Pure Water Annie’s FAQ Series.

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

 Aer-Max aeration systems, for treatment of iron and hydrogen sulfide.

 

How does Aer-Max work?

Aer-Max works by providing a pocket of compressed air in the top third of a closed tank. When water containing hard-to-treat contaminants like iron, manganese, and hydrogen sulfide falls through the air pocket, the contaminants are oxidized so they can be easily removed by a filter. The compressed air is supplied by a small air pump.  A vent is provided to keep the air pocket fresh.  The Aer-Max system is not a filter.  It prepares contaminants for easy removal by a filter that follows the aeration tank.

There are 110-volt and 220-volt systems.  Which is better?

The voltage needed depends mainly on how the unit is to be controlled. The pump and vent can be turned off and on by having them wired directly into the electrical circuit that turns the well pump off and on.  Since most well pumps run on 220 volt current, if you choose this method of control it’s easiest to use a 220-volt Aer-Max.  If you use an alternative control system, like a flow switch or a simple timer, however, you would want the 110-volt system.

Which is the best way to control the system?

For residential use, the flow switch is the last choice.  It turns the Aer-Max unit on when water flows through the pipe toward the home.  Usually this results in frequent and short on/off cycles and is the least efficient way to operate the system.  The conventional method is to bring 220-volt electrical receptacles for the air pump and the vent solenoid out of the pressure switch that controls the well pump.  With this system, the AerMax is activated when the well pump runs and turns off when the well pump is not running. This is a proven system and it works well.  Use of a simple timer, the kind used to turn lamps off and on at specified times, is becoming the most popular,  however.  It’s easiest to install: you just plug the pump and vent solenoid into the timer and plug the timer into a wall receptacle.

Standard Aer-Max System

But doesn’t the air pump have to be running while water is going through the treatment tank?

This is probably the biggest source of misunderstanding about how Aer-Max works.  The rich pocket of compressed air in the top of the treatment tank needs only to be refreshed from time to time: effective treatment does not depend on fresh air entering while water is running through the tank.  With hydrogen sulfide, for example, while a small amount of the offensive gas may be vented out of the tank by the drain system, treatment consists mainly of reducing the odor-causing gas to elemental sulfur so that it can be removed by the filter that follows the air treatment tank. Residential users who control the unit with timers usually run the air pump only about three times a week.  This vents the tank and refreshes the air pocket.  Unless you run large amounts of water, three times a week is enough.

What is the function of the three tubes attached to the aeration head in the illustration above?  

From left, the first, the shortest, is a baffling device. It creates turbulence to enhance aeration as water entering the tank falls through the air pocket. The middle tube is the vent tube.  It maintains the level of the air pocket in the tank.  The long tube is the pickup tube for treated water being sent to the home.

What kind of filter has to be used after the Aer-Max?

Aer-Max enhances the performance of any standard iron filter medium.  It works especially well with Birm, Filox, and Katalox Light.  Media like Zeolite (Turbidex) and Filter Ag can be used as iron filters if the water is pre-treated with Aer-Max, and an especially effective treatment for both iron and low pH can be accomplished by using a backwashing calcite filter after Aer-Max.  For large amounts of iron it’s best to use the best–Filox or Katalox Light.  Both media will treat both iron and hydrogen sulfide after aeration.

Both Filox and Katalox Light work well with both hydrogen sulfide and iron.  If hydrogen sulfide is present, Birm is not a good choice.

For hydrogen sulfide, catalytic carbon is the best available, but standard carbon also works well. Actually, any granular filter medium will remove odor after AerMax, but carbon is best. If no iron or manganese is present, a cartridge style carbon filter (4.5″ X 20″ preferred) can be used to treat hydrogen sulfide odor, but a cartridge filter will stop up quickly if there’s iron in the water.  With iron and manganese, a backwashing filter is required.

Standard Air Pump Used for Aer-Max

I’m using a water softener to remove iron, but it isn’t quite doing the job.  Can I install an Aer-Max unit in front of it to improve its performance?

No. The Aer-Max will actually interfere with the softener’s ability to remove iron by turning the ferrous iron to ferric.  Filters catch ferric iron easily, but a softener is an ion exchanger, not a filter.  If your water is hard and has iron, either remove both with the softener or use both filter and softener. The correct order of treatment if aeration is used is Aer-Max,  iron filter, then softener.

How loud is the pump?

Approximately 50 decibels.

How long does the pump last, and does it need regular maintenance?

The pump usually runs 20,000 to 25,000 hours before bearings need replacement. It’s an easy pump to work on, and parts are available. The most common maintenance issue is cleaning.  Although the pump has an air filter, in some environments it will need an occasional cleaning (see instructions).

