Reverse Osmosis is an extremely effective process in which pressurized water is pushed through a membrane-filter to remove amazingly small, and even atom-sized contaminants down to almost undetectable amounts. Typically only found in under the counter filtration systems, and used by all of the major bottled water companies, this is considered the “gold standard” of water filtration.
A 4-stage reverse osmosis water purification system will removes virtually all of the contaminants from your water. Here are the states of a typical system:
In stage one, the water passes through a mechanical filter that removes larger particles like sediments, rust and cloudiness from water.
Stage two is the activated carbon pre-filter that removes more than 99% of chlorine and chloramines.
In stage three, the reverse osmosis membrane filters out dangerous chemicals and contaminants including lead, chromium 6, fluoride, radium, uranium and living organisms such as bacteria and parasites.
And finally, in stage four, an activated carbon filter removes toxic organic chemicals including pesticides, fertilizer, and rocket fuel. Stage four is also where many unregulated contaminants like PFA's and drug residue are removed.
Water filtered or treated by Reverse Osmosis is pure, clean, and healthy. It is currently the only technology that can remove most of the emerging contaminants (i.e., prescription drugs and perchlorate) including other contaminants (i.e., Arsenic, Cyanide, and Fluoride) that are difficult to remove by other treatment methods. Some consumers have voiced concerns that Reverse Osmosis water may not be healthy because it removes even essential minerals. However, in 2009 the World Health Organization stated that consumers should not be concerned about this, and in 2011 the Water Quality Association pointed out, that the human body obtains vast majority of minerals from food or supplements, not from drinking water.