Topic: Uncategorized

Using RO Water Filters in Drought Conditions

This winter is shaping up to be one of the driest on record for much of western USA. The governor of California has ruled the state under a “Drought Emergency” (which will loosen up some regulations and the flow of federal funds). Here in Oregon, where we just relocated, the winter so far is the second driest recorded, and in Washington State there is also considerably less rainfall this winter than normal.

If you live in an area where the water supply is being constrained due to drought, there are a few things you can do when using a BEV300 system (or any reverse osmosis based system) to help minimize the amount of “brine” water sent to the drain.

Keep in mind a BEV system from Pure Water Systems is more than just a “typical” reverse osmosis (RO) system. All of our BEV systems include deionization after the RO process, cleaning up and removing greater than 97% of any contaminants left behind by the RO process. Where a brand new RO system, using a high quality membrane, might remove 95+ percent of contaminants (decreasing over time), our BEV systems consistently remove greater than 99.6% of all contaminants.

All reverse osmosis units use water to make water pure. The same way we use water to clean ourselves, our clothes, our fruits & vegetables, our cars, etc. Many competitors in the water business, whose systems only slightly purify water, are quick to mention this as “waste” water. We prefer to call it “working” water, i.e. water used to perform a particular purpose.

Poorly engineered RO systems will use 7-12 gallons of water to produce 1 gallon of purified water. We do consider this to be wasteful, when there are reverse osmosis membranes and designs that can use far less. For example, one of our PWS® BEV Systems typically sends 2.5 – 3 gallons of water to the drain for every gallon of pure water that is produced. (Restricting flow beyond this range will cause membranes to become “fouled” quickly with the buildup of mineral plaque or scale, reducing effectiveness or reducing output.)

Also, most under-the-sink RO systems use a pressurized storage tank/reservoir of some kind. These tanks have a diaphragm or bladder that holds the pure water; on the opposite side of the diaphragm there is a small amount of pressurized air. As the tank fills with water it further compresses the air, and this compressed air acts as the driving force to push water out of the tank when the faucet is opened.

As the tank pressure builds it exerts back-pressure on the RO membrane. This reduces the effective RO driving force which will slow the production rate, causing the pure-water/brine-water ratio to increase—sending more water to the drain. (And with many cheap RO membranes, also reducing the rejection rate resulting in TDS creep—another way to say the purity of the water goes down.)

So why do I care you ask? Why are you telling me all this? And what does this have to do with drought conditions?

Well, the answer is simple—if you want to send the smallest amount of water to the drain for every gallon of pure water you produce (with our systems or any other RO system) you could close the valve on your storage tank and fill your own containers directly from your pure water faucet. After you drain your tank your system should be in production mode. Just leave the sink faucet open and the slow dribble that comes from the faucet is the rate your system produces water. Since you are bypassing the tank and making water right into your own container there will be no back pressure—your system will produce water at the fastest rate possible for your membrane.

Depending on your RO system and how much pure water you use each day, you can feel much better knowing you’ve reduced the amount of water you are using to “make” pure water. In less-than-well-designed systems, this can be a significant water savings. Even with the highest quality designs, like those from Pure Water Systems, you may save several gallons each day.


If you really want to reduce your water use but still enjoy the benefits of your RO system, you could, if you were so inclined, disconnect the drain line from your system and route the line into a bucket, collecting the “brine” water for other uses like flushing the toilet. DO NOT, however, extend your drain line more than about 8 feet or you will create back pressure on the brine line which will have a negative impact on your system. This is a little bit more of an extreme measure, but worth consideration should water use become rationed. (WARNING: Don’t be foolish and walk away from a system configured like this or you might waste a ton of water and flood your home at the same time. NOT FUN!)

AND, if you really wanted to use the least amount of water and still enjoy the extreme purity offered by one of our PWS® BEV water filters, you might chose one of our BEV200 water purifiers with a booster pump which would allow you to return the brine water to go through the filter a second or third time (depending on the amount of Total Dissolved Solids, or TDS in your tap water).

