Chris Culverwell

NOVOBLUE™ WATER TESTING SOLUTIONS Page |1 Introduction Congratulations for deciding on NOVOBLUE™ as your water testing solution of choice! Water chemistry is a fascinating science which involves accurate and demanding attention to detail. Nevertheless, your NOVOBLUE™ testing strips are designed to give you all the tools that you may need to accurately understand what your water is doing – without any of the usual testing headaches seen in many other products. Armed with the accurate information contained herein, you will be in a strong position to treat your water effectively so that it is safe for drinking, and sparklingly fresh and clear for bathing. What You Will Find in This Pamphlet In this pamphlet you will find each test parameter in its own brief section. Each section contains a table that conveniently summarizes the most important information that a typical home tester might need to know in order to take appropriate action. In addition to the handy tables of information, you will find a brief discussion of any other interesting and relevant details – things discussed typically include descriptions of why a certain substance is needed or unsafe, as well as an explanation of how these substances may have gotten into your pool or drinking water in the first place. In general, our discussions of each parameter explore drinking water issues and pool/spa operational issues separately where appropriate. A swimming pool has different demands to drinking water in terms of high-volume public use and safety. Drinking water, on the other hand, is consumed in far larger amounts internally than is pool/spa water as such regulations tend to be far stricter for drinking water systems than for pools. Finally, the relatively complex issue of pool maintenance chemistry and drinking water disinfection comes with its own set of appropriate standards and compromises. All information is referenced from supporting documentation (listed on the final page) and consists of six documents containing all the data for our parameter values as well as other miscellaneous information published by the World Health Organization (WHO), the Environmental Protection Agency (EPA), the American National Standards Institute Inc (ANSI), and the Association of Pool & Spa Professionals® (APSP). We encourage anyone interested to read these fascinating resources for themselves as they contain a wealth of interesting and important water-based information. NOVOBLUE™ WATER TESTING SOLUTIONS Page |2 Finally, we provide this information to empower our customers with the most accurate and important information possible. This is done to enable our customers to be able to treat their own pools/spas effectively and to make appropriate choices regarding drinking water quality and purity. We have gone to the utmost lengths to try to ensure that the information contained here is accurate, up to date, and safe to implement. That being said, as in any document, there is the possibility of error and we cannot be responsible for a misunderstanding or misapplication of this information. We caution all our customers to consult with a professional before handling any chemicals or treating drinking water or pool water – especially if you are inexperienced. We wish you all the best with your water testing! Regards, The NOVOBLUE™ Team NOVOBLUE™ WATER TESTING SOLUTIONS Page |3 Hardness (Calcium Hardness) POOL/SPA LEVELS LOW: OPTIMAL: HIGH: <200 mg/l 200 – 400 mg/l >400 mg/l DRINKING WATER LEVELS World Health Organization: No health-based guideline value set. EPA: No health-based guideline set. The most common maximum guideline value set by countries worldwide at the time of printing was 500 mg/l. This value has been set for taste purposes, to minimize corrosion, and to minimize scale deposits on infrastructure/household items. Hard water is NOT harmful to health. Most countries set targets lower than 500mg/l as “desirable” (100 – 200 mg/l). HIGH/MAX: OK: OPTIMAL: 500 – 1000 mg/l 200 – 500 mg/l 100 – 200 mg/l Hardness is a measure of the total dissolved calcium and magnesium ions in water. Usually, tests simply measure the calcium ions in a solution, hence the test is often called a “calcium hardness” measure. The more Calcium ions (and Magnesium