Making Used Water Potable Again
Water Amid growing concerns over the global supply of water and droughts here at home, innovators are tapping unlikely sources for fresh water—and achieving startling results.
Unless we can figure out how to harvest water from Mars, for the foreseeable future, we’re going to have to be creative with the water available here on Earth.
But just like Matt Damon found creative ways to summon new sources of water in the movie “The Martian,” today’s scientists and innovators are showing us what the future holds and, increasingly, the process of “potable reuse” is part of the picture.
How it works
Wastewater that comes from our homes and businesses—including water from our bathrooms—is first cleaned to a point where it is most often discharged back to the environment. Rather than sending it back into a river or ocean, however, the cleaned wastewater is further purified through a combination of cutting-edge technologies, such as microfiltration or ultrafiltration, reverse osmosis, advanced oxidation processes using ultraviolet or ozone, among others.
Collectively, these advanced technologies remove any remaining harmful bacteria, viruses and other contaminants—even trace chemicals. By the end of the lengthy purification train, water engineers can produce a stream of water that is as clean as and cleaner than the water that now comes from your tap (or bottle, for that matter).
“The truth is, with today’s technology, all water this side of Mars is potential source of water.”
Why we need it
Ultimately, the purified water can be used to augment available water supplies, making communities more resilient in the face of water shortages.
There have been starts and stops for potable reuse in the United States, with the primary barrier being public perception. But with experience and education, attitudes are likely to change. Drought and the specter of climate change have water managers examining how to make every drop go further by expanding and diversifying their water portfolios—including purifying and reusing water.
Last year I visited arid El Paso, TX, where a fully functioning pilot project was cleaning wastewater to quality that was suited for drinking. Two other Texas utilities have already successfully implemented potable reuse, and there are a small number of existing and planned projects in California.
So you might say potable reuse is coming of age. The truth is, with today’s technology, all water this side of Mars is potential source of water. And as water supply concerns grow, the notion of widespread potable reuse may not seem so out of this world after all.