The Pure Water Occasional for November 18, 2013

With an attention-grabbing article about demand pumps, an inspiring piece about farming in dry lands, a really good study of TILT, and people who are allergic to life,  a lackluster article that goes on and on about the three types of chlorine used in water treatment, plus the usual array of water news from around the world.

 You'll like this issue better if you'll read it here,  on the Pure Water Gazette website.


Extreme Chemical Sensitivity Makes Sufferers Allergic to Life

Its sufferers were once dismissed as hypochondriacs, but there’s growing biological evidence to explain toxicant-induced loss of tolerance (TILT).

By Jill Neimark

Gazette’s Introductory Note:  At Pure Water Products, we get fairly regular calls from chemically sensitive people who have what are 
usually impossible requests for special water treatment devices. Some are for equipment that we can guarantee to “remove 100%” of a targeted contaminant–like chloramine or fluoride.  We have to tell them that water treatment is always about reduction, not removal, and that if 90% or even 99% reduction isn’t good enough,  we can’t help.  The other most frequent impossible request is for equipment that contains no plastic.  These callers usually are drawn to our website by products with stainless steel housings, but we have to explain that stainless steel units have cartridges inside that have plastic end caps and in most cases plastic binders mixed with the media, plus it is almost impossible to avoid plastic tubing or plastic pipe in installations. 
 Jill Neimark’s article, reprinted below in its entirety, should help us all  better understand those who are “allergic to life.” –Gene Franks,  Pure Water Products.

One night in August 2005, Scott Killingsworth, a 35-year-old software designer in Atlanta, dragged his dining-room table out to the porch and lay down on it. The house he’d just rented — on 2 acres in an upscale suburb north of the city — was meant to be relatively free of man-made chemicals, his refuge from the world. For years he had been experiencing debilitating reactions to a cornucopia of common chemicals that others don’t even notice.

But this house, like the one before it, was making him sick with flulike symptoms — nausea, headaches and muscle stiffness.

Lying on the table and breathing in fresh air, Killingsworth thought back to the morning seven years ago when his office was sprayed with Dursban, a potent organophosphate pesticide that has been banned for indoor use since 2000. Within minutes of the pesticide treatment, he was unable to concentrate, and he felt like he had a bad flu. When he returned to the office a week later, he felt sick again. He asked his supervisor to move him to a different office.

“I thought that was the end of it,” he recalls. “But that was the beginning of it.”

Instead of recovering, he got sicker as each year passed. Newly renovated buildings, fresh paint, gasoline odors, pesticides, herbicides — the list of substances he reacted to grew longer and longer. After his apartment was painted by mistake one day while he was at work, he got so ill that he took a leave of absence and moved.

But each subsequent home left him with the familiar panoply of headaches, flulike symptoms, insomnia, the inability to concentrate and fatigue. After sleeping on his dining table for a week, he bought a camping cot and slept on it each night for years. When he became reactive to the almost imperceptible outgassing of chemicals from his own computer, he switched to a Bluetooth keyboard and looked at his computer monitor through the porch window.

Before he got ill, Killingsworth had a girlfriend and an active social life. As his unusual illness escalated, he began to live like a hermit. During his final two years in Georgia, he had fewer than 10 visitors, he says.

Finally, in fall 2007, nine years after his run-in with Dursban, Killingsworth applied for Social Security disability, packed his belongings, and drove west in his Honda Civic to search for housing among a community of folks like himself — all suffering from what is loosely called “environmental illness” — in the remote high desert of Arizona.

Today, in his 40s, he lives in a renovated travel trailer specially designed for his sensitivities: It has porcelain tile floors, sealed walls and sealed wood cabinetry. He camps alone and with friends. He relies on solar power, hauls his own water at times and moves seasonally to avoid extremes of heat and cold. Most days, however, he can tolerate the trailer only for a while, even with windows open, and sleeps on a cot in the back of his truck, under the protective camper shell.

Please go here for the rest of the article.

Demand Pumps: How to use them with residential reverse osmosis units

 by Gene Franks

Demand or Delivery Pumps are pumps used to send water from a storage tank to a point of use. They should not be confused with “booster pumps,” which are used to increase the pressure going into the the reverse osmosis unit. Typical applications for demand pumps are to send water from a non-pressurized tank to a water vending machine or to increase water pressure from an undersink reverse osmosis unit to a refrigerator or icemaker that it is supplying.

