Desalination is a Viable Response to Water Crises

Thank you Purple_Circle!I will now respond to my opponent's arguments in the order listed.1. Energy CostsThe cost to maintain and operate desalination plants has been tremendously reduced in the last few decades. The image below shows how much less expensive they have become. “The historic downward trend of the cost of desalination is generally associated with technology improvements such as improved SWRO membrane performance and significant advances in the ability to recover more energy from the desalination process” [1]. Also, new ideas are constantly being put forth that would further reduce expenses, such as the nanoparticle desalination system that I mentioned in round two. Other methods such as renewable energy will not only reduce costs over time, but allow us to depend on energy sources other than oils and gasses. 2. Air PollutionThe power of desalination plants and their large output capacity does come at a cost. The burning of fossil fuels can be detrimental to the environment over time, as it releases unnatural gasses such as SO2 (sulfur-dioxide). Fortunately, there are several techniques that are being adopted by desalination plants to limit their environmental impact. For example, the use of fuel oil with a low sulfur content can reduce SO2 emissions by 72% [2]. Using natural gasses can nearly eliminate SO2 emissions. To further reduce emissions, desalination plants can implement end of pipe control, such as flue gas desulphurization. This technique can almost eliminate SO2 emissions. "[It is] used to remove sulfur dioxide (SO2) from exhaust flue gases of fossil-fuel power plants” [3]. The following image demonstrates what this process looks like [3]. 3. Ecological ImpactsMy opponent writes “Desalination will create a lot of waste products including salt...Dumping this salt into water sources like the ocean will have massive ecological problems because the increased salinity of the water will kill aquatic life.” Con is right to worry about this, but this is no longer a problem with modern desalination plants. Rather than dumping the salt straight back into the ocean, they have methods to gradually disperse the salt back into the sea, such as sprayers, or in the case of one facility in California, pipes. “[The pipe] runs thousands of feet out to sea, with small holes spaced ten feet apart, so not too much brine [extremely salty water] would pour out in any one place” [4]. Alternative methods are also being utilized, such as in the San Diego desalination plant I mentioned earlier. “The captured salt is diluted with the cooling water from the neighboring power station, and that’s discharged back into the ocean” [5]. The main priority of desalination plants, after ensuring that a region is not deprived of water, is to inflict the least amount of harm possible onto both the local environment and the planet as a whole.Next, Con states “Also, when the saline water is pumped into the desalination plants, aquatic organisms tend to get sucked up along with the water. Plankton, fish eggs and larvae are among some of the things that are killed during the desalination process, many of which are vital for the aquatic ecosystems.” This is yet another issue that is no longer present in modern desalination facilities. Desalination plants will place grates in front of the pipes that bring in the ocean water, which prevents most water life from entering. Another relatively new technique being utilized is called directional drilling, which eliminates the chance of sucking in water life. “From below 200 feet of sand, and well insulated from any vulnerable sea life, Cal Am hopes to suck up a couple thousand gallons of water per minute” [4].Sources1. https://www.watereuse.org... 2. http://www.lenntech.com... 3. https://en.wikipedia.org... 4. http://ww2.kqed.org... 5. http://www.pbs.org...