Desalination is a process that converts saltwater resources into freshwater products. When it goes through the filtration steps necessary to remove the extra sodium from the liquid, the water becomes usable for agriculture, industrial needs, and for drinking purposes.
The United States uses desalination plants to supplement the water supply, like in San Diego, CA, where 10% of the usable water goes through this process. In the Middle East where freshwater supplies are scarce, up to 48% of the drinking water availability in some countries is because of the work of desalination.
This advantage can help people meet their basic needs, grow food, and support their livelihood. Desalination can also create a devastating brine that contains significant salt levels and other chemicals. There are some significant trade-offs to consider when using this technology, which is why a thorough look at its pros and cons is necessary.
List of the Advantages of Desalination
1. Desalination is a proven technology.
We know that the desalination process is an effective way to create safe, usable water for large populations when the work is performed correctly. You can also use this technology on a personal level to create usable emergency water for the times when utility or municipal systems are unavailable for some reason. That means there are large-scale and small solutions that can fit almost any need, whether you want to create a viable water source at two pints per hour or two gallons per second.
2. More usable water means we can eliminate problems in the food supply chain.
Famine can create numerous hardships on significant population centers. It results in undernutrition, chronic hunger, high mortality rates, and creates an urgent need for help. In 2011, the United Nations announced that Somalia was dealing with this issue and that up to 750,000 people were in danger of imminent starvation. About 260,000 people died in a two-year period afterward because there were minimal food supplies, restricted water access, and a lack of activity from the international community.
Having access to desalination technologies won’t solve all of these problems overnight, but it can help families get to the next day as they fight for survival. Over 20% of Africa, 11% of Asia, and 6% of Latin America and the Caribbean deal with conditions of undernourishment every day.
3. Desalination gives us water access during a time of drought.
Drought is another significant problem that human civilizations face every year. As the weather patterns change around the world, there are places receiving more rainfall than normal while others can go extended periods of below average activity. This issue doesn’t just impact the Middle East or Africa either. Texas and California are still recovery from extended periods of drought that lasted for more than five years in some locations. Although there are only areas of extreme or exceptional drought in the Marshall Islands and Hawaii at the moment, there are a handful of areas in the United States managing the short-term impacts of severe drought right now.
Desalination provides us with a tool that we can use to get water to those who need it the most. Although it may not be a perfect solution in every circumstance, having water access is a critical component of life.
4. It can stop some of the political wrangling that occurs with water diversion.
Beginning in the 1920s, the states of the U.S. West began to divvy up the water supply from the Colorado River to meet their needs. This channel runs south for over 1,500 miles, traversing canyons and deserts, until it reaches the deltas of the Gulf of California. Now that cities like Phoenix, Denver, San Diego, and Los Angeles use the water through diversions to irrigate crops and create drinking water supplies, over 70% is now siphoned off for some need before it reaches its end point.
There are points in some reservoirs where the water levels from the Colorado are 130 feet lower than they were in the year 2000. Some officials believe that the reservoirs may never be full again. Desalination technologies could help to change this issue.
5. We could use the water movement from desalination to create more energy.
When desalination plants pump water into their facility to start the processing work, it creates water movements that could be useful for turbine rotation. Placing usable hydropower technologies at these inlets could help us to generate power while gaining the advantage of more freshwater to use at the same time. It could be theoretically possible that some facilities could create the power they need to process saltwater through their current activities.
The creation of additional water resources can reduce our global energy costs in other ways as well. 25% of the energy we use in the world today is to reinforce the food supply. Agriculture is the largest consumer of freshwater. If we are more efficient with this advantage, it could let us reserve more energy for other uses.
6. Desalination works to stabilize economies at every level.
Water is what allows us to complete our daily routine. Without access to it, then we cannot function as effectively. By generating additional reservoir supplies that are accessible to the general public, we can stabilize economies all around the world.
We could create newly expected cost structures for local utility consumers with more consistent access. We would be able to deliver more products, fabricate more assets, and maintain horticultural production levels. Diversified water supplies create stable local and international economies.
7. We could create a future water reserve that the next generation could use.
Our planet progresses through regular weather cycles. Some years may bring lots of snow or rain. Other years may bear very little precipitation that is useful for agricultural purposes or drinking water. Through the process of desalination, we have the chance to create freshwater reserves that are used when access to new water rations becomes restricted.
We already have the foundation in place to hold this water because of our hydropower facilities, storage reservoirs, and other areas of retention. We could also place desalinated water in underperforming lakes and rivers if the chemicals and brine are adequately removed from them.
8. Communities could have more water independence.
Most communities purchase water from others as a way to create a municipal supply. This process happens for big cities and small ones. The city of Oak Harbor, WA, which has a significant military presence, purchases water wholesale from the nearby city of Anacortes while maintaining several wells. Instead of transferring taxpayer funds toward resources that may not always be available, investments into desalination could help small towns like the ones mentioned in this advantage create usable infrastructure that would produce water supplies that could be placed in reservoirs for future consumption.
9. Multiple industries benefit from the presence of desalination facilities.
The salt we take from water during the desalination method is highly concentrated and dangerous if left recklessly in the environment. A variety of industries can also use it in several unique ways. Sodium products are usable as de-icing agents. Aqueous brine solutions are effective at keeping ice off of transportation networks.
The side products of desalination are useful in the restriction of dust levels. We use them as injection materials for fracking activities. It is even mixed with concrete supplies to make a product called “saltstone.”
10. We can use desalination facilities at almost any location.
The only restriction in place for desalination facilities is that a significant saltwater access point is necessary. That means we are restricted to coastal regions where ocean water is typically present, although the Great Salt Lake or the Dead Sea are two inland options to consider. That means we can limit the environmental exposure of chemicals and brine away from population centers while creating holding areas that protect marine life simultaneously. This advantage allows us to reduce the pressure we have on our freshwater resources while still providing access to safe, healthy liquids for our overall needs.