ions) in water, the ‘harder’ the water is. The ‘hardness’ of water is not a health concern for drinking water. Hardness does affect the taste of drinking water and can result in white scale deposits on tap-heads, shower-heads, inside kettles, and inside hot water geysers and piping at values higher than 200 mg/l. Harder water does not form a lather as easily as soft water and may totally resist lather formation which would cause soaps and detergents to be less efficient. (3) NOVOBLUE™ WATER TESTING SOLUTIONS Page |4 For pools, hardness is an important measure that needs to be monitored because too high or too low hardness can cause damage to the pool walls or fabric (etching on surfaces and corrosion). Hardness less than 100 mg/l can be corrosive to water piping in municipal drinking water supply systems and pool systems, whilst levels above 400 mg/l can cause scale deposits in piping and affect filtration systems depending on the Ph. (1) (3) pH POOL/SPA LEVELS W.H.O. (Cl based disinfectant): 7.2 – 7.8 (Br based disinfectant): 7.2 – 8.0 ANSI/APSP 7.2 – 7.8 OPTIMAL: 7.2 – 7.8 DRINKING WATER LEVELS W.H.O. *No health-based guideline given (Common Levels Found: 6.5 – 8.5) EPA: *Secondary Standard: 6.5 – 8.5 *Commonly found pH levels in water distribution systems are not a health concern. EPA: pH is to be maintained in the range 6.5 – 8.5 to enhance taste, prevent corrosion on piping, and aid chlorine-based disinfection. pH is a measure of the total hydrogen ions in a solution. Another way to think about pH is that it is a measure of how acidic a liquid is. ` Lower values of pH (<7.0) are more acidic and higher values (>7.0) are less acidic (more “alkaline”, or “basic”). A pH reading of 7.0 is perfectly neutral, neither acidic nor basic. The human body tightly controls pH levels because pH affects the way chemical reactions proceed. However, different pH levels are normal in different parts of the body. In the stomach, for example, the presence of hydrochloric acid used to dissolve food can bring the pH down to a value of about 2 (extremely acidic), whilst human blood has a very small range of values that the body tightly controls ranging from 7.35 to 7.45. If blood pH drops below 7.35 then it becomes too acidic and causes major health complications – a condition known NOVOBLUE™ WATER TESTING SOLUTIONS Page |5 as acidosis. On the other hand, blood pH levels above 7.45 are also dangerously leading to an alkaline condition known as alkalosis. Generally speaking, the food and water we ingest have almost no effect on our pH levels. This is because the body buffers and controls these levels so tightly. Thus, drinking water shouldn’t affect our blood pH at all. However, ingesting water of high or low pH over long periods of time does put a slight nutritional demand on the body to keep our buffer compounds in good supply – any reasonably varied diet will automatically contain the required nutrients to suit this purpose. The main concern with pH levels in drinking water is not so much to do with health but rather aesthetic. Taste is linked to pH, as is hardness/softness. Alkaline water (high pH) has a distinctive taste that many people find unappealing. Extreme pH readings should obviously always be avoided in drinking water – by analogy, we don’t want to be drinking hydrochloric acid (stomach/pool acid) or caustic soda, nor would we bathe in such corrosive substances – in either case, we would suffer chemical burns. In terms of pool use, pH is very important for a few reasons. Very acidic or very basic pH levels in pool water can be corrosive to pool machinery and irritating to the skin, eyes, and mucous membranes. The ideal pH for nonirritating water for the eyes and skin is around 7.4 which is similar to the pH of the eyes and skin. Another factor to consider regarding pool water is that the pH of the water affects the chemistry of the water – particularly chlorine or disinfectant chemistry. pH values higher than 7.5 start to decrease the effectiveness of most of the common pool chlorination products. The pH scale, or measure, is a logarithmic scale. This means that a small numerical difference actually represents a massive difference in the acidity of a solution. Each 1 unit of the scale is literally an