Archive for January, 2011

Chloramine Removal

Chloramine Removal

Chloramine or NH2Cl is commonly used in low concentrations as a secondary disinfectant in municipal water distribution systems as an alternative to free chlorine chlorination. This application is increasing. Chlorine ,sometimes referred to as free chlorine),is being displaced by chloramine, which is much more stable and does not dissipate from the water before it reaches consumers. NH2Cl also has a very much lower, however still present, tendency than free chlorine to convert organic materials into chlorocarbons such as chloroform and carbon tetrachloride. Such compounds have been identified as carcinogens and in 1979 the United States Environmental Protection Agency‎ began regulating their levels in U.S. drinking water. Furthermore, water treated with chloramine lacks the distinct chlorine odour of the gaseous treatment and so has improved taste. In swimming pools, chloramines are formed by the reaction of free chlorine with organic substances.

Chloramines, compared to free chlorine, are both less effective as a sanitizer and more irritating to the eyes of swimmers. When swimmers complain of eye irritation from “too much chlorine” in a pool, the problem is typically a high level of chloramines.Pool test kits designed for use by homeowners are sensitive to both free chlorine and chloramines, which can be misleading.

Chloramines are disinfectants used to treat drinking water. Chloramines are most commonly formed when ammonia is added to chlorine to treat drinking water. The typical purpose of chloramines is to provide longer-lasting water treatment as the water moves through pipes to consumers. This type of disinfection is known as secondary disinfection. Chloramines have been used by water utilities for almost 90 years, and their use is closely regulated. More than one in five Americans uses drinking water treated with chloramines. Water that contains chloramines and meets EPA regulatory standards is safe to use for drinking, cooking, bathing and other household uses.

Many utilities use chlorine as their secondary disinfectant; however, in recent years, some of them changed their secondary disinfectant to chloramines to meet disinfection byproduct regulations. In order to address questions that have been raised by consumers about this switch, EPA scientists and experts have answered 29 of the most frequently asked questions about chloramines. We have also worked with a risk communication expert to help us organize complex information and make it easier for us to express current knowledge.

The question and answer format takes a step-wise approach to communicate complex information to a wide variety of consumers who may have different educational backgrounds or interest in this topic. Each question is answered by three key responses, which are written at an approximately sixth grade reading level. In turn, each key response is supported by three more detailed pieces of information, which are written at an approximately 12th grade reading level. More complex information is provided in the Additional Supporting Information section, which includes links to documents and resources that provide additional technical information.

EPA continues to research drinking water disinfectants and expects to periodically evaluate and possibly update the questions and answers about chloramines when new information becomes available.

Chloramine-treated water has a greenish cast, the source of the colour is uncertain. Pure water by contrast normally is bluish. This greenish color may be observed by filling a white polyethylene bucket with chloraminated tap water and comparing it to chloramine-free water such as distilled water or a sample from a swimming pool.

Adding chloramine to the water supply can increase exposure to lead in drinking water, especially in areas with older housing; this exposure can result in increased lead levels in the bloodstream and can pose a significant health risk.

There is also evidence that exposure to chloramine can contribute to respiratory problems, including asthma, among swimmers.Respiratory problems related to chloramine exposure are common and prevalent among competitive swimmers.

Chloramine use, together with chlorine dioxide, ozone, and ultraviolet, has been described as a public health concern and an example of the outcome of poorly implemented environmental regulation. These methods of disinfection decrease the formation of regulated byproducts, which has led to their widespread use. However, they can increase the formation of a number of unregulated byproducts, some of which pose greater health risks than the regulated chemicals.

Many animals are sensitive to chloramine and it must be removed from water given to many animals in zoos. Aquarium owners remove the chloramine from their tap water because it is toxic to fish. Aging the water for a few days removes chlorine but not the more stable chloramine, which can be neutralised using products available at pet stores.

Chloramine must also be removed from the water prior to use in kidney dialysis machines, as it would come in contact with the bloodstream across a permeable membrane. However, since chloramine is neutralized by the digestive process, kidney dialysis patients can still safely drink chloramine-treated water.

