Gazette Technical Wizard Pure Water Annie Takes on the Persistent Questions about TDS Measurement in Home Reverse Osmosis Units

 How do I know when to change my RO membrane?

Some sellers say every two years, other say every three.  Actually, the only really good way to know is to own a TDS tester, test the water from the unit once or twice a year, and change the membrane when the meter tells you it’s time.  Membranes can last many, many years, and there is no reason ever to change a membrane that is performing well.

What does TDS mean, and what’s a TDS meter?

TDS stands for “Total Dissolved Solids.”  It is basically a measurement of all the “solids,” or minerals, dissolved in the water.  The “dissolved solids”  consist mainly of calcium and magnesium (hardness minerals) and sodium, chloride, and sulfate.  A TDS tester for home use is a small electronic tester that measures these solids by passing a weak electrical current through the water and determining how well the water conducts electricity.  The higher the dissolved solids content, the more easily the water conducts electricity and the higher the number shown on the meter.

Does my RO unit remove the TDS from the water?

Yes, a healthy RO membrane will normally “reject” 90% or more of the dissolved solids and send them down the drain pipe.  RO units and distillers lower dissolved solids. as do “deionizers.” Filters don’t removed dissolved minerals.  No matter how many sediment filters or carbon filters you run the water through, the TDS reading will remain the same.

Is TDS bad?  How high should it be?

Within the normal range of fresh water, TDS isn’t a big health issue.  The EPA sets a limit of 500 parts per million Total Dissolved Solids as a drinking water standard, but many US cities violate that and their citizens do fine. Obviously, there is a point where water starts tasting bad. This varies depending on which minerals are involved. Naturally soft water with a TDS of 500 that’s mainly sodium, for example, can taste very good.  There is, of course, a limit: sea water is over 30,000 parts per million and is undrinkable. When water gets over 1000 ppm TDS you normally won’t like the way it tastes.

My local tap water is 250 ppm Total Dissolved Solids.  If you’re saying this isn’t “bad for me,” why bother to measure my RO unit’s dissolved solids performance?  What does it matter whether the RO unit reduces the TDS or not?

TDS measurement is the standard way of evaluating overall performance of the RO unit.  The assumption is that if the unit is making a 90% reduction of calcium and sodium, it’s also reducing arsenic and fluoride with equal effectiveness.  As it loses its ability to reduce TDS, it loses its ability to remove chromium. In other words, TDS readings are taken to determine how well the membrane is working.

What does “% rejection” mean?

Percent rejection is a calculation used to express how well the RO unit is working.  It is determined as follows:

TDS of the feed water (determined by testing your tap water at the kitchen sink) minus the TDS of the permeate (the water that comes out of the RO unit’s faucet) divided by the TDS of the feed water and multiplied by 100.

So, for example, if your tap water reads 280 and your RO product water reads 15, you determine the percent rejection of the RO unit by subtracting 15 from 280 to get 265, dividing 265 by 280 to get 0.946, then multiplying by 100 to get 94.6% rejection.  Your RO unit is running well.

You actually don’t have to work through this whole formula to know if you’re RO unit is running well.  If the RO water tests 1/10 or less of the tap water, it’s doing fine. If your tap TDS is 280 and the RO water reads 28 or less, leave the membrane alone.

At what TDS reading should you change the membrane?

That’s a personal choice and there isn’t a specific answer that fits all situations.  Consider, for example, that if your tap water TDS is only 65  you might want to cut your membrane some slack and not stick strictly to the 10% rule.

Are there factors that affect TDS readings that should be considered?  

First, never test your TDS immediately after changing your filters.  You’ll get an artificially high reading because of impurities that your eye can’t see being put out by the new post filter.  Also, keep in mind that cold water reads lower than warm and a stopped up pre-filter can rob the membrane of pressure and diminish its performance. Lots of things can affect TDS readings, so don’t pull the plug on your membrane if you get one bad test reading.

