Category Archives: drinking water

New Research Casts Doubt on Doomsday Water Shortage Predictions

New Research Casts Doubt on Doomsday Water Shortage Predictions: Scientific American.

MELTDOWN: The melting of mountain glaciers around the world may not contribute as much to water supplies as thought, new research argues. Image: Abhishekjoshi/Flickr

From the Andes to the Himalayas, scientists are starting to question exactly how much glaciers contribute to river water used downstream for drinking and irrigation. The answers could turn the conventional wisdom about glacier melt on its head.

A growing number of studies based on satellite data and stream chemistry analyses have found that far less surface water comes from glacier melt than previously assumed. In Peru’s Rio Santa, which drains the Cordilleras Blanca mountain range, glacier contribution appears to be between 10 and 20 percent. In the eastern Himalayas, it is less than 5 percent.

“If anything, that’s probably fairly large,” said Richard Armstrong, a senior research scientist at the Boulder, Colo.-based Cooperative Institute for Research in Environmental Sciences (CIRES), who studies melt impact in the Himalayas.

“Most of the people downstream, they get the water from the monsoon,” Armstrong said. “It doesn’t take away from the importance [of glacier melt], but we need to get the science right for future planning and water resource assessments.”

The Himalayan glaciers feed into Asia’s biggest rivers: the Indus, the Ganges and the Brahmaputra in India, Pakistan and Bangladesh, and the Yellow and Yangtze rivers in China. Early studies pegged the amount of meltwater in these river basins as high as 60 or 70 percent. But reliable data on how much water the glaciers release or where that water goes have been difficult to develop. Satellite images can’t provide such regular hydrometeorological observations, and expeditions take significant time, money and physical exertion.

New methods, though, are refining the ability to study this and other remote glacial mountain ranges. Increasingly, scientists are finding that the numbers vary depending on the river, and even in different parts of the same river.

Creeping hyperbole
“There has been a lot of misinformation and confusion about it,” said Peter Gleick?, co-director of the California-based Pacific Institute for Studies in Development, Environment and Security. “About 1.3 billion people live in the watersheds that get some glacier runoff, but not all of those people depend only on the water from those watersheds, and not all the water in those watersheds comes from glaciers. Most of it comes from rainwater,” he said.

A key step forward came last year when scientists at Utrecht University in the Netherlands, using remote sensing equipment, found that snow and glacier melt is extremely important to the Indus and Brahmaputra basins, but less critical to others. In the Indus, they found, the meltwater contribution is 151 percent compared to the total runoff generated at low elevations. It makes up about 27 percent of the Brahmaputra — but only between 8 and 10 percent for the Ganges, Yangtze and Yellow rivers. Rainfall makes up the rest.

That in itself is significant, and could reduce food security for 4.5 percent of the population in an already-struggling region. Yet, scientists complain, data are often inaccurately incorporated in dire predictions of Himalayan glacial melt impacts.

“Hyperbole has a way of creeping in here,” said Bryan Mark, an assistant professor of geography at Ohio State University and a researcher at the Byrd Polar Research Center.

Mark, who focuses on the Andes region, developed a method of determining how much of a community’s water supply is glacier-fed by analyzing the hydrogen and oxygen isotopes in water samples. He recently took that experience to Nepal, where he collected water samples from the Himalayan glacier-fed Kosi River? as part of an expedition led by the Mountain Institute.

Based on his experience in the Rio Santa — where it was once assumed that 80 percent of water in the basin came from glacier melt — Mark said he expects to find that the impact of monsoon water is greatly underestimated in the Himalayas.

Jeff La Frenierre, a graduate student at Ohio State University, is studying Ecuador’s Chimborazo glacier, which forms the headwaters of three different watershed systems, serving as a water source for thousands of people. About 35 percent of the glacier coverage has disappeared since the 1970s.

La Frenierre first came to Ecuador as part of Engineers Without Borders to help build a water system, and soon started to ask what changes in the mountain’s glacier coverage would mean for the irrigation and drinking needs of the 200,000 people living downstream. Working with Mark and analyzing water streams, he said, is upending many of his assumptions.

Doomsday descriptions don’t fit
“The easy hypothesis is that it’s going to be a disaster here. I don’t know if that’s the case,” La Frenierre said. He agreed that overstatements about the impacts are rampant in the Himalayas as well, saying, “The idea that 1.4 billion people are going to be without water when the glaciers melt is just not the case. It’s a local problem; it’s a local question. There are places that are going to be more impacted than other places.”

