What is Reverse Osmosis?

Clean drinking water is a priority for every community, and achieving it comes with many challenges. Finding a solution that tackles heavy metals, PFAS, microplastics, and other contaminants, while also being reliable and sustainable, seems incredibly difficult, and may require a combination of systems. One solution that has gained popularity over the past few decades is reverse osmosis, a process in which water is pushed through a very small filter using pressure. 

The filter pore size is about 0.0001 microns, allowing water molecules to pass through, but trapping most other substances, even those dissolved in water, leading Forbes to call it “one of the most effective forms of water filtration”. However, the filtration process being so effective has some unexpected consequences. While more pure water is good for things like cooking, some minerals are healthy for humans to consume and have benefits, such as calcium, potassium, and fluoride. Sacrificing positive minerals to avoid the negative effects of heavy metals like lead may seem worth it, however reverse osmosis can also make water more acidic, making the treated water more corrosive. Acidic water breaks down lead and copper pipes faster, so old plumbing systems could still end up leaching heavy metals into drinking water anyway.

In communities where water pollution is a major concern, reverse osmosis can be very useful. For example, many towns in Iowa struggle with nitrates contaminating their water supply. Iowa Public Radio (IPR) reported on this issue, explaining that the excess nitrates are largely due to fertilizers and manure. High levels of nitrates have been linked to infant methemoglobinemia, more commonly known as “blue baby syndrome”, cancer, and other negative health effects. By adopting reverse osmosis systems, many Iowans are making their water supply safer. 

Unfortunately, there is a major financial barrier in installing reverse osmosis filters. These systems can cost anywhere from hundreds to thousands of dollars, and it is highly recommended to hire a professional to install it, adding more to the total cost. Filters must be replaced regularly, ranging from a couple of times a year to once every few years, depending on the system and water usage. Forbes also cautions that reverse osmosis systems can be costly to maintain in general and may require professional assistance. IPR also notes that customers not changing filters is a problem professionals run into sometimes, and that this mitigates the benefits of the system.

In addition to the steep price of installation and maintenance, reverse osmosis systems use and waste a lot of water. The United States Environmental Protection Agency (US EPA) reports that a typical point-of-use reverse osmosis system wastes about 5 gallons of water per gallon produced, with more inefficient models wasting 10 or more gallons. Not only is this not environmentally friendly, but the increased water usage will increase water bills. While many forms of water purification have water waste, wasting five to ten times as much water as is produced is very significant.

Reverse osmosis is one of the most effective filtration solutions available for removing a wide range of contaminants, making it a good option for communities with significant water quality concerns. However, its cost, maintenance requirements, and significant water waste mean it is not the ideal solution for every home or building. Instead, reverse osmosis may be most effective if paired with other strategies that address corrosion, plumbing infrastructure, and overall water quality.

References:

1. Learn The Pros And Cons Of Reverse Osmosis Water Filtration Systems

2. Experts say reverse osmosis may be effective but isn't a solution for everyone

3. Point-of-Use Reverse Osmosis Systems