The Negative Impact Of Desalination On The Marine Environment

While desalination sounds like a great way to solve the world’s water issues, there are many problems related to the sustainability of this process. Obviously, as discussed earlier, desalination has many negative impacts on the marine environment, but there are as well other reasons that it is not sustainable. For instance, desalination requires a very high-energy demand, which contributes to the reliance on fossil fuels and therefore the emission of pollutants such as greenhouse gasses. On average desalination requires 15,000 kWh per million gallons. Compare that to a modest 500 kWh per million gallons on average for traditional water treatment (Cooley 2013). The burning of large amounts of fossil fuels to desalinate water, and as a consequence
the release of large amounts of greenhouse gasses, is obviously not a sustainable way of acquiring freshwater. Desalination is also far more expensive then our traditional forms of acquiring fresh drinking water. This high-energy demand makes up the majority of the cost, as much as one-half, to desalinate water (Cooley 2013). Another factor in the high cost is the transportation from the plant. The production alone can cost up to $8.35 per thousand gallons and if you include transportation costs, that number can go as high as $9 to $10 per thousand gallons. With this in mind, desalination is simply uneconomical compared to urban water prices that can range from $1 to $3 per thousand gallons (Cooley et al. 2006). Another issue with desalination is the disposal of the brine. As we discussed earlier, one option of disposal practiced is dumping the brine back in the ocean. This has ecological impacts that range from single species to entire ecosystems. Other options for disposal of brine are evaporation ponds and deep-well injection, but these methods also have their negative impacts. Along with requiring large plots of land, evaporation ponds