Which works best — Aer-Max or the newer style single tank aeration/filtration systems that are becoming popular?

Aer-Max and the newer single tank units, which have the filter and the aeration treatment in the same tank, work on exactly the same principle but there are some significant differences. In general, the Aer-Max is more robust and will handle higher contaminant levels and higher flow rates. It can also be used to pre-treat for multiple filters. Single-tank setups, which use a venturi draw rather than an air pump, are more compact (one tank  rather than two), easier to install, and less expensive to purchase.  Once installed, both systems are low maintenance unless high levels of iron are involved.  Any equipment removing iron will eventually need some cleaning. The Aer-Max plus filter arrangement is definitely preferred over single tank units for large amounts of iron or hydrogen sulfide–over 8 parts per million of either.

Does the Aer-Max have to be vented outdoors when treating hydrogen sulfide because of the odor?

Odor isn’t an issue, but water is.  The 3/8″ drain tube will vent both air and water when when the vent valve is open, so it needs to be connected to a suitable drain.  It is often teed into the drain tube or pipe that serves the backwashing filter, but it can simply be allowed to drain onto a lawn or water a shrub. The drain water isn’t toxic.

Is there only one size Aer-Max system?

No, there is a high capacity pump available and it can be used with larger aeration tanks to create high flow systems. The higher capacity pump is usually preferred on “constant pressure” wells, where a higher air pressure needs to be maintained in the treatment tank. The 10″ X 54″ treatment tank, with the standard air pump, works in almost all residential applications, so it the the system most frequently sold. See high capacity systems here.

Will Your Water Filter Protect You if  You Have a Boil Water Alert?

 

Adapted from an email communication by Marianne Metzger of National Testing Laboratories.

With the cold weather comes the increased possibility of water mains and pipes bursting.  Pipes and mains are at risk in colder weather due to the expansion and contraction of the pipe material.  Even a 10° change in temperature of air or water can cause significant stress on the pipes. Other factors like the material the pipe is made of, corrosion, soil conditions age. and ground movement also contribute to breaks.

There are approximately 250,000 water main breaks every year in the United States. That’s 685 breaks per day.

Water customers in the area of the break may experience a shut off of water while repairs are being made. Additionally, if customers do have access to water, they may be under a boil advisory.

For those with water treatment equipment this can be confusing. Many people assume that their water treatment device will take care of the problem and they can simply ignore the boil water alert. If an ultraviolet light is part of the equipment, they are right. However, homeowners with other types of treatment equipment cannot simply ignore the alert and they may even may be faced with additional maintenance. It is good practice to change out any carbon-based cartridge filter after a boil advisory because carbon can provide the optimum environmental for any bacteria that may be present as a result of the break. This applies to undersink filters and reverse osmosis units. Whole house carbon filters are also at risk of becoming growing beds for bacteria. For water softeners, it is a good rule of thumb to disinfect the system according to the manufacturer’s instructions after any boil advisory to ensure bacteria are not present.

If  you have doubts about the state of your water filter after a boil water advisory, a simple test for bacteria is a good idea. Bacteria tests can be arrange through most city water departments and through independent agencies that do water testing.

Providing clean water to the developing world

Household water treatment offers the best hope for nearly 900 million people.

by Michael D. Robeson

Many Americans take clean drinking water for granted. However, much of the developing world is still grappling with the challenges of supplying water that is safe for human consumption. The problem affects nearly 900 million people around the globe and leads to 2.2 million deaths by waterborne diseases annually. More than half of the victims are under the age of six.

While the danger in urban areas stems from aging or inadequate water treatment infrastructure, the risk is most acute in rural communities lacking the density or the resources to build and support water treatment facilities.

Many rural residents still fetch water from rivers, lakes, ponds and streams contaminated with human and animal waste, whether from open defecation or factors such as seepage from septic tanks and pit latrines. Even people with access to cleaner water from common wells, collected rainwater or centralized taps face the risk of pollution by an unsanitary container or improper storage in the home.

For these reasons, groups such as UNICEF and the World Health Organization (WHO) have long recognized that the most practical immediate strategy for improving rural drinking water quality is to provide solutions for treating and safely storing water at the household level.

The upshot has been the development of a variety of household water treatment and safe storage (HWTS) technologies designed to improve water quality at the point-of-use (POU), as well as the publication of WHO specifications for evaluating the microbiological performance of different HWTS systems in 2011. That 2011 WHO document was the first to establish target performance levels for bacteria, virus and protozoa in POU water treatment, providing a benchmark for measuring the relative effectiveness of each technology option.

