Archive for the 'water filtering' Category

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Zimbabwe: Filtering Fact From Fiction About D.I.Y. Water Treatment

Photo retrieved from:

“The southern Zimbabwean city of Bulawayo has not been spared the heavy rains that have fallen across Southern Africa; the water is welcome in this semi-arid part of the country, but the coming of the rainy season has provoked fresh memories of the 2008 cholera epidemic.

“Sikhulekile Banda, who lives in Tshabalala, a crowded low-income township, uses makeshift sand filters for both the rainwater she harvests and the brown water she gets sporadically from her kitchen tap.

“”This is what we used when we were growing up in the rural areas, way before independence [in 1980],” she says as she filled a bucket with a perforated bottom with sand.

“She then pours water into the bucket, where it will slowly drip through the night into another container set below. The previously muddy water emerges sparkling clean, but Banda is not sure whether this is enough to protect her family’s health.”

Read More: All Africa

Clean Water At No Cost? Just Add Carbon Credits

Photo retrieved from:

“The villages of Africa and South Asia are littered with the ghosts of water projects past. A traveler winding through the dirt roads and trails of rural India or Ethiopia will find wells, pumps and springs with taps ─ but most of the wells will be contaminated, the pumps broken, the taps rusted away. When the British group WaterAid began its work in the Konso district of southwestern Ethiopia in 2007, the first thing it did was look at what had come before. It found that of 35 water projects built in the area, only nine were functioning.

People who work on providing clean water in poor countries estimate that about half the projects fall into disrepair soon after their builders move on. Sometimes someone loots the pump. Or it breaks and no one knows how to fix it. Or perhaps spare parts are available only in major cities. Or the needed part costs too much for the village to afford ─ even if it is just a few dollars.

Unlike one-shot vaccines, water systems need to function all day, every day, forever. So sustainability ─ the issue we find so important that it started off the Fixes series ─ is particularly crucial. It’s important to donors, who don’t want to see their money wasted. It’s important to the groups that do the work: no project is successful unless it’s taken over by local people to run. And it’s most crucial to villagers themselves, who grow cynical about promises after they see project after project inaugurated only to fail.”

Read more: New York Times

Preparing For A Water-Limited World

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“The data and statistical tools used to plan $500 billion worth of annual global investments in dams, flood-control structures, diversion projects, and other big pieces of water infrastructure are no longer trustworthy,” she writes. “In other words, when it comes to water, the past is no longer a reliable guide to the future.”

The uncertainty of future water supplies and flow patterns is not limited to concerns over dams and diversions. Food security, public health, and life as we know it are also at risk.

Postel describes a “day of reckoning on the horizon” in the U.S. Southwest, for instance. Some scientists predict there is a 50 percent chance that Lake Mead, which stores Colorado River water for tens of millions of people and one million acres of irrigated land, will dry up by 2021.

And she notes that as much as 10 percent of the world’s food is produced through tapping too deep into residual and unreplenished groundwater resources. “This creates a bubble in the food economy far more serious than the recent housing, credit, or dot-com bubbles, for we are meeting some of today’s food needs with tomorrow’s water.”

The Solutions

“The water challenges confronting us locally, regionally, and globally are unprecedented,” Postel writes. The good news, she says, is that we have the economic and technological capacity to make sure global water needs are met. We just have to start using it.

The smarter path to water sustainability also requires us to work with nature and assign it a value for flood protection, water filtration, and other beneficial services it provides, according to Postel. And smarter water users-individuals, cities, utilities, businesses, and farmers-will be more aware of their water footprints and how to reduce them.”

Read more: National Geographic

Why Are We Still Allowing Coastal Development?

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“Agribusiness giant Cargill, which owns the Redwood City site, has made salt in San Francisco Bay for decades. Cargill has downsized in recent years, selling 16,500 acres of salt ponds in the area — 60 percent of its local operations — to the state and federal government in 2002 for $243 million in cash and tax credits. But it held on to the 1,400-acre site near Redwood City that the company believes is suitable for building.