order of magnitude of difference. This means that the difference of between say 6.0 pH and 8.0 pH is massive, 6.0 is quite acidic and 8.0 is quite basic. Any values outside this range are notable, and people should take care in their handling of water with such pH values. NOVOBLUE™ WATER TESTING SOLUTIONS Page |6 Total Alkalinity POOL/SPA LEVELS World Health Organization: No Operational or Health Based Guideline Given EPA: No Operational or Health Based Guideline Given ANSI/APSP: MIN – 60 mg/l MAX – 180 mg/l OPTIMAL: DRINKING WATER LEVELS World Health Organization: No health-based Guideline Given EPA: No Health Based Guideline Given Total alkalinity is not considered a direct health concern for drinking water. * 80 – 120 mg/l The total alkalinity test measures how resistant water is to changes in pH. The higher the total alkalinity the more resistant to pH changes the water will be, especially in response to adding chlorine. Total alkalinity is usually measured as mg of calcium carbonate per liter of water. Keeping water pH stable when adding disinfectants is desirable. On the other hand, if the total alkalinity is too high, then we may find it difficult to adjust pH to our liking - so we should maintain optimal levels of carbonate for buffering our pool environments, not too much and not too little. ANSI/APSP sets a minimum and maximum standard of 60 mg/l and 180mg/l respectively. Keeping carbonate levels (as calcium carbonate) between 80 mg/l and 120mg/l is considered optimal for nearly all pool/spa environments. (1) (6) *In terms of drinking water, no health-based guidelines are set because levels of calcium carbonate in drinking water do not pose any health risks. However, the ability for alkaline salts to buffer pH is still an important factor when considering how the pH of drinking water systems can lead to corrosion of piping, especially of metals in piping. As such, stabilizing the pH in some optimal range protects piping from being corroded and leaching metals into the water provided the pH is in an optimal range already. The water supply authority in each NOVOBLUE™ WATER TESTING SOLUTIONS Page |7 local district will likely set some desired alkalinity according to their operational parameters but levels will almost always be greater than 40 mg/l. Carbonate Unless you are a pool maintenance professional, or a professional chemist, the carbonate measure will be as useful to your pool cleaning needs as the total alkalinity measure. Professionals tend to need to work out carbonate levels directly so that they can calculate what is called a “Saturation Index”. For general everyday home use, carbonate levels can be considered to be very similar to total alkalinity. The main purpose of maintaining proper carbonate saturation and good overall total alkalinity is to buffer water against pH changes. Saturating water correctly also helps to reduce scale deposits and prevent corrosion. However, if the pH is kept within optimal ranges and the total alkalinity is also kept in optimum ranges, then in most cases a carbonate test would not be necessary. This test is provided mostly as an extremely useful convenience for professionals in the pool maintenance industry because it makes the computation of the LSI (saturation index) easier to perform. Like total alkalinity, carbonate levels have no health guideline value since they are not a health concern. For the relevant guideline levels please refer the total alkalinity table above, or to your own personal pool maintenance standard operations manual of choice. NOVOBLUE™ WATER TESTING SOLUTIONS Page |8 Chlorine Tests There are two direct tests for Chlorine, “total chlorine” and “free chlorine”. These two tests are related to each other, and both taken together can give vital information for drinking water systems or recreational water systems. Free Chlorine Test POOL/SPA LEVELS W.H.O./EPA/ANSI/APSP: MAX: (POOLS) 4 mg/l (SPAS) 5 mg/l MIN: (POOLS) 1 mg/l (SPAS) 2 mg/l OPTIMAL: As close to 1 or 2 mg/l for pools and spas respectively. DRINKING WATER LEVELS W.H.O. (as Free Cl2): MAX 5.0 mg/l MIN 0.2 mg/l EPA (as Free Cl2): MAX 4.0 mg/l Free Chlorine levels should not exceed 4 or 5 mg/l. Minimum residuals should be at least 0.2 mg/l at the tap. OPTIMAL: As close as