 

From chlorination to filtration

One common POU solution involves chlorination — essentially the same treatment used to disinfect public water supplies in the early 1900s. The most widely adopted model in this scenario was developed by the Centers for Disease Control and Prevention (CDC) and the Pan American Health Organization in response to a 1990s cholera epidemic in South America. Under this model, diluted sodium hypochlorite is manufactured locally, bottled and added to water by the capful for disinfection. Users agitate the water and wait 30 minutes before drinking.

Benefits of this approach include low cost per treatment and proven reduction of most bacteria and viruses. Drawbacks include relatively low protection against parasites such as Cryptosporidium, potentially objectionable taste and odor, lower effectiveness in turbid waters and the need for a reliable supply chain as well as the financial resources to continually replenish the chlorine-bleach solution.

An alternative household water treatment is solar disinfection. Initiated by the Swiss Federal Institute for Environmental Science and Technology in 1991, this strategy requires users to fill plastic soda bottles with low-turbidity water, shake them for oxygenation and place them on a roof or rack for six hours in sunny weather or two days in cloudy conditions. Ultraviolet (UV) light from the sun works in conjunction with increased temperature to improve water quality.

The pros include ease of use, virtually no cost and effective pathogen reduction. The cons include the need to pretreat even slightly turbid water, long treatment times, especially in cloudy weather, the need for a large supply of clean bottles and the limited volume of water that can be treated at one time.

Most other POU options involve some form of filtration designed to remove pathogens by passing water through porous stones and a variety of other natural materials.

 

Multiple filter varieties

Clay-based ceramic filters, for example, remove bacteria through micropores in the clay and other materials such as sawdust or wheat flour that are added to improve porosity. The best-known design in this category is a flowerpot-shaped device by the nonprofit organization Potters for Peace that holds eight to 10 liters of water and sits inside a 20- to 30-liter plastic or ceramic receptacle, which stores the filtered water. Some ceramic filters are also coated with colloidal silver to ensure complete bacteria removal and prevent growth of the bacteria within the filter itself.

Slow sand filters, on the other hand, remove pathogens and suspended solids through layers of sand and gravel. One common household biosand filter consists of a concrete container incorporating layers of large gravel, small gravel and clean medium-grade sand. Prior to use, users fill the filter with water every day for two to three weeks until a bioactive layer resembling dirt grows on the surface of the sand. Microorganisms in the bioactive layer consume disease-causing viruses, bacteria and parasites, while the sand traps organic matter and particles.

As with chlorination and solar disinfection, both varieties have virtues as well as limitations. Ceramic filters are effective against bacteria and protozoa but not as effective against viruses, are breakable, typically last only two years, require as often as weekly cleaning and have a flow rate of only one to three liters of water per hour. Slow sand filters have a flow rate of 30 liters of water per hour — enough to suit a family’s needs — but again, lack adequate virus reduction abilities, are costly and difficult to transport at 170 lbs. and require periodic agitation and regrowth of the biolayer that can reduce filter efficiency if done improperly.

Both ceramic and slow sand filters also lack residual protection for filtered water, such as that provided by chlorine, raising the risk of recontamination unless a disinfectant is added after treatment.

A third option is a hybrid of the ceramic and sand designs. This approach utilizes porous ceramic particles blended with silver, zinc and copper, and deploys them in a layered configuration similar to slow sand filtration solutions. The filter is delivered in a barrel-shaped device with a strainer that filters out large debris, a ceramic/metal layer that neutralizes harmful microorganisms through an ion exchange process made possible by the unique properties of the clay itself and a built-in storage chamber for up to 18 liters of clean water.

Advantages consist of validated effectiveness in bacteria, protozoa and virus disinfection including industry-first compliance with WHO’s new household water treatment specifications, ion-based residual disinfection that keeps filtered water safe, minimal maintenance and a 10-year lifespan with no added costs for post-filtering chemical treatment or filtration media replacement, keeping costs low over the life of the filter. Downsides include a higher initial cost compared to other products and difficulty in outsourcing fabrication to developing world factories because the unique filtration materials are not locally available.

 

Implementation challenges

While household water treatment technologies for developing countries are not new, adoption still falls woefully short of need. According to the CDC, over two million people in 28 developing countries now use solar disinfection for daily drinking water treatment; however, that pales in comparison to the 900 million people who lack access to safe drinking water. Likewise, Potters for Peace has distributed over 200,000 ceramic filters in Cambodia and many more in other countries, but this only scratches the surface of a public health problem killing the equivalent of the entire population of Houston every year.

