Lead in Drinking Water - Another Reason for Point Of Use Water Treatment

by Keith B Published 2.10.2016

There is much coverage in all the media lately regarding lead in the water in Flint, Michigan and now in Sebring, Ohio.  We can also remember the same issue in Washington DC about 12 years ago.  According to the Mayo Clinic's website Lead poisoning is a serious subject and one where elevated lead levels in children and pregnant women can cause learning disabilities and other health problems.  The symptoms of lead poisoning in children are varied and may seem similar to other common juvenile ailments, such as irritability, loss of appetite, abdominal pain, and hearing loss, just to name a few.

It is also fully understood that lead in the water supply is only one of many causes of elevated lead levels.  Others being lead paint, lead in soil, lead in toys, pottery etc. 

In almost all cases, lead in a water supply comes from exposure to lead in the plumbing, either in lead used to solder copper pipe together or from actual lead pipes, once commonly used as the feed lines to homes in older city water systems.  Naturally aggressive waters can dissolve the lead in contact with the water and add it to the water.  Even at elevated levels the lead is odorless, tasteless, and adds no color to the water.  The chemistry of lead in water is complex and lead can be found in many forms in water, both soluble and particulate. 

In June of 1991, the EPA published the Lead and Copper Rule which set new lower limits for lead (15 parts per billion) and set new sampling guidelines with a regulated number of actual "in home" samples now being part of the requirements based on the number of people the water system serves.  This rule also offered treatment techniques such as corrosion control as a means of controlling the possible lead content in those regions where the risks existed.  It is the results of these types of tests and the state and local government's reaction to them that has fueled much of the controversy in both Flint and Sebring.

As with many water contaminant issues, the lead problem is one where the use of a "Final Barrier" Point of Use (POU) drinking water system may make a lot of sense.  First, the US Centers for Disease Control and Prevention (CDC) confirms that drinking lead contaminated water leads to the elevated lead levels in the bloodstream.  Bathing in lead contaminated water is not a source, as lead is not absorbed by the skin.  Therefore a POU device treating only the drinking water is an acceptable option.  Second, if there is lead present in your water, why not remove as much of it as you can?  If I am advised not to use tap water that has 16 parts per billion (ppb) of lead in it (over the EPA limit), should I be comfortable using water with 13 ppb?  Especially if I am making formula for an infant.

If you agree that taking on this responsibility for the quality of your (and your family's) water seems prudent and logical, then the Final Barrier product you choose should be certified by an ANSI approved laboratory to meet ANSI/NSF standards covering the removal of the contaminant(s) in question.  (Std 53 for filters and Std 58 for reverse osmosis (RO) systems).  The technologies that will work effectively for lead reduction are RO, adsorptive media filters, distillation, and ion exchange.  Keeping in mind the complexity of the chemistry, a best choice for a treatment product might be one that can handle both the particulate and dissolved forms, like a RO membrane.  Kinetico's certified products for lead reduction include the K-5 Drinking Water Station, the a 200 Drinking Water System, the MACguard Model 7500 Drinking Water Filter, and the Kube model Kube 14 Advanced Water Filtration System.  To learn more about these products and where to find them visit our website www.kinetico.com.  Further information about lead in drinking water can be found at the Water Quality Association's website at https://www.wqa.org/Portals/0/Technical%20Fact%20Sheets/2014_Lead.pdf



Not All Carbon Is Created Equal

by Abbey R Published 8.13.2015

So, you are interested in a carbon drinking water filtration system?  It may seem like the only choice that you have to make is where you want the filter: on your faucet, under the sink, in your fridge, etc.  Nothing could be farther from the truth.  Each of the systems have different capacities and capabilities.

To hone in on one of the major differences, not all carbon is the same.  To start with, carbon that is used in water purification applications can come from different sources.  Two of the most popular are coconut shell carbon and coal based carbon.  Through processing some of these can be used interchangeably, but not all.

