Even though the earth is made up of 70% water, most of the water have high salt content which makes it unfit for drinking. However, removing the salt from the water can make the water fit for drinking. Desalination companies are equipped with the facilities to purify saline water that is pumped from the sea into safe drinking water. Many different methods can be used in purifying the saline water. Reverse osmosis is one of the methods that desalination companies use in carrying out purification of the sea water. Reverse osmosis uses filters to filter out the salt, solid particles and microorganism that exist in the sea water.

The water has to passes through several stages in the reverse osmosis desalination process. The raw sea water must first go through two pre-treatment stages. In the pre-treatment stage, the water enters into a tank that has several filtration layers at the bottom including anthracite, sand and gravel. Contaminated particles like algae and microorganisms that are floating around the sea water will be removed.

After it has passed the first pre-treatment stage, it will move on to the secondary pre-treatment stage. The secondary pre-treatment stage consists of filters with even more microscopic holes so that smaller particles can be filtered away before it is progressed to the membranes where the actual reverse osmosis desalination process takes place.

The reverse osmosis building is where the actual desalination process takes place. In the reverse osmosis building, there are thousands of pressure vessels and membranes. The pressure vessels ensure that there is enough pressure to push all the water through the membranes. The semi permeable membranes are microscopic strainers with holes just big enough to enable the water molecules to pass through so that the contaminants can be effectively filtered out. All kinds of chemicals including leads, ammonia and etc can be filtered out through the reverse osmosis desalination technology.

Another method is the distillation process where the sea water is being heated to a certain boiling point so that the water can be evaporated into another tank. The evaporated water is the clean water produced in the desalination process. Both reverse osmosis and distillation method uses a lot of energy to produce clean water from the ocean.

Many desalination companies are equipped with thousands of energy recovery device to recover the energy that is used in implementing the desalination process. The energy recovery device plays an important role in helping the desalination company to save millions of kilowatt hours of energy every year. The energy that is saved is equivalent to the tens of thousands of metric tons of carbon dioxide that is being emitted from thousands of vehicles.

In California, desalination is used as the last resort to provide clean water since it because they are leave with no other options. Desalination costs twice the cost of obtaining water from the fresh water sources. However, the desalination companies are investing in research development to lower the cost of producing clean water through desalination.