Major Study in Great Britain Links Fluoride in Water to Hypothyroidism, and A New US Study Links Fluoride ot ADHD in the United States

Gazette Introductory Note: A bad week for promoters of water fluoridation saw two significant research publications.  One, from the prestigious British Medical Journal, reported a significant increase in hypothyroidism in fluoridated areas in the UK as compared with unflouoridated; the second, from the journal Environmental Health, revealed a rise in attention deficit hyperactivity disorder  (ADHD) in American children exposed to artificial water fluoridation.  These studies both received wide press attention at a time when fluoridation is being rejected or discontinued in a growing number of American cities.–Hardly Waite.

A major new fluoridation study was published this week in the Journal of Epidemiology and Community Health–a British Medical Journal (BMJ) publication—and it has already received major media attention.  The study, entitled Are fluoride levels in drinking water associated with hypothyroidism prevalence in England?  A large observational study of GP practice data and fluoride levels in drinking water, is the first study to ever look at fluoridation and hypothyroidism in a large population (in this case, England).  The study found a relatively strong and statistically significant effect, with General Practice (GP) areas being 62% more likely to have high rates of diagnosed hypothyroidism if their drinking water fluoride levels were above 0.7ppm compared to areas with fluoride levels below 0.3ppm.  This was after researchers had accounted for key variable, which are other factors that influence hypothyroid rates.

In an additional comparison of two large metropolitan regions, one that is artificially fluoridated at a level of about 1.0 ppm (greater Birmingham area), and the other which is nearby and similar demographics but is not artificially fluoridated (greater Manchester), the study found a 94% greater probability that GPs in fluoridated Birmingham would have high hypothyroidism rates compared to Manchester.

For all of England, the prevalence rate of hypothyroidism was almost 10% greater in.those GPs with higher fluoride levels compared to those with lowest levels .

The findings led to the researchers calling for a “rethink of public health policy to fluoridate the water supply,” adding “consideration needs to be given to reducing fluoride exposure, and public dental health interventions should stop [those] reliant on ingested fluoride and switch to topical fluoride-based and non-fluoride-based interventions.”

Read the report of the study.

Additional studies on thyroid and fluoride:

Here are other media articles reporting on the BJJ study:

-The Telegraph, Fluoride in drinking water may trigger depression and weight gain, warn scientists

-Newsweek, Water fluoridation may increase risk of underactive thyroid disorder

-The Yorkshire Post, Fluoride in water increases risk of thyroid illness ‘by 30 per cent’

-Boots WebMD (Boots is the largest pharmacy in the UK), Scientists call for rethink on fluoride in water

-The Telegraph, The extent of water fluoridation in the UK

Just when you thought we wouldn’t get any more bombshells this week, a study was published later in the week linking fluoridation to attention deficit hyperactivity disorder (ADHD) in the United States.

The study entitled, “Exposure to fluoridated water and attention deficit hyperactivity disorder prevalence among children and adolescents in the United States: an ecological association,” was published in the journal Environmental Health.  According to the authors:

“State prevalence of artificial water fluoridation in 1992 significantly positively predicted state prevalence of ADHD in 2003, 2007 and 2011, even after controlling for socioeconomic status.

A multivariate regression analysis showed that after socioeconomic status was controlled each 1% increase in artificial fluoridation prevalence in 1992 was associated with approximately 67,000 to 131,000 additional ADHD diagnoses from 2003 to 2011. Overall state water fluoridation prevalence (not distinguishing between fluoridation types) was also significantly positively correlated with state prevalence of ADHD for all but one year examined.

Conclusions: Parents reported higher rates of medically-diagnosed ADHD in their children in states in which a greater proportion of people receive fluoridated water from public water supplies.” 

Reference: Fluoride Action Network.

A Thirsty, Violent World

by Michael Specter

Angry protesters filled the streets of Karachi last week, clogging traffic lanes and public squares until police and paratroopers were forced to intervene. That’s not rare in Pakistan, which is often a site of political and religious violence.

But last week’s protests had nothing to do with freedom of expression, drone wars, or Americans. They were about access to water. When Khawaja Muhammad Asif, the Minister of Defense, Power, and Water (yes, that is one ministry), warned that the country’s chronic water shortages could soon become uncontrollable, he was looking on the bright side. The meagre allotment of water available to each Pakistani is a third of what it was in 1950. As the country’s population rises, that amount is falling fast.

