The Pure Water Occasional for August 25, 2014
In this end-of-summer back-to-school Occasional, you’ll hear about a California town that’s out of water, a city in Brazil that’s low on water, the low-water crisis of the Great Salt Lake, and evidence of huge water losses in the American west. Drought and more drought. Then there’s the economic failure of big dams, what life is like beneath the ice in Antarctica’s lakes, how oil affects fishing in Ghana, and how fracking affects the San Antonio River. More about the Detroit water crisis, big sewage spills in Detroit and Baltimore, and excessive fluoride in wells in Maine and New Hampshire. Find out what to do with your abandoned swimming pool, learn how backwashing water filters work, and, as always, there is much, much more.
To read this issue on the Pure Water Gazette’s website, please go here. (Recommended! When you read online you get the added advantage of the Gazette’s sidebar feed of the very latest world water news.)
Drought leaves California homes without water
Nearly 1,000 people in East Porterville, CA whose wells have gone dry due to drought received an emergency allotment of bottled water August 22, 2014.
PORTERVILLE, Calif. (AP) — Hundreds of rural San Joaquin Valley residents no longer can get drinking water from their home faucets because California’s extreme drought has dried up their individual wells, government officials and community groups said.
The situation has become so dire that the Tulare County Office of Emergency Services had 12-gallon-per person rations of bottled water delivered on Friday in East Porterville, where at least 182 of the 1,400 households have reported having no or not enough water, according to the Porterville Recorder.
Many people in the unincorporated community about 52 miles north of Bakersfield also have been relying on a county-supplied 5,000-gallon water tank filled with non-potable water for bathing and flushing toilets, The Recorder said.
Emergency services manager Andrew Lockman, said the supplies of bottled water distributed by firefighters, the Red Cross and volunteer groups on Friday cost the county $30,000 and were designed to last about three weeks but are only a temporary fix. To get future deliveries, officials are asking low-income residents to apply for aid and for companies to make bottled water donations like the one a local casino made a few weeks ago.
“Right now we’re trying to provide immediate relief,” Lockman said. “This is conceived as an emergency plan right now.”
Officials said the problem is partly due to the shallowness of some residential wells in East Porterville that are replenished by groundwater from the Tule River, the Fresno Bee said. But river flows are way down due to the ongoing drought, leaving some wells dry.
East Porterville resident Angelica Gallegos fought back tears as she described being without water for four months in the home she shares with her husband,, three children and two other adults.
“It’s hard,” she told The Bee. “I can’t shower the children like I used to.”
Farmworker Oliva Sanchez said she still gets a trickle from her tap, but dirt started coming out with the water about a week ago.
“I try to use the least possible. I’ll move if I have to,” she said.
Along with experiencing inconvenience and thirst, some residents have been reluctant to speak up about being waterless because they are afraid their landlords will evict them or social workers will take their children away, The Recorder reported.
“We want to make it abundantly clear we are not going to make this harder for anyone,” Lockman stressed. “These lists aren’t going anywhere. (Child Welfare Services) isn’t getting a list. They (CWS) made it abundantly clear they are not going to remove children because of no water. We just want to help the people.”
Source: SF Gate.
Large Dams Just Aren’t Worth the Cost
by Jacques Leslie
Introductory Note: The dam is a perfect example of the many things in our lives that are “mixed blessings.” That’s why dams are always controversial.
In one of my favorite novels, Paradox, Rey by Pio Baroja, progressive Europeans bent on saving the world go to Africa to build a dam. Among people and animals there are mixed reactions. The dam helps some and hurts others: the frogs love it, but the snakes hate it; poor people who are promised cheap electricity love it, but poor people who lose their homes hate it. The dam provides water for irrigation, but it covers up much valuable farmland. It provides water for some cities, but it forces abandonment of other cities. It helps one species of fish but hastens extinction of another.
If we are allowed to generalize, we can say that dams are mainly an advantage to the rich and a burden for the poor. But there are exceptions even to that, as the Times editorial reprinted below shows.
Dams are not permanent. They eventually die, choked by the sediment they have collected, and have to be removed. Sometimes they are an advantage to the generations that benefit from their use but they are always a burden to the generations that pay for building them and tearing them down.–Gene Franks.
Dams have pros can cons, but in most ways they are losers for both the builder and the displaced population.