So much of what the carbon will remove is determined when it is processed from the carbon ashes.  The processers can modify the carbon so that different particle sizes are allowed through.  We offer carbon cartridges that range in particle removal capability from 5µm (micron) to 50µm.  For example, 50µm is about half the size of a human hair.  Besides size influences, carbon processors can add a variety of ingredients to help the carbon attract certain contaminants.  Some of the carbon that we use has been formulated to remove contaminants like lead or volatile organic compounds (VOCs) or chloramines, a common disinfectant found in municipal water.

As you are comparing products to purchase it is important to know what the product is going to do for you.  Some filters might be tested and rated to an NSF standard to remove a minimum amount of the contaminant.  Others might be tested by a lab that isn't sanctioned to run NSF standards.  These products would still claim a certain percentage removal of a contaminant, but there wouldn't be a certification seal by NSF or Water Quality Association (WQA).  Still, more may claim that they reduce the amount of a contaminant in your water which could mean anywhere from 1% removal to 99%.  For example, a product may claim to reduce pharmaceuticals and it removes 20% of them.  While that may have seemed like a little bit of a rabbit hole that we jumped into, it is a useful tool for the consumer to know how their system is going to perform.

As tempting as it is, you can't get pulled in by the pretty boxes, catchy taglines or flashy TV commercials.  You either need to do some research ahead of time or read the box closely.  Figure out what contaminants the system removes.  Read how much of each contaminant the system removes.  Learn how long each system is supposed to remove the contaminant.  When you find the system that removes as much as you want of the contaminants that you want for as long as you want, then you can make your purchase with some peace of mind.

The Taste of Your Water Can Make You a Water Snob

by Abbey R Published 6.4.2015

Hi! My name is Abbey, and I am becoming a water snob. Okay, okay! I am a water snob. I can taste the difference between well water, bottled water and municipal water. I can even taste the difference between different brands of bottled water, but I don’t drink it often enough to have a brand preference. I have a hard time drinking water in restaurants when I travel because of the taste. I only drink it if I am really thirsty. So yes, I am a water snob at least when it comes to the water I drink.

Woman Drinking WaterA year or so ago, we finally got around to installing a reverse osmosis system at my house. Before then, I’d like to think I was an average Jane when it came to drinking water, but that wouldn’t be entirely true. I went through a period in college when I could really tell the difference in the types of drinking water. Since I grew up with city supplied water, I never enjoyed the taste of well water. Other than that time period, I would and could drink water from every source and not even notice a difference. 

What makes me think of it now is that I’ve read a couple comments recently that people don’t like the taste of their water when they changed from drinking tap water to drinking filtered water including reverse osmosis (RO) water. Really? You don’t like the taste of water now that you have tasted something closer to actual water?  It seems kind of mind-boggling. I guess it comes down to a couple things.

First, the same compound given to many different people will end in people thinking it tastes differently. While everyone can taste five different things: sweet, salty, sour, savory and bitter, it is perceived differently by different people. Did you know that iron in water tastes sweet to some people, but a bitter metallic taste to others? Copper typically has a metallic taste. For the small percent of people that can taste cyanide, it reminds them of almonds. Chlorides (e.g. sodium chloride aka salt) are also associated with an astringent or salty taste.   Sulfates are known to have a mix of metallic and earthy taste. If you have alkaline or high pH water, it may taste like you are drinking soda water.

The other idea is once you are used to certain impurities being in your water, it is hard to reset your brain to believe that water should taste differently. As a real life example, a colleague of mine had to force his cat to drink RO water. When they first moved into their house, they only had a water softener so the cat got use to that taste. They recently installed an RO system for their drinking water, but the cat wouldn’t drink out of its bowl! It would go to the shower and drink the remains of the water in the shower. Once they devised a method for keeping the cat out the shower, the cat finally started drinking the RO water. It can be hard for animals and humans to get use to a different taste even when you know the water is more pure.  

A random but relevant fact is that cinnamon is completely tasteless. If you plug your nose while eating a piece of hard cinnamon candy, you won’t even know that you are eating cinnamon. Along those lines, what you taste in the water could actually be an odor. Tannins in your water may remind you of dead plants. Sometimes when I turn on my tap water now, I can smell the chlorine in it so I associate it with poor tasting water. Maybe you think your water tastes bad, but it really only smells unpleasant.