One stumbling block is the need to work through disparate non-retail channels to reach communities in need. Partnerships must be created with different nongovernmental agencies (NGOs) and multiple local organizations in each country. Finding willing partners is difficult, as is developing sustainable financial models for projects requiring donor funding and subsidies.

Therefore, distribution strategies vary widely. In the case of chlorination, implementations range from a faith-based group in northern Haiti making and bottling its own hypochlorite solution to a large-scale program in which NGO Population Services International both promotes and distributes its own product on a country-by-country basis through local channels such as community health workers and private pharmacies. In the case of ceramic filters, Potters for Peace helps local communities set up filter-making factories that in turn sell their products to NGOs. Each solution and supplier must forge its own path.

Equally challenging is the need to select the most appropriate treatment method for a community’s specific circumstances. Variables such as existing water and sanitation conditions, water quality, cultural acceptability, implementation feasibility and availability of a supply chain for refills or replacement parts will affect the decision. In addition, any implementation must include an education component to teach the use of each technology as well as proper sanitation, food and water handling.

Nevertheless, household water treatment holds the potential to save millions of lives. Until universal access to piped treated water is available, if ever, these decentralized technologies and the small-scale humanitarian models required to deploy them are the best hope for reducing the disease and death toll related to dirty water. Creative solutions, entrepreneurship and new business models will be needed to remove distribution obstacles, provide government funding or microfinancing and bring relief to millions of people who put their lives in danger simply by taking a drink.

Source: Water Technology.

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Think of our water supply as a giant milkshake

by Hardly Waite

 

Think of our water supply as a giant milkshake, and think of each demand for water as a straw in the glass. Most states permit a limitless number of straws—and that has to change.

You may receive a water bill every month, but you’re not actually paying for water. You’re paying for the cost of service, and this free-rider problem is contributing to the worsening water crisis that threatens to dehydrate the US.

Last year, metro Atlanta—home to 5 million people—came within 90 days of watching its principal water reserves dry up, and one Tennessee hamlet ran out of water entirely. Small towns in Texas and California ran completely out of water in 2014. More than 30 states are now fighting with their neighbors over water, and a surging US population means increasingly less to go around. Proposed solutions range from the expensive (desalination of ocean water) to the just plain unpopular (reuse of municipal waste).

Some may find the idea of charging for water itself immoral, as water authority Robert Glennon counters, “Precisely because water is a public—and exhaustible—resource, the government has an obligation to manage it wisely.”

The Types of Lakes


Posted January 25th, 2015

All Lakes Are Not Alike

by Kacy Ewing and Gene Franks

 

Lakes have always been a source of awe and mystery for human beings. Their formation can be just as amazing and mysterious.

The definition of a lake is any body of water that is not an ocean, that is of reasonable size, and that impounds water with little or no horizontal movement. There are a great variety of lake sizes and types. On one hand, you have pools that are slightly larger than ponds. The line between a pond and a lake is hazy and subjective. Where I come from, the body of water that Thoreau called Walden Pond would definitely be called a lake.  On the other hand, you have giant lakes such as Lake Superior which contains enough water to submerge all of North and South America under a foot of water. All lakes, large or small, are part of the diverse ecosystem known as a lentic (Latin for sluggish) habitat. Probably even Thoreau didn’t know that.

Much of what causes lake formation is due to the work of glaciers. Glacial activity caused the creation of most of the natural lakes in the world. The process of glaciers scraping over time creates depressions that hold surface water, forming lakes. In mountain regions a cirque lake can form if glacial debris block the upper reaches of a mountain valley and then fill with water. Cirque lakes (from the French word for circus, named because of their concave amphitheater shape) are common to many mountain ranges in the United States and Canada including most ranges of Colorado, Wyoming, Montana, Alberta, and British Columbia.

A Cirque Lake

While glacial activity is responsible for many lakes, lakes form in dry climates due to changes in precipitation during seasonal climate changes. Pluvial lakes are formed in this manner. These lakes, however, have long since disappeared through evaporation.  They are also referred to as paleolakes.

A Pluvial Lake in the Mojave Desert

In addition to climate changes and glaciers, some lakes were formed by extraterrestrial forces. Almost eerie in its perfection, Lake Chubb (now called the Pingualuk lake) in Quebec is a perfectly shaped circle that occupies a meteorite crater that is 1.4 billion years old. At 876 feet (267 meters) deep it is one of the deepest lakes in North America. It is also one of the most transparent lakes in the world with objects used to measure water transparency visible more than 115 feet (35 meters) deep. There is a similar meteor crater near Flagstaff Arizona formed about 50,000 years ago that contained a much smaller, but similarly shaped pluvial lake.

