Placed under the dual supervision of drinking water network managers and the Ministry of Health, tap water is very controlled.
Where does tap water come from ?
“First of all, there is not one but tap water, indicates Professor Yves Levi, associate pharmacist in public health. There are as many as there are different origins! “Tap water comes from where there is water near municipalities! In France, 60% of it comes from groundwater (springs or boreholes) and 40% surface water (rivers, lakes…).
Contrary to what half of the population thinks (according to the 2018 TNS-Sofres barometer of the Water Information Center), drinking water is therefore not produced from the recycling of wastewater. “There are two very distinct circuits,” specifies our expert. That of drinking water, which captures groundwater or surface water and transforms it into drinking water, and that of sanitation, which collects and cleans wastewater before discharging it into the natural environment. ”
How much does tap water cost?
Its cost varies between producers / distributors and municipalities, but on average 1 liter of tap water costs € 0.004, taxes and fees included (source: La Gazette des communes). In stores, 1 liter of bottled water varies between € 0.15 and € 0.60, or up to 150 times more expensive!
Does it provide interesting nutrients like certain bottled waters?
“Its mineral characteristics can be very different from one municipality or region to another, says Yves Levi. In some like Île de France, the water is ‘hard’, that is to say rich in calcium and magnesium. In others, this mineral presence is less marked. “To find out, just consult the analyzes posted in town hall.
“In all cases, tap water contributes significantly to the mineral intake of the population.”
Why does tap water sometimes have a particular smell and / or taste?
It’s chlorine! Too dosed or applied to insufficiently purified water, it can degrade the organoleptic qualities of the water. If this has no consequences for health, it represents an inconvenience that should be noted.
“Sensitivity to chlorine being individual, it is better to first ask your neighborhood, recommends Professor Levi. And notify the municipality, the mayor being responsible for the quality of the water.”
Where can I get information about my tap water?
Data on the quality of tap water are public and can be consulted:
- On the website of the Ministry of Health eaupotable.sante.gouv.fr. It contains, updated, the results of health checks carried out by the Regional Health Agency, municipality by municipality.
- In town hall. The latest results of the checks carried out by the ARS are displayed.
- From the person responsible for the production and distribution of water. It varies according to the municipality of residence.
- With the water bill. Once a year, it is accompanied by a health summary drawn up by the ARS.
- On the ARS websites ars.sante.fr. They regularly publish regional reports.
What treatments for tap water?
“It all depends on the quality of the water taken, explains Yves Levi. In some municipalities, the pumped water is of such good quality that it is almost drinkable in its natural state. Conversely, when water is taken from the Seine for example, many treatments are essential. “In most cases, water drawn from underground or surface resources undergoes several treatments before being compliant with standards. European.
Captured and sent to treatment stations, it first passes through gates to stop floaters and dfiner sieves to stop smaller particles. Then theaddition of a coagulant (iron or aluminum salts) precipitates suspended particles which are also filtered.
“Some waters, especially those taken from rivers, are more likely to be polluted, adds Professor Levi. They therefore undergo a additional treatment to remove pesticides, nitrates and plasticizers by means of an oxidizing gas (ozone) then are filtered through activated carbon, which also eliminates unwanted tastes and odors. Some factories use ultraselective membranes such as nanofiltration. “Viruses and bacteria are then neutralized, with chlorine and sometimes ultraviolet radiation. Drinking water is then stored, with a residual disinfectant to maintain its quality up to the tap.
Tap water: what standards must it meet to be drinkable?
It is subject to strict health regulations, drawn up by the Ministry of Health, based on European directives established according to the recommendations of the World Health Organization.
Potability is thus evaluated by more than 70 criteria (health and organoleptics) calculated in relation to the most vulnerable populations (pregnant women, infants, etc.). “These criteria are established on the basis of scientific data which made it possible to establish maximum admissible doses (AMD), that is to say doses that a person can absorb, all intakes combined, each day of his life. without risk to his health, “explains Professor Levi.
Drinking water must not contain bacteria, viruses, pesticide residues or drugs and natural constituents (iron, sodium, etc.) at concentrations that exceed health standards. They must not have no taste, no smell, no particular appearance.
When and how are the checks carried out?
There are several controls: those of the regional health agencies (ARS) and those that the water producer is obliged to carry out regularly.
“The frequency of checks depends on the size of the populations served,” says Yves Levi.
During these analyzes, the bacteriological, chemical and organoleptic parameters, as well as radioactivity indicators are checked. “In the event of an anomaly, the water is considered unfit for consumption, the inhabitants are informed and the municipality organizes a water distribution, continues the specialist. It is very rare in mainland France. ”
Checks are also carried out by the ARS with regard to the sanitary quality of the installations.
Drugs, pesticides, lead, nitrates … can tap water still be polluted?
Can tap water contain viruses and bacteria?
“There is nothing to fear, believes Dr. Frédéric Saldmann, cardiologist and nutritionist. The level of treatment and control is such that the risk of being contaminated is very low. “If samples have made it possible to find traces of virus (including the coronavirus without measuring active virus) in certain wastewater before its depollution, the treatments make it possible to neutralize all of them, as well as the bacteria.
Can tap water contain medicines?
In 2011, a study of ANSES demonstrated the presence of drug residues in tap water. This presence, due to the pollution of the natural environment by wastewater, is strongly limited by specific treatments. However, in the absence of hindsight with regard to prolonged exposure, a National Plan for Drug Residues in Water (PNRM) was put in place from 2005 to 2015. These contaminants are now integrated into the national plan plus global on all micropollutants.
Can tap water contain nitrates?
According to ARS balance sheet on the quality of tap water published in 2019, more than 99% of the population was supplied with water respecting the limit, set at 50 mg / l. In addition, water is far from being the major source of nitrate intake found in certain vegetables (radish, beetroot, spinach, etc.): even with a concentration of 50 mg / l, the contribution of l Water exposure to nitrates is estimated at only 34%.
Can tap water contain lead?
Since December 2003, the maximum lead content in tap water has been reduced by five, from 50 μg to 10 μg / l. The problem does not come from the production units. It is through its course in the interior distribution networks in the habitats that its lead content can increase, in contact with old pipes prior to 1950.
Can tap water contain pesticides?
“The National Food Safety Agency (ANSES) considers that tap water represents less than 10% of our exposure to pesticides against 90% for food, notes Yves Levi. We must be aware that our entire environment (air, clothing, etc.) exposes us to chemical pollutants and that water, even treated and controlled, is only one of the sources of our exposure. ”
Can tap water contain treatment products?
Our exposure to aluminum is 95% food-based, of which less than 5% comes from drinking water. Moreover, even if its presence is worrying, no link has yet been established between exposure to this element and the development of certain diseases (cancer, Alzheimer’s).
Four practical tips to improve the quality of tap water
1. Let the water run before drinking it
“This is essential, especially in case of prolonged absence, insists Dr. Saldmann. This avoids any risk of consuming water contaminated with bacteria or lead when it stagnates in the pipes. ”
2. Draw cold water to cook food
“A hot water tank is a favorable environment for the development of germs,” continues the nutritionist. Better to boil cold water. ”
3. Leave the water in a cooler before drinking it.
“Chlorine being volatile, taste and smell fly away,” recommends the expert. We put it in the fridge, cover it and change it regularly. ”
4. Be careful with filter jugs
In the opinion of our experts, having recourse to filters present on the market is not always advantageous and can even prove to be risky in the event of poor maintenance of the carafe.