Home brewers use reducing agents such as sodium metabisulfite or potassium metabisulfite to remove chloramine from brewing liquor as it, unlike chlorine, cannot be removed by boiling . Residual sodium can cause off flavors in beer  so potassium metabisulfite is preferred.

Chloramine cannot be removed from water by boiling, distilling or reverse osmosis, which at least helps to narrow your options! Beware of any company trying to sell you one of these as they simply don’t work.

The best method, and recommended by the US EPA, is an activated carbon block system. The very best will use a twin or multi-stage process with sub micron filtering and ion exchange for the best results. These can remove chloramine from water at a rate of 99.9%, and also the same removal rate for lead, pesticides, prescription drugs and all the other contaminants.

Chlorinated Swimming Pools Can Cause Asthma In Swimmers

From Allan Finney, Mainstream Water Solutions

Chlorinated indoor swimming pools can cause asthma, according to research from several sources. These findings may explain why swimmers using indoor pools are more prone to Asthma than athletes in other sports.

“Our results show, indeed, that nitrogen trichloride (produced by Chlorine) is a cause of occupational asthma in indoor swimming pool workers like lifeguards and swim instructors,” says Dr. K. Thickett of the Occupational Lung Diseases Unit at the Birmingham Heartlands Hospital.

In Dr. Thickett’s study, each of the subjects either stopped taking inhaled corticosteroids altogether, or their asthma symptoms resolved significantly once they were placed in other occupations away from the swimming pools. Dr. Thickett’s study was backed up by research from other European and Australian sources.

The problem isn’t the chlorine, but what chlorine turns into when combined with organics. The organics are contributed by bathers in the pool in the form of sweat, dander, urine and other organics. The chlorine reacts with the organics and produces nitrogen trichloride, aldehydes, halogenated hydrocarbons, chloroform, trihalomethanes and chloramines. If these sound like dangerous chemicals, they are. During the Olympic Games held in Australia, it was reported that more than one-quarter of the American swim team suffered from some degree of asthma.

Meanwhile, investigators in Belgium presented research showing that exposure to such chloramines greatly increases permeability of the lung epithelium, a condition associated with smoking cigarettes. In a study presented by Dr. Simone Carbonnelle, of the industrial toxicology and occupational medicine unit at the Catholic University of Louvain in Brussels, 226 otherwise healthy school children, mean age 10, were followed to determine how much time they spent around indoor swimming pools, and the condition of their lung epithelium. The children in Dr. Carbonnelle’s study were exposed to air around the school swimming pool for a mean of 1.8 hours per week.

The level of lung permeability would be the equivalent of what she would expect to see in a heavy smoker, according to Dr. Carbonnelle. “These findings suggest that the increasing exposure to chlorine-based disinfectants used in swimming pools and their by-products might be an unsuspected risk factor in the rising incidence of childhood asthma and allergic diseases,” she said. The variation in lung surfactants persisted whether the children lived in a rural area or in the city, and whether they were from upper income, or less well-off families, she added.

As part of Dr. Thickett’s study, three employees of a local public swimming pool who complained of asthma-like symptoms were subjected to chloramine challenge tests in which, in the lab setting, they were exposed to roughly the same amounts of chloramine as they would be exposed at work (i.e., around the swimming pool, close to the surface of the water).

Measurements of nitrogen trichloride were taken at 15 points around the pool, 1 m above the surface of the water. When exposed to equivalent amounts of the chemical in the lab, the three subjects all experienced significant reductions in forced expiratory volume in one second (FEV1), and high measurements on their Occupational Asthma Expert System (OASYS) scores, a measurement of asthma and allergy severity.

In the Belgium study, chloramines in the air around the surface of the pool were measured. In addition, three specific proteins were measured in the children: SF-A and SF-B (surfactant A and B) and Clara cell protein 16 (CC16). Surfactant A and B are lipid-protein structures which enhance the bio-physical activity of lungs lessening surface tension in the lung epithelium and preventing the collapse of the alveoli at the end of expiration. Anything that impairs the function of these surfactants will clearly impair lung function as well, because it makes the epithelium more permeable.