Pure water is tasteless. Since all consumable drinking water has a least some small amount of impurities, it will impart some flavor in our food and drinks. Some coffee chains treat the water that goes into their coffee so that it tastes the same no matter where you buy it.  They want the exact same water chemistry at each store so that end product is exactly the same. For more about how water can affect food and drinks check out some of Chef Steve Schimoler’s blogs. Maybe that is why some people think their filtered water doesn’t taste good; their water actually has less of a taste. Drinking water systems strive to provide you the purest water based on its capability which we think tastes pretty awesome!

Contact Abbey R.

Reverse Osmosis (RO) vs. Carbon Filtration: Which one is a better fit for your drinking water?

by Abbey R Published 3.9.2015

If you have been thinking about a drinking water system for your home, you may have seen two popular technologies: carbon filtration and reverse osmosis filtration. What are the differences between these two filtration methods?

Carbon filters, sometimes called “activated carbon” or “carbon block,” filter water by running it through a specially manufactured carbon medium. As the water moves through the filter, impurities like chlorine and iodine bond with the carbon, which reduces tastes and odors in the water. Carbon filtration is commonly used in standalone systems and pitcher filters, appliances like refrigerators and water coolers, and even water treatment systems which include other technologies like RO filtration.

Kinetico's K5 Reverse Osmosis system and MaCGuard filtration

As you can see, Kinetico makes standalone carbon filters and reverse osmosis systems—each has its own purpose and strengths.

Reverse osmosis filters separate water molecules from other molecules by forcing the water through a semi-permeable membrane. RO systems often include several stages—ours include a prefilter, the RO membrane, a storage tank and a postfilter—each of which plays a part in ensuring the water is as high-quality as it can be when it reaches your faucet.

ContaminantApproximate Size(s) (μm)Effectively Filtered By
Bacteria 0.2–10 Reverse Osmosis,
Sometimes Carbon
Viruses 0.004–0.1 Reverse Osmosis
Lead 0.1–0.7 Reverse Osmosis,
Sometimes Carbon
Pesticides & Herbicides 0.001 Reverse Osmosis
Sugars 0.0008–0.005 Reverse Osmosis

This table shows that a number of common contaminants get right through carbon filtration, while reverse osmosis filtration removes just about everything.

These two technologies are very different, and they serve different purposes. When it comes to drinking water filtration for your home, though, there are a few important differences in the results they produce.

First, carbon filtration removes much less from your water than reverse osmosis. Carbon filtration systems have a variety of filtration ratings, from 0.5μm (micron) to 50 micron. Many carbon filtration systems have NSF Class I particulate rating which means that the filter can remove 85% of .5–1μm sized particles, whereas reverse osmosis systems can filter down to about .001μm—that’s a difference of about 500 times. To give you a size comparison, the average width of a human hair is 100μm.

Because an RO membrane’s pores are so small, it can effectively reduce or remove a much wider range of contaminants than a carbon filter can. Carbon filters can be formulated to remove specific contaminants like VOCs, arsenic, or lead, but an RO filtration system takes care of all of these and is much more effective at removing things like fluoride, which are too difficult to efficiently filter out with a carbon filter.

Carbon filtration excels at removing chlorine taste and odor. It also does a great job of capturing large particulates. Reverse Osmosis, on the other hand, will remove almost anything from your water, but it works better if the large particles are removed ahead of it to prevent premature fouling of the membrane. With a fouled membrane the quality and quantity of water is decreased.

There are many other factors to consider when choosing a drinking water treatment system for your home: price, space constraints, contaminant levels in your incoming water, etc. Getting your water tested and knowing what’s in your water is the best way to determine the right type of system for your home.

Contact Abbey R.


Drink Local. Drink Tap. Continues Their Mission to Bring Safe Drinking Water to Uganda

by Guest Bloggers Published 9.19.2014

Erin Huber is the founder and executive director of Drink Local. Drink Tap., Inc.™ a non-profit organization focused on creatively reconnecting people to local water. She inspires people to become better stewards of water through education and awareness in the west and she designs and implements sustainable water projects in the east (Africa). Huber’s passion for safe drinking water is supported by more than a decade of volunteer work and awards, a B.S. of Environmental Science and an M.S. of Urban Studies from Cleveland State University, emphasizing sustainability policy and new economics.