Finally, keep in mind that a well engineered reverse osmosis system will still be one of the most cost effective methods of water purification. Compared to distillation, for example, the cost of the tap water used to purify water for your daily cooking and drinking will be far less expensive than the electricity needed to operate a distiller. (And high quality distillers are the only types of water purifiers that compete with our BEV systems in terms of purity.)

What to do in an emergency?

We are often asked how to use our systems in the event of an emergency, and many folks want to know if there is a manual pump that can be used to drive their BEV system:

There is no manual pump that can power a BEV system. You must have constant water pressure, and purifying water through the BEV systems takes time. The only solution is an electric pump, and our booster pumps are excellent for this purpose, though they are primarily designed for instances where the user has low tap water pressure.

Loss of water pressure is less frequent than loss of electricity, but in a true emergency situation (earthquake) it is possible the water lines are ruptured and one will have no water pressure. That means no showers, no toilet flushing, no running water of any kind. If there is no water pressure, you are likely to be in a situation with no electricity either.

So, what to do about pure water? Step one is to store some water. In my home I have four 5 gallon water jugs filled with pure water. I replace the water in the jugs 3-4 times annually, and I add a drop or two of chlorine bleach to each bottle before sealing it. (I am willing to accept a trace of chlorine in an emergency situation vs. any possibility of a bacterial infection. Though pure water in a clean container is highly unlikely to get any bacteria.)

The 20 gallons of water I have on-hand will get me through a few days. After that I will resort to pumping and purifying my water. As I mentioned, in a no water pressure scenario I am also likely to be out of electrical power, so I have a generator for my home. With electrical power it is easy to use one of our booster pumps to draw water from a 5-gallon bucket and pump it into the BEV system. I return the brine water to the bucket and recycle the water again through the BEV system, allowing me to harvest as much pure water as possible before the water in the bucket is too salty to continue. This way I can typically get 3-4 gallons of pure water out of a 5 gallon bucket. I use a test meter to monitor the water in the bucket so if it starts to approach 2000ppm I know its time for a fresh bucket of water. (Be sure it is clear water, not cloudy or muddy.)

Several enterprising customers have reported using a small solar panel to provide power for the pumps. The pumps use very little energy so a solar panel is applicable, but you would need to work with a solar panel professional to get the right size for our pumps, which draw about 19 watts peak. The pumps are 24v and all ship with a transformer to convert standard 110v to power the pump.

You can also run the pumps by putting a pair of 12v batteries together in series to create a 24v power source. This is my preferred method if I am completely “off the grid.” This way my generator can re-charge my batteries when it is running, as it makes no sense to run the generator to power a 19w device. In my home I have several backup power supplies for my computers. I can pull the batteries from one of these units to power my booster pump. Since the pump actually draws only about 16w while running, I can get several gallons of purified water out of the charge on these batteries.

All our pumps are the same, but configured differently for each unit. The BP100 pump comes in a nifty plastic case so it looks nice on the counter next to a BEV100 countertop system. The BP200 is a raw pump, transformer, sediment pre-filter, along with tubing and fittings. It is not elegant, the way the BEV200 is not elegant. Functional and efficient are the hallmarks of the BEV200 system and BP200 pump. The pump for the BEV300 system (BP300) comes with a solenoid and pressure switch so that it can be installed under the sink with the BEV300 system. All the pumps can be used to purify water from a bucket in the event of an emergency, provided you have a source of power.

-KW, Customer Service Team

Some more thoughts on alkaline water…

I get a lot of emails asking about alkaline water. Many of these come from promotors of alkaline water and they seem to be wanting an argument. Often, they want to know why, if were are not big promotors of alkaline water, we even make an alkaline add-on for our BEV systems? An example email is just below, with my comments following:

Billy asks: “Is the BEV water considered to be alive and vital water or just super clean water? Do you need to add sea concentrace to the water or add anything to the water? It is mentioned on your website that this Vincent guy clamied that alkaline water can cause cancer/morbidity and that you want the water to be slightly acidic so why do you now offer this pHplus attachment to make alkaline water? Has it been discovered that alkaline water is actually good for you or why would you even offer alkaline water?”