THAYER SCUDDER, the world’s leading authority on the impact of dams on poor people, has changed his mind about dams.
A frequent consultant on large dam projects, Mr. Scudder held out hope through most of his 58-year career that the poverty relief delivered by a properly constructed and managed dam would outweigh the social and environmental damage it caused. Now, at age 84, he has concluded that large dams not only aren’t worth their cost, but that many currently under construction “will have disastrous environmental and socio-economic consequences,” as he wrote in a recent email.
Mr. Scudder, an emeritus anthropology professor at the California Institute of Technology, describes his disillusionment with dams as gradual. He was a dam proponent when he began his first research project in 1956, documenting the impact of forced resettlement on 57,000 Tonga people in the Gwembe Valley of present-day Zambia and Zimbabwe. Construction of the Kariba Dam, which relied on what was then the largest loan in the World Bank’s history, required the Tonga to move from their ancestral homes along the Zambezi River to infertile land downstream. Mr. Scudder has been tracking their disintegration ever since.
Once cohesive and self-sufficient, the Tonga are troubled by intermittent hunger, rampant alcoholism and astronomical unemployment. Desperate for income, some have resorted to illegal drug cultivation and smuggling, elephant poaching, pimping and prostitution. Villagers still lack electricity.
Mr. Scudder’s most recent stint as a consultant, on the Nam Theun 2 Dam in Laos, delivered his final disappointment. He and two fellow advisers supported the project because it required the dam’s funders to carry out programs that would leave people displaced by the dam in better shape than before the project started. But the dam was finished in 2010, and the programs’ goals remain unmet. Meanwhile, the dam’s three owners are considering turning over all responsibilities to the Laotian government — “too soon,” Mr. Scudder said in an interview. “The government wants to build 60 dams over the next 20 or 30 years, and at the moment it doesn’t have the capacity to deal with environmental and social impacts for any single one of them.
“Nam Theun 2 confirmed my longstanding suspicion that the task of building a large dam is just too complex and too damaging to priceless natural resources,” he said. He now thinks his most significant accomplishment was not improving a dam, but stopping one: He led a 1992 study that helped prevent construction of a dam that would have harmed Botswana’s Okavango Delta, one of the world’s last great wetlands.
Part of what moved Mr. Scudder to go public with his revised assessment was the corroboration he found in a stunning Oxford University study published in March in Energy Policy. The study, by Atif Ansar, Bent Flyvbjerg, Alexander Budzier and Daniel Lunn, draws upon cost statistics for 245 large dams built between 1934 and 2007. Without even taking into account social and environmental impacts, which are almost invariably negative and frequently vast, the study finds that “the actual construction costs of large dams are too high to yield a positive return.”
The study’s authors — three management scholars and a statistician — say planners are systematically biased toward excessive optimism, which dam promoters exploit with deception or blatant corruption. The study finds that actual dam expenses on average were nearly double pre-building estimates, and several times greater than overruns of other kinds of infrastructure construction, including roads, railroads, bridges and tunnels. On average, dam construction took 8.6 years, 44 percent longer than predicted — so much time, the authors say, that large dams are “ineffective in resolving urgent energy crises.”
DAMS typically consume large chunks of developing countries’ financial resources, as dam planners underestimate the impact of inflation and currency depreciation. Many of the funds that support large dams arrive as loans to the host countries, and must eventually be paid off in hard currency. But most dam revenue comes from electricity sales in local currencies. When local currencies fall against the dollar, as often happens, the burden of those loans grows.
One reason this dynamic has been overlooked is that earlier studies evaluated dams’ economic performance by considering whether international lenders like the World Bank recovered their loans — and in most cases, they did. But the economic impact on host countries was often debilitating. Dam projects are so huge that beginning in the 1980s, dam overruns became major components of debt crises in Turkey, Brazil, Mexico and the former Yugoslavia. “For many countries, the national economy is so fragile that the debt from just one mega-dam can completely negatively affect the national economy,” Mr. Flyvbjerg, the study’s lead investigator, told me.
To underline its point, the study singles out the massive Diamer-Bhasha Dam, now under construction in Pakistan across the Indus River. It is projected to cost $12.7 billion (in 2008 dollars) and finish construction by 2021. But the study suggests that it won’t be completed until 2027, by which time it could cost $35 billion (again, in 2008 dollars) — a quarter of Pakistan’s gross domestic product that year.
