Closing the Water Cycle

Abstract

This article discusses how wastewater can be recycled for consumption if there is scarcity of water. It gives the example of the Orange County plant that is in operation since 2008, and is the largest “indirect to potable reuse” plant in the world. It is “indirect” because that water does not flow straight from the plant to the faucet. Instead, after being treated with microfiltration, reverse osmosis, and then ultraviolet light, the water is pumped back into the ground. Pumping water to an underground basin gives the county time to react if there’s a problem. The soil also works to remove accidental contaminants. The Orange County facility processes some 70 million gallons of water a day, using 14 different reverse osmosis units. Currently, the water is tested – for total organic carbon – at the point where it is all mixed to a single stream.