When I last wrote, Drink Local. Drink Tap. had been planning to bring three sustainable water projects to children in Uganda. Well, we did that, and then some. A gravity-fed tap system was installed as Phase III to our St. Bonaventure school borehole project, we built our first gravity-fed irrigation system for Family Spirit AIDS Orphanage and Child Center’s farm, and we installed a borehole project at Family Spirit Primary School where 267 orphaned children live, attend school and try to battle sickness such as AIDS, malnutrition, and previously, illnesses from dirty water.

There are some extremely important points to make about these special projects. Kids will have a sustainable food supply (healthy and with variety) for the first time at Family Spirit AIDS Orphanage and will also learn job skills as many of them have to enter the "real world" after 7th grade or age 13. Already, they have vegetables growing and their health has improved.

cabbage field and worker

The borehole at their school has allowed the children to stay safer not looking for "dirty" water, stay healthier by not drinking dirty water and get a better education because they are in school and not spending precious daylight hours carrying heavy containers of water from a nearby swamp or spring. Something else really special? Most of students at St. Bonaventure, and the villagers in Mulajji, have now seen running tap water for the first time in their lives. The 500-700 kids there no longer have to fill dirty containers with water, no longer have to pump water, and even no longer have to carry it one single foot when they need a drink, to wash their hands or to bathe. With your generous support, we were also able to use a few hundred dollars to rehabilitate two water tanks that were completely infested with parasitic worms and sludge where children were drinking (see photo below). We also purchased cups for all 700 students and staff at one school so everyone can stay hydrated all day and get the most out of class each day.

dirty borehole being cleaned

This year has been life changing, and life saving. One of these schools lost two children just months before we came - there is an emergency now, children are dying and we have proved that we can do something to make life possible there. We can all do something to help children and vulnerable people live more healthy, happy and dignified lives.

Here’s what’s next!

We are going back to Uganda in the summer of 2014 to begin planning projects with seven new schools, to follow up on past projects and to continue building our network of support. Ten schools were interviewed in January 2014 and only seven were chosen to continue to move forward with us in planning sustainable and safe water projects. After combing the south and western parts of the country, we found some children walking four miles, roundtrip at times, to collect water from swamps, crowded and polluted public water sources and 50-100% of the children at these schools have worms (bilharzia) because even cattle share their water source. This has to change if we want our world to change.

Read more about our current projects here.

Our Wavemaker Program students, volunteers, churches and businesses are all making their drops in the bucket. What’s even more special? Kinetico has given DLDT an amazing jumpstart and committed to help build one full project this year with their Gold Level support!

It can be overwhelming to think about all of the pollution in the world, the one billion people without access to safe drinking water or the fact that more people have access to a cell phone than to a toilet. But, if we work together to make positive change, we can truly impact those unimaginable statistics- we’ve proved it and will continue to work hard, with you, to save our water and save lives.

Ways to get involved:

We are able to offer our Wavemaker Program to schools. Send us an email at info@drinklocaldrinktap.org if you’d like us to work with your school or youth group.

Additionally, you can help by hosting a fundraiser or screening our documentary, Making Waves from Cleveland to Uganda. You can also donate directly. For information on these fundraising and outreach programs visit the Drink Local. Drink Tap. website.

women laughing with water

How does a carbon filter work?

by Abbey R Published 9.4.2014

Most drinking water applications involve a carbon filter, either by itself or as part of a more complex system. As I said in a previous post, many reverse osmosis system have a carbon filter as the post filter. There are many stand-alone carbon filters too—think about the water coming out of your fridge or the household pitchers that filter.

We have all come in contact with carbon filters, and probably used them more than once. But how does something as seemingly dirty as carbon deliver refreshing filtered water to you?

