Water quality of my well

Source: MDDEFP

The quality of my well water

The water is as precious as a vital resource. As the owner of a private well or a small network with fewer than 21 people, you have the responsibility to ensure its quality with a view to protecting your health and that of your family. In this document you will find all the necessary information to do so.

The quality of the water in my sink and my responsibilities ...

When it comes from a well or surface pipe (commonly called "artesian") and is intended for human consumption, the water must be of good quality and meet the standards laid down in the regulation respecting the quality drinking water. It is the owner of the individual wells or small network (serving fewer than 21 people) have the responsibility of ensuring the quality and safety of the water it provides for consumption.

Although she may have a crystal clear appearance and have no odor or taste particular, the collected water can contain elements that may have adverse effects on health, eg pathogenic microorganisms (bacteria, viruses and protozoa) -nitrites and nitrates.

Groundwater, which is generally of better quality than surface water (lake, river, stream) through the filtering capacity of the soil, may be vulnerable to contamination and precautions must be taken to ensure at all times supply of good quality water.

Thus, the Department recommends the analysis of water at least twice a year, in spring and autumn. It is appropriate to conduct additional analyzes when you notice sudden changes in taste, odor or appearance of water, or changes are made to the well or surrounding soil. These analyzes should be performed by an accredited laboratory.

The analysis of the water is not enough in itself to ensure the quality of drinking water. In fact, besides the analysis advocated must regularly check the condition of the well and septic system, examine possible sources of contamination in the environment well and make the appropriate corrections. Well this document layout standards to be met for three types of wells (tube wells, shallow wells and sand point).

As part of the development of a new well, the regulations require certain analyzes, including those of Escherichia coli (E. coli), enterococci bacteria, total coliform bacteria and nitrate-nitrite. These parameters are most likely to vary over time, and it is recommended to include in the regular monitoring of the quality of well water.

Microbiological indicators of water ...

The majority of pathogenic microorganisms (viruses, bacteria or protozoa that can cause disease) may be in the water from human or animal waste. As it is technically impossible to analyze all pathogens, rather microbiological indicators that are inherently safe is used: the bacteria E. coli, enterococci bacteria and total coliform bacteria.

The bacteria E. coli are very abundant in human and animal intestinal flora, and it is also the only species that origin is strictly fecal. The bacteria E. coli are considered the best indicator of fecal contamination. Their presence in water means that it is contaminated with fecal pollution and can therefore contain pathogenic microorganisms.

Gastroenteritis is the most common associated with the contaminated faecal water ingestion disease. Although the disease is often mild, it can sometimes have serious health consequences. Other more rare diseases such as hepatitis or meningitis can also be caused by drinking contaminated water. This risk includes not only family members who consume water from a well, but all their visitors.

Enterococci bacteria are less abundant in the intestinal flora of humans and animals as the bacteria E. coli, and some species of this group are not of faecal origin. The detection of enterococci bacteria in well water may indicate faecal contamination or infiltration of surface water. However, it is prudent to consider the presence of enterococci bacteria as an indicator of faecal contamination.

Total coliforms are a heterogeneous group of faecal bacteria and environmental origins. In fact, most species of total coliform bacteria can occur naturally in soil and vegetation. Their presence in water does not indicate faecal contamination and a health risk, but a degradation of bacterial water quality. This degradation can be attributed, among other things, an infiltration of surface water into the well, or the gradual development of a layer of bacteria on the walls called "biofilm". The analysis of total coliforms in particular allows to obtain information on the potential vulnerability of a well-to-surface pollution.

Presence of bacteria E. coli or enterococci in my water

Drinking water should not contain any trace of bacteria E. coli or enterococci. If this is the case, it is essential to keep the water boiling for at least one minute before drinking it, or to get drinking water from a distribution network or bottled water. It should also use boiled water or water from these alternative sources for making ice cubes, beverages and baby food, washing food that will be eaten raw and brushing teeth. You can continue to use the well water for the shower and bath (taking care to avoid swallowing), however, children and babies should be washed with a sponge. These recommendations should be followed until further analyzes show compliance with water standards.

It is recommended to determine the source of contamination and to provide, if possible, the appropriate corrections. Then a shock disinfection treatment may well be appropriate, especially when the contamination is linked to specific circumstances (cast iron, heavy rain, etc..).

Disinfection of a well is carried out as follows:

1. Clean the well, if available, using a ladle in order to remove material, deposits, animal or plant materials, etc..;

2. Pour into the well of the bleach in the amounts indicated in the following table titled "Required quantity of bleach to disinfect a well.";

3. Mix bleach with water from the well and, if possible, wash and brush the inside wall. Can also be connected to a hose closest tap and flush the inner wall of the well to ensure complete mixing of chlorine and water throughout the well ;

4. Open all faucets in the home. When the smell of chlorine is noticeable faucets, shut the well pump and close the valves ;

5. Wait 24 hours before circulating the water in the pipes;

6. Perform subsequently extended by running water from a faucet until the chlorine odor disappears purge. Then open all taps to completely rinse the tubing;

7. Conduct further analyzes of water a week following disinfection and four weeks later to see if the water meets quality standards.

Total coliforms in my water

The presence of total coliforms reinforces the importance of regular analysis and make appropriate adjustments to prevent faecal contamination potential. If further analysis confirms the presence of total coliform concentrations exceeding the standard (beyond 10 cfu/100 ml), it may be appropriate to make a shock disinfection of the well treatment.

Determine the source of contamination

It is important to determine the source of contamination and make the appropriate corrections to improve water quality in the long term. Local sources of contamination can be multiple:

  • Poor management of the well (leaking lid or sealing material degradation, etc.);
  • Inadequate slope surrounding soil (without a mound around the well to keep the runoff from the surface);
  • Septic system failed;
  • Unsafe places (eg, manure, and other activities of fecal pollution in the vicinity).

In these cases, it is therefore necessary to carry out the work to correct the situation or raise the head of the source of contamination. The person with a contamination problem can contact the municipal officer concerned, who will help guide the search for solutions. Subsequent analyzes of the water quality will verify the effectiveness of corrective actions taken.

The quality of my well water in flood conditions

During a flood, the owners of individual wells should take special precautions because such events generate significant risks to the quality of groundwater, it can be contaminated by both water the river and septic systems nearby. To prevent risks related to the consumption of contaminated water diseases, the Department recommends that affected individuals the following measures:

  • During the flood water from any well located in a flooded area should be considered unsafe. Those affected should get drinking water from an alternative source (eg, water from a distribution network or bottled water) or boil for one minute any water for ingestion or preparing uncooked foods.
  • After the flood after the final withdrawal of flood water, the owner should first verify the integrity of the well equipment and especially the electrical circuit. It should then wait at least ten days prior to disinfect the wells as described below, and ensure that the results of two series of tests recommended thereafter comply before starting to consume water.