Water Analysis
Bacteriological analysis
The bacteriological analysis of your water will identify the level of contamination by bacteria that make it unfit for consumption. The identification of fecal coliforms, enterococci, HAA (Heterotrophic Aerobic and Anaerobic Bacteria), and atypical colonies follows a scientific laboratory method, from a sample of your water.
Bacteriological water analyses focus on the following bacteria:
Fecal Coliforms
Fecal coliforms come from the intestines and excrement of humans and warm-blooded animals. The presence of these so-called pathogenic bacteria is very risky for the health of humans and animals. The bacterium E. coli (Escherichia coli) belongs to this category of coliforms.
The consumption of water infected with fecal coliforms can lead to very serious illnesses and, in some cases, can cause death. The first symptoms are generally gastrointestinal in nature (nausea, vomiting, and diarrhea).
It should be noted that the maximum acceptable concentration of E. coli bacteria in public and private drinking water supply systems is zero (0) detectable microorganisms per 100 ml.
Enterococci
Enterococci are bacteria similar to fecal coliforms, so they are pathogenic bacteria, meaning pose a serious health risk. Almost always related to fecal contamination, enterococci are very resistant to aseptic substances that should prevent their growth. Some enterococci can turn into germs that initiate several diseases such as tonsillitis, otitis, meningitis, and others just as serious.
Total Coliforms
Total coliforms concern the total count of coliform-type bacteria. Although most derive from plant substances, some total coliforms can be of fecal origin (10 to 15%). These bacteria serve as indicators of pollution or microbiological contamination. In the case of a well, this may reveal the presence of surface water infiltration. If the water analysis detects the presence of total coliforms in a concentration of more than 10 CFU/100ml, the well must be disinfected. It is also suggested to take a new sample of drinking water within 30 days.
HAA (Heterotrophic Aerobic and Anaerobic Bacteria)
Heterotrophic Aerobic and Anaerobic Bacteria represent the total count of germs present in the water. A count greater than 500 CFU per milliliter makes the water unfit for consumption. Fortunately, the vast majority of HAAs found in drinking water are non-pathogenic. However, some are, and they can cause infections in people with weakened immune systems.
HAAs can also serve as an indicator of pollution, particularly to detect the presence of residual organic matter in supply lines. Organic matter promotes the growth of bacteria. The role of HAAs as an indicator is therefore valuable for better control of drinking water quality.
Atypical Colonies
Atypical colonies are bacterial colonies that are part of the HAAs but their presence in drinking water is not desirable. They do not have a metallic green color during the analysis of coliforms using the membrane filter method. Coliforms usually start to grow when their number is greater than 200 CFU/100 ml. In large numbers, they make bacteriological analyses useless and disinfection must be done preventively.
Experteau transacts exclusively with accredited laboratories.
Fecal coliforms – recommended level: less than 1 CFU/100 ml
Enterococci – recommended level: less than 1 CFU/100 ml
Atypical colonies – recommended level: less than 200 CFU/100ml
Taking a water sample for bacteriological analysis is subject to a strict procedure.
- The container provided by the laboratory is sterilized, must be opened only at the time of sampling, and must never be rinsed because it contains preservative agents required for the analyses. The internal walls or the inside of the lid must not be touched by fingers.
- The sample must come from the most used cold water faucet, and the water from this faucet must not have been modified by a filtration system.
- The faucet must be free of any accessories completing its spout, such as aerators, screens, spray heads, hoses. If it is impossible to remove these accessories, another faucet must be chosen.
- The exterior and interior of the faucet spout must be cleaned using a clean piece of cotton soaked in a bleach solution (about 5% sodium hypochlorite) or alcohol (rubbing alcohol).
- To ensure that the water taken is representative of that circulating in the distribution system, the water must be allowed to run for 5 minutes before taking a sample.
- The container must be filled at least to the level indicated on the bottle and below the air space of at least 2.5 cm between the liquid surface and the stopper.
- The carefully completed analysis request form must always accompany the sample.
- The sample must be kept at approximately 4°C between the time of sampling and reception at the laboratory.
- The sample must arrive the same day as the sampling.
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Bacteriological analysis must be carried out in a laboratory recognized by the Ministry of the Environment (Laboratory Analysis Accreditation Program).