Illustration of an uncrowded train station

The carbon that is inside the filter is special. It is called activated carbon because unique manufacturing techniques create immeasurable amounts of bonding sites for organic impurities. Impurities that pass through a carbon filter are removed from the water by adsorption, which is different than absorption. In this case, adsorption occurs when the impurities chemically bond to the carbon. Absorption, on the other hand, occurs when the impurities are dissolved. To “flow” you through the process, let’s start when water enters the carbon element. As impurities like chlorine and iodine see a bonding site, they leave the water stream and stick to the carbon. By the time the water works its way through all the nooks and crannies of the carbon, the water that leaves the element has less stuff in it. I like to think about it like a train full of people heading from the city to the country. At each stop more people get off the train until you reach the last stop when most of the people are gone.

While the manufacturing process does activate the carbon and create more bonding sites, that doesn’t mean that everything is getting removed from your water. Some molecules like sodium don’t bond to carbon, so they will pass right through. Manufacturers can add additional compounds to target different molecules like lead or arsenic for removal. The amount of impurities that are removed also depends on how fast your water is flowing and how depleted your carbon is. The impurities need a chance to bond with the carbon or they won’t get out of the water; this is why the flow rate coming out of your fridge is slower than an unfiltered kitchen sink faucet. Similarly, if all of the bonding sites have already been taken by previous impurities that have gone through, then they have no choice but to stay in the water. Using the train example again, if the train always went 100mph, then you wouldn’t have very many people trying to exit. Or, if the unloading platforms were too crowded, no one would be able to exit the train even if they wanted to.

Let’s recap. Carbon filters use specially processed carbon to attract impurities in the water. The water needs to take its time through the carbon so that the impurities get a chance to jump out of the water. Plus, it needs an empty bonding site that is just right for them. So the next time you grab a drink of water, you’ll know how it came to taste so good.

Contact Abbey R.

Kids and Drinking Water

by Brian L Published 7.31.2014

Ew, Yuck! That is the commentary I received from my five year-old when he tasted the contents of the bedtime cup of water I brought for him. I filled it from the new state-of-the-art carbon filter I recently installed in our upstairs bathroom. We have a Kinetico reverse-osmosis drinking water system downstairs in the kitchen, but I was getting tired of going down nearly every night to refill the boys’ water cups. So when the opportunity presented itself, I thought installing a filter upstairs would save me a few extra steps each night. No such luck. I cannot even sneak it past them. They can instantly tell the difference in taste, and will not drink the water from upstairs.

Boy drinking from water fountain

It is not that our water is necessarily bad-tasting; it is just that the water treated with reverse osmosis is that much better. I recall my daughter asking me why our water tastes so much better than the water at her school. They really can taste the difference, as can my wife and I. And, we’ve had guests from out of town comment on how wonderful our coffee tastes. I’m quick to remind them that it is probably not the coffee, but rather the water that went into it.

So apparently we’ve spoiled our children. They’ve come to appreciate and expect really good drinking water. I guess there are much worse things we could have spoiled them with. Interestingly enough though, the quality of the water is not so important to the boys when it is coming out of a drinking fountain. If they spot a drinking fountain, they instantly become thirsty and will drink heartily. Perhaps to save those steps at night I need to install a drinking fountain upstairs. Except that usually after drinking from a fountain they have dripped water all over themselves and the floor and are now soaking wet. Oh well, boys will be boys.

Contact Brian L.

Fluoride in Your Drinking Water—How Much is Too Much?

by Diana M Published 3.21.2014

I frequently get calls from people asking about fluoride in their water. Some people call about removing the fluoride, and some call about making sure it remains in their water supply. These opposing opinions piqued my curiosity about fluoride. What is it? How does it get into the water supply? Should it be removed, or is it a good thing to have in your drinking water?

It turns out there are mountains of documentation available on the subject of fluoride, but two points really stayed with me. First, there are all sorts of natural sources of fluoride in addition to intentionally fluoridated water and toothpaste. I had no idea! Second, the debate about the pros and cons of fluoride is endless.

Illustration of smiling girl pointing to a glass of water

As Ed R says in this his post, fluoride can be found naturally in water, food and the atmosphere. In fact, it’s the 13th most abundant element found on earth. 5 major global fluoride belts run through the earth, transversing approximately 31 countries. A percentage of this fluoride is soluble, and ends up in the water supply—even the oceans contain some fluoride.

Fluoride can also be found in the atmosphere. Some of it comes from airborne dust with naturally occurring fluoride, and some comes from industry.