I replied:

Water is a molecule containing one oxygen atom and two hydrogen atoms. Therefore any claims of it being “alive” run into the area of pseudo-science at best or perhaps the idea came after a night of particularly heavy drinking? Water is no more alive than a rock.

There is no need to add anything to the water, unless perhaps you are on a fasting diet of many days, in which case I would recommend perhaps some juices or some other drink which might help ensure the electrolyte balance is maintained. Otherwise, if you are like most people and you eat food several times per day, there is no reason to worry about the mineral content in your drinking water. (Exceptions exist for 3rd world populations with very poor access to nourishing food, but then those folks are not buying expensive water purification systems.)

Prof. Vincent never claimed that alkaline water causes cancer or disease. His research is correlative. The statistics point to tendencies, not causes.

We offer the pHPlus™ because many people spend up to several thousand dollars on alkaline water machines which are incapable of removing all dangerous toxins. The absence of contaminants will always supersede any potential benefit of altered pH. So our module adds a small trace of alkaline minerals (calcium & magnesium) and due to the high purity this small trace is all that is needed to change the pH to about 9.5. For $125 one can add a pHPlus™ to one of our systems and if they don’t like alkaline water they are only out $125, not several thousand. Remove the pHPlus™ and you still have the most effective water purification system available.

Removing radioactive particles (radionuclides) from water…

OK, forgive me, I’m going to get all technical on you for a moment… with the growing concern of radioactive particles floating down into our water supplies, it is instructive to gain a little knowledge to make sense of the news reports.

First, lets cover a vocabulary term: “radionuclide

A radionuclide is any manmade isotope or natural element that emits radiation with an unstable nucleus that spontaneously decays or disintegrates, producing radiation.  They may also be termed as alpha, beta, photon, or gamma ray emitters and include radon, uranium, radium-226, radium-228, polonium, actinium, lead (Pb-212), thorium, strontium and measured in picoCuries per litre (pCi/L).  One picoCurie equals approximately one disintegration every 27 seconds per litre of water.

The Pure Water Systems BEV Series removes all radionuclides. You will see many reverse osmosis (RO) manufacturers making claims their systems protect against radioactivity, but it is VERY important to know that not all reverse osmosis systems are created eqaul, with the key component being the reverse osmosis membrane itself. The quality of RO membranes varies considerably, with some needing replacement in as little as six months, where superior quality membranes can last 5 years. (Yep, we use the superior quality membranes in our systems.)

As an RO membrane ages, the ability to remove contaminants begins to drop off. Many RO companies say replace the membrane when the overall rejection rate drops to 80%. That means you’re drinking 20% contaminants. Ugh!

With the PWS™ BEV Series systems, we use the second most recommended method for radionuclide removal (the most recommended method is RO) in our third phase of purification: ion exchange. In our case, we have a “de-ionization” module which exchanges the ions that get past the RO membrane for the ions that make up a water molecule: H+ and OH- (or H2O if your math skills are weak!).

This combination makes the BEV Series systems the most effective home water purification designs available. Very high quality distillers can also make extremely pure water, but they use one heck of a lot of electricity to do it. And would you really want those radioactive particles hanging around in the boiling chamber of a distiller?

Can you recycle spent filters?

We’ve been asked the question “Can you recycle the spent filter cartidges” more and more frequently… the short answer is “no.”

A longer answer, by way of analogy, may offer more of an explanation. Consider the plastic garbage bags you use to line your trash cans — once you have discarded all kinds of waste into these bags you would not think to dump them out at the landfill, wash them, and repackage them. The same is true for the used filter housings in our water purification systems. After capturing all kinds of toxic substances the filters are full of contaminants and should be thrown away.

We understand how important it is to reduce our environmental impact (e.g. carbon footprint), but the cost to ship spent filters back to us, the cost to disassemble, discard the contents, sterilize and repacked the housings would have a much greater impact than discarding the filters.

While we generally do not comment on products under development, our R&D department is working to develop a housing for our final phase of purification that will make this module reusable. At this time we do not have a projected date to bring this design into production.