Using the study’s criteria, most of the world’s planned mega-dams would be deemed cost-ineffective. That’s unquestionably true of the gargantuan Inga complex of eight dams intended to span the Congo River — its first two projects have produced huge cost overruns — and Brazil’s purported $14 billion Belo Monte Dam, which will replace a swath of Amazonian rain forest with the world’s third-largest hydroelectric dam.
Instead of building enormous, one-of-a-kind edifices like large dams, the study’s authors recommend “agile energy alternatives” like wind, solar and mini-hydropower facilities. “We’re stuck in a 1950s mode where everything was done in a very bespoke, manual way,” Mr. Ansar said over the phone. “We need things that are more easily standardized, things that fit inside a container and can be easily transported.”
All this runs directly contrary to the current international dam-building boom. Chinese, Brazilian and Indian construction companies are building hundreds of dams around the world, and the World Bank announced a year ago that it was reviving a moribund strategy to fund mega-dams. The biggest ones look so seductive, so dazzling, that it has taken us generations to notice: They’re brute-force, Industrial Age artifacts that rarely deliver what they promise.
Source: New York Times Sunday Review
Water News of the Week
Water crisis threatens thirsty São Paulo. São Paulo is thirsty. A severe drought is hitting Brazil’s largest city and thriving economic capital with no end in sight, threatening the municipal water supply to millions of people.
Does Ghana’s oil boom spell the end for its fishing industry? Fishermen in Ghana say the foreign firms exploring for oil and gas are forcing them out of the waters they have trawled for centuries.
Metro Detroit treatment plants released 4.5B gallons of sewage into rivers after storm. Metro Detroit treatment plants released about 4.5 billion gallons of raw and partially treated sewage into local streams and rivers as a result of last week’s massive rainstorm, according to a preliminary report from the state Department of Environmental Quality.
Ice Bucket Challenge in drought-stricken California? Use dirt, men say. Most everyone by now has heard of the Ice Bucket Challenge, but two men in drought-stricken California are trying to push a message of water conservation by using dirt instead. As in, dumping a bucket of dirt on their heads.
August downpour results in sewage overflow of 12 million gallons in Baltimore. Baltimore city officials belatedly disclosed Friday that sewage overflows topped 12 million gallons during last week’s downpour, four times what had previously been acknowledged.
San Antonio River in frack impact study. A recently published U.S. Geological Survey study looked at the San Antonio River Basin for compounds associated with hydraulic fracturing and produced water – the first of its kind for the river, which flows through some of the busiest areas for Eagle Ford Shale oil and gas drilling.
Researchers who drilled deep into the ice below Antarctica put a camera down the borehole. This is what it looks like on the icy lake bottom.
The discovery of bacteria in an ice-bound lake bolsters the case that similar life could exist elsewhere in the solar system. But on Earth, the find raises the prospect that Antarctic melting will release greenhouse gases.
Researchers have uncovered a thriving community of microbes in a lake some 2,600 feet below the surface of the West Antarctic Ice Sheet, the first direct evidence of life in such lakes and the first window on the ecosystem the microbes occupy.
Genetic evidence extracted from samples of lake water indicates that the lake teems with a wide variety of microbes that make up a complete food chain, with those at the bottom drawing their energy from chemicals in rocks and sediment in the lake bed.
In essence, the community is a frosty variation on the microbial communities that form the bottom of the food chain around hydrothermal vents in the lightless depths of the ocean floor.
The discovery proves the dark, cold bottom of Antarctica is not a sterile domain.
The key significance of the study is not the confirmation that life exists under the ice sheet, but that those organisms will persist in their cold surroundings far from any light energy.
The Occasional has previously featured two stories about similar Russian findings about Lake Vostok.
Nearly 19,500 Detroiters have had their water service interrupted since March 1. The Water and Sewerage Department, under pressure to reduce more than $90 million in bad debt, ordered shutoffs for customers who owed at least $150 or had fallen at least two months behind on their bills. The decision to take such drastic measures, done with little warning, ignited a controversy that prompted protests and arrests, more bad publicity for the struggling city, global dismay, and a warning from the United Nations.
As unusual as it is for the U.N. to raise public health concerns in a country like the United States, these are unusual times in Detroit. The fortunes of this once-prosperous home of the auto industry have plummeted so far that last year it became the largest city ever to file for bankruptcy. The population has dropped from nearly 1.8 million a half century ago to fewer than 700,000 today. Democratic rule was suspended last year when Michigan’s governor appointed an emergency manager to take control.