Dozens of other countries face similar situations—not someday, or soon, but now. Rapid climate change, population growth, and a growing demand for meat (and, thus, for the water required to grow feed for livestock) have propelled them into a state of emergency. Millions of words have been written, and scores of urgent meetings have been held, since I last wrote about this issue for the magazine, nearly a decade ago; in that time, things have only grown worse.

The various physical calamities that confront the world are hard to separate, but growing hunger and the struggle to find clean water for billions of people are clearly connected. Each problem fuels others, particularly in the developing world—where the harshest impact of natural catastrophes has always been felt. Yet the water crisis challenges even the richest among us.

California is now in its fourth year of drought, staggering through its worst dry spell in twelve hundred years; farmers have sold their herds, and some have abandoned crops. Cities have begun rationing water. According to the London-based organization Wateraid, water shortages are responsible for more deaths in Nigeria than Boko Haram; there are places in India where hospitals have trouble finding the water required to sterilize surgical tools.

Nowhere, however, is the situation more acute than in Brazil, particularly for the twenty million residents of São Paulo. “You have all the elements for a perfect storm, except that we don’t have water,” a former environmental minister told Lizzie O’Leary, in a recent interview for the syndicated radio show “Marketplace.” The country is bracing for riots. “There is a real risk of social convulsion,” José Galizia Tundisi, a hydrologist with the Brazilian Academy of Sciences, warned in a press conference last week. He said that officials have failed to act with appropriate urgency. “Authorities need to act immediately to avoid the worst.” But people rarely act until the crisis is directly affecting them, and at that point it will be too late.

It is not that we are actually running out of water, because water never technically disappears. When it leaves one place, it goes somewhere else, and the amount of freshwater on earth has not changed significantly for millions of years. But the number of people on the planet has grown exponentially; in just the past century, the population has tripled, and water use has grown sixfold. More than that, we have polluted much of what remains readily available—and climate change has made it significantly more difficult to plan for floods and droughts.

Success is part of the problem, just as it is with the pollution caused by our industrial growth. The standard of living has improved for hundreds of millions of people, and the pace of improvement will quicken. As populations grow more prosperous, vegetarian life styles often yield to a Western diet, with all the disasters that implies. The new middle classes, particularly in India and China, eat more protein than they once did, and that, again, requires more water use. (On average, hundreds of gallons of water are required to produce a single hamburger.)

Feeding a planet with nine billion residents will require at least fifty per cent more water in 2050 than we use today. It is hard to see where that water will come from. Half of the planet already lives in urban areas, and that number will increase along with the pressure to supply clean water.

“Unfortunately, the world has not really woken up to the reality of what we are going to face, in terms of the crises, as far as water is concerned,” Rajendra Pachauri, the chairman of the International Panel on Climate Change, said at a conference on water security earlier this month. “If you look at agricultural products, if you look at animal protein, the demand for which is growing—that’s highly water intensive. At the same time, on the supply side, there are going to be several constraints. Firstly because there are going to be profound changes in the water cycle due to climate change.”

Floods will become more common, and so will droughts, according to most assessments of the warming earth. “The twenty-first-century projections make the [previous] mega-droughts seem like quaint walks through the garden of Eden,” Jason Smerdon, a climate scientist at Columbia University’s Lamont-Doherty Earth Observatory, said recently. At the same time, demands for economic growth in India and other developing nations will necessarily increase pollution of rivers and lakes. That will force people to dig deeper than ever before into the earth for water.

There are ways to replace oil, gas, and coal, though we won’t do that unless economic necessity demands it. But there isn’t a tidy and synthetic invention to replace water. Conservation would help immensely, as would a more rational use of agricultural land—irrigation today consumes seventy per cent of all freshwater.

The result of continued inaction is clear. Development experts, who rarely agree on much, all agree that water wars are on the horizon. That would be nothing new for humanity. After all, the word “rivals” has its roots in battles over water—coming from the Latin, rivalis, for “one taking from the same stream as another.” It would be nice to think that, with our complete knowledge of the physical world, we have moved beyond the limitations our ancestors faced two thousand years ago. But the truth is otherwise; rivals we remain, and the evidence suggests that, until we start dying of thirst, we will stay that way.

Source: The New Yorker.