possible to 0.2 mg/l at the tap outlet. Chlorinated drinking water has a strong odor and taste if levels are much higher than 0.2 mg/l The free chlorine test measures the amount of chlorine in your water available for disinfection. Your free chlorine is simply the chlorine actually available to disinfect your water because it is not bound (or combined) with other compounds - it is ‘free’ to react with other things. NOVOBLUE™ WATER TESTING SOLUTIONS Page |9 Free chlorine present in water is often called “residual chlorine”. It is called this because after adding chlorine in sufficient amounts there will be some fraction of the chlorine you added which remains as free chlorine and some fraction that gets bound or used up. This ‘residual’ is what protects your water from contamination as time passes, and is the main reason why pools, drinking water, and stored water can remain clear for a time after adding chlorine. If you test for free chlorine, you are testing your residual ‘available’ chlorine. If there is some residual chlorine present, then that means that the water you are testing will resist contamination for as long as that residual remains present – effectively the water is sterilized and will remain so. Fortunately, free chlorine is toxic to microorganisms. Unfortunately, very high chlorine levels in water can also be harmful to humans. So, there are maximum drinking water guidelines for chlorine residuals because of this. There are also minimum guidelines for drinking water which are set to ensure that the water is not contaminated by disease-causing organisms. Likewise, keeping a swimming pool clean, clear, and free of microorganisms requires similar guidelines. The optimal free chlorine values are listed in the table under the free chlorine heading above. Total Chlorine Test There are no maximum guidelines for total chlorine test values. This is because this test is mainly used to help us find out how much bound chlorine is in the water versus the amount of free chlorine. The total chlorine test measures all the chlorine in your water. In other words, it measures your free chlorine (see the previous section) and your bound or combined chlorine. Subtracting the free chlorine from the total chlorine will tell you how much chlorine is bound to other molecules. Chlorine that is bound to other molecules is not freely available to kill off pathogens and disinfect water. Usually, our free chlorine becomes bound because it binds to and reacts with compounds in the water. This is why free chlorine gets used up in the disinfection process, and also why we need to keep adding chlorine to make sure levels of free chlorine stay high enough to keep our waters free of harmful microorganisms. As mentioned, if we subtract the free chlorine from our measure of the total chlorine we are left with ‘combined’ or ‘bound’ chlorine. Bound chlorine is often found in molecules called NOVOBLUE™ WATER TESTING SOLUTIONS P a g e | 10 “chloramines” which are the molecules responsible for skin irritation, eye irritation, and the strong obnoxious chlorine fumes commonly found around indoor pools. The W.H.O. states that bound chlorine levels (i.e., levels of chloramines) should be no more than half the free chlorine levels and that ideally bound chlorine levels should be kept at 0.2 mg/l or less to prevent eye irritation and strong odors in pool areas. The same levels are given for drinking water. How to calculate the “combined” (Bound) chlorine. (TOTAL CHLORINE) – (FREE CHLORINE) = (BOUND CHLORINE) (as chloramines) Below are some suggested values for bound chlorine levels to keep your pool water from causing eye and skin irritation, and to keep drinking water from having a chlorinated odor. **BOUND CHLORINE LEVELS (e.g., Chloramines): POOL/SPA LEVELS WHO: Bound chlorine should not be more than half the amount of free chlorine. As little as possible is best. World Health Organization: MIN: MAX: n/a 3 mg/l MAX: Optimal: Optimal: ≤ 0.2 mg/l EPA: MAX: 3 mg/l 0 – 0.2 mg/l DRINKING WATER LEVELS EPA: 4 mg/l OPTIMAL: As little as possible. MIN: MAX: Optimal: n/a 4 mg/l not given **NOTE: Bound chlorine must be calculated from free chlorine and total chlorine. Please carefully read the sections on free and total chlorine tests before