a footprint of approximately thirty feet in
diameter. The larger the plant water volume the lower
the cost is per acre-foot. The plant energy
consumption is on the order of about 5 to 21 kw per
1000 gallons produced based on the design, volume
produced and type of energy.

The system can also be used in industrial treatment
and recovery of effluent water. The life cycle of the
plant is based on a 25 year time line which can be
extended through proper preventable maintenance and overhaul.