Much of the western United States pipes obtain water from far way. A number of states divide up the waters of the Colorado River, in some cases using many miles of canals to get it to its final destination. So much of the water of the Colorado River is divided up that the mouth of this mighty river has all but dried up.
This is just one example of the degree to which growing population and modernization have put an excess demand on the available supplies of freshwater across the world. It is increasingly necessary to turn to other potential sources of water, specifically saltwater and wastewater.
Obviously, salt water and wastewater cannot be used as is. That would be inordinately harmful to human health and welfare, as well as the health and welfare of the ecosystems upon which people depend upon for so many vital resources and basic needs, including food.
Commercial reverse osmosis systems play an important role in this growing trend of maximizing feasible water sources. Such systems are capable of removing salt, other minerals, and even contaminants, like pesticides and certain microorganisms.
Mankind is now facing the limits of freshwater availability, and some places have long exceeded them. As this situation worsens, reverse osmosis will become an increasingly important piece of the puzzle. You can only go so far with using less before quality of life goes down. Reverse osmosis makes more freshwater available from promising water supply sources.