Your exclusive Culligan Representative in Halifax Regional Municpality

Fact Sheet: Microbiological Contaminants

Over the last few years an increasing number of questions on and a lot of misconceptions about bacteria in our water supply have been addressed. As a result we have decided to write this article to clean up some of the misunderstandings about this topic.

Let’s take a look at some general considerations first.

Maybe the best way to approach this topic is to first differentiate between the actual water sources and then conclude, what appropriate solutions can look like.

Natural water supplies:

To fulfill the current residential legal requirements for bacteria testing, for example the ones required for the transfer of real estate, it is mandatory to test for Total Coliforms and E.-Coli.

But this is exactly where the danger lies for residential testing. Usually it is just a one-time sample – we call it a “grab-sample” – and bacteria does not spread out evenly in the water. In other words if a series of samples was taken from the same supply, the results might differ quite a bit with respect to the presence of bacteria. On top, other factors such as season, temperature, precipitation and many more come into play as well.

Let’s take a look now at the bacteria and their “friends”. First of it needs to be realized that the presence of bacteria does not necessarily mean the water supply is harmful – but it can be; neither does it mean it is harmless! Consequently ignoring microbiological activity in your water supply would be quite the gamble.

We have more coliform-type bacteria in our bodies than you will most likely ever find in a natural water supply. So what do we need to take into account then? Well, the pathogens are the culprits here and this refers to the disease causing bacteria. Pathogens – in a nut shell – are those types of bacteria, which can reproduce themselves within our bodies and can potentially cause diseases.

On top it is crucial to understand that bacteria are just one component of the microbiological contaminants. So in order to make sure your water supply is potable, hypothetically it is necessary to ensure your water supply is free of disease producing organisms but testing for any relevant contaminant is certainly far from a “budget-friendly” approach.

Yet please note there are many other potentially harmful microbes. Generally speaking, disease-producers are categorized into five main types: 1. Bacteria, 2. Protozoa, 3. Worms, 4. Viruses and 5. Fungi. And then there are many other forms from different so called kingdoms, such as for example algae (Monera or Protista kingdom); Diatoms (Protista); mold, mildew, mushrooms, yeast, rust, smut (Fungi); iron-, sulphur, manganese-bacteria (Bacteria); flatworms, nematodes, rotifers, flukes, tapeworms, hookworms, ascris, pinworms, trichina, filaria (Worms); cysts, giardia lamblia, cryptosporidium (Prostita) and many more – you get the idea!

Now would that not bring up the question why we just test for 2 types of bacteria if there is so much more to consider? A valid question and the answer is that on the one hand sanitation, disinfection and regular testing are crucial but on the other hand it is necessary to understand the actual function of the “normally” applied test.

Basically the Total Coliforms and E.-Coli Bacteria are used as the “Indicators” to determine whether “something else” is wrong and might require further investigation. The presence of those two types of bacteria is certainly a direct concern but more so it is an indicative measure for the potential presence of other organisms and/or problems. Good news is that successfully treating these two types of bacteria will look after most other microbiological contaminants as well.

Touching on all types (so called kingdoms) of the above mentioned organisms is beyond the scope of this article. It is important to understand that since the bacterial presence is used as an indicative measure, these bacteria often times grow and thrive by utilizing other contaminants and impurities in your water. And this can even correlate to any technical problems.

Iron, Manganese, Sulphur and other contaminants can contribute to growing the number of bacteria in your water supply. Other contaminants in your water, such as organics (organic carbon, tannins, lignin’s etc.), can provide a good feeding ground for those bacteria. Certain types of microbes even contribute to distinct taste and odour in the water. Some can only exist if there is enough oxygen in the water; others just require a very tiny amount of oxygen or none at all to reproduce.

Municipal Water supplies:

Overall municipal water can be considered a safe water source according to the legal definitions. The water supply and treatment technologies are closely monitored and the regulated use of qualified personnel as well as feed-backed monitoring and regular testing ensure a consistent level of quality.

And even if the odd time a so called “bleed-through” occurs, stringent and explicit procedures must be exercised. The following link might be an interesting read for you:

But all this does not mean that the Water Improvement Industry cannot provide means to improve the level of quality in the municipal water supply. Factors, which do not fall under the municipalities mandate but taking care of those definitely contributes to improved water quality, should not be neglected. Metals, hardness, chlorine, fluorides and other impurities can be addressed properly to anyone’s objectives.

Adequate Steps:

Taking a look at the size of certain contaminants is an intriguing comparison as well. Using a prominent example, if for example a bacterium is of the size of a tennis ball, then viruses can comparably take up the size of the Sphinx in Egypt and cysts can actually gain the relative size of Mount St. Helena’s. But it would not be prudent to apply this example across the board. A lot of microbes can be present in all different sizes and shapes.