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 Pure Water Annie’s FAQ Series

Gazette Technical Writer Pure Water Annie Answer’s the Persistent Questions about Water Treatment

This Week’s Topic: Regenerating Water Softeners with Potassium Chloride

Why do some people use potassium chloride rather than salt to regenerate their water softener?

The main reason is to avoid using  sodium–for health or environmental reasons.  In fact, some cities require its use in an effort to limit sodium levels in wastewater.

How does the cost compare with standard softener salt?

Potassium chloride (KCl) is more expensive, considerably more expensive in some areas. Also, salt is more readily available.  Since potassium is used in farm fertilizer, it’s in much shorter supply and it may eventually get very expensive.

I’ve heard you have to use more potassium chloride than standard softener salt to regenerate the softener.  Is this true?  

In theory, it would seem to be true, but research has shown that this isn’t a big factor.  In one study, when using 15 lbs. of salt per cubic foot of resin for regeneration, standard salt was only about 2% more efficient than potassium chloride.

Are there problems with potassium chloride?

Other than the cost and in some areas the lack of availability, one issue is the tendency under certain conditions (mainly temperature swings when softeners are installed in unheated areas) for a condition called recrystallization to occur.  This is similar to the condition called “salt bridge,”  with regular salt, but when temperatures fluctuate potassium chloride can precipitate and drop to the bottom of the brine tank forming a solid mass beneath the salt grid platform. There are strategies to alleviate this which include insulating the brine tank or elevating the tank on a wooden platform.

I have a reverse osmosis drinking water system.  They told me it takes the sodium out of my softened water.  Is this true?

Yes.  It will also remove potassium, so if you have an RO unit for drinking water, your choice of a regenerant has no health implications.

And if I don’t have an RO unit?

The amount of sodium you ingest in softened water is pretty insignificant when compared with your total sodium intake, so drinking softened water normally isn’t important. For people trying to eliminate all sources of sodium, of course, it may be a different story.

If I want to try potassium chloride in my softener, do I need to make modifications?

No,  salt and potassium chloride both work well in standard water softeners.

How razing the rainforest has created a devastating drought in Brazil

Twenty million people in Sao Paolo now face severe rationing due to the disruption of the far-away Amazon’s rain-making machine,

by Geoffrey Lean

 ^{The vast forest generates its own rain, which then falls across the country.}

Arsenic, nitrates among pollutants in California drinking water

California’s public drinking water systems violated safety levels for contaminants more than 1,000 times during the 2012-2013 fiscal year says a report that cites high levels in some water systems of arsenic, nitrates and other pollutants.

The report, ordered by the state Senate’s Environmental Quality committee, is part of a broader effort to improve compliance with drinking water regulations, prompted by criticism of the state’s oversight and a court settlement.

“Although the vast majority of Californians who receive drinking water from a public water system receive water that met quality standards in recent years, there are still many who may have consumed unsafe water,” Senate researchers said in the report, which was released on Wednesday.

According to the report, about 98 percent of water provided by the state’s public water systems met standards for water quality in 2013. But the systems regulated by the state, which provide water to 38 million Californians, were subject to about 1,800 enforcement actions by state regulators during the fiscal year 2012-2013.

Water in California violated federal quality standards more than 1,000 times during the fiscal year, triggering reports to the Federal Environmental Protection Agency (EPA), the report said.

The most common violations were for high levels of such contaminants as arsenic, nitrates, naturally occurring radioactive minerals and perchlorates, which are natural and man-made chemicals used in rocket fuel and explosives, the report said.

The nitrates, which can cause serious illness, including blue-baby syndrome in infants, tend to come from fertilizer run-off, sewage leaks and erosion, the report said.

Arsenic, which causes skin damage, circulatory system problems and increased cancer risks, occurs naturally, but when present at high levels usually involves a human component, the report said.

“Water is a basic human right and we need to do everything possible to protect it,” said Senate Democratic leader Kevin de Leon, who said the report will guide policy decisions as the state grapples with a drought that is entering its fourth year.

Lawmakers will use the report in deciding how to spend revenues from $7.5 billion in bonds authorized by voters to pay for projects to shore up the state’s water supply, de Leon said.

The State Water Resources Control Board, which last year assumed oversight of drinking water quality from the Department of Public Health, said Wednesday it was reviewing the report and would soon submit its own safe drinking water plan.