Additionally, fertilizers, pesticides and fungicides used on fruits and vegetables usually contain a level of fluoride. If you’re one of the folks trying to keep your exposure to a minimum, giving the fruits and vegetables a good washing can remove most of the fluoride from produce. Choosing organic produce also eliminates exposure to the pesticides that leave fluoride residues.

So, if I have so much fluoride exposure naturally, why are some water supplies fluoridated intentionally? Well, as early as the late 1800’s, it was noted that children exposed to higher doses of naturally occurring fluoride had healthier teeth. At that time, several studies were launched both overseas and in the US which showed that fluoride’s presence in the mouth could prevent tooth decay. Adding fluoride to water supplies seemed to be the logical approach to dental health, because it resembled the natural method of exposure.

The United States is one of few countries that add fluoride on a consistent basis. Here, the decision to add fluoride to the water is up to the city or town. Grand Rapids, MI was the first city to add fluoride to the water supply in 1945, and many cities and towns followed suit until recently, in 2012, 72% of the US received fluoridated water from their municipalities. But in 2011, approximately 200 cities and towns in the US decided to stop adding fluoride to the water. Not only would removing the fluoride cut costs, but more data was becoming available on the negative aspects of overexposure to fluoride.

According to the Center for Disease Control (CDC), children have the highest risk of over exposure. In a household, the child and adult may consume the same levels of fluoride, but because of the child’s body size and weight, the same dosage can be an overexposure. Children overexposed to fluoride will have “fluorosis”—pittingand/or grey discoloration—of the teeth. One of the concerns of overexposure to adults is bone degradation. It’s believed that too much fluoride will actually weaken bone density. Organizations monitoring the use of fluoride all recommend that we have conversation with our dentists and physicians regarding our personal limits.

According to the World Health Organization, the average adult is naturally exposed to approximately .6 milligrams of fluoride per day using an un-fluoridated water supply. Their target exposure guidelines suggest that .8-1.2 milligrams per litre per day will maximize the benefits of fluoride and minimize any possible harmful effects. In the US, the EPA has set a maximum contamination level of 4 milligrams per liter per day. If you’re not sure whether your water is fluoridated or how much fluoride it might contain, you can check with your water supplier. They will have published detailed reports about the contents of your water.

Now, when people call about fluoride in their water, I know more about what they might be thinking. As with anything found in and around water, we at Kinetico encourage you to learn about the water in your home and how it affects your life. Take charge of the water you drink, as your body is the ultimate water filter.

Contact Diana M.

How does hard water affect my coffee and tea?

by Mark B Published 12.11.2013

A cup of tea or coffee is 99% water, so the water used for brewing makes a big difference in the quality of what you drink. There are hundreds of compounds that are released when hot water hits the beans and leaves. When we taste, we actually use both the tongue and the nose to create a complete picture. (Just try eating soup with one hand pinching your nose…it won’t taste the same.) So if the water isn’t especially good, it can rob you of what should be a pleasurable break—chlorine and hardness are major culprits.

Chlorine will attack the flavor compounds and may be strong enough to compete with the aroma from the cup. A good carbon filter is all that’s needed to eliminate this bad actor from your diet, and the rest of your drinking water will taste better too.

Hardness is typically Calcium and Magnesium and maybe a little Iron that’s dissolved in your water. (Learn more about hardness or iron). When these minerals combine with compounds in tea and coffee, they bind together to form solids. Flavors and aroma are tied up and taken away from your mouth and nose. A water softener and/or reverse osmosis system are effective ways to fix this problem. My personal preference is an RO system, because it has a carbon filter for the chlorine, a membrane to purify, and a mineral cartridge polisher to ensure a complementary balance of ions for the tea and coffee to steep in.

Here’s something you can try just for fun if you have hard water at home or work. It also makes a simple, but safe and effective science fair project. Buy a bottle of water at the supermarket, making sure to pick one that’s been treated by reverse osmosis. Brew two cups of tea at the same time in the microwave: one with hard water, and the other with RO water. About 90 seconds should do it. Take the cups out of the microwave and remove the teabags. Now compare color; is one muddier than the other? Smell and taste; the cup made with RO water will be brighter and livelier on the palate, and you may also detect a cleaner flavor. It’s easy to observe that just because a cup of tea is darker does not mean it is stronger or richer, or that is has a full range of flavors for you to enjoy.