About 63 trillion gallons of water have been lost to drought in the western United States, enough to blanket the region with 4 inches of water, according to a study published Thursday.
Researchers at the Scripps Institution of Oceanography at the University of California, San Diego, arrived at the conclusion by measuring the level of the earth’s crust with a network of GPS stations that is normally used to predict earthquakes.
When water is lost because of a lack of rain and snow, the earth’s crust rises. The sensors show that the earth’s crust has risen an average of 4 millimeters in the western United States since last year and as much as 15 millimeters in the California mountains.
Wondering what to do with that unused swimming pool in your back yard?
When Dennis and Danielle McClung bought a foreclosed home in Mesa, Ariz., in 2009, their new yard featured a broken, empty swimming pool. Instead of spending a small fortune to repair and fill it, Dennis had a far more prescient idea: He built a plastic cap over it and started growing things inside. Details in Grist.
Is Fluoride in Private Wells Causing an IQ Decline?
Excess fluoride, which may damage both brain and bone, is leaching out of granite and into Maine’s drinking water—and potentially other New England states
by Dina Fine Maron
Locals call it the “Switzerland of Maine” for its breathtaking mountains and picturesque waters, yet Dedham is just one of a cadre of communities in The Pine Tree State where tap water may not be as safe as it appears.
Like the majority of the state, many of Dedham’s denizens rely on private wells for the water they drink, bathe in and perhaps use to make infant milk formula. But the water trickling from the tap—unlike water from its public water sources—goes untested and is not subject to any state or federal guidelines. And although homeowners are encouraged to get their water regularly tested to ensure that worrisome levels of bacteria or naturally occurring minerals have not crept in, many residents do not follow that advice.
Yet newly available data, released in recent months, indicates that in some 10 communities in the state wells harbor dangerously high levels of fluoride. In some cases, the wells contain more than double the level that the U.S. Environmental Protection Agency has deemed the acceptable maximum exposure level.
In small quantities fluoride is known for helping to tamp down the blight of tooth decay; most municipalities in the U.S. add it to their water supplies as a public health measure. The U.S. Centers for Disease Control and Prevention recognizes water fluoridation as one of the top 10 greatest public health achievements of the 20th century.
But at higher levels, fluoride can lead to pitted teeth and discoloration. It also makes bones brittle and more prone to fractures. And recent studies have also linked high levels of fluoride exposure with IQ deficits. A 2012 review article examined some two dozen relevant studies performed outside the U.S.—mostly in China but also a couple in Iran—and found that high fluoride exposures reduce children’s IQs by an average of about seven points. (The studies did not all account for exposures to other potentially harmful substances such as lead, but the sheer volume of them does raise concerns about this association.)
Mainers may be sipping similar amounts of fluoride. “The sort of levels we’re talking about that are high in China are the sort of levels we see in some private wells,” says Andrew Smith, Maine state toxicologist.
In Dedham, for example, data from 37 wells indicates that 37.8 percent of that water is above the state’s maximum exposure guideline for fluoride. Dedham is not alone: in Surry, Prospect, Franklin, Sedgwick, Penobscot, York, Harrison and Stockton Springs, more than 10 percent of the wells appear to have fluoride levels higher than the state cutoff. The level of potential fluoride exposure encountered by residents may be even higher when factoring in fluoride exposures from dental rinses and toothpaste.
The new data on fluoride levels in Maine water is not from a random sampling of homes in Maine nor is it complete. The data comes from homeowners who voluntarily sent water samples into state labs for testing, which potentially skews the sample. But it does provide the first snapshot of what may prove to be a larger problem.
The state’s suggested limit of two milligrams per liter is half of the EPA limit but many public health advocates argue that limit is far too high. The agency is currently considering lowering its cutoff for fluoride exposure, although it does not expect to have completed its review of the issue until 2016. The U.S. Department of Health and Human Services has proposed adding fluoride to water in concentrations no greater than 0.7 milligram per liter to avoid any unwanted health effects.
Why are the Maine levels so high? Geology. Granite—especially certain kinds such as alkali and peraluminous granites—contains high levels of fluoride, boosting the chances of wells drawing it from that water. Certain other New England states such as New Hampshire (known as “The Granite State”) and Rhode Island may also have private wells at risk because they, too, sport large amounts of the potentially problematic rock.