Lake Chubb

While these two lakes were created by forces out of this world, Kettle lakes are created by what lies beneath the earth’s surface. They are depressions formed by stranded blocks of buried glacial ice that slowly melted during the Pleistocene epoch. As they melted the land surface above them collapsed and created a hole. If the collapse created a hole large enough to reach groundwater, a lake was formed. Kettle lakes are found generally in Ohio, Minnesota, North Dakota, Wisconsin, Michigan, Alaska, Colorado, Idaho, Pennsylvania, British Columbia, Manitoba, Ontario, Saskatchewan, Quebec, and central and northern Europe. Most lakes in Michigan, in fact, could be described as kettle lakes.

Kettle Lake

The age of a lake can have a great impact on its characteristics. Lakes can be young, middle-aged, or old. Young lakes are known as oligotrophic lakes, and have bottoms that are very clean and lacking in organic material. A clean lake may sound pristine, but lacking this material means the lake also lacks a sufficient food source to provide appropriate habitat to produce plants and freshwater organisms. Over time, however, earthen particles and other organic materials from decaying plants and animals can build layers of materials making the lake a suitable home for plants and animals.

Middle aged lakes that have allowed for aquatic growth are referred to as mesotrophic lakes. When a lake ages, the amount of organic material and mineral deposits may become excessive and actually inhibit or stop the growth of aquatic plants and animals. An old lake of this type is called an eutrophic lake and is typically filled with an excess of organic and mineral materials.

In addition to all the naturally formed lake varieties, humans have formed many lakes as well. A reservoir is a human-made feature created by construction of a dam or dike. These man-made lakes are created for a variety of reasons including hydroelectricity, direct water supply, and of course, recreation. Salty or fresh lakes are some of the only freely available water sources on land. Mysterious and majestic, they are an important part of human and animal life.

Hoover Dam Created Lake Mead, a Man-Made Lake or Reservoir

Reference: Thomas V. Cech, Principles of Water Resources and the Wikipedia.

 The Dangerously Clean Water Used to Make Your Iphone

 The ultra-pure water used to clean semiconductors and make microchips would suck vital minerals right out of your body.  Plus it tastes really nasty.

by Charles Fishman

 

FACT: Water can be too clean to drink—so clean that it’s actually not safe to drink. 

That’s the kind of claim about water that people scoff at—it seems ridiculous on the face of it.

Water too clean to drink?

Give me a break. It’s water. Cleaner is better.

But this is one wild water story that’s true.

Every day, around the world, tens of millions of gallons of the cleanest water possible are created, water so clean that it is regarded as an industrial solvent, absolutely central to high-tech manufacturing but not safe for human consumption.

The clean water—it’s called ultra-pure water (UPW)—is a central part of making semiconductors, the wafers from which computer microchips are cut for everything from MRI scanners to greeting cards.

Chips and their pathways are built up in layers, and between manufacturing steps, they need to be washed clean of the solvents and debris from the layer just completed.

But the electronic pathways on microchips are now so fine now so fine they can’t be seen even with ordinary microscopes. The pathways are narrower than the wavelengths of visible light. They can only be seen with electron microscopes. And so even the absolute tiniest of debris can be like a boulder on a semiconductor—so the chips have to be washed, but with water that is itself absolutely clean.

The water must have nothing in it except water molecules—not only no specks of dirt or random ions, no salts or minerals, it can’t have any particles of any kind, not even minuscule parts of cells or viruses.

And so every microchip factory has a smaller factory inside that manufactures ultra-pure water. The ordinary person thinks of reverse-osmosis as taking “everything” out of water. RO is the process you use to turn ocean water into crystalline drinking water. And in human terms, RO does take most everything out of the water.

But for semiconductors, RO water isn’t even close. Ultra-pure water requires 12 filtration steps beyond RO. (For those of a technical bent, the final filter in making UPW has pores that are 20 nanometers wide. At the IBM semiconductor plant I visited, they send the 20 nm filters out to be inspected by a private company, using a scanning electron microscope. They want that company to find filters with nothing in them.)

Just the one IBM microchip plant in Burlington, Vermont, makes 2 million gallons of UPW a day for use in manufacturing semiconductors, and there are dozens of chip plants around the world. UPW is also used in pharmaceutical manufacturing, but it is a purely human form of water—water that is literally nothing like the stuff that exists naturally on Earth.

Water is a good cleaner because it is a good solvent—the so-called “universal solvent,” excellent at dissolving all kinds of things. UPW is particularly “hungry,” in solvent terms, because it starts so clean. That’s why it is so valuable for washing semiconductors.

