Recently it was announced that a new desalination plant located in Carlsbad will begin operating in the fall, and the company plans to build another plant in Huntington Beach. The idea of desalination of sea water seems like a good one at first, but many are questioning whether this method is actually the best way to address a drought.
The current mainstream process for purifying sea water into potable water uses a process called reverse osmosis. This process forces salt water through a membrane which removes the salt and impurities, leaving a brackish solution. This highly saline, brackish water solution is then released back into the ocean. The energy demand for the desalination process is extreme and expensive. However, the concept is successful at creating potable water.
Concerns over these desalination plants include the high cost—both in finance and energy, impacts on local ecology, and aesthetic appeal. Some concern arises over the placement of these plants on beaches where tourism has provided local communities with income, and some just don’t like the look of industrial facilities. Go figure.
Environmental concerns probably should be top priority, but they rarely are. Releasing highly saline brackish water into the ocean at these locations can alter the ecology of the local marine life. It can drive some species away and attract other, non-native species. The chemistry of the water changes drastically.
It seems to be a conundrum. We have an abundant source of sea water with which we can transform into potable water. But the desalination process comes with heavy price tags with regards to the environment, as well as the financial and energy costs. Before jumping on the bandwagon touting how great this is, let’s take a step back and evaluate the costs—especially environmental costs since those will cost more in the long run, and in many ways. If we choose to ignore the warning signs and go full steam ahead with these plants, we might regret it a few years from now when we are facing worse environmental challenges than we see now.
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