Both of these studies were concerned with chlorine byproducts in the air above indoor swimming pools. In the next article on the dangers of chlorinated pools, we’ll look at studies related to drinking water and swimming pools.

2010 in review

The stats helper monkeys at mulled over how this blog did in 2010, and here’s a high level summary of its overall blog health:

Healthy blog!

The Blog-Health-o-Meter™ reads This blog is doing awesome!.

Crunchy numbers

Featured image

A helper monkey made this abstract painting, inspired by your stats.

A Boeing 747-400 passenger jet can hold 416 passengers. This blog was viewed about 1,700 times in 2010. That’s about 4 full 747s.


In 2010, there were 55 new posts, growing the total archive of this blog to 67 posts. There were 5 pictures uploaded, taking up a total of 2mb.

The busiest day of the year was May 9th with 70 views. The most popular post that day was European Investigators Identify Potential Cause of Asthma in Swimmers.

Where did they come from?

The top referring sites in 2010 were,,,, and

Some visitors came searching, mostly for lsi calculator, breakpoint chlorination calculator, pool chlorine calculator, breakpoint chlorination diagram, and chlorine calculator.

Attractions in 2010

These are the posts and pages that got the most views in 2010.


European Investigators Identify Potential Cause of Asthma in Swimmers May 2010


Chlorine Calculator November 2009


LSI Calculator April 2010


Breakpoint Chlorination Diagram April 2010


Chloroform Detection and Quantification December 2009

Questions and Answers: Swimming in Chlorinated Pools

Swimming is a healthy form of exercise for people of all ages. For decades, chlorine has been used safely to help destroy waterborne germs that cause diarrhea, swimmer’s ear, athlete’s foot and other ailments. Unlike alternative disinfectants, such as ozone and ultraviolet radiation, chorine provides a residual level of protection that continues to disinfect long after it is applied.

Q. Does swimming in chlorinated pools cause cancer?
A. Any link between chlorinated pools and cancer is highly speculative. Scientists continue to study this issue, but in no case have they concluded that swimming in chlorinated pools causes of cancer. Respected public health authorities, including the World Health Organization, the U.S. National Cancer Institute, the U.S. Environmental Protection Agency and Health Canada, have each examined scientific research on swimming and bladder cancer, for example. These groups have each concluded existing data are insufficient to show an association. Other studies examining the effects on DNA of swimming in pools are limited and inconclusive.

Q. Is chlorine in swimming pools a health hazard?
A. Chlorine helps protect health by killing waterborne germs that can make swimmers sick. Independent and respected health authorities agree that chlorine itself poses no known health effects when levels are managed within the recommended range for swimming pool water. Research on swimming pools and potential health effects focuses, not on chlorine, but on substances formed in pool water called disinfection byproducts.

Q. What are disinfection byproducts?  Where do they come from?
A. Disinfection byproducts are produced when disinfectants such as chlorine, used to protect against waterborne germs, react with impurities, including perspiration, body oils, urine and lotions introduced into the pool by swimmers. All disinfectants form byproducts, but those formed with chlorine are the most well-studied. One type of disinfection byproduct, chloramines, are irritating substances responsible for swimmers’ red eyes and the strong chemical odor of some pools. Many people mistake the smell of chloramines for a sign that there is “too much chlorine” in the pool. The truth may be the reverse: more chlorine may be needed to help reduce chloramine levels.

Q. So, what can I do to reduce my exposure to these disinfection byproducts?
A. Pool managers have a responsibility to manage pool chemistry appropriately, which helps limit disinfection byproducts. Maintaining sufficient levels of chlorine is essential to protect against waterborne diseases. The goal is to limit the impurities in the water that lead to the formation of byproducts. Swimmers can do their part by showering before swimming and never peeing in the pool, for example. If the levels of impurities in pool water are kept low, the levels of disinfection byproducts will also be low.

