Desalination Plants in Australia: Do We Really Need Them?

If there's one natural resource that is as precious as life itself, that is none other than water. But did you know that only 3% of the water which the Earth contains is suitable for human consumption?

Due to drought, global warming, melting ice caps, fast population growth and improper use of this natural resource, there is already a shortage in potable water in all parts of the world. This is particularly true in Australia, where drought is one of the major causes of water shortage.

As such, the government is looking into the alternative ways that it can gather clean, fresh and potable water. Here, we will take a look at one particular process which aims to resolve the water shortage problem not just in Australia but in other parts of the world as well: desalination.

What exactly is desalination? What are the pros and cons when you go for this type of purifying water so that it can be potable? Does Australia really need more desalination plants? If it does, what are its consequences to the environment? Read on to find out.

A Quick Look at the Processes Involved in Desalination

First, here's a quick definition of desalination and a brief overview of the desalination process. Basically, desalination is the process of removing salt, minerals and other particulates from seawater so that it can be potable. Once enough of the salt from seawater has been removed, the liquid can now be suitable for irrigation or even human consumption.

There are several ways that desalination can be performed, including distillation and reverse osmosis. With distillation, the process of evaporation is used so that the impurities such as salt can be separated from the pure water.

The good thing about distillation is that the process involves utilizing alternative energy resources such as thermal energy and solar energy - so it has minimal effects to the environment. However, there is lesser fresh water recovered during the process as compared to reverse osmosis.

Desalination Plant Process
Flickr photo credits to willeting

On the other hand, reverse osmosis involves a process wherein a fan presses feedwater through membranes which allow water to pass through - while at the same time filtering salt and other pollutants.

Desalination Plants in Australia

As you may already know, drought and a lack of plentiful water supply is as much of a problem in Australia as it is with the rest of the world. Although the desalination process is already popular in more than 100 countries in the world, it is a relatively new concept in Australia - that is why its advantages and disadvantages are still being debated.

Let's take the city of Sydney as an example. In 2005, the issue of constructing a desalination plant in Kurnell was placed on hold and the project has undergone media scrutiny.

Despite the fact that Sydney has a seemingly limitless water supply from its extensive water storage network, there still has been a shortage of fresh water supply because of the recently prolonged droughts. As such, Sydney Water has invested $120 million in 2005 for a desalination plant to be built - and it is something that the government promises to utilize 100% renewable energy to reverse greenhouse effect.

What are the Pros & Cons of Desalination?

So what are the pros and cons of the desalination process as being an alternative means to acquire fresh water? Take a look at the following list:

The Pros

A desalination plant can supply millions of litres of water in a particular city, regardless of rainfall.
The ocean is considered to be an untapped fresh water resource, so why should it not be used?
Desalination guarantees that there will always be a supply of fresh water, even during the drought season.

The Cons

The desalination process itself requires a significant amount of energy to operate.
The desalination process has an end result of concentrated brine which, when pumped back out to sea, has a potential effect of damaging the sanctity of marine life.
Environmentalists believe that desalination will result to increased greenhouse gas emissions.
From an overall perspective, building a desolation plant is not a cost-effective solution at all when compared to other methods like water recycling and harvesting of storm water.

The Verdict: Does Australia Really Need More Desalination Plants?

Currently, there are desalination plants which are being built in Sydney. The locations of desalination plants which are to be built in the near future include Wonthaggi, Victoria and another one in Perth.

As mentioned earlier, the Sydney desalination plant will be powered by renewable energy resources so that the effects of greenhouse gases can be eliminated. Last December of 2007, the government of South Australia also announced that another desalination plant will be built at Port Stanvac in Adelaide.

With such constructions going on, does this mean that there really is a need for the government to be building more desalination plants? Sure, this process of purifying seawater and ridding it of salt for human consumption is a seemingly novel aspect, but there are still environmental issues which need to be addressed.

The desalination process is still an imperfect science, and further studies need to be made to ensure that it will not cause further harm to the environment.

However, given the fact that the shortage of water supply is something that Australians face on a seasonal basis - especially during drought - this alternative solution of adding more desalination plants is something that is worth pursuing.