There is a stigma, albeit an understandable one, that surrounds the use of treated wastewater as potable water. Because let’s face it, no matter how clean treated wastewater may be, people are still going to be focused on the water’s provenance.
Whether it’s water that’s been micturated in, or water that’s rife with bacteria or inorganic materials, most people would prefer not to have treated water going from these sources to their water taps.
For cities like Singapore that are experiencing explosive population growth amid a climate that continues to be impacted by global warming, turning to innovative methods like water treatment and desalination may help meet the high demand for the natural resource.
The issue of the world’s water supply has been front and center in recent years. An estimated one in every 10 people in the world (nearly 700 million) lack access to safe water, according to Water.org. During the next decade, that number is expected to grow to 1.8 billion people. In 2015, the World Economic Forum listed the water crisis as the No. 1 global risk based on impact to society, which is why turning to alternative sources of water has taken on a new sense of urgency in many countries.
“From a macro perspective, with worldwide population growth, economic vitality and security are dependent on a broader-based water supply portfolio, so communities can’t be dependent on one source,” says Paul Kelley, executive director of CalDesal, a Calif.-based water desalination advocacy group.
Singapore’s ‘NEW’ Solution
Providing 430 million gallons of water each day to the 5.5 million people who call Singapore home is a daunting task for local officials. This is why Singapore gets its water through Four National Taps: local catchment water, imported water, desalinated water and wastewater.
Spread across nearly 278 square miles, Singapore gets its catchment supply from rainwater that’s gathered in all 17 of its reservoirs (the Marina Reservoir alone can supply 10 percent of Singapore’s water demand). It also imports its water from the Johor River in Malaysia, although that agreement is set to end in 2061. Its SingSpring Desalination Plant and Tuaspring Desalination Plant also produce up to 30 million and 70 million gallons a day, respectively.
The truth is, all water is reused.
Then there is NEWater, or high-grade reclaimed water, that undergoes a thorough four-step process of microfiltration, reverse osmosis, ultraviolet disinfection and alkaline to remove contaminants and solids. By 2060, PUB, Singapore’s National Water Agency, predicts that 55 percent of Singapore’s water supply will be NEWater. Also exploring the “toilet-to-tap” strategy are Calif.’s Orange County and Wichita Falls in Texas—two states that have been dealing with historic droughts.
“The truth is, all water is reused,” says Zachary Dorsey, a spokesman for WateReuse, a water advocacy group, adding the water you may be drinking right now “could have once been dinosaur [waste].”
“[Water reuse] is a proven and safe technology,” adds Dorsey.
Countries around the world are already at the forefront of alternative water technologies. In Israel, the Sorek desalination plant, the largest of its kind in the world, can produce 627,000 cubic meters of water a day (roughly 166 million gallons). The M-Station in Jebel Ali in Dubai can produce 140 million imperial gallons of desalinated water each day. The recently opened Claude “Bud” Lewis Carlsbad Desalination Plant can produce 50 million gallons each day. Not to be outdone, Saudi Arabia is already at work with the Ras al-Khair desalination plant, which, at a cost of $7.2 billion, will purportedly have the ability to produce 264 million gallons of drinking water each day. Improvements in energy-efficient technology have also helped reduce the energy required for desalination (Ras Al-Khair uses solar energy as a power source).
Since the ocean covers over 70 percent of the earth’s surface, it makes sense for coastal cities to tap into this neighboring resource. This, in turn, can deliver potable and usable water to the millions of residences and commercial properties that rely on it on a daily basis.
For building owners in Calif., which imposed mandatory water restrictions following a historic drought in the state, keeping an eye on water usage has become an imperative decision, says Peter Scarpelli, global director of energy and sustainability for CBRE.
Water is life, and it’s really the key to social and economic success.
“You have to look at a building’s water usage and where that water is being utilized,” says Scarpelli. “About 70 percent of water is used for outside the building,” he adds, “which is why we have, in recent years, focused on implementing technologies that help us gauge where that water is being used and by how much.” (Calif. recently lifted its drought restrictions.)
Employing existing monitoring technologies and exploring new ways to treat all sources of water (including groundwater and brackish water) will help maintain and meet what’s certain to be an escalating demand for the resource.
“These are the [solutions] we need to think about when it’s a non-emergency situation,” says Dorsey.
Adds Kelley: “Water is life, and it’s really the key to social and economic success.”
28 July 2016 by Daniel Rosen
12 January 2016 by Adam Bonislawski