interpreting the above table. NOVOBLUE™ WATER TESTING SOLUTIONS P a g e | 11 Fluoride (Fl-) POOL/SPA LEVELS DRINKING WATER LEVELS World Health Organization: Fluoridation is not a relevant issue for the operation of pools/spas other than incidental levels that may arise from water sources used in the filling process. MAX: 1.5 mg/l (as fluoride ions) EPA: Considered a contaminant. MAX: 2 mg/l (as fluoride ions) The artificial addition of Fluorine ions into drinking water supply systems has been a longtime practice in many countries. According to the World Health Organization, artificial water fluoridation is done to ‘prevent tooth decay’. (2) The EPA lists fluoride as a secondary water contaminant which has negative cosmetic health effects at levels in excess of 2 mg/l. The World health organization cites the same negative health effects but at levels 25% less (1.5 mg/l). In a global comparison of fluoride regulatory guidelines by country, the highest ‘acceptable’ maximum guideline value set was 4 mg/l, the lowest was 0.6 mg/l, and the most common level was set at 1.5 mg/l. (2) (3) (5) Fluoride is found relatively often in natural sources of drinking water and contractions vary considerably. Fluorine is also a natural component of plants and soils. Fluorine is always found in ionic form (i.e., fluoride ions) in natural or water-based contexts. Common health problems linked to excessive fluorine exposure include severe discoloration of the teeth (called ‘dental fluorosis’) on the mild end. Higher concentrations lead to ever increasingly severe health problems with the most serious complications involving severe bone weakness and massive vulnerability to crippling bone fractures (at levels of 10 mg/l or higher). (3) NOVOBLUE™ WATER TESTING SOLUTIONS P a g e | 12 Cyanuric Acid (Chlorine Stabilizer) POOL/SPA LEVELS1 00 – 30 mg/l Low/OK 30 – 50 mg/l Optimal 50 - 100 mg/l OK/High >100 Too Much DRINKING WATER LEVELS World Health Organization: 40 mg/l No national regulatory values were set by any country at the time of publication2 Cyanuric acid (CYA) is used as a chlorine stabilizer in swimming pools. More specifically, CYA prevents chlorine from being lost due to sunlight exposure. Too much CYA will render chlorine ineffective (the greater the amount of CYA the less effective your chlorine is at sterilizing your water) - the usual recommended optimum CYA levels for pool use are between 30 and 50 mg/l. Too little CYA in your pool means that your chlorine will degrade much more rapidly when exposed to sunlight, making your chlorine far less efficient – you will have to add chlorine daily in relatively large amounts to maintain your pool. The World Health Organization has set a drinking water limit of 40mg/l. However, not a single country has implemented any maximum regulation (so far) because CYA is considered safe in the typical concentrations used to enhance chlorine stability. Another reason why many countries may not have implemented a regulatory guideline for CYA in drinking water is that CYA is not considered useful in typical municipal closed water supply systems – it isn’t used in such systems. This is because there is almost no sunlight exposure in a closed or piped municipal water supply network. CYA is only really useful because it extends the longevity of free chlorine in water exposed to sunlight. One final fact to take note of is that CYA takes very long to degrade once added to pool water, which means that over time your CYA levels may rise. Two consequences of this fact are that once you reach your optimal CYA levels in your pool you should stop adding any more CYA, probably for a very long time. The other consequence is that decreasing CYA levels in a pool that already has too much CYA can be tricky. The most common method used to decrease CYA levels is to partially or fully drain the pool and then refill it from a source absent of CYA – this essentially dilutes or completely removes CYA as appropriate. NOVOBLUE™ WATER TESTING SOLUTIONS P a g e | 13 Bromine (Bromide/Bromine ions) POOL/SPA LEVELS1 DRINKING WATER LEVELS2 3 World Health Organization OPTIMAL (pools): 2.0 – 2.5 mg/l (as Bromine) (In Combo with Ozone): 15 – 20 mg/l (as bromide) Using BCDMH (bromochlorodimethylhydantoin) MAX: 200 mg/l World Health Organization: No health-based guideline given. * EPA: No health-based guideline given. * ANSI/APSP OPTIMAL (pools): OPTIMAL (spas): 4 – 5 mg/l** 4 – 6 mg/l** *2 mg/l is given as a conservative maximum value for drinking water for children and 3 mg/l for adults. 