Several years ago Cargill hired Arizona development company DMB to identify future uses for the site, which is separated from downtown Redwood City by busy Highway 101. DMB has proposed Redwood City Saltworks, a planned community with 8,000 to 12,000 low-rise housing units. It includes new schools and retail stores, sports parks and open space along the bay and mass transit links connecting the development with regional bus, train and ferry lines. “This project is the poster child for an integrated, walkable community” said DMB vice president David Smith.

Opponents have other priorities. A long list of conservation groups, neighboring cities, and local government agencies has endorsed restoring the salt flats to their original state: tidal marshes, which filter bay water, provide habitat for fish and birds, and buffer shoreline communities against flooding by soaking up storm surges.”

Read more: AlterNet

E. coli in B.C. water supplies a growing threat: expert

Prof. Asit Mazumder says that to protect water suppplies properly, B.C. municipalities need more authority to control activity around watersheds. (University of Victoria)

“British Columbia could start to see more frequent cases of contaminated drinking water in smaller communities across the province, an expert warns.

“Asit Mazumder, who leads a water research team at the University of Victoria, said he isn’t surprised by the current boil water order in the Comox Valley and last month’s order in White Rock.

“Neither watershed is adequately protected from human activity, but that’s not the fault of the small municipalities, Mazumder told CBC News.

“”Legally, [municipalities] are responsible to provide absolutely safe drinking water,” he said. “But they do not have the authority on the watershed to keep it clean.”"

Read more: CBC News

Clean water bottle wins UK leg of James Dyson Award

Tim Whitehead shows off his invention

Tim Whitehead is now in the running for a £10,000 prize. Photo retrieved from: BBC

“The water bottle contains two chambers. Dirty water is put in an outer chamber and the inner chamber is plunged through it, filtering water particles as small as four microns.

“Once filtered, the water is sterilised by a wind-up ultraviolet bulb in a process lasting 90 seconds.

“A prototype was effective in killing 99.9% of bacteria and viruses.

“Professor Matthew Harrison, who is one of the judges and also director of education programmes at the Royal Academy of Engineering, commented: “Pure provides a practical solution to a real problem – how to get clean drinking water in the most hostile of conditions.

“It has the potential to make a real difference to people’s lives.”

read more: BBC

LA; Water pollution spreading in the Valley

Department of Water and Power, Assistant Manager of Operations, Kathie Hirata walks next to a series of carbon filters that treat the well water at the Tujunga Spreading Grounds in Sun Valley, Calif. (Dean Musgrove/Staff Photographer); LA Daily News

“A plume of toxic chemicals under the San Fernando Valley has expanded so much in recent years that city officials have had to close dozens of water wells and may have to stop drawing local water altogether unless a massive $850 million cleanup effort is undertaken.

“The plume of contaminated water has now grown to about 2 miles wide and 7-10 miles long, and the Department of Water and Power has been forced to close a growing number of wells, said Pankaj Parekh, the DWP’s director of water quality.

“In 2007, the DWP only had to shut down one well because of contamination of the city’s only local water supply. Today, 50 to 55 are shut down at any given time in the North Hollywood and Rinaldi-Toluca well fields.

“As a result of the closed wells, the annual amount of money DWP has had to spend to import water has increased from $7.3 million in 2007 to $174 million now.

“DWP gets 13 percent of its water from the aquifer, 37 percent from the California Aqueduct, 1 percent from recycled water and the agency buys 49 percent from the Metropolitan Water District.

“But the Colorado River, which supplies the MWD, and the Sacramento Delta, which feeds into the aqueduct, have been increasingly limited in recent years because of rising demand, drought and new environmental restrictions.