Thoughts About Minerals in Water…

A prospective customer recently asked if there is a way to remove just the Fluoride and Chlorine from his water, but leave the minerals?

Yes, technically, it would be possible to remove fluoride and the chlorine. In the water business, fluoride is a “metal” and targeting it for removal would require a method designed to remove metals. Activated Alumina is the preferred media for fluoride removal, and a high quality carbon filter will remove the chlorine.

This question has a several assumptions that are worthy of further thought…

Assumption #1:
Minerals in water are valuable for human nutrition

Assumption #2:
The mineral quantity found in water is consistent

Assumption #3:
The mineral make-up in drinking water is the same

Assumption #4:
There are no other contaminants in the water, or likely to appear in the water, besides fluoride and chlorine

In regards to the first assumption, it is true that macro minerals and trace minerals are an essential component in human nutrition. The question is whether water is a viable source for trace minerals. This leads to the second and third assumptions, that the trace minerals found in drinking water is relatively constant in both quantity and in composition. Nothing could be further from the truth. In Vancouver, BC, for example, the total mineral content measures less than 10 parts-per-million [milligrams/liter] excluding the chlorine and fluoride.

As the recommended amount of calcium in the diet for adults is >1200 mg per day, and Vancouver water has less than 5 mg/l of calcium, you can see there is no way you could consider Vancouver water a viable source for minerals, either macro or trace.

Now take Lubbock, Texas as another example. The water there has >2000 parts-per-million, and more than half of that is sodium-chloride (table salt). Areas of the southwest with very high mineral content in the water also report very high incidence of circulatory disease, thrombosis, and diseases of deposition as those minerals come out of solution and form deposits – kidney stones, hardening of the arteries, etc.

In our opinion, minerals are better obtained through the food you eat. Plants eat rocks, and we eat plants (and the animals that eat plants.) Plants have enzymes for the breakdown of minerals and formation into new organic molecules. We have enzymes to digest plants, but not rocks – if we did we could get our minerals by sucking on stones. High quality mineral supplements are inexpensive and you will have known quantities and quality.

Finally, targeting specific contaminants will leave you exposed to the variety of contaminants not targeted, and the news reports, on at least a weekly basis, if not daily, show there is growing exposure to a wide variety of contaminants in water. See the following link for a summary of just a few:

We believe if you are going to filter your drinking/cooking water, you might just as well do a thorough and complete job of removing ALL classes of contaminants, not just a select few. To that end, the minerals must go so that we get everything that may be harmful. You’ll get more bio-available minerals from an organic apple or carrot than from several gallons of water.

Drugs Are in the Water. Does It Matter?

By Cornelia Dean
New York Times

Residues of birth control pills, antidepressants, painkillers , shampoos and a host of other compounds are finding their way into the nation’s waterways, and they have public health and environmental officials in a regulatory quandary.

On the one hand, there is no evidence the traces of the chemicals found so far are harmful to human beings. On the other hand, it would seem cavalier to ignore them.

The pharmaceutical and personal care products, or P.P.C.P.’s, are being flushed into the nation’s rivers from sewage treatment plants or leaching into groundwater from septic systems. According to the Environmental Protection Agency, researchers have found these substances, called “emerging contaminants,” almost everywhere they have looked for them.

Most experts say their discovery reflects better sensing technology as much as anything else. Still, as Hal Zenick of the agency’s office of research and development put it in an e-mail message, “there is uncertainty as to the risk to humans.”

In part, that is because the extent and consequences of human exposure to these compounds, especially in combination, are “unknown,” the Food and Drug Administration said in a review issued in 2005. And aging and increasingly medicated Americans are using more of these products than ever.

So officials who deal with these compounds have the complex task of balancing reassurance that they take the situation seriously with reassurance that there is probably nothing to worry about. As a result, scientists in several government and private agencies are devising new ways to measure and analyze the compounds, determine their prevalence in the environment, figure out where they come from, how they move, where they end up and if they have any effects.