Q. I guess I thought the chlorine would “take care” of any pee in the pool. Is that not the case?
A. Chlorine, as well as other disinfectants, reacts with any organic matter in the pool, including urine. If chlorine reacts with urine, it is used up so it is not available to destroy germs. And when chlorine reacts with compounds in urine, DBPs are formed. Bottom line: Don’t pee in the pool.

Q. Is peeing in the pool really that common?
A. A 2009 Water Quality & Health Council survey of 1,000 U.S. adults found that one in five adults admit to peeing in a pool. (How many more did not “own up”? We can only speculate.)  Swimmers must understand that such practices affect the quality of pool water. While at the pool, parents can take children on “bathroom breaks” and ensure everyone washes their hands after using the toilet.

Q. Does swimming cause asthma?
A. There is no convincing evidence that swimming in chlorinated pools causes asthma in otherwise healthy people.  In fact, physicians often prescribe swimming for their asthmatic patients. They say the benefits of swimming as a healthy form of exercise offsets any potential respiratory risk.  Research on swimming pools and asthma center around substances formed in pool water called disinfection byproducts (DBPs), which form when disinfectants, such as chlorine, chemically react with impurities, including perspiration, body oils, urine and lotions introduced into the pool by swimmers. Some DBPs are highly volatile and can lead to noxious odors and irritating conditions, particularly at indoor pools. Properly operated and maintained pools should keep the level of DBPs low, while protecting swimmers from waterborne germs. Swimmers must also do their part by showering before swimming and never peeing in the pool.

Pool Treatment 101: Introduction To Chlorine Sanitizing

Mastering the knack of pool science is not difficult with the right information and a little diligence. As for those readers who are experienced poolside chemists, put this article in the hands of anyone learning the ropes.

Think of the perfect swimming pool and visions of sparkling water and happy swimmers likely dance in your head. Keeping this scene intact involves taking the proper steps to sanitize the pool and prevent any health or aesthetic problems. The water will then remain clear of algae, free of disease causing pathogens and users won’t complain about red eyes or chlorine smell.

Because you use chlorine, whether you’re responsible for running a public facility or a water park, you have the necessary tools to make your job easier. For general pool treatment, chlorine has three essential characteristics: it acts as a rapid and persistent sanitizer, an effective algaecide and a strong oxidizer of undesired contaminants.

Understanding the role of chlorine in maintaining safe water is not difficult once you learn the basics of pool chemistry.


Chlorine is regularly fed into the pool water and should be tested daily — at a minimum — for proper disinfection. Routine chlorination kills harmful microorganisms that can cause health-related problems, such as gastroenteritis, Legionnaires disease, ear infections and athlete’s foot. Learning how to properly test your water will allow you to identify the chlorine residual and demand in pool water. More frequent testing is needed if there is heavy bather use.

Listed below are some helpful definitions that will assist you in understanding the terms and tasks of applying chlorine-based sanitizers.

  • Free available chlorine (FAC). The portion of the total chlorine remaining in chlorinated water that has not reacted with contaminants — and is “free” to go to work to kill bacteria and other contaminants. Make sure your test kit can measure FAC; many only test for total chlorine.
  • Combined available chlorine (CAC) or chloramines. The portion of chlorine in the water that has reacted and combined with ammonia, nitrogen-containing contaminants and other organics such as perspiration, urine and other swimmer waste. Some chloramines can cause eye irritation and chlorine odors.
  • Total chlorine. The sum of both the free available and combined chlorines.
  • Forms of chlorine commonly used in commercial pools. Pools are treated with chlorine gas, sodium hypochlorite (liquid bleach), calcium hypochlorite (granular or tablet), lithium hypochlorite or chlorinated isocyanurates. When any of these compounds contact water, they release hypochlorous acid (HOCl), the active sanitizing agent. Chlorinated isocyanurates, a family of chemical compounds such as sodium dichloroisocyanurate and trichloroisocyanurate, also add cyanuric acid or stabilizer. A stabilizer, which can also be added separately, helps reduce excess loss of chlorine in water due to the ultraviolet rays of the sun.
  • Parts per million (ppm). Measurement that indicates the parts of a substance, such as chlorine, by weight in relation to one million parts by volume of pool water. A rule of thumb to follow to maintain good water quality in pools is to keep FAC levels between 2.0 and 4.0 ppm. (see NSPI recommendation chart)
  • Shock treatment. The practice of adding significant amounts of an oxidizing chemical to water to destroy ammonia, nitrogen-containing and organic contaminants. Adding chlorine as a shock treatment can also control algae and bacteria, but read the label to make sure that your product can do this.


