The Water Classroom

Learn the basics of water chemistry and water treatment.

What's in Your City Water Supply? Part One

by Dan M Published 7.30.2015

City water supplies generally come from surface water sources.  Surface water sources can be lakes, rivers, ponds, reservoirs and virtually any large collection of water.  Now, think about your local lake for a minute. Is the water clear; can you see the bottom of the lake on a sunny day? If the lake is clear does that mean the water is free of contaminants and safe to drink?  What if the water is cloudy and dirty?  What is the cause of cloudiness and could it be harmful to me?  I bet you have not really thought about how your city deals with removing contaminants from the water supply.  So, let’s take a look at how cities treat water.

Most water treatment facilities utilize the same basic treatment operations, so I am going to focus on one city in particular, Cleveland, Ohio. Cleveland gets its water from Lake Erie, one of the best fishing lakes of the great lakes. Water is drawn in through large screens miles off shore to ensure that it starts out as clean as possible.  (Water drawn near the shore has a high potential to be more concentrated with surface run-off and pollution.) The screens help remove large organic matter such as fish, plants and garbage, to name a few.  The water is then drawn to a rapid mix where chemicals are added for the first phase of treatment.  These chemicals are comprised of a disinfectant, a chemical for taste and odor and a coagulant.  For Cleveland city water these three chemicals are chlorine, activated carbon and alum.  Alum is a coagulant used to bind small particles into large clumps that can be filtered out or that will settle out of the water.  The settling out process is called sedimentation. The water continues to be filtered through large-scale sand and coal filters which will remove smaller organic particles that did not settle to the bottom of the tank during the sedimentation process.  Finally, after the water travels through sand and coal filters, it is again treated with more chemicals.  Cleveland water has chlorine added for disinfection, fluoride for dental hygiene (It is a law in the state of Ohio that fluoride be added to all city water supplies.) and orthophosphate to help reduce the leaching of lead from household pipes.  The water is then deemed good for distribution. 

That is a very simple explanation of how a city water treatment plant treats water.  But even though the water has been disinfected and filtered, I go back to my original questions. Is the water free of contaminants or could it still be harmful to me? It is important to note that city water treatment facilities are closely regulated and undergo strict inspections.  Water that is distributed from the facility is within a healthy range for consumption for the majority of the population that utilizes the water and the general public is notified about any possible contamination from a regulated substance.  However, it is not regulated to protect your home.  Additionally, most city water is not treated to remove taste and odor, hardness, iron, lead, pharmaceuticals and many other natural and man-made substances. 

In my next blog, we’ll take a look at what could be left in the water (bacteria, lead, iron, hardness minerals?) after it has gone through the city’s water treatment process and what you can do about it.


Garret A. Morgan Water Treatment Plant in Cleveland, Ohio.

Contact Dan M.

Disinfecting Your Water

by Mark B Published 5.13.2015

In 1854 there was an outbreak of cholera in London. A doctor named John Snow was very intent on finding out the source of what was killing people. He went door to door to map out household deaths, and determined that what everyone had in common was they had all drawn water from the same community pump on Broad Street. Legend has it that he took the handle off the pump to stop its use. It was then found that this particular pump was drawing water contaminated with the city's waste. It can be argued that John Snow was the father of what we now know as modern Public Health.

Woman Filling a Glass

A major triumph of civilization is our ability to treat drinking water to prevent water borne diseases. This is the single most important factor in lengthening human life expectancy. Take a look at some waterworks built starting in the late 1800's. Many were built from stone, contain polished brass and bronze fixtures, and were meant to serve as lasting monuments to a community's commitment to the health of its citizens. Sand filtration and the addition of chlorine are common methods used to remove or kill microbes in the water supply. Sadly, cholera still causes illness and death in the world today because so many people still don't have access to even these basic tools.