It’s also why it’s not safe to drink. A single glass of UPW wouldn’t hurt you. But even that one glass of water would instantly start leeching valuable minerals back out of your body.

At the chip plants, the staff comes to regard UPW as just another part of a high-tech manufacturing process. One senior IBM official was stunned when I asked her what UPW tasted like. Despite presiding for years over the water purification process, she not only had never tasted it, it has never even occurred to her to taste it. One of her deputies had, though, and he piped right up. “I stuck my tongue in it,” he said. “It was horrid.”

In fact, super-clean water tastes flat, heavy, and bitter. The opposite of what we like. The appealing freshness in water comes not just from it’s temperature and its appearance, but from a sprinkling of salts and minerals that give it a crisp taste.

So there it is: Not only is it possible for water to be too clean to drink—it’s exactly that kind of water that makes your iPhone possible.

Adapted from The Big Thirst: The Secret Life and Turbulent Future of Water, to be published in April by Free Press / Simon & Schuster. © 2011, Charles Fishman.

Read the feature from  Fast Company‘s April issue.

Read more from The Big Thirst on FastCompany.com.

Source: Fast Company.

Reducing Algae in Lake Erie


Posted January 20th, 2015

Plan targets farmers in 3 states to reduce Lake Erie algae

by John Seewer

 

TOLEDO, Ohio (AP) — Farmers in Ohio, Michigan and Indiana are being asked to be part of the solution in fixing the algae problem in Lake Erie. Federal officials on Friday outlined a program that will make $17.5 million available to farmers who take steps to reduce the pollutants that wash away from the fields and help the algae thrive.

Algae in water at Toledo’s water uptake point.

How will it work?

First, it’s a voluntary program so farmers won’t be forced to take part. And it only applies to those who have land in the western Lake Erie watershed, which is mostly made up of northwestern Ohio, southeastern Michigan and northeastern Indiana.

The U.S. Department of Agriculture will work with those farmers to reduce their field runoff by developing a plan that could include planting strips of grass or cover crops that help soil absorb and filer the phosphorus found in farm fertilizers and livestock manure.

Farmers would receive a payment from the government.

“We will not go to a farm and say ‘you will do this,'” said Terry Cosby, the USDA‘s state conservationist in Ohio. “They’re in charge of their farm.”

But that doesn’t mean all farmers who apply will be selected or get a payment.

The agriculture department will rank the applications based on what farms are most likely to have the biggest impact on reducing runoff. The department has been working with university scientists and soil experts to determine what areas they should target.

“We have hot spots,” Cosby said. “We’ve identified all that.”

Why target farm runoff?

Researchers have found that agriculture is the leading source of the phosphorus that feeds the algae in Lake Erie and other fresh water sources. Some researchers say as much as two-thirds comes from agriculture.

The algae blooms produce the type of toxins that contaminated the drinking water supply for Toledo and a sliver of southeastern Michigan for two days last August.

Source: Seattle Pi.

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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:  Reverse Osmosis Flow Restrictors.

What’s the purpose of the flow restrictor?

The flow restrictor, as the name suggests, restricts the flow of brine (reject water) in drain line leaving the membrane. It provides resistance, creating pressure against the membrane and  forcing some of the water, the permeate, or product water, through the membrane.  Without the resistance provided by the drain line flow restrictor, all the water entering the membrane housing would simply take the path of least resistance and exit through the drain line.  In short, without the flow restrictor, the reverse osmosis process wouldn’t take place.

Where is the flow restrictor located on my home RO unit?

The most common situation is to insert a tiny restrictor into the 1/8″ threaded fitting where the reject water leaves the membrane housing.  Better units now normally use larger capillary restrictors that are inserted into the drain line itself.  These are easily visible and have the advantage of having the “size” of the restrictor printed on the surface. This is especially valuable, because if you can read the output of the restrictor you can guess the size (output capacity) of the membrane.

In RO units larger than undersink, flow restrictors are often electronically controlled or variable-output hand-controlled needle valves that allow adjustment to suit different treatment challenges.

Tiny fitting-insert-style flow restrictor that inserts into the elbow fitting where drain water leaves the membrane housing.

Capillary-style flow restrictor.

Are flow restrictors all the same output?

No, the fixed-output flow restrictors used in undersink and countertop RO units are sized in accordance with the membrane output.  In other words, a membrane that produces 25 gallons per day product water does not need as much drain water to keep it rinsed as a membrane that produces 50.  The higher the membrane’s permeate output, the looser the flow restrictor. In small units, sizing is usually done so that the restrictor size is about four times the membrane’s permeate rating: a 25 gpd membrane is matched with a 100 gpd flow restrictor.

