Nitrogen Levels Drop In Groundwater

Animal farms and fertilizers add huge amounts of nitrogen pollution to the environment across the developed world. But regulations on agricultural use and disposal of the vital nutrient in Denmark may have successfully curbed nitrogen in groundwater, according to new research published in Environmental Science & Technology.

Excess nitrogen has caused environmental problems such as dead zones in the Chesapeake Bay and Gulf of Mexico estuaries. Groundwater, which is recharged by rainfall and water flowing over the Earth's surface, also carries nitrogen pollution. Since groundwater is a source of drinking water, such pollution also causes concern about human health because of its potential to form carcinogenic compounds called nitrosamines.

In Europe, countries must monitor their nitrogen levels and aim for strict limits set by the European Union Water Framework and Nitrates Directives. To meet these directives' goals, Denmark established a monitoring program 20 years ago. Now researchers from the Geological Survey of Denmark and Greenland and from Aarhus University have put its groundwater data to use.

They started by using the groundwater's levels of chlorofluorocarbons (CFCs) to estimate the date when each pocket of water sampled seeped into underground rocks: because atmospheric CFC levels have changed over time in a known pattern, the researchers could determine the age of each water sample. The researchers then measured nitrate concentrations in the samples and used those findings to estimate how much nitrogen trickled into groundwater from agricultural use over the past 60 years. The nitrogen inputs to groundwater increased between 1950 and 1981, rising from 60 to 180 kg of nitrogen per hectare. Concentrations stagnated until 1995, when levels started to drop. By 2007, the average nitrogen inputs dipped to 117 kg per hectare.

Lead author Birgitte Hansen, a senior scientist at the geological survey, comments that Danish government initiatives enacted in 1985, including limits on how much nitrogen farmers can apply to different crops, seem to have worked. Despite decades-long growth in Denmark's milk and pork production, accompanied by the increases in nitrogen use, less of the nutrient has found its way into groundwater. Hansen speculates that decreases in nitrogen that the team reported to have occurred before 1985 could have stemmed from widespread changes in agricultural practice like reducing the runoff from manure heaps or livestock sheds.

more from Chemical and Engineering News

Drought Drops Lake Mead To Lowest Water Level Since 1937

Lake Mead, the massive reservoir that supplies water to millions of people across the southwestern U.S., has reached its lowest levels in nearly 75 years. Water levels dropped to 1,083 feet above sea level on Oct. 17, the lowest elevation since 1937, when the lake was first filled with the completion of the Hoover Dam. The dropping water level — which beats a previous record set in the 1950s — underscores the effects of drought and increased water demands on the Colorado River. “Everyone needs to know when we turn on the tap, it drains water out of the river and it has ecological consequences,” Gary Wockner, a campaign coordinator for the conservation group Save the Colorado, told the Arizona Republic. If water levels fall another eight feet, officials would have to implement water restrictions for Arizona and Nevada.

from Yale 360

Water Use in Southwest Heads for a Day of Reckoning

A once-unthinkable day is looming on the Colorado River.
Barring a sudden end to the Southwest’s 11-year drought, the distribution of the river’s dwindling bounty is likely to be reordered as early as next year because the flow of water cannot keep pace with the region’s demands.

For the first time, federal estimates issued in August indicate that Lake Mead, the heart of the lower Colorado basin’s water system — irrigating lettuce, onions and wheat in reclaimed corners of the Sonoran Desert, and lawns and golf courses from Las Vegas to Los Angeles — could drop below a crucial demarcation line of 1,075 feet.

If it does, that will set in motion a temporary distribution plan approved in 2007 by the seven states with claims to the river and by the federal Bureau of Reclamation, and water deliveries to Arizona and Nevada would be reduced.

This could mean more dry lawns, shorter showers and fallow fields in those states, although conservation efforts might help them adjust to the cutbacks. California, which has first call on the Colorado River flows in the lower basin, would not be affected.

But the operating plan also lays out a proposal to prevent Lake Mead from dropping below the trigger point. It allows water managers to send 40 percent more water than usual downstream to Lake Mead from Lake Powell in Utah, the river’s other big reservoir, which now contains about 50 percent more water than Lake Mead.

In that case, the shortage declaration would be avoided and Lake Mead’s levels restored to 1,100 feet or so.

more from the NY Times

Bad water? It's the cheese.