In many cases, the compounds enter the water when people excrete them or wash them away in the shower. But some are flushed or washed down the drain when people discard outdated or unused drugs. So a number of states and localities around the country have started discouraging pharmacies, hospitals, nursing homes and residents from disposing of drugs this way. Some are setting up “pharmaceutical take-back locations” in drugstores or even police stations. Others are adding pharmaceuticals to the list of hazardous household waste, like leftover paint or insecticides, periodically collected for safe disposal, often by incineration.

For example, Clark County, Wash., has a program in which residents with unwanted or expired drugs can take so-called controlled substances, like prescription narcotics, to police stations or sheriffs’ offices for disposal. They can drop noncontrolled drugs at participating pharmacies, and 80 percent of the pharmacies in the county participate.

In guidelines issued in February, three federal agencies, including the E.P.A., advised people with leftover medicines to flush them down the drain “only if the accompanying patient information specifically instructs it is safe to do so.” Otherwise, the guidelines say, they should dispose of them in the trash (mixed with “an undesirable substance” like kitty litter to discourage drug-seeking Dumpster divers) or by taking them to designated take-back locations.

Worries about water-borne chemicals flared last summer when researchers at the United States Geological Survey said they had discovered “intersex fish” in the Potomac River and its tributaries. The fish, smallmouth and largemouth bass, were male but nevertheless carried immature eggs.

Scientists who worked on the project said they did not know what was causing the situation, or even if it was a new phenomenon. But the discovery renewed fears that hormone residues or chemicals that mimic them might be affecting creatures that live in the water.

In a survey begun in 1999, the agency surveyed 139 streams around the country and found that 80 percent of samples contained residues of drugs like painkillers, hormones , blood pressure medicines or antibiotics . The agency said the findings suggested that the compounds were more prevalent and more persistent than had been thought.

Meanwhile, the Food and Drug Administration started looking into the effects of residues of antibiotics and antiseptics in water, not just to see if they might affect people but also to assess their potential to encourage the development of drug-resistant bacteria.

Reports of contamination with pharmaceutical residues can be alarming, even when there is no evidence that anyone has been harmed. In 2004, for example, the British government reported that eight commonly used drugs had been detected in rivers receiving effluent from sewage treatment plants. A spokeswoman for the Department for Environment, Food and Rural Affairs said it was “extremely unlikely” that the residues threatened people, because they were present in very low concentrations. Nevertheless, news reports portrayed a nation of inadvertent drug users — “a case of hidden mass medication of the unsuspecting public,” as one member of Parliament was quoted as saying.

Christian Daughton, a scientist at the Environmental Protection Agency and one of the first scientists to draw attention to the issue, said P.P.C.P. concentrations in municipal water supplies were even lower than they were in water generally because treatments like chlorination and filtration with activated charcoal alter or remove many chemicals. Dr. Daughton, who works at the agency’s National Exposure Research Laboratory in Las Vegas, said he believed that if any living being suffered ill effects from these compounds, it would be fish and other creatures that live in rivers and streams.

Dr. Daughton and Thomas A. Ternes of the ESWE-Institute for Water Research and Water Technology in Germany brought the issue to scientific prominence in 1999, in a paper in the journal Environmental Health Perspectives. They noted that pollution research efforts had focused almost exclusively on “conventional” pollutants — substances that were known or suspected to be carcinogenic or immediately toxic. They urged researchers to pay more attention to pharmaceuticals and ingredients in personal care products — not only prescription drugs and biologics, but also diagnostic agents, fragrances, sunscreen compounds and many other substances.

They theorized that chronic exposure to low levels of these compounds could produce effects in water-dwelling creatures that would accumulate so slowly that they would be “undetectable or unnoticed” until it was too late to reverse them. The effects might be so insidious, they wrote, that they would be attributed to some slow-moving force like evolution or ecological change.

Initial efforts concentrate on measuring what is getting into the nation’s surface and groundwater. The discharge of pharmaceutical residues from manufacturing plants is well documented and controlled, according to the E.P.A., but the contribution from individuals in sewage or septic systems “has been largely overlooked.”