Are restrictors rated by their GPD (gallons per day) output?

Some are, but most manufacturers use MLM (milliliters per minute).  This leads to confusion.  If the restrictor size is stated in mlm, it can be roughly converted to gpd by multiplying by 0.38.  Thus, a 400 milliliter per minute flow restrictor would flow around 150 gallons of water per day to drain if it ran continuously for 24 hours.

Can I save water by reducing the flow size of the flow restrictor–for example, replacing  my 250 mlm restrictor with a 180 mlm?

Yes, you can, but in most cases it’s a bad idea.  Unless the water has very low TDS and little hardness, you’ll probably get poorer TDS performance, reduced production because of hardness scaling of the membrane,  and reduced membrane life. The water that flows to drain is not “waste.”  It’s an essential part of the RO unit’s operation.  Its function is to rinse the membrane, keep it clean, and to wash the impurities rejected by the membrane down the drain.

Do flow restrictors have to be replaced?

Sometimes–if they fail.  Some manufacturers say that you should replace the restrictor each time you replace the membrane, but most of us let them run until they have a problem.  Usually this is never.

What are symptoms of flow restrictor failure?

Either too much water or not enough water (which can be no water at all) flowing to drain.  If the restrictor stops up and no water goes to drain, the RO unit is in effect constipated and the water quality gets bad, then it stops making water completely.  If the restrictor is too loose, you waste water, and if the problem is bad enough, the unit won’t make enough water and it won’t shut off properly.

How do you know if the flow is too much or too little?

The best way is to pull the drain tube out of its fitting and measure the amount of water that comes out with a measuring cup.  250 mlm means that literally 250 mlm should be coming from the drain.  Catch the water from the drain tube in a measuring cup and see how much comes out in one minute. It won’t be exactly the rated figure, but it should be in the ballpark. Remember that the TDS of the water, the temperature, and the water pressure are variables that make it unlikely that you’ll come up with a perfect reading.

There’s a lot more about flow restrictors on the Pure Water Products website.

 

 

Dirty Water Is Leading to Obesity and Diabetes in California

by Colleen Curry

 

A lack of access to clean drinking water in rural California farm communities is leading residents to turn to sugary drinks and soda, contributing to obesity and Type 2 diabetes, researchers said in a new policy paper.

The report, from the University of California Davis Center for Poverty Research, finds that many agricultural immigrant communities in California’s Central Valley have difficulty obtaining clean, drinkable water. And even in those that do have clean water, a persistent belief in the contamination of water leads individuals to buy alternatives, including soda and other sugar-heavy drinks.

Researchers at the school interviewed mothers in poor, rural, unincorporated towns in the Central Valley for the report. They found that the women would not drink the water or give it to their children because of its “unpleasant taste, dirty or yellow appearance, excessive iron, and/or general contamination.” Instead, the women purchased bottled water or other drinks at nearby stores. They reported that their children drink soda or sugary drinks at least two to three times per week.

“The prevalence of obesity and Type 2 diabetes in California is higher among low-income minority populations than white affluent populations. A combination of environmental factors, including a lack of access to healthy foods and nutrition education — and safe drinking water — likely contribute to these disparities,” the team wrote. “Decreasing sugar-sweetened beverage consumption is key to preventing obesity and nutrition-related chronic disease.”

According to information provided by the Community Water Center, the San Joaquin Valley, which is part of the Central Valley, has the highest rates of drinking water contamination and the greatest number of public water systems with contaminant violations in the state. The water supply is tainted with nitrates, arsenic, coliform bacteria, pesticides, disinfectant byproducts, and uranium, according to the group, which attributes the contaminants to fertilizers, pesticides, large-scale animal feed operations, and mining.

Ryan Jensen, a community organizer with the Community Water Center, an advocacy group serving the region, explained that it’s not just environmental issues at play.

“It’s also an institutional and structural issue,” he told VICE News. “You’re dealing with a lot of very small unincorporated communities, a very poor population. So they don’t have the resources to deal with issues or the technical knowledge to be able to address it effectively.”

Jensen said some studies have found that as many as one-quarter of all of the communities in the Central Valley don’t have drinkable water.

“At one time the pinnacle of modernization was that you could walk into your home or apartment and turn on the water and it would be safe to drink,” said Harold Goldstein, the director of the California Center for Public Health Advocacy.

Goldstein told VICE News that the policy report from UC Davis highlights the dangers of sugary drinks and their disproportionate effect on poor immigrant communities. He said that nearly one-third of all patients over 35 admitted to hospitals in California have diabetes, while that figure jumps to 43 percent among Latinos.