A century ago, a band of Swedish families settled in California’s Central Valley, attracted by land that cost $25 an acre and life-sustaining water from the gushing San Joaquin and Merced rivers.

The Mords, the Ahlems, the Nymans and the Wickstroms started dairy farms, milking cows and growing oats and corn for feed. The settlers, joined by Portuguese immigrants, relied on one another to tend irrigation canals and survive choking dust storms and crop-stripping plagues of jackrabbits and grasshoppers. In 1984, to add value to their milk, descendants created an enterprise that grew into Hilmar Cheese Co., one of the world’s largest cheese producers.

Now, much of the well water around the cheese plant, located in the agricultural heart of California, isn’t fit to drink.

New documents show that the cheese is the likely culprit in spoiling at least 18 water wells – probably more – in and around Hilmar. High in nitrates, arsenic, barium and salts, the well water tastes bad and violates federal health standards, increasing the risk of cancer and other health problems.

more from Environmental Health News

On China’s Beleaguered Yangtze, A Push to Save Surviving Species

In the early 20th century, fishers on the Yangtze River regularly snared what may have been the biggest freshwater creature of modern times: the Chinese paddlefish. The behemoth once reached 23 feet in length, a third of that being a paddle-like snout that it used presumably to stir up the river bottom to flush out food. A single paddlefish could feed a village and was especially prized for its caviar. But decades of industrialization in China’s heartland have sounded a death knell for the king of the Yangtze. The last time one was caught was in 2003, and it hasn’t been seen since.

The paddlefish is not the only Yangtze creature to have become the stuff of legend. The last confirmed sighting of the Yangtze river dolphin, or baiji, was in September 2004. The Yangtze giant soft shell turtle, perhaps the largest freshwater turtle on Earth, is apparently extinct in the wild. The last two known individuals, a male and a female, have been united in a Suzhou
Yangtze River
Andrew Wong/Getty Images
About 40 percent of China’s 1.3 billion people live in the Yangtze River basin.
zoo but may be too old or too frail to mate. The Chinese alligator and the Chinese giant salamander are both critically endangered. The Chinese puffer fish and the Yangtze sturgeon are rarely spied these days. The Chinese sturgeon is on life support thanks only to hatcheries that release tens of thousands of fingerlings into the Yangtze each year.

Overfishing, pollution, and habitat fragmentation from dams — including the massive Three Gorges Dam — have brought the Yangtze to its current state. With more dams planned and Chinese officials intoxicated with unbridled economic growth, the future looks just as grim for the Yangtze’s vanishing species. Much of the river basin “will soon be a mere semblance of its natural state, offering few prospects for persistence of what remains of the river’s unique biodiversity,” says David Dudgeon, an aquatic ecologist at the University of Hong Kong.

All is not yet lost, however. Seasonal fishing bans have given some species a breather. “We can save the remaining ecology of the Yangtze,” argues Xie Songguang, an ecologist at the Institute of Hydrobiology in Wuhan. The potential savior that he and others are counting on is a 10-year fishing moratorium. Such a ban may seem drastic, but it would have a tiny effect on fish markets, as the Yangtze supplies less than 1 percent of China’s freshwater fish production, including aquaculture. A ban is feasible — if the political willpower can be summoned to implement it. With the Yangtze’s ecological health in obvious decline and the economic toll of a ban manageable, the prospects for a moratorium are looking better and better, experts say.

more from Yale 360

In China, Three Gorges Dam's image showing some cracks

White-haired Zhao Chengmu lives just below the Three Gorges Dam, China's largest construction project since the Great Wall. If the colossal structure fails, the fragile 77-year-old shop owner will be one of the first to die.

But that's never going to happen, he says.

"This dam will be here for eternity," Zhao boasts. "Even if this dam is hit by a U.S. missile, it won't break — it'll just shake once."

Like Zhao, most Chinese herald their government's monumental enterprise to defy the mighty Yangtze River, choke off its devastating annual floodwaters and harness its raw power to provide cleaner energy. Such a mammoth engineering feat, they say, only serves to underscore mankind's supremacy over nature.

Critics consider the dam in less lofty terms: as Beijing's boondoggle. With an official price tag of $25 billion — and some estimates claiming three times that much — the costliest hydropower project in history demonstrates China's sheer arrogance in trying to tame nature's whims, they say, never mind the 3,000 tons of garbage that have been flowing every day into the reservoir recently.

