Are there any known negative impacts on the environment from desalination? True or False. Environmentally, “No”, because no energy or water is lost in the process of separation. False.
There are, however, potential negative effects on the marine life that may be affected by the method of desalination
One possibility is that saltwater may become too alkaline for marine life to live in. The alkalinity of seawater is rising due to human activities. In addition, some pollutants already in the water have an acid nature that could upset the balance between the minerals in the water and the freshwater. If the process of separation causes too much acid in the seawater to mix with the freshwater, this could further upset the ecosystem and potentially lead to a major problem. However, the jury is still out on whether or not this is a true possibility.
Another issue that is being looked at is the pollution that would be caused by any potential surface spills. Desalination plants need to rely on external sources of water in order to provide freshwater to their facilities. That means that any pollutants in the ocean water that would make it to the plants would also find their way into the fresh water supply that they are drawing from. The amount of pollution that might occur is unknown, but it is being looked at as a possible problem.
Perhaps one of the biggest concerns of those in the industry is the potential of contamination of drinking water
In the production phase of the desalination process, saltwater is pumped into the process that separates it from seawater, typically in the form of brine. The brine is then pumped back into the seawater, as it is removed for reuse and further processing. Over time, the levels of salt and minerals in the brine water are reduced, and thus it begins to become safer to drink.
There have also been some questions raised as to the impact of using desalination for freshwater use in areas where fresh water is already highly endangered. One issue that has been noted is the possibility of rising pressure from natural disasters, which could cause groundwater pressure to increase and ultimately flood inland basins. If this happens, and it has been noted that many natural disasters are increasing and resulting in more water being demanded from freshwater supplies, there is the possibility that desalination plants could be damaged or destroyed, resulting in the closing of facilities. While the damage would obviously be permanent, there have been no reported reports of such occurrences, making the potential still unknown.
In terms of the environment, a final concern is from the ocean life
Since most desalination plants are located along coastlines, ocean acidification can occur. This results from the introduction of new materials and salts into the ecosystem. There have been no concrete reports on the effects of acidification on marine life, but one study has found that dead fish in test patches had lower pH than those found in nearby bodies of water. The lack of evidence proves that there might be some benefit to the marine life, however, and scientists agree that the problem should be addressed in more detail in the future.
There are two major environmental concerns that have been noted as associated with the process of desalination plants. The first concern is that of mercury, a toxic metal that has been linked to developmental and reproductive problems in humans. Studies have shown that low levels of mercury are safe for humans, but high levels can cause neurological damage, brain damage, and developmental delays in children. This particular concern is more of an environmental risk with the potential for more harmful problems to come as the mercury builds up in the environment, potentially poisoning wildlife and human beings in the process. Another environmental issue noted with the process of freshwater desalination is the effect on ocean acidification.
Ocean acidification occurs when excess salt from seawater reacts with water, releasing sulfuric acid
The concentration and amount of this acid vary between bodies of water, with effects on different marine life depending on their composition. This type of natural occurrence is considered to be a by-product of desalination plants, although the actual source of sulfur in seawater has not yet been identified. One of the possible negative impacts of the process of desalination on acidity is that excess salt created in the process may act as a blanket, shading the surface of the aquatic organisms that live in the water. These creatures could then become more vulnerable to disease, possibly reducing their ability to reproduce. While this is one of the concerns noted with ocean acidification, other factors, such as nutrient loading from outside the water system, could also be problematic.