4 mg/l However, such high levels of bromide in drinking water are extremely unlikely. That is why the W.H.O. has not set a formal or informal guideline. **(as Bromine) OPTIMAL: (As total bromine) This is presumably also the case for the EPA which does not even discuss the issue. ` OPTIMAL: < 2.2 mg/l Extremely unlikely to find bromide levels in drinking water anywhere close to this value. (Less is better) NOVOBLUE™ WATER TESTING SOLUTIONS P a g e | 14 Lead (Pb) POOL/SPA LEVELS 1 DRINKING WATER LEVELS 2 3 World Health Organization: MAX: 0.01 mg/l Lead contamination is not a relevant issue for the operation of pools/spas other than incidental levels that may arise from water sources used in the filling process. EPA MAX (Ideal Goal): MAX (enforceable): OPTIMAL: zero 0.015 ZERO mg/l Lead contamination of water is toxic to human health. Ideally, we should never drink it in any amount. Lead is an extremely toxic metal for human health which is why such stringent controls are in place to limit its occurrence in drinking water systems. Typically, Lead may enter drinking water via industrial effluent, pesticides, environmental pollution, erosion of natural lead sources, and corrosion/seepage of piping and household plumbing. The effects of lead exposure as reported by the EPA include: Retarded or slow mental and physical development in infants; learning disabilities and attention span deficits in young children; and in adults, exposure can lead to kidney problems and high blood pressure. Lead plays absolutely no useful role in any pool/spa management so levels of lead should conform to the drinking water standards for complete safety. NOVOBLUE™ WATER TESTING SOLUTIONS P a g e | 15 Iron (Fe) POOL/SPA LEVELS1 Iron is not a relevant issue for the operation of pools/spas other than incidental levels that may arise from water sources used in the filling process. High levels of iron may cause water to be discolored and stain pool equipment and surfaces an orange/brown color. DRINKING WATER LEVELS2 3 World Health Organization: Precautionary max value: 2 mg/l* Aesthetic MAX value: 0.2 mg/l** Most Common value: 0.3 mg/l *This level is not harmful to health and is set by the W.H.O. only provisionally as a precautionary value. **The aesthetic maximum is given because at levels higher than this the taste of the water is negatively affected and the water will stain clothing, appliances, fixtures, and infrastructure an unsightly orange-brown color. EPA: Aesthetic MAX value: 0.3mg/l*** (Secondary Contaminant guide) ***Reasoning is the same as for W.H.O. value; please see entry (**) above. OPTIMAL: ≤ 0.3 mg/l Iron is very abundant in the natural environment and common levels seen in natural waters range between 0.5 and 50 mg/l. The abundance of iron in the natural environment is the main reason why it enters our drinking supply but it can enter our water from corroding water pipes. Iron is needed as an essential nutrient and, depending on various factors, we need roughly between 10 – 50 mg/day for optimum health. NOVOBLUE™ WATER TESTING SOLUTIONS P a g e | 16 As a precaution against excessive iron exposure the W.H.O. recommends a maximum value of 2 mg/l, however, this recommendation is only precautionary as levels of 2 mg/l are not harmful to health. However, Iron is not really regulated for health reasons, but rather for aesthetic reasons. Too much iron in your pool or drinking water will tend to be a ‘brackish’ brown color and can stain surfaces, clothing, and equipment. High levels of iron in water can taste ‘rusty’ or like blood – most consider this unpleasant. The standard threshold for aesthetic concerns is between 0.2 – 0.3 mg/l as recognized by the W.H.O. and the EPA. Copper (Cu) POOL/SPA LEVELS1 Copper is not a relevant issue for the operation of pools/spas other than incidental levels that may arise from water sources used in the filling process. High levels of copper may cause water to be discolored, and stain pool equipment or surfaces agree/blue