11. We can preserve marine life through desalination.
By reducing the amount of freshwater resources we take to support our communities around the world, the different deltas, marshes, and rivers that we use for our needs today can see a restoration of sorts. That means we can begin the process of restoring natural habitats if we are responsible with the ways that we dispose of the brine and chemicals that are useful in the freshwater creation process.
If we were to use reverse osmosis technologies without the chemicals to create drinkable water, then this advantage could be a significant part of our infrastructure with only minor investments.
12. Various fuels can operate desalination technologies today.
There are several different fuel resources that allow us to create a desalination power supply. Portable units often operate on battery power. Some low-flow options can even work with solar panels. Industrial activities will tap into the local power grid to take advantage of coal-fired, nuclear, or hydropower resources. Communities can use diesel, ethanol, or unleaded gasoline to begin filtering the water. This advantage adds even more flexibility to the placement options which are possible with this technology.
List of the Disadvantages of Desalination
1. There are significant chemical waste disposal needs to consider.
Desalination creates several byproducts which require specific disposal steps that must be followed to keep people and the environment safe after making fresh water for use. There are pre-treatment and cleaning steps that help to make the process more efficient than a simple strainer. Most facilities use hydrogen peroxide, chlorine, and hydrochloric acid to prepare the water for this process. Once the chemicals are used, then must be disposed of correctly to prevent them from entering the water table.
2. Desalination creates plenty of brine that must be managed as well.
The side product of a desalination effort is brine. Facilities will send the purified water for further processing once the salt is gone, but the remainder is a super-saturation product of sodium that requires careful disposal. Many facilities just put it back into the ocean, but there are numerous marine species which are ill-equipped to manage the higher sodium levels. Too much salt will decrease the oxygen levels in the water, which can cause local life to suffocate if there is too much brine dumped into the local supply.
3. It impacts the smallest creatures the most often.
When there are chemical discharges or brine dumping activities that occur around a desalination plant, then it is the smallest creatures of the food chain that experience the most severe impacts from these activities. Phytoplankton helps to form the base of all marine life, which means reducing food levels for other creatures will impact the entire ecosystem. There are also issues with entrapment when a facility brings in water for processing as well, a concern that is referred to as impingement.
4. There are health concerns to manage with desalination.
Although desalination can provide a significant portion of the water supply to some countries, especially those in the Middle East where the climate is challenging, it is not a perfect technological solution. There are times when the water released by the facility is harmful to human health as well. The chemical byproducts can leech into the system, exposing people and plumbing systems to the acidic nature of the purification process. If the pH balance is off, then the lead and other problematic elements in some plumbing systems could literally poison you at the same time you think that you’re drinking something safe.
5. Desalination plants consume a lot of energy.
Energy is becoming a precious commodity for us these days as we seek to reverse some of the issues that climate change is bringing our way. Some scientists suggest that we have until 2030 to begin reversing the processes that got us to where we are today before we cross a point of no return. Using desalination for water can be beneficial in several ways, but it requires a significant portion of power to create something usable. There are other water treatment options that require less energy while still providing us with the drinkable water needed for our survival.
6. The capital cost of desalination technologies is quite high.
Home-based desalination pumps and filters that a single household might need in a coastal community to have daily usable water can cost upwards of $5,000. If you want to look at what the investment is at an industrial or national level, then proposed projects in the United States or the Middle East show us that it can be up to $6.50 per gallon when all processing needs are accounted for in the cost profile. Even highly affordable facilities, like one that recently opened in the state of Florida, can create freshwater resources at $1.10 per gallon.
7. Energy costs can be very high for desalination plants as well.
The average household in the United States pays about $0.45 per gallon for their municipal water access. Homeowners that live on personal wells can spend even less than that. Even in places like the Middle East where the need for desalination is clearly established, the cost of access for the average consumer can be up to 75% higher. When you consider the taxpayer expenses to construct a facility in the first place, only the places where water scarcity issues are prevalent frequently typically benefit from this technology.
8. Some desalination efforts remove the electrolytes from the water supply.
Desalination efforts through reverse osmosis require the fluid to travel through a membrane. This activity removes the impurities from the water so that it can become a usable product. It will also remove all of the nutrients that are in the water, including the magnesium, potassium, and calcium that are needed for healthy living. Industrial plants typically add these items back into the supply before distributing the fluid for consumption, but this disadvantage adds even more to the cost of the product.
9. Desalination does not create a helpful water ratio.
When desalination facilities process saltwater to create freshwater reserves, then the return can be as low as 5%. That means we get 5 gallons of usable water for every 100 gallons of processing. These facilities then send the unusable water to a local wastewater treatment facility, which then discharges the fluid where it usually goes back to its original point of processing to start the battle all over again. That’s why the power and cost disadvantages are such an important element of this technology to consider.
Verdict of the Advantages and Disadvantages of Desalination
There are places in the world, especially in the arid Middle East, where desalination makes it possible to have enough usable water for everyone. Activities like damming or building reservoirs can only take population centers so far, especially with all of the diversionary tactics that are in use today.
Although the cost of desalination can be an obstacle for implementation at the personal level, most communities can subsidize this activity through their usual cost payments and taxing structures so that everyone can have what they need.
The advantages and disadvantages of desalination work to balance cost vs. productivity to see if it is a useful investment. As more drought and famine issues impact our planet because of global warming, these key points are going to become essential to consider for more communities in the future.
Natalie Regoli is a seasoned writer, who is also our editor-in-chief. If you have any questions about the content of this blog post, then please send our editor-in-chief a message here.