Demand pumps are versatile tools that can also be used to send water to a car wash location, a fish pond, aquarium,  or a hot tub. They are sometimes used to move water from a non-pressurized distiller tank to a sink-mounted spigot. They work anywhere a pump is needed to move water to a point of use. They work with a non-pressurized water source or they can increase the pressure from bladder tanks like RO tanks

When there is a “demand” for water, the pump comes on and supplies it. When the demand is removed, the pump shuts itself off.

When you push a button to fill a water bottle from a supermarket’s water vending machine, the button-push activates a solenoid that opens a closed valve in the water line. When the valve is open, the pump senses a demand for water and comes on. It pumps water through the open line until you release the button, closing the solenoid-controlled valve and shutting off the demand. Closing the valve causes pressure to build in the delivery line and the pump senses the pressure and stays off until there is another demand for water.

In the pump pictured above, the water line is installed in the ports marked by the yellow fitting protectors. The pressure switch is the appendage at the extreme left in the picture. It simply shuts off the pump’s electrical supply when water pressure builds builds in the water line.

Small demand pumps are usually trouble free operators, but in some installations a pump tank should be added to assure smooth operation. Without a tank to provide constant back pressure for the pump’s pressure switch, a phenomenon called “pump chatter” sometimes occurs. If the pressure drops slightly, the pump has to turn on briefly to renew the pressure when no demand for water has been made. Installation of a pump tank prevents this constant on/off cycling and also provides more water in storage and protects downstream plumbing and appliances from the shock of sudden pressure surges. A pump tank, while not always essential, improves the performance of virtually any demand pump installation.,

The illustration below shows a demand pump installation on an undersink reverse osmosis unit designed to send pressurized water to a remote refrigerator or icemaker. This is a good design, but there are other placement options. If the pump is installed in tube labelled “Outlet to Refrigerator,” the sink-top spigot will get water only from the tank at right and the pump will not turn on to serve the sink-top spigot.

The pressure tank at right is the RO unit’s regular storage tank. The tank at left is an additional “pump tank” added to smooth out the pump’s operation and to provide extra storage. Water in the second tank is available for both the kitchen ledge faucet and the refrigerator. A check valve (one way valve) built into the pump head prevents migration of water back to the RO unit.

More about Demand Pumps.



 This Week's Top Water News

Jellyfish proliferating along Kerala coast. The jellyfish population is abounding along India's Kerala coast, threatening other species and creating havoc for fishing operations. Scientists studying the phenomenon feel that the proliferation of the species indicates the impact of human activities on the marine environment.  

70,000 private Minnesota wells are in line for nitrate testing. The Minnesota Department of Agriculture wants to test 70,000 private wells throughout the state’s farming regions as part of an ambitious but controversial plan to measure and fix nitrogen contamination in drinking water.

Western Alaska villages survey damage, call for aid as storms pass. Damage assessments are kicking into gear in coastal communities in western Alaska after a pair of storms left a bruising swath of flooding and ice this week.

Sewage swamps Gaza streets as Egypt tunnel closures cut off power. Children waded through sewage submerging the streets of a central Gaza neighborhood on Thursday, a day after one of the blockaded Palestinian enclave's largest waste water treatment plants stopped for lack of fuel.

The invisible killers in our water. A lecturer in epidemiology and community health at Stellenbosch University says she realised South Africans were facing a health crisis because of high levels of pollution and sewage in our water back in 1998. The required action is yet to be taken.

Oil and effluents spell slow death for Mumbai creeks. An oil spill that destroyed a large stretch of mangroves around Mahul creek was reported last week, but the disturbing revelation is just the tip of the iceberg when the bigger picture of abuse of the creeks in the city is considered.

New toxic hot spots linked to sewers. Environmental Protection Agency officials told residents Tuesday that the only plausible explanation so far for the mysterious "hot spots" of sky-high levels of toxics under Evandale Avenue is a leaking sewer line or storm drain -- potentially placing the blame on semiconductor manufacturers.

Toxic contamination of the New River continues. It's filthy. It's toxic. And it's a breeding ground for deadly diseases. Yet, this contaminated sewage water, also known as the New River, flows right into the Salton Sea - exposing its dangerous hazards to Imperial Valley and beyond.

Desalination isn't the answer to California's water problem. Utilities throughout California should be thinking about how to use less water imported from Northern California and the Colorado River, and developing "homegrown" water through recycling and conservation. Desalination should be a last resort.