color. DRINKING WATER LEVELS2 3 World Health Organization: Max value: 2.0 mg/l Aesthetic MAX value: 1.0 mg/l* Most Common value: 1.5 mg/l *The aesthetic maximum is given because at levels higher than this the taste of the water is negatively affected and the water will stain clothing, appliances, fixtures, and infrastructure a green-blue color. EPA: Aesthetic MAX value: 1mg/l** (Secondary Contaminant guide) **Reasoning the same as for W.H.O. please see entry (*) above. OPTIMAL: ≤ 1.0 mg/l NOVOBLUE™ WATER TESTING SOLUTIONS P a g e | 17 Copper piping and geysers can corrode staining giving water a beautiful blue/green color. Unfortunately, just like for iron, Copper tends to stain bathroom fittings, clothes, and walls. At certain levels, copper lends a ‘coppery’ taste to water which many find unappealing. The corrosion of copper piping is usually due to soft, acidic water (pH < 6.5 and hardness < 60 mg/l calcium carbonate). So, offsetting the acidity and managing the hardness of drinking water can prevent the corrosion of copper piping. Copper is not used in the context of pool or spa maintenance unless the piping or pump has copper parts for aesthetic purposes – in these cases managing hardness, pH and alkalinity should ensure the longevity of the equipment. Nitrates & Nitrites Nitrate (NO3−) and nitrite (NO2−) are nitrogen-containing ions that are commonly found in water systems. Nitrates are found naturally in the environment in plentiful supply. Nitrates are an important nutrient for plants and are an integral part of the nitrogen cycle. Surface water runoff can bring nitrogen into water systems, as can fertilizers that enrich the nitrogen content of the soil. In terms of pool water, aside from the possible sources of nitrates already mentioned, one of the main sources is human sweat and urine which contain nitrogen compounds. Being a nutrient for plants and algae, nitrates in the pool will tend to help algae and some other organisms proliferate in the pool. Higher levels of algae and bacteria in a pool will always require more chlorine as a disinfectant – increasing the demand for chlorine. It is not the nitrate ion itself that creates the increased demand for chlorine, but rather the increased amounts of microorganisms in the water that raises the chlorine demand. Nitrites are not usually present in the environment in great numbers because as a chemical, nitrite is less stable and prefers to be in the form of nitrate. Nitrites are often formed when microorganisms ingest nitrate and release nitrite. In water distribution networks, nitrite can also be formed by particular bacteria when water stagnates whilst also being rich in natural nitrogen content. NOVOBLUE™ WATER TESTING SOLUTIONS P a g e | 18 The presence of nitrogen compounds in your surface or groundwater usually indicates contamination by ammonia and/or organismal proliferation. Examples of the kinds of things that could lead to such a situation include non-organic over-fertilization and manure seepage, careless wastewater disposal, and human sewerage entering water distribution systems. It is sometimes possible that nitrites in groundwater can come from natural vegetation. Surface water is much more likely to contain nitrates or nitrites than groundwater, or closed water systems. According to the W.H.O, the most important source of human exposure to nitrate and nitrite is from our diet – through vegetables and meat. Vegetables are rich sources of nitrates and meat is often preserved with nitrites, especially cured meats. Nevertheless, it is possible that drinking water can become a major source of nitrate/nitrite exposure and as such levels of both nitrate and nitrite are regulated for health and safety. Some of the negative health effects of excessive nitrite/nitrate exposure (especially in infants under six months of age) include shortness of breath and blue baby syndrome amongst other complications.4 Controlling nitrates and nitrites in pools is a matter of simply maintaining proper management of the pool environment and disinfection residuals – regular testing is vital to catching nitrate and nitrite compounds early before microorganisms like algae use the nitrogen as food and multiply. The drinking water maximum guidelines for both