Those aren’t messages that environmental activists will likely find easy to hear. Armstrong recalled giving a presentation in Kathmandu on his early findings to a less-than-appreciative audience.

“I didn’t agree with the doomsday predictions, and I didn’t have anything that was anywhere near spectacular,” Armstrong said. But, he added, “At the same time, it’s just basic Earth science, and we want to do a better job than we have been.”

The more modest numbers, they and other scientists stressed, don’t mean that glacier melt is unimportant to river basins. Rather, they said, they mean that the understanding of water systems throughout the Himalayan region must improve and water management decisions will need to be made at very local levels.

“We need to know at least where the water comes from,” Armstrong said. “How can we project into the future if we don’t know where the water comes from now?”

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500

The Problem with the Nation's Drinking Water Standards

Is It Safe to Drink? The Problem with the Nation’s Drinking Water Standards: Scientific American.

More than 6,000 chemicals pollute U.S. drinking water, yet the U.S. Environmental Protection Agency has added only one new pollutant to its regulatory roster in the past 15 years. Environmental groups have long raised questions about this track record, and the U.S. Government Accountability Office recently joined the chorus, releasing a report that charges the agency with taking actions that have “impeded … progress in helping assure the public of safe drinking water.”

Among other things, the GAO report says, the EPA relies on flawed data. To determine the level of a particular pollutant in drinking water—which the EPA does before making a regulatory ruling on it—the agency relies on analytic testing methods so insensitive that they cannot identify the contaminants at levels expected to cause health effects. In addition, since 1996 the EPA has been required to make regulatory decisions about five new pollutants each year, ruling on those that might pose the biggest threats to public health. The GAO report asserts that the agency has been ruling only on the “low-hanging fruit”—contaminants for which regulatory decisions are easy rather than those that might be the most dangerous. “They’re not actually doing anything to protect public health,” says Mae Wu, an attorney at the Natural Resources Defense Council.

For its part, the EPA has pledged to review the nation’s drinking-water standards and to add at least 16 new contaminants to the list of those it regulates. This past February the agency reversed a long-standing decision to not regulate the rocket-fuel ingredient perchlorate, making the chemical the first new drinking-water contaminant to be regulated since 1996. In its response to the GAO, the EPA stated that “no action” was necessary to better prioritize the contaminants on which the agency will rule in the future, nor did it acknowledge the need for improvements in data collection. The agency did, however, agree to consider improving its methods for alerting the public when there are drinking-water advisories.

Shale Gas Needs More Openness & Better Data – ScienceInsider

Federal Committee: Shale Gas Needs More Openness, Better Data – ScienceInsider.

A U.S. Department of Energy committee has waded into the fracas over the production of natural gas from shale using the controversial hydrofracturing, or fracking, technology, with a call for shared data. Much about how industry produces shale gas must be improved, a report released today finds, in order to reduce shale gas’s environmental impact. “We share the belief that development can be done in a way that results in minimal impacts,” says geophysicist Mark Zoback of Stanford University, one of seven members of the subcommittee advising Secretary of Energy Steven Chu. But “to do that, there have to be improvements in the way shale gas companies do their business.”

The subcommittee to the secretary’s Energy Advisory Board was not asked who should be regulating shale gas, Zoback says. Regulation now lies primarily with the states. But “we’re pointing out what can and should be done.” To regain public trust, the report says, much information about shale gas should become readily available to the public, starting with the chemical recipes for the fluids pumped at high pressure into shale to free up the gas. Those fluids sometimes spill onto the surface and into waterways. And much more information should be gathered on the environment before, during, and after drilling. The debate over whether and how drilling and fracking contaminate groundwater with gas—the infamous flaming water faucet of the documentary Gasland—would benefit especially. “We feel very strongly that having good data will advance a lot of the issues,” Zoback says.

Some sort of national organization focused on shale gas should also be formed, the report says. It could create a national database of all public information as well as disseminate best practices to industry as they evolve. Added support for existing mechanisms that aid communication among state and federal regulators would also help.

“It’s a remarkable report,” says Philip Sharp, president of the think tank Resources for the Future in Washington, D.C. “It’s a balanced, high-caliber group with public input. The report is remarkable in having honest, actionable proposals in it. What they say will get attention.”