“We cannot be guaranteed of those supplies into the future,” Parekh said. “We no longer have the luxury to rely on purchasing water to make up for our own water loss.”

read more: LA Daily News

Desalination Nation

The largest U.S. desalination plant is located in Tampa Bay, Florida, and is co-located with a power plant. Image: Natural Resources Defense Council (NRDC)

The largest U.S. desalination plant is located in Tampa Bay, Florida, and is co-located with a power plant. Image: Natural Resources Defense Council (NRDC) Retrieved from:

“There’s no question that the idea of a drought-proof supply of drinking water is a tantalizing one, especially in water-challenged areas. But, as most of us learn pretty early in life, nothing comes for free.

“The process of converting salt water to drinking water is highly energy-intensive. In San Diego it takeseight times more electricity to produce about 325,000 gallons of water through desalination than it takes to pump the same amount of groundwater. Because desalinated water is so energy-dependent, water customers are vulnerable to rises in energy costs.

“This is where desalination stumbles its way into the “energy-water nexus.” In short, generating electricity requires a lot of water, while treating and moving water requires a lot of electricity. Desalination does not help to ease the burden of these interconnected demands, in fact it makes the situation worse.

“Consider the added demand from a new desalination plant on the electric grid – a grid fed by power plants that also require a tremendous amount of water for cooling. In other words, we’re creating drinking water for one water-starved location using massive amounts of electricity generated with massive amounts of water somewhere else. Such a scenario raises an obvious question – Does this make good sense?”

read more: Huffington Post

Wastewater upgrade filters gender-bending chemicals

A mobile fish lab on Boulder Creek is helping researcher assess the health of fish exposed to endocrine-disrupting chemicals polluting the waterway that can cause male fish to be feminized and decline in numbers. REUTERS/Alan Vajda/University of Colorado Denver/Handout

A mobile fish lab on Boulder Creek is helping researcher assess the health of fish exposed to endocrine-disrupting chemicals polluting the waterway that can cause male fish to be feminized and decline in numbers. Retrieved from: Reuters/Alan Vajda/University of Colorado Denver/Handout

“Our bodies are being exposed every day to a variety of chemicals capable of altering our physiological development, including impacts on sensitive human fetuses.”

“Upgrades to a wastewater treatment plant in Colorado helped filter out gender-bending chemicals that were affecting fish, U.S. researchers reported on Monday.

“They said male fish are now taking longer to be feminized by so-called hormone disrupters in one creek in Colorado after standard improvements to a wastewater treatment plant in Boulder in 2008.

“David Norris of the University of Colorado at Boulder had earlier found ethinylestradiol, a female hormone used in contraceptives, in Boulder Creek. His team also had measured bisphenol A and phthalates, which are both used in plastics and which can mimic the effects of hormones, as well as pesticides and antidepressants in the water.”

Sustainable wastewater treatment plant planned in Netherlands

Contract signing ceremony. Seated L-R: Paul Spaan (Managing Director, Water Board Veluwe) and Piet van Helvoort (Board Member, DHV). Standing L-R: Robbert van der Kuij and George Onderdelinden (DHV); Douwe-Jan Tilkema and Patrick Blom (Water Board Veluwe).

“EPE, Netherlands, June 18, 2010 — Water Board Veluwe and engineering consultancy DHV have signed a Design & Build contract with a value of approximately 15 million euro for the replacement of the existing wastewater treatment plant at Epe with a new plant utilizing DHV’s Nereda® technology.

“Water Board Veluwe is the first water management authority to make full use of the highly innovative and sustainable Nereda® technology.

“The new treatment plant will be exceptionally sustainable and cost-effective. DHV intends to replace the existing system with a Nereda® plant, which will treat all wastewater produced in and around the town of Epe (in the east of the Netherlands). This will result in a doubling of the plant’s treatment capacity without increasing its footprint. The new plant will be taken into operation in mid-2011.

“The planned construction of the Nereda® plant in Epe is considered being a milestone in wastewater treatment. International interest in the technology is on the rise, with many experts viewing Nereda® as a major breakthrough in wastewater treatment. The technology is suitable for newly build as well as retrofit projects and for both domestic and industrial wastewater treatment systems; it achieved several national and international awards.”

read more: Water World