Clean drinking water is easy to take for granted when you, your parents and grandparents have all lived with it. Without chlorine or chloramine added to our water supply, our world would be a very different place indeed. A friend of mine says he likes the smell of chlorine in his drinking water because then he "knows it's working." But for many of us the taste and odor of disinfectants can be disagreeable. We like being protected, but prefer not to drink it. Fortunately, this is one of the easiest things to treat. Activated carbon is most commonly used in a tank for the whole house or a cartridge at the point of use. Carbon removes chlorine, chloramine and a number of contaminants by a process called adsorption, which is kind of like how dirt is held onto sticky tape. Standard activated carbon works great for chlorine reduction, but catalytic activated carbon is better for chloramine. Carbon has a finite life span and needs to be replaced periodically. How often it is replaced mostly depends on how much water has been used and how much chlorine or chloramine needed to be removed.

So eat, drink, and be merry, for you have safe water today and tomorrow, and it can taste good too.

Contact Mark B.

Tiny Bubbles—The Chemistry of Carbonation

by Ed R Published 10.20.2014

If you read the title and started humming the song, then you are probably at least as old as I am. If you don’t know what I am talking about, then you will have to wait till the end of this blog post to find out. Chemically speaking, the term “carbonation” is somewhat misleading in that it implies conversion to carbonate or the addition of carbonate to a solution. Most carbonate compounds are not very soluble. That is to say that they don’t go into solution very well. But we won’t get hung up on that because when most of us hear the term we think “fizzy.” The generally accepted definition of carbonation is the process of dissolving carbon dioxide (CO2) into a solution.

Carbon dioxide is a gas. It can be generated through a chemical reaction such as acidifying a carbonate compound (the volcano experiment with baking soda and vinegar). It can be the result of microbial action (fermentation), or it can be directly injected into a solution. So just what happens when we carbonate something? Well, a lot of things actually. But before we talk about what is going on, we have to ask the question, why do we carbonate beverages? Without getting too biological, it basically tickles our taste buds. The bubbles themselves and some of the compounds generated in the process stimulate our taste receptors. Dissolved gases are also an effective way of transferring certain flavor compounds in beverages.

When CO2 is dissolved in water a series of chemical reactions can take place. Initially CO2 forms carbonic acid (which can stimulate the sour taste receptors).

H2O + CO2 ↔ H2CO3 (carbonic acid)

The carbonic acid can then disassociate into a hydrogen ion and bicarbonate (often referred to as alkalinity).

H2CO3 ↔ H+ + HCO3- (bicarbonate)

This whole series of reactions is often referred to as the bicarbonate buffering system, and it is an important system for all living things (but that is another lesson).

By now you are probably wondering what that double arrow (↔) means. It is a chemist’s way of depicting an equilibrium reaction. Basically this is showing that the reaction can go in either direction depending on which compounds are there in the highest concentration. Which one will predominate is dependent entirely upon pH (see my “What is pH” blog post). At low pH there will be more carbonic acid present, at higher pH the bicarbonate concentration will be the greatest. The more CO2 we pump into a solution, the more carbonic acid we form which subsequently reduces the amount of alkalinity. This is why most carbonated beverages are slightly acidic. So that’s the chemistry of it, but what most people want to know is what makes the solution “fizz” when I open the bottle?

The answer to this lies in one of the Ideal Gas Laws, specifically “Henry’s Law.” Henry’s Law basically concerns the effect of pressure on the solubility of a gas in a solution. You can find a lot of information on this elsewhere. When beverages are carbonated, they are subjected to infusion with a high pressure stream of CO2 gas. This has the effect of forcing the CO2 into solution (gasses don’t like to stay in solution). As long as the pressure is maintained, the CO2 will stay in solution. When we open the bottle, we relieve the pressure and the CO2 will come out of solution in the form of tiny bubbles.

“Tiny Bubbles” is the signature song of Don Ho, a Hawaiian born singer and former USAF pilot. It was released in 1966 and it is one of those songs that after you heard it, you just can’t get it out of your head.