Source: Reuters.

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Pollution concerns heighten hog conflicts

by David Pitt

From Washington state to North Carolina, federal lawsuits are challenging the efficient, profitable livestock industry to change its ways. The arguments found in the lawsuits are based on studies that increasingly show the impact phosphorous, nitrate and bacteria from fertilizer and accumulated manure have on lakes and rivers as well as air pollution that may be harmful to respiratory health.

Large-scale livestock farmers insist they’re using techniques to keep manure and fertilizer from draining into waterways, though fifth-generation farmer Bill Couser of Des Moines says, “We realize this is not going to happen overnight or in two years.”

However, those who rely on rivers and lakes for drinking water or live near such farms — especially in the top two hog-producing states of Iowa and North Carolina — are growing impatient, and their lawsuits serve to highlight the debate between the right to raise livestock and the right to clean water and air.

Earlier this year, a federal judge in eastern Washington ruled that an industrial dairy farm’s manure management practices posed an “imminent and substantial endangerment” to the environment and to thousands relying on well water. And Des Moines Water Works has filed a notice of intent to sue farmers in three counties populated by 1.2 million pigs and a million turkeys, as the water it sources from two central Iowa rivers must be run through a costly system to strip out nitrates.

About 68 percent of the nation’s lakes, reservoirs and ponds and more than half of its rivers and streams are impaired, according to the U.S. Environmental Protection Agency, whose reports show the main culprit is agriculture.

“Pork is cheap and cheap to produce in large factories because they don’t pay for cleaning up the Des Moines water supply and they don’t pay for the asthma neighbors get, they don’t pay for polluting downstream water that used to be potable and they don’t pay for the loss of property values,” said Steve Wing, a University of North Carolina at Chapel Hill epidemiologist.

The hog industry’s national shift from small family farms to large-scale farms is dramatic — from more than 200,000 in the early 1990s to just over 21,600 in 2012. A driving force behind some of the farms is Murphy-Brown LLC, which is part of China-based WH Group — the world’s largest pork producer. WH Group aims to feed China’s appetite for meat with cheaper hogs from the U.S., according to lawsuits.

Advocates of locally grown food and animal-rights and environmental activists are behind many of the suits, but in some cases, farmers are going after farmers.

Barb Kalbach has fought against the construction of huge hog operations in Iowa, where pork is a $7 billion industry and there are seven times more hogs than humans. “I have in the back of my mind this idea that we have thousands of miles of clean water, which is a gift in this state and we just throw manure in it,” the 61-year-old crop farmer said.

Hog farmer Matt Schuiteman said farmers care about the environment and are willing to work on improvements that will minimize impacts, but doesn’t think lawsuits are the best course of action. “Maybe we can all get to where we want to be together instead of drawing the battle lines and forcing the issue,” the 40-year-old from Sioux Center said.

In North Carolina, 10 million hogs produce as much fecal waste in a day as 100 million people, and Duplin County is the nation’s top county for hog production, according to the U.S. Agriculture Department.

Treated, liquefied manure and urine is pumped to large sprinkler systems and flung on fields for fertilizer. The resulting odor is a daily drag for Richard Brown, whose home is nearly surrounded by fields that soak up hog effluent. Brown is among the roughly 500 people in who’ve joined the lawsuits against Murphy-Brown, alleging that the farms deprive them of enjoying their property.

Murphy-Brown encourages residents to raise concerns about operations, but only a handful do in a given year, the company said in a statement.

The choice, said Iowa State University economist Catherine Kling, will come down to consumers: “We don’t know how to produce food and fuel from this incredibly rich land without having nitrogen and nutrient pollution, so society has to figure out what balance it wants.”

Source: Des Moines Register.

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Pure Water Annie’s FAQ Series

Pure Water Gazette Technical Wizard Pure Water Annie Answers All the Persistent Questions about Water Treatment.

This week’s topic: Quick Connect Fittings

Why do they call these things John Guest fittings?

The British company, John Guest, was the originator of the popular quick connect fittings used almost exclusively in small water filtration equipment these days. In the same way that all soft drinks are referred to as “cokes,” the brand name John Guest has become generic. Actually, there are several very good brands of “John Guest” fittings on the market.