Study: Groundwater "lag" may delay Chesapeake Bay cleanup. The Chesapeake Bay's cleanup may be delayed "several decades" by the slow pace at which farm pollution is being flushed from ground water on the Delmarva Peninsula.

Device makes turning human waste into compost safer. Your toilet bowl may hold the key to replenishing forests, growing crops and saving countless gallons of water. And that's why Gary Andersen, a senior scientist at Lawrence Berkeley National Laboratory, is so excited about poop.

Invasive species surface on Belle Isle. Round gobies are an invasive fish found in the Black and Caspian seas and are believed to have arrived in the Great Lakes two decades ago in the ballast water of ocean freighters. They have a habit of consuming more food than the native species of fish and pushing them out of the territory.

Typhoon Haiyan: Worse than hell. Long accustomed to fearsome storms, floods and earthquakes, Filipinos are usually stoical in the face of natural disasters. Yet the sheer magnitude of the super-typhoon that ripped through the middle of the archipelago on November 8th was unprecedented. The scale of the damage left in its wake was shocking.


Maryland drops farm pollution rule. Amid an outcry from Maryland farmers, state officials pulled back again Friday from a new regulation aimed at cleaning up the Chesapeake Bay by restricting the use of animal manure to fertilize crops


 Types of Chlorine Used in Water Treatment

by Pure Water Annie

 Pure Water Occasional Technical Wizard Pure Water Annie Explains the Different Forms of Chlorine Used in Water Treatment. This Isn’t Really Very Interesting, but It’s Something You Should Know

The most common use of chlorine in water treatment is to disinfect water.  As a disinfectant, it has drawbacks, but it also has benefits. Other methods of disinfection such as ultraviolet and ozonation are effective disinfectants but they do not provide a residual to prevent pathogen regrowth as chlorination does. When treatment plants are distant from the point of use, chlorination is the best way to provide save water to the end user. Municipal water providers usually rely on measurements of “chlorine residual”—the amount of chlorine remaining in the water after it reaches its destination—as proof of safety. Residual requirements vary, but a typical residual goal would be for 0.2 to 1 mg/L.

In addition to disinfection, chlorine is effectively used to oxidize iron, manganese and hydrogen sulfide to facilitate their removal, to reduce color in water, and to aid in such treatment processes as sedimentation and filtration.

Chlorine and pH

In general terms, the lower the pH of the water, the more effective chlorine is as a disinfectant. Again, speaking generally, a reason for dosing effectively is that chlorination raises the pH of water, so overdosing often raises the pH to levels where chlorine does not work effectively as a disinfectant. More is not always more powerful.  Chemically, this has to do with the relationship between the two constituents of chlorine that together are often referred to as “free chlorine”–hypochlorus acid and hypochlorite ions. Hypochlorus acid is the more effective disinfectant and it dominates at lower pH levels, so a lower pH is preferred for disinfection. Conversely, a higher pH is needed for water treatment strategies that depend on chlorination to oxidize iron and manganese.

Types of Chlorine Used in Water Treatment

“Pure chlorine” is seldom used for water treatment. The three most common chlorine-containing substances used in water treatment are chlorine gas, sodium hypochlorite, and calcium hypochlorite. The choice of thechlorine type to be used often depends on cost, on the available storage options and on the pH conditions required. Chlorination affects pH and pH affects results—a fact that is commonly overlooked in residential water treatment.

Chlorine Gas

Chlorine gas is greenish yellow in color and heavier than air. Its high toxicity makes it an excellent disinfectant for water but also a hazard to humans who handle it. Chlorine gas, of course, is a deadly weapon when used in chemical warfare. It is a respiratory irritant and can irritate skin and mucous membranes and can cause death with sufficient exposure. Because of chemical changes that occur when it is introduced into water, chlorine gas is no more toxic to humans when used to treat drinking water than other forms of chlorine. Chlorine gas, which is actually sold as an amber-colored compressed liquid, is the least expensive form of chlorine and is, consequently, the preferred type for municipal water systems.

Calcium Hypochlorite

Calcium hypochlorite is manufactured from chlorine gas. It is best known as chlorine pellets and granules in residential water treatment. It is a white solid with a very pungent odor and it can create enough heat to explode, so it must not be stored near wood, cloth or petroleum products. Calcium hypochlorite increases the pH of the water being treated.