Contact Ed R.

Understanding the In-Home Water Test

by Diana M Published 10.2.2014

Kinetico Dealers offer free in-home water tests. Many people call Kinetico Consumer Relations to ask why we require a representative in their home to test the water. Some are concerned that they will be subjected to a hard-sell salesman who won't leave until the homeowner makes a purchase. Some view the water test as hocus-pocus water changing colors just for effect, with no real value.

The in-home appointment serves multiple purposes and is designed to establish a relationship between the homeowner and the water treatment provider. The water treatment expert tests the water for a variety of problem-causing materials, and discusses the homeowners' water concerns and expectations. The benefits of treated water are reviewed using a variety of hands-on visuals. A plumbing and installation site analysis helps pull all the other information together to ensure the proper equipment is installed.

hands holding test tube

Our standard in-home water test includes testing for hardness, iron, pH and TDS (total dissolved solids). Depending on the area of the country, it may also include checking whether the iron is ferrous or ferric (dissolved or particulate), and testing for manganese, hydrogen sulfide (often called "sulfur"), tannins and chlorine. The best test results are achieved on site and in real time. In a drawn sample, the characteristics of iron, hydrogen sulfide, manganese and chlorine can change quickly. The in-home analysis provides immediate results, is free and might be more accurate for some things such as hydrogen sulfide and iron.

Ferrous iron (dissolved iron), also known as clear water iron, is invisible in the water but leaves stains on clothing, fixtures, toilets and bathtubs. A drawn glass of water with ferrous iron left sitting may develop reddish-brown sediment at the bottom of the glass. That sediment is ferric (particulate) iron. Ferrous iron becomes ferric or particulate iron once it's been exposed to oxygen.

Ferrous iron and ferric iron require different methods of treatment. Ferrous iron can be removed from the water using a water softener. The level of ferrous iron and the amount of hardness (along with the plumbing audit) determines the size softener required for the home. Ferric iron requires filtration. This filtration might be a simple in-line sediment filter, but higher levels of ferric iron require a more aggressive type of treatment, such as a mechanical backwashing filter.

Manganese testing and treatment are similar to that of iron. Manganese in the water can result in gray or black stains. Again, this can be treated either with a softener or filtration system depending on whether the manganese is dissolved or particulate.

Hydrogen sulfide is usually present as a rotten-egg-smelling gas. The method used to treat hydrogen sulfide is dependent upon the rest of the water quality. For instance, if the hydrogen sulfide is a low-level gas, the Dealer might install an aeration tank that vents the gas. Or, if the hydrogen sulfide level is high with a lot of iron, an oxidizing agent might be introduced—usually chlorine which eliminates the hydrogen sulfide and oxidizes the iron to ferric iron, which is then filtered. Accurate tests are crucial to make certain your treated water is odor-free.

Chlorine is tested on-site for a couple of reasons. The pre-filter in the reverse osmosis drinking water system is selected based on the absence or presence of chlorine. The pre-filter assists performance and provides longevity to the workhorse of the RO—the membrane—by protecting the system from chlorine or sediment that is present in the incoming water.

Knowing the chlorine level also ensures the proper water softener or dechlorination system is installed. Chlorine can shorten the life of your softener if it is not dealt with properly.

Treating the water is truly a scientific process—no hocus-pocus. There is a proper detailed method of diagnosis and many proven methods of treatment. Third-party, unbiased organizations such as the Water Quality Association and the American Water Works Association are great sources of information about water testing and treatment. You can read more at or Or of course, you can always call your local water treatment expert and let them guide you through the processes.

Contact Diana M.

Helping Kids Explore Water Treatment with Fab Lab

by Ed R Published 6.6.2014
Fab Lab truck

Recently I had the opportunity to participate in a rather unique project called the “Fab Lab”. The Fab Lab, short for Fabrication Laboratory, was developed by MIT’s Center for Bits & Atoms. It is basically a large van which contains high-tech production equipment to assist students with their STEM (Science, Technology, Engineering and Math) projects. There are only two mobile units like it in the country.