How do they work?

When a piece of tubing is inserted into the fitting it passes through an o ring and is grabbed and held tightly in place by metal teeth that are mounted on a small collar called a collet. The tube is held tightly by the collet. Outward pressure makes the fitting tighter–something like a Chinese finger puzzle. It’s the small o ring that makes the seal. The metal teeth on the collet hold the tube in place. To release the tube, push in on the collet toward the body of the fitting and at the same time pull out the tube.

Do they leak?

Yes, but not often. They’re probably more reliable than standard threaded compression fittings because they aren’t as susceptible to installer error. Best of all, leaks are usually small drips–not the catastrophic blow-outs you can get with a poorly installed compression fitting.

What causes leaks?

New fittings seldom leak. Usually leaks occur after o rings in the fittings have been degraded by chemicals (chloramine is the worst) or by physical stress caused by improper placement. For example, if the installer fails to leave enough “slack” in a tube, causing the tube to be pulled hard to one side, a leak will usually occur because the o ring is flattened by physical stress. Fittings equipped with double o rings are less likely to leak than standard quick connects,  

When the fitting leaks, can it be replaced?

Yes, it’s easy to replace fittings.  There are many good brands on the market and they interchange well.  But you really don’t have to replace leaking fittings because they are just as easily repaired.  Replacing the o ring(s) almost always fixes the leak.  Here’s a good article that tells how to fix them.

Once the collet has been popped out, the o ring is easy to remove and replace.

Sometimes they don’t release easily.  Why?

If there’s any pressure at all on the fitting,  it won’t release.  You have to have the inlet water of your unit turned off an a downstream faucet open. And some fittings are harder to release than others.  The double o ring variety–the ones that never leak–are also the hardest to release. Another of life’s tradeoffs.

John Guest Fittings

Mur-lok Fittings

Brazilians hoard water, prepare for possible drastic rationing

Brazilians are hoarding water in their apartments, drilling homemade wells and taking other emergency measures to prepare for forced rationing that appears likely and could leave taps dry for up to five days a week because of a drought.

In São Paulo, the country’s largest city with a metropolitan area of 20 million people, the main reservoir is at just 6 percent of capacity with the peak of the rainy season now past.

Other cities in Brazil’s heavily populated southeast such as Rio de Janeiro face less dire shortages but could also see rationing.

Uncertainty over the drought and its consequences on jobs, public health and overall quality of life have further darkened Brazilians’ mood at a time when the economy is struggling and President Dilma Rousseff’s popularity is at an all-time low.

After January rains disappointed, and incentives to cut consumption fell short, São Paulo officials warned their next step could be to shut off customers’ water supply for as many as five days a week – a measure that would likely last until the next rainy season starts in October, if not longer.

State officials say they have not yet decided whether or when to implement such rationing, in part because they are still hoping for heavy rains in February and March. Indeed, thunderstorms in recent days have caused lakes to rise a bit.

Still, independent projections suggest that São Paulo’s main Cantareira reservoir could run out of water as soon as April without drastic cuts to consumption.

As such, the race is on to secure water while it lasts.

Large hospitals in São Paulo are installing in-house water treatment and recycling centers, among other measures, to make sure they can still carry out surgeries and other essential tasks if regular supply stops.

Meanwhile, companies are competing with each other to secure deliveries from large water tanker trucks, which have already become a common sight on São Paulo’s gridlocked streets.

“It’s like seeing 10 liters in your gas tank and knowing you won’t make it to the next station,” said Stefan Rohr, environmental director for industry group Ciesp in Campinas, a metropolitan area of more than 3 million people just north of São Paulo.

Many large water-intensive industries, including beverages, cellulose and steel, long ago made contingency plans to truck in water or use underground wells, which may stave off a full-fledged economic disaster.

But smaller ones, ranging from beauty salons and restaurants to car washes and light industry, may have to close or severely restrict activity.

“The economic impact will be job losses,” Rohr said.

40 Million Could Be Affected

Sabesp, São Paulo’s state-controlled water utility, told Reuters it did not yet know when or if rationing would begin. State Governor Geraldo Alckmin, who has also seen his popularity plummet due to the water crisis, declined requests for an interview.

