I have heard so many times people not caring (especially in Hawaii) if they overuse/waste water because well, there’s a whole damn ocean that some engineers can figure out when/if we ever need it. Yeah, because with the way we consume water in this country and with hundreds of millions of people living within a drought-ridden area, it’s GOING to happen. It IS happening. Ever heard of the water crisis?? The key to changing this incorrect point-of-view is to learn what the process of desalination is actually about to see if it is the appropriate alternative for your area and then change behavior to CONSERVE water! Wow, that is going to be very difficult.
In the past half a century, there has been a huge increase of technology dedicated to decreasing energy consumption. Unfortunately, desalination has an incredibly high demand of energy, emits green house gas, disturbs local marine environments, is an excuse for our poor behavior, etc., so why backtrack? More attention and funding should go towards preserving what clean fresh water resources we have left rather than push for alternative methods to continue our exuberant rate of consumption.
There are two popular processes of desalination, multi-stage flash distillation using heat to evaporate water leaving the salt behind (dirty, dirty, dirty) and reverse osmosis desalination that pumps water through filtration membranes (cha-ching, lots of money). Then, what do you do with the concentrated salt stream that is produced as a result of multi-stage flash desalination? How do not damage the environment with such a volume of salt? Yes, plant designs take this into consideration and in the U.S. and Europe an EIA/EIS would determine whether the consequence is a concern or not. However, what if desalination is only used for extreme situations, such as along the equatorial belt where there is a high proportion of drought and poverty?
There are facilities such as, inland desalination plants like in El Paso and a lot of rich countries like Saudi Arabia, China, U.S., Israel, UAE, etc. all do it already. But to complicate the problem further, who is going to fund these large projects, especially in developing nations? Then the conversation gets really political and someone is always going to be left out especially if they lack the mineral/resources to attract outside investors. So, solution is easy… hold off on the desalination excuse and start conserving water.
Here in the U.S., City & Country, State, and Federal policies should focus on Reuse facilities and demand golf courses, toilet water, agriculture, etc. use recycled water. That would save up so much of our clean fresh drinking water. There are also easy solutions out there such as storm reclamation and rainwater harvesting; we just need our policy makers to understand the alternatives. The technology is there, the engineering capabilities are there, we just need to do it.