Experience shows that many consumers, when in doubt between tap water and mineral water, choose to install a purification filter in their homes. Without discussing the freedom of choice, it should be pointed out that these devices “often tend to make the water worse, softening it too much and sometimes becoming the site of bacterial proliferation”: datum resulting from a test by 'Altroconsumo', taking 18 samples of tap water before filtration and after treatment, comparing their quality, and then repeatedly confirmed by our laboratory.
The water that reaches our homes is drinkable. So why install a water purifier? Perhaps we should shake off a few clichés. First, it is not true that hard water is always bad for our health, as already mentioned in "When water is calcareous, is it bad for our health?". Some filters soften the water too much, causing it to fall below the legal hardness limit: removing one problem (scaling water) and creating a new one (aggressive water). And by using these filters there is a risk, if maintenance is not carried out as it should be, of encouraging the growth of bacteria.
If we then consider the environment, even if plastic bottles are no longer used, Altroconsumo points out that these systems use more than twice as much plastic to obtain one litre of filtered water (considering the backwashing cycles of the filters).
We should also ask ourselves whether the use of these filters in the home offers a real benefit to our household budget. Drinking tap water, a typical family (three people) spends about 1 Euro a year (total cost of about 1000 litres of water); the average cost of purification systems, including maintenance, is around a few thousand Euro.
If you decide to install a domestic system following the correct practice, remember that:
- There is the Ministerial Decree D.M. 25 of date 07/02/2012 - Technical provisions concerning the equipment aimed at treating water intended for human consumption.
- This decree states that only treatments that allow compliance with the limits set down in the current Legislative Decree on water intended for human consumption are permitted.
For further insight on this subject, see the "Guidelines for information on equipment for the treatment of water intended for human consumption" (ISTISAN Reports 15/8) at the following link
The quality of drinking water in our areas is good: there are no well-founded reasons to believe that mineral water is healthier. This does not mean that bottled water is not of good quality. However, it is just as unreasonable to overestimate mineral water as it is to mistrust water from the aqueduct, which is strictly and regularly checked under the hygiene aspect. Drinking one or the other is above all a choice of taste, linked to flavour and possibly the desire for sparkling water. On the one hand, advertising is pushing and enticing, presenting mineral water less and less as a drink to accompany food and increasingly as a source of health and even of beauty. On the other hand, as there is little or no information on the quality of the water that comes out of the tap at home, people are naturally inclined to think that it does not have any of the properties boasted by bottled water so tap water is looked upon with suspicion.
Perhaps, it is worth providing a little more information, so we become informed consumers. First of all, it should be noted that water intended for human consumption (tap water) and mineral water are regulated by different laws:
Water intended for human consumption: Legislative Decree 31 of 2 February 2001 - Implementation of Council Directive 98/83/EC (and subsequent Legislative Decree 27 of 2 February 2002).
Mineral waters: Decree of 29 December 2003 - Implementation of Directive 2003/40 EC (Ministerial Decree 542 of 12 November 1992 and subsequent amendments) While, previously, the gap between the limits for tap water and mineral water was decidedly unbalanced (more restrictive for drinking water) we can now see from the following table that the limit values are now mostly comparable:
|
Parameter |
UM |
Drinking water |
Mineral waters |
|
Antimony |
µg/l |
5 |
5 |
|
Arsenic |
µg/l |
10 |
10 |
|
Barium |
mg/l |
n.p. |
1 |
|
Boron |
mg/l |
1 |
5 |
|
Cadmium |
µg/l |
5 |
3 |
|
Cyanide |
µg/l |
50 |
10 |
|
Chrome |
µg/l |
50 |
50 |
|
Fluorides |
mg/l |
1.5 |
5* |
|
Manganese |
µg/l |
50 |
500 |
|
Mercury |
µg/l |
1 |
1 |
|
Nickel |
µg/l |
20 |
20 |
|
Nitrates |
mg/l |
50 |
45** |
|
Nitrites |
mg/l |
0,5 |
0.02 |
|
Lead |
µg/l |
10 |
10 |
|
Copper |
mg/l |
1 |
1 |
|
Selenium |
µg/l |
10 |
10 |
Generally, we have enough water to supply our aqueducts in our area. However, we should not forget that only 2% of precipitation goes into groundwater and can be used for drinking water. The cost of supplying water includes the cost of building the infrastructure to bring it to the tap in our homes: water is a product of nature... but it is not inexhaustible, at least not with the features required for human consumption.
