Understand your test results
Drinking water (microbiology)
Help me understand my certificate of analysis
My water is not drinkable (non potable) - Why and what can I do ?
You should NOT drink your water unless you boil it at least one minute.
The presence of Escherichia coli (E. coli) or enterococci in the water indicates that it has been contaminated by fecal matter. The contaminated water can contain microbes (bacteria, viruses or parasites) that cause health problems. To be safe, drinking water should not contain any of these microorganisms.
It is important to determine the source of the contamination and to take the appropriate corrective measures to improve the quality of the water in the long term. Then, you should proceed to a disinfection of your water well. It is recommended to do another Drinking water (microbiology) analysis 1 to 2 weeks after the procedure has been done. If result is compliant to the regulation, do your next analysis a few months later to make sure the contamination’s source really has been eradicated. If result is still non conform or non potable, you should investigate with a specialist.
My water is not compliant - Why and what can I do ?
Your water is not compliant, because there is possibly an excessively high presence of total coliforms or atypical colonies. Those kind of bacteria are not related to pathogen (see section What are total coliforms and What are atypical colonies) but there presence beyond the recommendation indicates a poor quality of your water.
Non compliance water is not considered non potable. However, it is recommended, as a preventive mesure, to boil it at least one (1) minute before consuming it until you eradicate the contamination.
It is important to determine the source of the contamination and to take the appropriate corrective measures to improve the quality of the water in the long term. Then, you should proceed to a disinfection of your water well. It is recommended to do another Drinking water (microbiology) analysis 1 to 2 weeks after the procedure has been done. If result found to be in compliance with the regulation, do your next analysis a few months later to make sure the contamination’s source really have been eradicated. If result is still not compliant, you should investigate with a specialist.
My water is compliant - Why and what do I have to do ?
All microbiological parameters that have been analysed are under the recommendation related to the Regulation respecting the quality of drinking water
To be sure water is safe for consuming, it is strongly recommended to also proceed at least once to the 2-Healt (chemical). analysis.
Why is my result TNI, N/A or ND ?
TNI (or TNC) means Too Numerous to Count. Due to too many bacteria in the sample, it’s not possible to have a count or to determine the absence of E.coli which automatically leads to non potable water.
N/A means not applicable, due to too many bacteria (see TNI or TNC). If you have a TNI or TNC result’s for total coliform and/or E.coli, atypical colonies count is not applicable (N/A).
N/D (not determined) means the total coliforms can not be determined due to too many bacteria of the “atypical colonies” type. Atypical colonies are a group of bacteria found in the same conditions as total coliforms but do not have the same morphology and biochemical characteristics. Having more than 200 CFU of atypical colonies automatically leads to a N/D results for total coliforms. At that amount of atypical colonies per analysis, the count of total coliforms could be underestimated or hidden.
Help me understand the terms on my certificate of analysis
What are total coliforms ?
Most species of total coliforms can occur naturally in soil and vegetation. Their presence in water does not indicate fecal contamination or a health risk, but rather a degradation of the quality of the well water. The presence of total coliforms reinforces the importance of carrying out regular analyses and making the appropriate corrections to prevent any possible fecal contamination. If new analyses confirm the presence of total coliforms in concentrations exceeding the standard (above 10 cfu / 100 ml), the water is therefore not compliance with the regulation (RQEP) and it may be best to perform a shock treatment to disinfect the well.
Their presence in treated water does not necessarily imply an imminent risk to public health since most of these bacteria do not have a fecal origin. However, it may be a good initiative to boil it at least one minute before consuming it as a preventive mesure until the source of contamination has been found and eradicated.
What are atypical colonies ?
Atypical colonies are a group of bacteria found in the same conditions as total coliforms but do not have the same morphology and biochemical characteristics. They are not considered as pathogen (causing health problem). However, having more than 200 CFU /100ml of atypical colonies automatically leads to a N/D results for total coliforms. At that amount of atypical colonies per analysis, the count of total coliforms could be underestimated or hidden leading to results that are not compliance with the regulation (RQEP).
What is E. coli (Escherichia coli bacteria)?
E. coli is a species of bacteria found naturally in large number in the intestines of humans and animals. To be safe, drinking water should not contain any of these microorganisms.
Water contaminated with pathogen related microorganisms can cause health problem. Presence of E.coli can be related to the presence of other potential pathogens. Even if you have no symptoms, you must not drink contaminated water unless you boil it at least one (1) minute.
You can use water contaminated with a result of 20 CFU/100ml or less of E.coli*, without boiling it, for:
- wash dishes in hot water;
- washing clothes;
- wash your hands with soapy water;
- take a shower or a bath..
*You should not use water contaminated with a result greater than 20 CFU/100ml of E.coli , unless it has been treated or boiled.