And unlike pesticides, which are intentionally released in measured applications, or industrial discharges in air and water, whose effects have also been studied in relative detail, the environmental agency says, pharmaceutical residues pass unmeasured through wastewater treatment facilities that have not been designed to deal with them.

Many of the compounds in question break down quickly in the environment. In theory, that would lessen their potential to make trouble, were it not for the fact that many are in such wide use that they are constantly replenished in the water.

And researchers suspect that the volume of P.P.C.P.’s excreted into the nation’s surface water and groundwater is increasing. For one thing, per capita drug use is on the rise, not only with the introduction of new drugs but also with the use of existing drugs for new purposes and among new or expanding groups of patients, like children and aging baby boomers.

Also, more localities are introducing treated sewage into drinking water supplies. Researchers who have studied the issue say there is no sign that pharmaceutical residues accumulate as water is recycled. On the other hand, the F.D.A. said in its review, many contaminants “survive wastewater treatment and biodegradation, and can be detected at low levels in the environment.”

Some say the spread of these substances in the environment is an example of how the products of science and technology can have unintended and unpredictable effects. In their view, when the knowledge about these effects is sketchy, it is best to act to reduce risk, even if the extent of the risk is unknown, an approach known as the precautionary principle.

Joel A. Tickner, an environmental scientist at the University of Massachusetts , Lowell, says that it is a mistake to consider all of these compounds safe “by default,” and that more must be done to assess their cumulative effects, individually or in combination, even at low doses.

In his view, the nation’s experience with lead additives, asbestos and other substances shows it can be costly — in lives, health and dollars — to defer action until evidence of harm is overwhelming.

Others say the benefits of action — banning some compounds, say, or requiring widespread testing or treatment for others — should at least equal and if possible outweigh their costs.

“You have to somehow estimate as well as possible what the likely harms are and the likely benefits,” said James K. Hammitt, a professor of economics and decision sciences at the Harvard Center for Risk Analysis.

And while it is possible that some of the tens of thousands of chemicals that might find their way into water supplies are more dangerous in combination than they are separately, Dr. Hammitt said in an interview, “it’s perfectly possible that they counteract each other.”

Anyway, he said, assessing their risk in combination is a mathematical problem of impossible complexity. “The combinatorics of this are truly hopeless.”

Given all this uncertainty, policy makers find it difficult to know what to do, other than continuing their research. Studies of “the fate and transport and persistence” of the P.P.C.P.’s will allow scientists to make better estimates of people’s exposure to them, Dr. Zenick said, and “to assess the potential for human health effects.”

But even that normally anodyne approach comes under question because of something scientists call “the nocebo effect” — real, adverse physiological reactions people sometimes develop when they learn they have been exposed to something — even if there is no evidence it may be harmful.

“The nocebo effect could play a key role in the development of adverse health consequences from exposure even to trace elements of contaminants simply by the power of suggestion,” Dr. Daughton wrote recently in a paper in a special issue of Ground Water Monitoring and Remediation, a publication of the National Ground Water Association, an organization of scientists, engineers and businesses related to the use of groundwater.

In fact, the idea that there are unwanted chemicals in the water supply has many characteristics that researchers who study risk perception say particularly provoke dread, regardless of their real power to harm. The phenomenon is new (or newly known), and the compounds are invisible and artificial rather than naturally occurring.

But scientists at agencies like the Geological Survey say it is important to understand the prevalence and actions of these compounds, even at low levels. If more is known about them, agency scientists say, researchers will be better able to predict their behavior, especially if they should start turning up at higher concentrations. Also, the Geological Survey says, tracking them at low levels is crucial to determining whether they have additive effects when they occur together in the environment.

Comprehensive chemical analysis of water supplies “is costly, extraordinarily time-consuming, and viewed by risk managers as prompting yet additional onerous and largely unanswerable questions,” Dr. Daughton wrote in his paper last year.

But it should be done anyway, he said, because it is a useful way of maintaining public confidence in the water supply.

“My work is really categorized as anticipatory research,” he added. “You are trying to flesh out a new topic, develop it further and see where it leads you. You don’t really know where it leads.”