Saving water is therefore necessary. We must use our drinking water, which is an excellent resource of our territory, without wasting any of it.
But let us not forget the "cultural" value of "qualitative protection" of aquifers to ensure that water is not polluted and that it does not require any subsequent treatment before it can be used for drinking.
If we always keep in mind that water is a foodstuff, and that it is still in short supply in many parts of the world, we would be more aware to not waste water, even for 'ethical' reasons, by using it carefully.
Water is an excellent solvent. In nature, it flows over the ground, over gravel and through the subsoil into the aquifers. By doing so, it is enriched with valuable minerals including calcium carbonate and magnesium, better known as limestone.
The more limestone the water collects, the harder it becomes. This does not compromise the quality of the water from a health point of view. In fact, with the exception of particular pathologies, the calcium contained in water is the most easily assimilated and the association, often made spontaneously, between limy water and kidney stones is incorrect: recent studies have also shown that limy water has a protective effect against the onset of cardiovascular diseases.
Limescale water can cause problems in domestic installations: too much limescale in the water is a problem when in contact with alkaline substances (such as soaps) or when the water is heated. In fact, limescale builds up in these cases. Boilers, washing machines, shower heads and hot water pipes are often affected by it.
In these cases, all that is needed are small measures, like dosing the detergent adapting it to the hardness of the water, and a suited maintenance of the appliances that can also be carried out by installing small magnetic limescale removers (ionic accelerators) that do not change the concentration of calcium but make the calcium carbonate deposit less compact and therefore easier to remove from the water flow.
In general, types of water are classified according to their hardness, expressed in French degrees (°F) as follows:
- up to 7 °F very soft
- from 7 °F to 14 °F soft
- from 14 °F to 22 °F non-hard (or medium-hard)
- from 22 °F to 32 °F modarately hard
- from 32 °F to 54 °F hard
- over 54 °F very hard
Besides being expressed in French degrees (°F or F), hardness is often expressed in German degrees (DH). To obtain the hardness value in German degrees, multiply the value expressed in French degrees by 0.56. (1 DH = 1,79 FH o °F).
Sodium is a quite common element in nature, found in all drinking water and foodstuffs. It is estimated that the daily requirement of an adult is around 500 mg (from various sources).
Potassium is also an extremely common element in nature and is one of the most important minerals for our bodies. Humans are not able to synthesise it on their own, so it must be introduced through the diet.
On average, its intake through water and nutrition (fruit, vegetables, and legumes) is sufficient to provide the necessary daily intake.
Sodium and potassium play an essential role in our bodies by regulating the hydro-saline balance to maintain a constant circulating blood volume and blood pressure.
The limescale build-up can be reduced by taking a few steps
- Reduce the hot water temperature to 60°.
- Avoid stagnant water in certain parts of the domestic installation: draw water regularly from all taps. If the house has been uninhabited for a long time, let the water run for a while before using it, starting with cold water and then hot.
- Washing machine: follow the instructions in the instruction manual on how to adjust the water hardness and use the correct amount of detergent.
- Coffee machines: Use the descaler recommended by the manufacturer.
- Dishwashers: descaling agents are unnecessary. All appliances have regulators and ion exchangers: for this reason, add salt periodically.
- Limescale deposits on taps and sinks are best removed using diluted vinegar or a moderate use of marketed like limescale remover products.
- Maintenance: regular maintenance reduces repair costs.
- For tea lovers: hard water is not that popular. However, even hard water can be used well for tea with a little trick: just boil the water two or three times with the kettle open. This way the limescale is deposited (the pan can easily be descaled later on using a small amount of vinegar).