A year after the dam went into full operation, cracks are already showing in the public image of the project. This year's torrential rains, the nation's worst in a decade, have severely tested the project's capacity to control the surging Yangtze, the world's third-longest river.

Last month, when floodwaters poured into the dam's 400-mile-long reservoir at 565,000 cubic feet per second, a government official acknowledged that "the dam's flood-control capacity is not unlimited" and hinted that more severe flooding could even risk the structure's collapse.

That's a far cry from the highfalutin claims of just a few years ago. In 2003, officials boasted that the dam could withstand the worst flood in 10,000 years. In 2007, the estimate was reduced to 1,000 years. In 2008, it was dropped yet again, this time to just 100 years.

more from the LA Times

Kids in Punjab villages losing sight to polluted drinking water

Shankar Singh, 22, lost his eyesight a decade ago. His younger brother, Visakha Singh, who had no vision problem when he was born, too, lost his sight as he grew up. Welcome to Dona Nanka, a village on the Indo-Pak border where children are going blind apparently after drinking contaminated water.

At least a dozen children were either born blind or have been gradually losing sight within a few years of birth. "I started losing my sight when I was studying in the fifth standard. Gradually, I turned completely blind," Shankar says.

It's the same story in several villages nearby. At Teja Ruhela and Noor Shah villages, scores of children are similarly going blind. Residents say together these villages have at least 50 children and adults who have lost their vision to contaminated water.

At Teja Ruhela, Veena, now 7, lost sight in one eye when she was barely two years old. Veena's father Gurnam Singh took her to Sriganganagar in Rajasthan to restore her eyesight. She underwent an operation but it was not successful.

Shimla Bai, who will turn 11 this year, was born blind. She cannot keep her eyelids open for long as it hurts. Thirteen-year-old Saroj and her friend Jyoti have also been losing sight slowly. These villages drink groundwater hoisted to the surface by several hand-driven pumps.

Shankar's father Mohinder Singh draws water from a hand pump and pours it into a glass.

In about 20 minutes, the water turns yellowish.

"This is what we have been drinking for years," he says.

"There is no other source from which we can draw clean drinking water," he adds.

The government, on its part, has simply painted warnings on the walls of houses that the groundwater is unfit for human consumption.

India Today

Prince of Tides: A Mammoth Turbine

What is being described as the world’s largest tidal power turbine was unveiled this week in Scotland. Dubbed the AK1000 by its developer, the Atlantis Resources Corporation, the one-megawatt turbine weighs 1,430 tons, stands nearly 75 feet tall and has six 60-foot diameter blades that can produce enough electricity to supply more than 1,000 homes.

The turbine will be installed later this summer at the European Marine Energy Center in the far north of Scotland, where it will be used to power a computer data center.

“Today is not just about our technology, it is about the emergence of tidal power as a viable asset class that will require the development of local supply chains employing local people to deliver sustainable energy to the local grid,” Timothy Cornelius, chief executive of Atlantis, said in a statement on Thursday. “The AK1000 takes the industry one step closer to commercial scale tidal power projects.”

Tidal power represents just a tiny fraction of the renewable energy produced worldwide, mostly because of the significant technical hurdles of deploying large turbines in flowing water. The majority of turbines in operation are experimental prototypes deployed in Europe.

Yet as the unveiling of the AK1000 clearly shows, the allure of producing clean, reliable power from the daily in-and-out flux of the tides continues to attract significant investment. And Atlantis faces substantial competition in the race to develop affordable commercial-scale tide power, with dozens of other companies developing a variety of turbine designs.

Flowing water can be tapped for power just as wind is, but because water is far denser than air, its movement contains far more potential energy. Tidal energy has other benefits: as turbines are placed underwater, they are silent and out of sight. And many tidal inlets with significant energy potential are found close to the densely populated urban areas where electricity demand is highest.

Rough and cold seas can cause heavy wear and tear on tidal turbines, but Atlantis says its machines are designed specifically to withstand the rigors of the North Atlantic.

“In order to get a robust turbine, we have had to make what we call ultimately the dumbest, simple but most robust turbine you could possibly put in such a harsh environment,” Mr. Cornelius told BBC Scotland.

from the NY Times