Simulation shows it’s possible to tow an iceberg to drought areas

Simulation shows it’s possible to tow an iceberg to drought areas.

Iceberg

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Image credit: Trevor Williams.

(PhysOrg.com) — Way back in the 70’s Georges Mougin, then an engineering graduate, had a big idea. He suggested that icebergs floating around in the North Atlantic could be tethered and dragged south to places that were experiencing a severe drought, such as the Sahel of West Africa. Mougin received some backing funds from a Saudi prince but most “experts” at the time scoffed at his idea and the whole scheme was eventually shelved.

Cut to 2009 and French software firm Dassault Systemes, who thought maybe Mougin was on to something after all and contacted him to suggest modeling the whole idea on a computer. After applying 15 engineers to the problem, the team concluded that towing an from the waters around Newfoundland to the Canary Islands off the northwest coast of Africa, could be done, and would take under five months, though it would cost nearly ten million dollars.

In the simulation, as in a real world attempt, the selected iceberg would first be fitted with an insulating skirt to stave off melting; it would then be connected to a tugboat (and a kite sail) that would travel at about one knot (assuming assistance from ocean currents). In the simulated test, the iceberg arrived intact having lost only 38 percent of its seven ton mass.

A real world project would of course require hauling a much bigger berg; experts estimate a 30 million ton iceberg could provide fresh water for half a million people for up to a year. There would also be the problem of transporting the water from the berg in the ocean to the drought stricken people. The extraordinary costs for such a project would, it is assumed, come from the price tag for the skirt, five months of diesel fuel for the tugboat, the man hours involved and then finally, distribution of the fresh water at the destination.

Scientists estimate that some 40,000 icebergs break away from the polar ice caps each year, though only a fraction of them would be large enough to be worth the time and expense of dragging them to a place experiencing a drought, such as the devastating one currently going on in the Horn of Africa.

Mougin, newly reinvigorated by the results of the recent study, at age 86, is now trying to raise money for a real-world test of the idea.

'Super sand' to clean up dirty drinking water?

BBC News – ‘Super sand’ to help clean up dirty drinking water.

Papua New Guinea The technology could help improve access to clean water in developing countries

Contaminated water can be cleaned much more effectively using a novel, cheap material, say researchers.

Dubbed “super sand”, it could become a low-cost way to purify water in the developing world.

The technology involves coating grains of sand in an oxide of a widely available material called graphite – commonly used as lead in pencils.

The team describes the work in the American Chemical Society journal Applied Materials and Interfaces.

In many countries around the world, access to clean drinking water and sanitation facilities is still limited.

The World Health Organization states that “just 60% of the population in Sub-Saharan African and 50% of the population in Oceania [islands in the tropical Pacific Ocean] use improved sources of drinking-water.”

The graphite-coated sand grains might be a solution – especially as people have already used sand to purify water since ancient times.

Coating the sand

But with ordinary sand, filtering techniques can be tricky.

“Given that this can be synthesized using room temperature processes and also from cheap graphite sources, it is likely to be cost-efficient” Mainak Majumder Monash University, Australia

Wei Gao from Rice university in Texas, US, told BBC News that regular coarse sand was a lot less effective than fine sand when water was contaminated with pathogens, organic contaminants and heavy metal ions.

While fine sand is slightly better, water drains through it very slowly.

“Our product combines coarse sand with functional carbon material that could offer higher retention for those pollutants, and at the same time gives good throughput,” explained the researcher.

She said that the technique the team has developed to make the sand involves dispersing graphite oxide into water and mixing it with regular sand.

“We then heat the whole mixture up to 105C for a couple of hours to evaporate the water, and use the final product – ‘coated sand’ – to purify polluted water.”

Cost-efficient

Sand “Super sand” is made using regular sand – and it could become a low-cost way to purify water

The lead scientist of the study, Professor Pulickel Ajayan, said it was possible to modify the graphite oxide in order to make it more selective and sensitive to certain pollutants – such as organic contaminants or specific metals in dirty water.

Another team member, Dr Mainak Majumder from Monash University in Melbourne, Australia, said it had another advantage – it was cheap.

“This material demonstrates comparable performance to some commercially available activated carbon materials,” he said.

“But given that this can be synthesized using room temperature processes and also from cheap graphite sources, it is likely to be cost-efficient.”

He pointed out that in Australia many mining companies extract graphite and they produce a lot of graphite-rich waste.

“This waste can be harnessed for water purification,” he said.