Let us quickly go back to the statement that the presence of Coliforms bacteria is indicative in nature. These two types of bacteria are used for laboratory testing since they have a dependable answer in a group of readily identified organisms that indicate possible contamination.

Fecal Coliforms bacteria are well known for growing in the intestines of human beings and other warm blooded animals. They reproduce in astronomical numbers when the environment is right. Since their life expectancy is fairly short but their prolonged life span can be observed, the question must be asked, what has provided the feeding ground for this sequence of reproduction and is it an indication for potential other contaminations of the water supply.

But even then it is hypothetically possible there are no pathogens in the water; but this is a bold and very risky assumption. The Canadian Water Quality Association clearly states that at any moment when the presence of these potential disease carrying microbes is a given, immediate corrective action must be taken.

If possible, the source needs to be detected and eliminated. Disinfecting and flushing – and re-testing of course – would complete an initial remediation sequence. Care must be taken when performing such steps because basically anything used in the process (tools, material and even our hands) can easily compromise the whole idea.

Of course it is quite often almost impossible to apply this rule to wells – drilled or dug wells – if the penetration is linked to the feeding aquifer. On the other hand, it is certainly a valid consideration to make sure there is no local contamination, which could be corrected easily. But once obvious signs of contamination have become part of any water supply, relying on more contained and sporadic disinfection methods like well-shocking, is not a permanent answer to the actual problem. And please keep in mind that treatment of a water supply along those lines is a safety factor, not a corrective measure of esthetical nature.

One of the most important sentences in the whole equation is this: The absence of Coliform or E.-Coli Bacteria does not assure absence of pathogens! What it means is that even when a lab report does not show any presence of bacteria, there is still a good chance for the presence of bacteria if water was collected at a different date and especially the absence of bacteria does not rule out the presence of other microbiological contaminants.

Recognizing the potential danger is a good start. But what can be done to provide adequate protection against contamination? Correcting measures should be taken at once but a good and comprehensive approach goes beyond just applying treatment devices.

Time to take a look at possible corrective measures: There are numerous disinfection methods which can be applied to make our water supplies legally “safe”. Please keep in mind, that the focus of this article is linked to microbial impacts only. In other words any other contaminants, which potentially constitute primary or secondary violations, are not discussed here in detail!

With respect to disinfection methods it is absolutely mandatory to ensure each application’s proper functionality. Any single disinfectant and/or device have their distinct strengths, weaknesses and limitations. Some work better on certain types of bacteria, others work better on certain types of cysts, worms, fungi or viruses or protozoa. It is absolutely crucial to size and calculate any disinfection means properly. In order to keep any disinfection method effective, numerous circumstances need to be taken into account. Things like seasonal fluctuations temperature, oxygen content in the water, pH, flow rate, water demand are just a few, which need to be considered to determine the appropriate choice of disinfection method.

As we mentioned earlier, every disinfection method has its strengths, weaknesses and limitations. Some of the most common applications include boiling water, ultraviolet light, bromine, chlorine, iodine, silver, copper, alkalis, ozonation, ultra filtration, specialized filtration and acids as well as many other so called “agents”.

But our approach has to go further. This is the point, where the other parameters in a water supply need to be taken into account! It is all nice and good having treatment technologies in place that are capable of looking after the microbial side but just as well we need to ensure, they actually can perform their tasks. And there are many factors that can compromise any application’s efficiency.

A simple example: If you were to install a UV light and ignore the parameters which compromise the effective penetration of the water by means of the specific UV-rays, such unit can potentially be a waste of money. As well you would certainly like to receive some evidence that a unit works perfect and for that purpose, we offer digital UV-Transmittance testing to our customers.

Summarizing all of the above, the following conclusions can be drawn as a result:

If there is a presence of microbiological contaminants in your water supply, corrective measures should be taken immediately.

  1. The absence of Coliform bacteria on a lab test does not mean the absence of pathogens in general.
  2. Disinfection methods need to be designed and calculated carefully and require regular service and maintenance to retain their efficiency.
  3. Using disinfectants a valid consideration for any water supply.
  4. Since a water contamination can be intermittently, regular testing, as advised by the government, is recommendable.
  5. Once certain disinfection measures have been implemented, testing their effectiveness is strongly recommended.
  6. Utilizing appropriate and functional disinfection methods on any water supply is never a waste of money.
  7. And finally we all need to face the unfortunate truth that – despite an enormously increasing population – neither water quantity nor water quality is improving, making the users’ diligent engagement all the more necessary.

Thank you very much for taking the time to read our input on bacteria. As you can imagine, there is a lot more information on this topic and as usual, we’d be happy to answer any specific questions you might have along those lines.

Your Perfect Water Nova Scotia Team