What are Enterococci ?
Enterococci are a species of bacteria found naturally in the intestines of humans and animals. To be safe, drinking water should not contain any of these microorganisms (0 CFU/100ml).
Water contaminated with pathogen related microorganisms can cause health problems. Presence of enterococci can be related to the presence of other potential pathogen microorganisms. It is also known to be more resistant to particular environment than E.coli, which make it very important to analyse.
Even if you have no symptoms, you must not drink contaminated water unless you boil it at least one (1) minute.
You can use water contaminated with a result of 5 CFU/100ml or less of enterococci bacteria*, without boiling it, for:
- wash dishes in hot water;
- washing clothes;
- wash your hands with soapy water;
- take a shower or a bath.
You should not use water contaminated with a result greater than 6 CFU/100ml of enterococci bacteria, unless it has been treated or boiled.
What does CFU mean ?
CFU means Colonies Forming Unit. It can be interpret as one bacteria which can form a visible colony in laboratory. It is a standard unit to count bacteria in microbiology.
What should I do once I have my results ?
Can I drink or use my water if it is non potable or not compliant ?
Non potable (non-drinkable)
If your water is contaminated, boil it at a full boil for at least 1 minute before consuming it or use bottled water for: drinking, preparing drinks, formula, washing fruits and vegetables that will be eaten raw, making ice cubes, brushing your teeth and rinsing your mouth
You can use tap water without boiling it for: washing dishes in hot water; washing clothes; wash your hands with soapy water; take a shower or a bath.
Not compliant
As a preventive mesure you could apply same instructions as if your water has been non potable until you find and eradicate the problem. However, non compliance results do not necessarly involve boilling water.
What are the sources of contamination in a well ?
It is important to determine the source of the contamination and to take the appropriate corrective measures to improve the quality of the water in the long term. The local sources of contamination can be multiple:
- Poor layout of the well (lack of tightness of the cover or sealing, degradation of materials, etc.);
- Inadequate slope of the surrounding soil (absence of a mound around the well to keep runoff from the surface);
- Defective septic system;
- Unsanitary conditions (e.g. spreading manure or other activities generating fecal pollution nearby)
Do I need to install a water treatment system ?
First step after having a non conform/non potable result is to proceed to inspection and evaluation of the sources of contamination. A well disinfection could be done to eradicate contamination. If contamination reoccures after disinfection*, you should consult a specialist in water treatment system.
*to consider contamination eradicated, results of two analysis have to be compliant. First test should be done 1-2 weeks after disinfection, and the second after a few months.
CHEMICAL (aesthetics and health)
Understanding aesthetics parameters
Here is a guide to help you understand your aesthetics package results (related to package 3, 5, 6 and 7)
| Parameters | Standard or maximal value recommended (aesthetic) | Effect on health | Effect on your house |
| Alkalinity | None | None | Could be involved in formation of a deposit – Often related to hardness |
| Calcium | N/A | N/A | Involved in hardness evaluation |
| Chloride | 250 mg/L (aesthetic) | None | At higher value than recommended, it could give an unpleasant taste to your water. |
| Conductivity | 1 500 µS/cm (aesthetic) | None | Gives indication about the amount of organique matter in suspension. |
| Color | 15 TCU (aesthetic) | None | At higher value than recommended, it could give a particular color to the water. |
| Hardness | 120 mg/L (aesthetic) | According to Health Canada, water with hardness in excess of 500 mg/L are unacceptable for most domestic purposes. | Household pipes can become clogged with scale, hard waters also cause incrustations on kitchen utensils and increase soap consumption. |
| Iron | 0.3 mg/L (aesthetic) | None | At higher value than recommended, it can stain laundry and plumbing fixture and produce undesirable tastes. It can also give a reddish-brown colour to water. |
| Magnesium | N/A | N/A | Involved in hardness evaluation |
| Manganese | 0.120 mg/L (Health Canada) | Some studies in humans suggest an association between manganese in drinking water and neurological effects in children, when found in higher concentration than recommended | At higher value than 0.02mg/L, discoloured water may be observed. Manganese in naturally found in surface water and soil. |
| pH | Between 6.5 and 8.5 UpH | None | At lower pH, metals leaching can occur. A higher pH, could cause pipe clogging. |
| Sodium | 200 mg/L (aesthetic) | None. | At higher concentration than recommended, water can have a unpleaseant taste. |
| Tannins and lignins | None | None | Originates from vegetal matter, can cause discoloured water. |
| Turbidity | 5 UTN (standard RQEP) | None | At higher value, water could get coudy. |
Understanding health parameters
Here is a guide to help you understand your health package results (related to package 2, 4, 6 and 7)