Carefully read and follow the manufacturer’s instructions printed on the chlorine treatment package. Test the water regularly – it’s a simple process to use a test kit. You want to maintain water balance by measuring:

  • Free available chlorine (FAC), which should be in the range of 2 – 4 ppm, but never fall below 1.0 ppm
  • Total chlorine, to assure that combined available chlorine (CAC) levels are less than 0.2 ppm
  • The pH level to keep it between 7.2 and 7.8, indicating that the chlorine is working effectively
  • Total alkalinity to make sure that pH levels stay steady
  • Calcium hardness to protect pool surfaces from corrosion.


The guidelines set by The Association of Pool & Spa Professionals are widely used, but to be certain, you should also check the health codes of the jurisdiction where you live. The chemicals a pool needs to maintain the required standards differ from pool to pool – and day to day. Keeping records to “get to know” a pool can help you interpret its characteristics and perform the correct task.


Suggested Chemical Standards for Swimming Pools
Free chlorine, ppm 2.0 – 4.0
Combined chlorine, ppm None
pH 7.2 – 7.8
(ideal range of 7.4 – 7.6)
Total alkalinity, ppm

  • For liquid chlorine, cal hypo, lithium hypo
  • For gas chlorine, dichlor, trichlor and bromine compounds
80 – 100


100 – 120

Total dissolved solids, ppm Not to exceed 1500 greater than at pool start-up
Calcium hardness, ppm 200 – 400
Cyanuric acid, ppm 30 – 50


Contrary to what most people think, a strong chlorine smell is not an indication of too much chlorine in the pool but actually a red flag that a “super dose” may be required to correct the problem.

Shock treatment adds a larger than normal amount of oxidizing chemicals to pool water. This additional dose destroys organic contaminants and oxidizes ammonia and nitrogen compounds to rid the area of irritating chloramine odor and, if chlorine is used for the purpose, to sanitize the water. Many chlorine shock products also provide usage instructions for destroying algae and bacteria, which can be an added benefit. Shocking should be done with the pump and filter operating, but after sundown to avoid the loss of chlorine to the sun’s ultraviolet (UV) rays.

Superchlorination is another term that is sometimes used for shock treatment with chlorine products when 5 or more ppm of FAC is added. This mode of shock treatment — in addition to oxidizing undesired wastes – is used to rid the pool of algae and bacteria that might be hiding in filters and hard-to-sanitize areas. Superchlorination also gets rid of chloramine odor. Adding 10 times the level of combined chlorine or chloramines in the water achieves so-called breakpoint chlorination when there is enough extra chlorine to consume the irritating chloramines.

According to NSPI standards for public pools, the ideal frequency for a super dose is every week, depending on use and water temperature. For high use pools, superchlorination may be required three times a week or more as a preventive measure. NSPI also suggests that a good indicator of the need for a super dose is when combined chlorine climbs near or above 0.2 ppm.


As you learn your way around the pump room, you’ll appreciate chlorine’s importance in contributing to safe, clean water – making those visions of swimming in a sparkling, clear pool a reality.

Basic Rules of Thumb

  • Always read and follow the manufacturer’s instructions.
  • Store chemicals in a cool, dry and shaded place.
  • Never mix different types of chlorine – add each to the pool separately.
  • Never mix chemicals together – add each to the pool separately.
  • Avoid breathing fumes or vapors.
  • Don’t buy more pool chemicals than you’ll use in a season – they lose effectiveness over time.
  • Make sure pool chemicals are inaccessible to children.

Cost-Savers Tip

Save on chemical costs by adding chlorine for shock treatment after dark – during the day some will be lost to sunlight.