Items inside the Fab Lab include a laser cutter, CNC Mill, vinyl cutter, 3-D printer and numerous other tools. It also comes fully staffed. The whole idea behind this is the “if you dream it, you can design and build it” concept. It is designed to stretch a student’s imagination and give them the means to make them come true. Besides all of the equipment the lab also serves as a classroom, complete with white board walls so students can sketch out their ideas and work out their measurements which are then translated into software programs which interface with the various pieces of machinery. All in all, pretty neat stuff!

Interior of the Fab Lab truck

The reason I got involved with this project was one of our local schools was able to secure a comprehensive continuous improvement grant which covered the cost of the Fab Lab visit and was also used to fund the materials needed for the project. What was the project you ask? Why to build a greenhouse of course!

You see, we are located in a somewhat rural area of the county. Agriculture plays an important role here. Yes, we have real working farms. When the Fab Lab idea was first proposed the school administrators thought long and hard as to how to incorporate the area’s culture and science curriculum into this project, and building a greenhouse seemed like a perfect fit. The students were overwhelming in support of the idea as well.Fab Lab fabrication equipment The greenhouse was to be composed of two elements: a regular soil based approach and a hydroponic element.

The students were tasked with coming up with items which would be needed to set up a greenhouse. They came up with all sorts of items, like pots, hooks to hang the pots, small marker stakes, shelves and small tools. These they constructed with the Fab Lab machinery.

They also recognized that the greenhouse would need water. Since two types of water were going to be used, rainwater and village water, I was asked to come up with a water element to incorporate. I came up with a “water station.” This part of the project had three parts to it as follow.

Students' water filtration solution

The Problem:

Depending on how they plan on collecting the rainwater it may contain suspended solids which need to be removed for the hydroponic element at the greenhouse. Leaves, twigs, dirt, (frogs?) may be present. The village water contains chlorine for public health purposes. Should it or should it not be removed or does it even make a difference?

The Solution:

Students needed to design an effective filter using a multi-media approach. They decided how much, what types of media and how to layer them. They needed to wash the media prior to placing it in the filter. Materials provided – scoops, screens, media, etc. Imagination – not provided!


Students were provided with testing equipment to monitor pH, EC (Electrical Conductance, an indirect measurement of TDS, Total Dissolved Solids which is important in the hydroponic element) and free chlorine levels for the village water. The purpose of this is to determine the optimal water conditions to promote plant growth.

This is what they came up with.

All of the students got to participate in the various phases of this project. I was told the K-2nd grade children had a ball washing the media. This is still a work in progress, but it’s off to a great start, and will serve as a valuable resource in the years to come. It was also a rewarding experience for me personally.

The finished greenhouse built by students

Contact Ed R.

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.

What is pH?

by Ed R Published 10.20.2012

What a funny word, pH. Actually, it’s not a word at all but an abbreviation. Most of us kind of know what it is. We learned about it in school, and then quickly forgot. But, if you have a fish tank or a garden you know that it is important and something that you have to pay attention to.

pH is essentially a measure of the relative acidity or basicity (alkalinity) of a solution or soil. Some things like tomatoes favor a slightly acidic soil, some plants don’t, which is why lime (calcium hydroxide) is added to “sweeten” the soil.

pH is measured on a scale of 0 to 14. A pH of 0 is extremely acidic and a pH of 14 is extremely basic. If something is acidic that means that it has a lot of Hydrogen (H+) ions associated with it. If it’s basic (alkaline) it has Hydroxyl (OH-) ions in a greater amount. A pH of 7 is neutral which means, that the H+ ions and OH- ions are in equilibrium. So, when they are in equal amounts, guess what you get? H+ + OH- = H2O. The pH of tomato juice is 4, Milk of Magnesia is 10 and blood is generally about 7.4. According to the EPA, the Secondary Maximum Contaminant Level (SMCL) for water should range between 6.5 – 8.5.