| Parameters | Standard or maximal value recommended | Effect on health* | Source |
| Antimony | 0.006 mg/L (Regulation) | At greater concentration than 0.006mg/L, antimony may have several effects on multiple human organs (Antimony Health Canada) | Antimony may enter the aquatic environment by way of natural weathering of rocks, runoff from soils, effluents from mining and manufacturing operations, and industrial and municipal leachate discharges. |
| Arsenic | 0.010 mg/L (Regulation) | At greater concentration than 0.010 mg/L, people exposed to arsenic are at higer risk of suffering from cancer. | Arsenic is a naturally occurring chemical element in soil. It can dissolve in groundwater and contaminate it. |
| Barium | 1.0 mg/L (Regulation) | Exposure at high concentration for a long period of time can affect blood pressure and kidneys. | Barium is a chemical element that occurs naturally in soil, often in low concentrations. It can dissolve in groundwater and contaminate it. |
| Boron | 5 mg/L (recommendation) | Unknow | Boron is ubiquitous in the environment. |
| Cadmium | 0.005 mg/L (Regulation) | Oral exposure to high levels of cadmium over a long period of time may result in adverse effects on the kidneys or on bones. | Cadmium is a metal that can be found in the environment. It may enter drinking water sources naturally or through leaching from some pipes and well components. |
| Chromium | 0.05 mg/L (Regulation) | At higher concentration, hexavalent chromium compounds are classified as carcinogenic to humans Given the presence of oxidants and disinfectants in treated water, the trivalent form (non toxic) is likely to be oxidized to hexavalent form after treatment. | Chromium occurs naturally in small amounts in rocks and soils, some of which is released into the aquatic environment through weathering and erosion processes. While oxidated in his hexavalent form, Chromium become toxic. |
| Copper | 1.0 mg/L (Regulation) | None | Copper can affect the taste of the water and cause the staining of laundry and plumbing fixtures at levels below the regulation. It can cause a blue-green color and/or deposit. |
| Fluoride | 1.5 mg/L (Regulation) | At greater concentration than 1.5mg/L, prolonged consumption of water containing fluoride can cause dental and skeletal fluorosis. | Fluoride is a naturally occurring mineral salt in soil. It can dissolve in groundwater. |
| Manganese | 0.120 mg/L (recommendation) | At greater concentration than 0.120mg/L, it may have effects on the neurological development of children. | Manganese is a chemical element that occurs naturally in soil. It can dissolve in groundwater and contaminate it. If found in concentration greater than 0.02mg/L (which is less than recommandation for health), it can change taste and colour of water, and even stained clothing and household appliances. |
| Nitrites-nitrates | 10 mg/L N (Regulation) | At greater concentration than 10mg/L N, babies can experience breathing problems due to a slowdown in oxygen reaching their tungs and tissues. Regular consumption on a prolonged period (over decade) may lead to a risk of cancer. | Nitrites and nitrates are tasteless and odorless and can only be detected by a laboratory analysis, Presence of the contaminant may result from chemical fertilizers and manure, failing septic systems and wastewater and decomposition of plant and animal matter. It can contaminate ground or surface water. |
| Lead | 0.01 mg/L (Regulation) | Inorganic lead compounds have been classified as probably carcinogenic to humans. | Lead is usually found in drinking water as a result of leaching from distribution and plumbing system components. |
| Selenium | 0.01 mg/L (Regulation) | Prolonged exposure to higer concentration than 0.01mg/L can cause chronic selenosis symptoms (hair/nail loss, skin anomalies, tooth decay or disturbances of the nervous system) | Selenium is a naturally occurring element which is ubiquitous in the environment |
| Sulphates | 500 mg/L (recommendation) | At concentration above 1000mg/L, sulphates have a cathartic effect on humans, resulting in purgation of the alimentary canal. | Sulphates occur naturally in numerous minerals. At 500mg/L, suphaltes give water an unpleasant taste. |
| Uranium | 0.02 mg/L(Regulation) | At greater concentration than 0.02mg/L uranium my cause minor damage to the kidneys and ulcers. | Uranium occurs naturally in soil. It can dissolve in groundwater and seep into wells. |
*If concentration exceed the regulation or maximal value recommended for health, boiling water will NOT be appropriate to eliminate contamination. In fact, doing so can increase the concentration of contaminant as they don’t evaporate. You should NOT consume water unless it has been properly treated.
Do I need to install a water treatment system ?
If some of the chemical of microbiological parameters exceed the standard or recommendation, you may want to install a residential water treatment system to make your well meet quality standards for drinking water.
The type to install depends on the contaminants that need to be eliminated. You can also choose an NSF/ANSI-certified device. Therefore, it is important that you consult with a certified specialist in domestic drinking water to make the right choice.
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