Sodium hypochlorite

Sodium hypochlorite is a chlorine-containing compound most easily recognized as household bleach. It is a light yellow liquid that has a relatively short shelf life. It is the easiest to handle of all the types of chlorine.  Sodium hypochlorite also increases the pH of the water being treated. A lower concentration of chlorine in this form is needed to treat water than with calcium hypochlorite or chlorine gas.

One-Quarter of World’s Agriculture Grows in Highly Water-Stressed Areas

By Francis Gassert – October 31, 2013

All living creatures need two things to survive: food and water. A new WRI analysis shows just how much tension exists between those two essential resources.

A new interactive map from WRI’s Aqueduct project reveals that more than 25 percent of the world’s agriculture is grown in areas of high water stress. This figure doubles when looking at irrigated cropland, which produces 40 percent of global food supply.

This analysis highlights the tension between water availability and agricultural production. Finding a balance between these two critical resources will be essential—especially as the global population expands.

Agriculture Under Stress

Already, water demand in many parts of the world is meeting or exceeding natural supply. Overlaying global crop production maps with Aqueduct’s Water Risk Atlas reveals agriculture’s current exposure to water stress.

In the face of this water-food nexus, three major points are important to keep in mind:

Different crops face different levels of stress in different regions. More than 40 percent of wheat is grown in areas facing high or extremely high levels of water stress. Fiber crops, such as cotton, are grown under even more stressed conditions. More than half of global cotton production happens in regions of high or extremely high stress.

Water consumption levels vary by crop type. Globally, roots (carrots and beets) and tubers (potatoes) require an average of 0.5 liters of water per calorie, whereas legumes (lentils and beans) require 1.2 liters per calorie, according to researchers at the University of Twente and the Water Footprint Network. In other words, different types of crops create different water footprints.

Irrigated land is twice as likely to be highly stressed. Irrigation alone – which can use surface water, groundwater, or both – can dramatically increase crop production. However, it is an enormous water consumer and the single-largest driver of water stress around the world. As ever-higher food demand drives more farmers to irrigate their land, the world’s rivers and aquifers will be increasingly strained.

These strained resources are a problem in themselves, but they also affect water users’ and managers’ ability to respond to droughts and other severe or chronic shortages. In areas where water is plentiful or where fewer users are competing, the excess supply acts as a buffer when droughts settle in. Droughts are more damaging in more arid areas or places where too many people compete for limited resources.

A Growing Risk

The tension between crop production and available water supply is already great, as agriculture currently accounts for more than 70 percent of all human water withdrawal. But the real problem is that this tension is poised to intensify. The 2030 Water Resources Group forecasts that under business-as-usual conditions, water demand will rise 50 percent by 2030. Water supplies, however, will not—and physically cannot—grow in parallel. Agriculture will drive nearly half of that additional demand, because global calorie production needs to increase 69 percent to feed 9.6 billion people by 2050.

The food-water tension won’t just be felt by agriculture, either. Agriculture’s growing thirst will squeeze water availability for municipal use, energy production, and manufacturing. With increasing demand in all sectors, some regions of the world, such as northern China, are already scrambling to find enough water to run their economies.

Ensuring a Water- and Food-Secure Future

Only by looking at food and water together is it possible to address the challenges within both. That is why WRI is working on mapping how the world’s relationship with water will be changing in the coming decades and identifying sustainable solutions to increase food production. For example, future food demand will only be met if farmers increase crop yields through better soil and water management. Furthermore, water use can be reduced through a suite of solutions like reducing food loss and waste, shifting to healthier diets, reducing biofuel demand, andachieving replacement fertility rates.

These are just a few of the solutions that will be necessary if we are to ensure a water- and food-secure future. With better data on where and how agriculture is constrained by water, countries and companies can create a more robust agricultural sector—without overtaxing water and other natural resources.

LEARN MORE: View the interactive map of agriculture’s exposure to water stress.

Article Source: Water Efficiency.

Please visit our RO Parts Page for tanks and accessories.

Thank you for reading.  Please come back next week.

Places to Visit on Our Websites in the meantime

Model 77: “The World’s Greatest $77 Water Filter”

Sprite Shower Filters: You’ll Sing Better!”

An Alphabetical Index to Water Treatment Products

Our famous whole house Chloramine Catcher

Pure Water Occasional Archive: Sept. 2009-April 2013.

Write to the Gazette or the Occasional:

Fair Use Statement

Please Visit

The Pure Water Gazette – now in an easier to navigate format.

The Pure Water Occasional

Pure Water Products