A member of Rousseff’s Cabinet told Reuters earlier this month on condition of anonymity that some degree of water rationing is expected in Brazil’s three largest metropolitan areas – São Paulo, Rio de Janeiro and Belo Horizonte, with a combined population of 40 million people.

Even without rationing, health problems are being felt.

The official number of dengue fever cases in São Paulo tripled in January from the previous year to 120. Officials blamed the rise in part on residents collecting rainwater in open buckets, which attracts mosquitoes.

Many richer Brazilians have large storage tanks built into their apartment buildings or houses which, combined with more conscious water use, may allow them to survive severe rationing without ever seeing their taps go dry.

But most working-class families can’t afford such measures. Some unions are planning demonstrations for next month to protest the government’s handling of the crisis and demand the poor don’t bear the brunt of it.

“We will not accept paying for the government’s irresponsibility with our jobs,” said Adi dos Santos Lima, president of the São Paulo state branch of Brazil’s largest umbrella union, the CUT.

Brazil’s economy is already expected to post zero growth this year. Worse yet, since Brazil depends on hydroelectric dams for about three quarters of its electricity, power shortages are also possible due to the drought, federal officials have said.

Combined water and electricity rationing could lop an additional 0.5 percent or more off of economic growth in 2015, according to Ilan Goldfajn, chief economist at Itaú Unibanco.

Inflation, which is running above 7 percent a year, could also rise as companies face increased costs.

São Paulo’s shopping centers are standing by for potential rationing and have signed contracts to truck in water as soon as needed, said Glauco Humai, who heads Brazil’s mall association Abrasce.

“Our plan is not to close the malls. Obviously this will raise costs,” he said.

Some local chicken processors and pasta makers will also likely raise prices for those products as a result of trucking in water, a local food workers’ union said.

 Even Carnival Cancelled

Sírio Libanês, one of São Paulo’s premier private hospitals, said it cut reliance on Sabesp from 65 percent of its water needs to 25 percent by recycling and installing its own treatment system. Another large upscale hospital, Albert Einstein, said it had increased storage capacity to last four days and would rely on trucks for emergencies.

Many neighborhoods have already experienced daily water outages as Sabesp turns down pressure in pipes to save consumption. Some residents of the Brasilândia slum said this week they were often without water 13 hours a day.

At least two towns in Minas Gerais, a massive coffee producing state adjacent to São Paulo, even canceled Carnival celebrations this month because of the lack of water.

In an upper-class neighborhood of São Paulo, a grocery delivery boy reported bringing 170 two-liter bottles of water to a single apartment over the weekend.

Ronaldo Guellen, who runs a small construction store, recently ordered 70 200-liter tanks that can be used to store water. They sold out in three days, he said, and he hasn’t been able to order any more because supplies are running short.

“People are really getting scared,” Guellen said.

Source: Reuters.

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 Bacterial Growth in Water Heaters

Which Heaters are Safest, and What’s the Ideal Temperature?

Harmful bacteria can grow in water that is up to 122º F.  At temperatures of 140º or higher, they are almost completely eliminated. When heaters run at low temperatures (about 99º –human body temperature–would be the worst) water heaters can become virtual hotbeds for bacterial growth.  An example of an organism that thrives in the water heater is Legionella (the microbe that causes Legionnaires’ Disease).  Surveys have shown that a third of water heaters tested contained Legionella.  The organism can cause illness when it is either breath in or ingested during showering.  Though you don’t hear a lot about Legionnaires’ Disease, there are between 10,000 and 20,000 cases each year in the US.

In addition to temperature, the type of heater matters in assessing the risk of Legionella. Gas heaters, which are heated from the bottom and not subject, therefore, to stratification in the tank (hot water rising to the top because it is lightest), are far less likely to support Legionella than electric heaters.  Though not a lot of research has been done,  bacterial growth in tankless water heaters regardless of the heat source seems unlikely.

The best temperature for your water heater is something of a tradeoff which must consider energy savings (the hotter you run the water, the higher your energy bill), the danger of scalding, and the possibility of bacterial contamination.  If you have a tankless heater or a conventional gas heater, low temperatures can be used.  With electric, you might choose to run the temperature at 140º and install anti-scald faucets.