I did this “tea test” with a standard bag of Lipton black tea and then took these photos.

Top view of the tea test results Side view of tea test results: RO waterSide view of tea test results: hard water

Can you guess which is which?

The tea made with RO water was, you guessed it, the one on the left. I chose a black tea (instead of a green or white) because I thought the result to be visually more striking. Doing this with a highly aromatic tea such as orange pekoe, or a more subtle green tea also demonstrates what a profound difference the right water makes.

Life is just too short for a bad cup.

Contact Mark B.

How a Reverse Osmosis System Works

by Abbey R Published 9.27.2013

With every passing year we learn more about what is in our water and the effects those contaminants can have on our health. It takes the EPA years of study to figure out what is an acceptable level for contaminants in our water or how best to treat them. Contaminants in residential drinking water can include almost anything, from industrial waste that was dumped in a river, to fertilizers and household cleaning products. Many times, treatment involves adding a chemical to the water to neutralize the contaminant—for instance, chlorine is added to water to control the amount of microbes—but these chemicals can give water undesirable tastes or odors. Technology like reverse osmosis systems exists to remove contaminants from water without adding any chemicals.

Reverse osmosis (RO) systems are becoming an increasingly important, needed appliance in our homes. RO systems utilize your water pressure and a semi-permeable membrane to reduce contaminants for great-tasting water without adding any chemicals. They are typically used to purify drinking water which is where contaminant levels matter the most. Some areas, however, have such terrible water that an RO system is used for the entire home.

Every reverse osmosis system has at least four parts: a prefilter, an RO membrane, a storage tank and a postfilter. Water supplied by the city or a well enters the system through the prefilter, which protects and extends the life of membrane by filtering out the things that can harm it, like chlorine and sediment.

A reverse osmosis membrane uses a semi-permeable membrane to separate water molecules from other molecules. “Semi-permeable” means that some things can pass through and others can’t. A familiar example would be your furnace’s air filter, although, semi-permeable membranes for water treatment allow passage based on the size of the particle as well its molecular charge whereas typical air filters separate the contaminants exclusively by size. Holes or pores in the membrane are sized just big enough for the passage of a water molecule—even small contaminants such as tobacco smoke or paint pigments are too big to go through an RO membrane. At this point, because the membrane only lets certain molecules pass through, there is some waste liquid with a highly concentrated amount of contaminants that goes to the drain. The virtually contaminant-free water that makes it through the membrane, called a permeate stream, is safe to drink and tastes great.

Reverse osmosis technology relies on pressure to push the water molecules through the. Water pressure varies with your water source. City water is usually supplied between 40 and 100 psi (pounds per square inch). Well water is usually less pressure, delivered between 20 and 60 psi depending on your pump. The production rate of the membrane is dependent on factors such as temperature, pressure and Total Dissolved Solids levels. Because flow and production rates vary, most RO systems also have a storage tank, allowing more pure drinking water to be available on demand, so you can fill your glass or pitcher much faster.

Because the water is so pure, bad tastes and odors from the storage tank’s bladder and walls can find their way into the water during prolonged contact, so they must be taken out. That’s why a postfilter is an important part of the reverse osmosis system; any odors or tastes picked up from the storage tank are removed and the water is once again great-tasting.

To raise the pH if it is too low, whole house systems use a “polisher” after the postfilter, which adds minerals to the water which protect the pipes and which come people feel enhances the water’s taste.

Sometimes seeing is believing. Personally, I love seeing ice cubes made with RO water because they are virtually colorless. Ice cubes made from city-supplied tap water are almost white in color, which tells me that there are minerals mixed in with the water molecules. Whenever I see transparent ice cubes, I know the RO system must be removing a lot from my water. If your home has questionable drinking water, maybe it’s time to check out a reverse osmosis drinking water system—you won’t regret it.

Contact Abbey R.

Water: Understand it, Value it, Respect it. Learn more about life’s most vital resource.

Search The Blog