The pH scale is logarithmic which means that each point on the scale equals a ten-fold difference. As an example, a solution with a pH of 6 is 10 times more acidic than a pH of 7, and a pH of 5 is 100 times more acidic. Most organisms, including us, prefer to have a neutral (7 or so) pH in our bodies and in our environment. Acid rain has been responsible for killing many creatures. Frogs and fish are especially susceptible to changes in pH.

It is relatively easy to measure pH; there are many kits available to test water or soil. It all depends on how accurate you want to be. Simple test strips, chemical color indicators and meters are often used. Meters are usually the best. Now that you have some background on what pH is, you might ask yourself why it is called pH. (Ha! Ha! Made you sit through the Chemistry and Math first!)

The generally accepted reason for the term and abbreviation pH has to do with the first person to describe it. In one of his papers, S.P.L. Sørenson made a reference to the “hydrogen ion exponent” and gave it the designation PH, or pouvoir hydrogene or the “power of hydrogen” (as in concentration). In 1920, W.M. Clark, as a matter of printing convenience (printing was done by the hand set type process, letter by letter and subscripts and superscripts posed difficulties), decided to adopt pH in place of PH.pH Chart

So, how can pH affect water? If you have low pH or acidic water it can corrode your plumbing and impart metals like lead into your drinking water. Blue-green staining from copper corrosion can be an indicator that the pH in the water is too low. The fix is relatively easy; all you need is a neutralizer. This is basically a tank with a special media inside, usually Calcite (Calcium Carbonate). The neutralizer technology is fairly simple and doesn’t require a lot of maintenance. For the most part, you’ll just need to add some more calcite when it gets low. The best thing to do if you suspect you have water problems due to pH levels is to consult your local water treatment professional.

Contact Ed R.

Fluoride: It's not just in toothpaste

by Ed R Published 6.15.2012

When we think about fluoride we immediately associate it with dental products, “Oh yeah, that’s the stuff they put in toothpaste isn’t it?” While true, this is not the only source of the substance. Most natural drinking water and nearly all food have trace levels of fluoride in them. What’s more, in the U.S. approximately 50% of our population drinks water that has had fluoride intentionally added to it. The reason: proponents of fluoridation and the ADA (The American Dental Association) specifically, have shown that fluoride, when ingested or added to dental products in the right amount, reduces the incident of tooth decay. Notice that I said in the right amount. I’m not going to get into the debate of whether fluoridation is good or bad. Like many things in life, a little of something may be good, and a lot may be bad. Nuff said.

Periodic table cell for FluorineThis whole subject has been controversial for more than 60 years. For an in-depth report on this subject I refer you to the August 1st 1988 C&E News Special Report “Fluoridation of Water” written by Bette Hileman. You may find the report through a web search or at your local library. While a little old, it contains a lot of very good information, both pro and con.

Fast forward to 2012. It seems that this topic is now coming back around. What we thought were proper levels back then, are now being re-assessed and it is generally believed the acceptable or beneficial amount of fluoride in drinking water should be lowered. Well, that’s not much of a problem for cities or towns that intentionally add it to their water; they will simply dial back the dose. But what about the estimated 15% of our population (43 million people) that get their water from private wells? How do they know if they have a safe level of fluoride?

Well, the answer lies with the agency in your particular state that is responsible for your drinking water. This is a great resource to find out about “What’s in your Water.” I didn’t say “wallet”, but it could be if your level is too high and you need to do something about it. An excellent example of the type of information that is available can be found at: pubs.aspx. You can just click on the fact sheet for the short version (about three pages) or the full report (10 pages). Your state may have a similar site. Or, if you are really concerned, have your water tested by an accredited lab, that way you will know exactly where you stand.


Contact Ed R.

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

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