What is Reverse Osmosis?

Q. What is Reverse Osmosis?

A. There are many different membrane technologies, but to removed dissolved contaminates, like nitrate, reverse osmosis (RO) would typically be used.

RO accomplishes essentially the same task as the Fleur Nitrate Removal Facility, albeit through a different approach. Using a special membrane RO prevents contaminants, like nitrate, from entering the finished water.  Unlike the Nitrate Removal Facility, RO removes a lot more than just nitrates, it removes almost everything from water. In fact, RO removes so much it can make the water corrosive.  That is why at the Saylorville Water Treatment Plant, only 60% of the treated water goes through the RO system.   

RO also has a waste stream which contains everything the RO system removed.  RO waste streams are typically much larger, upward of 20-25% of the RO flow.  As a comparison, the waste flow for one of the nitrate removal vessels at the Fleur Drive Plant is approximately 50,000 gallons per day for 1.4 million gallons of low nitrate water, or 3.5%.  

Reverse osmosis systems offer numerous advantages, with the primary one being their ability to remove almost everything. This safeguards against contaminated water sources and future regulatory changes.  The main drawbacks are the requirement for a substantial raw water source and the need to manage a larger waste stream.