As the world’s cities grow to depend increasingly on underground water for drinking and domestic use, better methods are needed to keep it safe from contamination, the CleanUp 2011 conference heard today.

The contaminants of groundwater can be mixed with the local water supply without proper sanitation.

Underground barriers – known as permeable reactive barriers or PRBs – offer a reliable and affordable way to prevent industrial and other forms of toxic pollution from entering the water supply, says Scott Warner, Vice President and Principal Hydrogeologist with the international engineering and project management company AMEC which has offices worldwide and in Australia.

“PRB technology was first applied commercially in California in 1994, and today there are more than 200 barriers installed across North America, Europe, Japan, and Australia,” Mr Warner says. “It is now an accepted and proven technology for passively treating a wide variety of chemicals, including organic solvents, metals, and radionuclides.” Read more

Slow-motion collisions of tectonic plates under the ocean drag about three times more water down into the deep Earth than previously believed, according to a seismic study that spans the Mariana Trench.

The observations from the deepest ocean trench in the world have important implications for the global water cycle, researchers say.

“People knew that subduction zones could bring down water, but they didn’t know how much water,” says Chen Cai, who recently completed his doctoral studies at Washington University in St. Louis and is first author of the paper, which appears in Nature. Read more

Scientists have reached a new low in the cooling of liquid water, hitting -45 degrees Celsius (-49 degrees Fahrenheit). That’s way below the usual freezing point, and shows we still have a lot to learn about the physics of this plentiful substance.

In two separate experiments, water was supercooled right down to 230 Kelvin and 227.7 Kelvin, which is -43.15°C (-45.67°F) and -45.45°C (-49.81°F), respectively.

At these kind of extreme temperatures, it’s almost as if water becomes two different types of liquid, the scientists say – fluctuating between two different states in the same way that we might deliberate over a decision. Read more

The International Energy Agency’s World Energy Outlook 2016 found that energy production currently accounts for 10 percent of the world’s total water withdrawals – most of which is used in power plant operations. If current trends continue, hydro and thermal power’s thirst for water will increase even more. This would result in even higher water withdrawals and water consumption (due to water that is withdrawn and lost to evaporation during the thermal power process).

The more the energy sector depends on water, the more it exposes itself to vulnerabilities. At the same time, climate change is bringing warmer temperatures, increased variability, and increased water scarcity in mid-latitude zones —all which negatively impact the electric power industry. The more the climate warms, the more the power sector will suffer: Experts predict that power production in European thermal plants could drop by 19 percent between 2031 and 2060 due to shut-downs impacted by climate change. Read more

Almost all of the world’s energy generation depends on water in one way or another.

Hydropower and thermoelectric power make up 98 percent of the world’s electricity generation. These two most common forms of power are also the most water-intensive, which makes them extremely vulnerable to drought, competition over water resources and other water shortages.

Hydropower’s dependency on ample water resources is clear. Dams convert falling water—mechanical energy— into electrical energy. Without water, there is no energy source to convert. Such is the case during Kenya’s drought. Read more