DID you know that nearly 70 percent of the world is covered by water, but only 2.5 percent of it is fresh? The rest is salt water. Of the measly 2.5 percent, only one percent is easily accessible. The rest is trapped in glaciers and snowfields. Furthermore, the available freshwater is not evenly distributed among nations.

In areas like the Middle East which is rich in oil but lacking in freshwater, they turn to desalination for their water needs. Desalination is the process of removing salt and other minerals from sea water to make it suitable for human consumption and/or industrial use. Due to its energy consumption, desalinating sea water is generally more costly than fresh water from rivers or groundwater, water recycling and water conservation.

According to the United Nations (UN) University, there are now 15,906 operational desalination plants found in 177 countries. Experts estimate the freshwater output capacity of desalination plants at 95 million cubic meters per day, equal to almost half the average flow over Niagara Falls. Two-thirds of such plants are in high-income countries. Almost half of the global desalination capacity is located in the Middle East and North Africa region (48%), with Saudi Arabia (15.5%), the United Arab Emirates (10.1%) and Kuwait (3.7%) being both the major producers in the region and globally.

The Philippines can be considered blessed with abundant source of freshwater, but growing demand and pollution is making clean water scarce. It is no surprise therefore that there are also desalination plants in our country. I could not find any data on how many facilities there are, but I read a news article which says that one company alone, Pilipinas Water Resources, Inc., operates about 60 desalination plants in the Philippines.

The desalination process, as simple as it may seem, has an environmental impact as well. Its byproduct called brine, water with a strong salt concentration, maybe harmful if not handled properly. According to a UN study, the world’s desalination plants discharge 142 million cubic meters of brine daily, which is enough in a year to cover the state of Florida in the US under a foot (30.5 cm) of brine.

The authors of the study cite major risks to ocean life and marine ecosystems posed by brine greatly raising the salinity of the receiving seawater, and by polluting the oceans with toxic chemicals used as anti-scalants and anti-foulants in the desalination process. High salinity and reduced dissolved oxygen levels can have profound impacts on benthic organisms (organisms that live in and on the bottom of the ocean floor), which can translate into ecological effects observable throughout the food chain.

With the right technology however, brine can be of beneficial use. It can be used in aquaculture, to irrigate salt tolerant species, to generate electricity, and by recovering the salt and metals contained in brine, including magnesium, gypsum, sodium chloride, calcium, potassium, chlorine, bromine and lithium.