People living in areas with high fluoride concentrations can take steps to mitigate the problem—but it is an open question whether they will. Countertop filters like Brita pitchers are not effective but advanced technology such as reverse osmosis systems (which may start around $150 per unit) will capture much of the fluoride.
Unfortunately even people whose water is contaminated with far more harmful chemicals frequently take no action. Researchers recently surveyed residents of central Maine whose well water contains high levels of arsenic—an odorless, tasteless element that can cause maladies including cancer, blindness and numbness in hands and feet. They reported that 27 percent of those Mainers did nothing about it. When asked why not, people reported a lack of concern about arsenic and reluctance to pay for any mitigating action.
The potential health concerns around arsenic are so much better publicized than fluoride, suggesting that fewer people will protect themselves from excessive fluoride concentrations. Yet Mainers should. “The studies of high fluoride should be taken seriously,” says Harvard University environmental health professor David Bellinger. “We have a long history of first identifying adverse effects at high levels and then, with further and better studies, discovering that there are adverse effects [milder] at levels that we thought were okay.”
Source: Scientific American.
Editor’s Note: Both arsenic and fluoride are easily managed by reverse osmosis.
How Backwashing Filters Work
Backwashing water filters are large tank-style filters that get their name from the fact that they clean and renew themselves by backwashing. Backwashing consists of reversing the flow of water so that it enters from the bottom of the filter bed, lifts and rinses the bed, then exits through the top of the filter tank.
The filter bed itself is a granular substance that is usually referred to as the filter medium. Media (media is plural, medium is singular) are numerous and varied. Common media are granular carbon, sand, garnet, anthracite, zeolite, granular manganese dioxide, and greensand. Many media are known by their brand names of the leading product in the category: Centaur, Filox, Birm, Filter Ag, and KDF, for example.
The picture above shows the filter in “service” position. This is how it works when it is doing the job it is designed to do. The unfiltered water enters from the left and is routed by the control valve into the filter tank. The water then filters slowly through the medium until it reaches the bottom of the tank where it is collected through a specially-designed sieved “basket” at the bottom of the center tube seen in the picture. The filtered water then passes up through the center tube, called a “riser” or a “dip tube,” passes through the control valve, and exits the right side of the filter.
Note that there’s a drain line in the picture, but no water goes through it during the filter’s “service” function.
As the filter operates in the service mode, it traps and holds particles in the filter bed. Also, since water’s nature is to follow the path of least resistance, after a time it begins to cut channels through the medium. As channels or holes in the media bed form, water begins to flow around rather than through the medium. This process is called “channeling,” and it can reduce the effectiveness of the filter considerably.
At a preset time, the control valve initiates a “backwash” to clean the medium of collected particles and to resettle the bed and eliminate channels that have formed.
The backwash is accomplished by sending water down the riser tube from which it enters the filter tank at the bottom. The force of the water is such that it actually lifts the media bed, swirling and tossing the granular medium. The water leaves the filter tank through the control valve, which routes it through the filter’s drain line. Particles that were being held in the bed are washed to drain.
The backwash is an intense rinsing and tossing of the medium that lasts for several minutes. In a standard residential filter, a typical backwash lasts about ten minutes.
After the backwash, the control valve initiates a “rinse” of the bed during which water flows downward through the medium, up through the riser tube, and out the drain. The purpose of this rinse is to rinse and settle the bed and prepare it for return to service flow.
To read the full article about how backwashing filters work, go to the Occasional’s website.
For information from our main website about backwashing filters, here are some places to look:
General Media Guide : Properties of the most common filter media.
Backwash & Flow Characteristics of Filter Media
Backwashing Filter Selection Page for Fleck Filters : Includes a variety of filter sizes. All filters have Fleck control valves.
Please visit our RO Parts Page for tanks and accessories. We also have dedicated parts pages for countertop water filters, undersink filters, and aeration equipment. We stock parts for everything we sell.
Thank you for reading. Please come back next week.
Places to Visit on Our Websites in the meantime.
Garden Hose Filters. Don’t be the last on your block to own one.
Model 77: “The World’s Greatest $77 Water Filter”
”Sprite Shower Filters: You’ll Sing Better!”
Write to the Gazette or the Occasional: firstname.lastname@example.org
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