“People have come from countries where the water wasn’t good to drink. There may be a sense that the water isn’t safe to drink from their own history and this enforces that,” he said.

“If that’s the case you’ve got to go to the store and buy something, and there’s a lot of marketing to induce people to consume the growing plethora of sugary drink. There are signs, ‘buy 12 packs of soda for the price of 2,’ you know? So making sure people have access to water is absolutely essential.”

He criticized the soda companies for their slogans, including Pepsi with “Live for Now,” and Coca-Cola with “Open Happiness.”

“Yeah, live for today, day of diabetes tomorrow,” he said. “Or Coke’s campaign is open happiness, it doesn’t say open a bottle of insulin.”

Goldstein advocates for a tax and warning label on sodas and sugary drinks, the profits from which could be used to make sure clean water is more readily available.

Ken McDonald, the city manager of Firebaugh, California, a small town about 45 miles outside of Fresno, said that his city has a water treatment system that provides clean drinking water to residents, but the problem is that many outlying residents — some up to 20 miles away — have a Firebaugh address but are not hooked up to the town water system.

“The whole thing is a little larger than just the city,” McDonald told VICE News, explaining that the Central Valley’s history as an ancient seabed made its groundwater vulnerable to mineral deposits trapped underground. “So our water in the municipal system has to go through a treatment process to make it potable. Unpotable water is an issue outside of city limits, out on Interstate 5, which is about 20 miles away.”

The state of California has become more responsive to pleas for help on behalf of the communities, Jensen stressed, though as they lack the resources, it can sometimes take three years to apply for grant money and use it to build water facilities.

“It’s changing and it’s changing very rapidly. The state is making a lot of strides toward improving that situation,” he said. “But there are a lot of communities that don’t have or aren’t very well equipped to deal with the structure.”

Source: Vice News.

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Music festival causes spike in ecstasy and caffeine in nearby river

by Rachel Feltman

Gazette Introductory Note: How do music and sports affect water?  This article will tell you that they may have more  than we thought to do with the growing problem of “emerging contaminants.” A local university professor published research a couple of years back showing how the calendars of our two local universities are reflected in the birth control drug content of our lakes. Are we approaching a time when special hazardous waste assessments are required for football stadiums and concert halls as they are now  for auto repair shops and dry cleaners? –Hardly Waite.

 

It turns out that massive music festivals might not just be a noise disruption for locals — they might be causing issues for nearby aquatic life, too. According to a study published Wednesday in the journal Environmental Science & Technology, these events could be introducing dangerous drugs like ecstasy and ketamine into the water supply, leaving traces of them in rivers and soil.

The study is part of an effort to research so-called “emerging contaminants,” (ECs) or things like drugs (both prescribed and recreational) and hygiene products that end up in waste water. According to recent studies, only about half of these contaminants are actually removed during the water treatment process. So eventually, they can end up back in our drinking water — and in our fish.

Researchers were particularly interested in how certain events — like football games, holiday weekends, and tourist attractions — could cause spikes or even changes in these sneaky contaminants. After all, it stands to reason that an influx of people (especially a large group all doing the same activity) would have an effect. The researchers measured contaminant levels in Hengchun, a popular vacation destination in Taiwan.

ECs were higher in Hengchun rivers than in other areas, despite the low population of the town. That wasn’t unexpected — since the area is popular with tourists, it often has extra people hanging around flushing their waste. These areas also showed a lower concentration of illicit drugs.

So the researchers also weren’t surprised that contaminants spiked during popular travel times, like weekends and seasons with good weather.

But during the “Spring Scream,” an event that draws over 600,000 young music fans to the beach town, things got a little crazy.

Daily sampling during the week of Spring Scream found big spikes in drugs like ecstasy, ketamine, and caffeine — exactly the cocktail of “fun” drugs one would expect hoards of young music festival goers to partake in. Meanwhile, more benign drugs — like ibuprofen — were fairly consistent before, during, and after the concerts.

This isn’t the first indication that sewage can be affected by one-off events.Studies of water near universities have found spikes in amphetamine (taken illicitly by many students to enhance their studying) during exam periods, for example. Another study found that levels of party drugs like cocaine and ecstasy spike in the London area on weekends.

It’s not as if going for a swim in this water could get you high. But the concern is that people and animals are being exposed to varying mixtures of different drugs at different concentrations — so it’s hard to guess just what the long-term effects might be. And research has indicated that some of the drugs that change behavior in humans might also change the behavior of aquatic animals exposed to them, so this party drug pollution is something that warrants a closer look.

Source: Washington Post.

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