nitrates and nitrites are listed in the tables on the following two pages: NOVOBLUE™ WATER TESTING SOLUTIONS P a g e | 19 Nitrate (R-NO3) Levels POOL/SPA LEVELS1 Nitrate (NO3-) is not a relevant issue for the operation of pools/spas other than incidental levels that may arise from water sources used in the filling process or contamination sources from rain, spillage etc. High nitrogen compound levels in your pool help to feed algae and bacteria. The increased numbers of these organisms create a greater demand for chlorine. Regular testing and proper consistent pool/spa care should prevent any problems. DRINKING WATER LEVELS2 3 World Health Organization: MAX: 50 mg/l (measured as Nitrate ions) EPA: MAX: 10 mg/l (measured as Nitrogen) OPTIMAL: ≤ 50 mg/l (as nitrate ions) (Less is always better) NOVOBLUE™ WATER TESTING SOLUTIONS P a g e | 20 Nitrite (R-NO2) Levels POOL/SPA LEVELS1 Nitrite (NO2-) is not a relevant issue for the operation of pools/spas other than incidental levels that may arise from water sources used in the filling process or contamination sources from rain, spillage etc. High nitrogen compound levels in your pool help to feed algae and bacteria. The increased numbers of these organisms create a greater demand for chlorine. Regular testing and proper consistent pool/spa care should prevent any problems. DRINKING WATER LEVELS2 3 World Health Organization: MAX: 3 mg/l (as NO2-) Most Common: 0.5 mg/l (as NO2-) = 50 mg/l (as NO3-) EPA: MAX: 1 mg/l (measured as Nitrogen) OPTIMAL: << 1 mg/l (as Nitrogen) NOVOBLUE™ WATER TESTING SOLUTIONS P a g e | 21 Closing Remarks On the next and final page is our list of document resources and we would like to once again encourage everyone who has come this far to definitely dive into some or all of them. They contain a wealth of interesting and important information on water management, water safety, health, water chemistry and much more. Please remember to use your common sense and ask a professional should something be unclear. It is vitally important that no mistakes are made with your drinking or bathing water as any errors could lead to serious health problems and severe injury. Many of the chemicals involved in water disinfection are extremely volatile and reactive – the proper care and handling of such chemicals is beyond the scope of this work as are the final choices you make in order to assess your personal pool or drinking water supply. “We hope this document may have been of some small benefit” - The Authors NOVOBLUE™ WATER TESTING SOLUTIONS P a g e | 22 Information & Data Sources Cited 1 World Health Organization. Water, Sanitation and Health Team. (2006). Guidelines for safe recreational water environments. Volume 2, Swimming pools and similar environments. Geneva: World Health Organization. http://www.who.int/iris/handle/10665/43336 (Accessed 06/2018) 2 World Health Organization. (2018). Global overview of national regulations and standards for drinking-water quality. Geneva: World Health Organization; 2018. Licence: CC BY-NCSA 3.0 IGO. Available at: http://www.who.int/water_sanitation_health/publications/national-regulations-andstandards-for-drinking-water-quality/en/ (Accessed 06/2018) 3 World Health Organization. (2017) Guidelines for drinking-water quality: fourth edition incorporating the first addendum. Geneva: World Health Organization; 2017. Licence: CC BY-NC-SA 3.0 IGO. http://www.who.int/water_sanitation_health/publications/drinkingwater-quality-guidelines-4-including-1st-addendum/en/ (Accessed 06/2018) 4 EPA (2009) EPA 816-F-09-004 National Primary Drinking Water Regulations. Available at: https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-waterregulations#main-content (Accessed 06/2018) 5 E.P.A. (2017) National Secondary Drinking Water Regulations (NSDWRs) (March 8 update) https://www.epa.gov/dwstandardsregulations/secondary-drinking-water-standards-guidancenuisance-chemicals#table (Accessed 06/2018) 6 ANSI/APSP-11 (2009) American National Standard for Water Quality in Public Pools and Spas. The Association of Pool and Spa Professionals. https://standards.nsf.org/apps/group_public/download.php/17496/ANSI-APSP-11%202009for-apsp-store.pdf (Accessed 06/2018). Latest version (2017) not available for free in the public domain.