Glossary
An aquifer is defined as a water deposit that collects in porous layers of the subsoil consisting of e.g. sands and gravels. It is fed by rainwater that infiltrates the ground. Aquifer waters generally maintain a constant temperature, close to the average temperature of the rocks they are embedded in. Deeper layers maintain their position undisturbed, often for millions of years. More superficial layers are involved in the hydrological cycle and play an important role in it.
Concentrations of substances dissolved in water are normally expressed in milligrams per litre (mg/l) – i.e. one thousandth of a gram in one litre of water, - in micrograms per litre (μg/L) - a millionth of a gram in a litre of water, - or in nanograms per litre (ng/L) - one billionth of a gram in one litre of water.
These are the greenhouse gas emission, the global warming effects of which are rendered CO2-equivalent according to established conversion tables. Methane (CH4) exerts a global warming effect that is 21 times that of CO2 while nitrous oxide (N2O) has an effect 310 times that of CO2.
Oligomineral water with a dry residue value between 50 and 500 mg/l at 180°C. Oligomineral water is suitable for daily use and has good diuretic properties.
Unit of measure of mass. A nanogram (ng) is one billionth of a gram.
These are organic substances containing halogens - fluorine, chlorine, bromine, iodine, and astatine. As concerns drinking water, organohalogenated substances of interest include certain solvents present in water as a result of environmental pollution (trichlorethylene, tetrachlorethylene) and the so-called "trihalomethanes" which are by-products of disinfection processes that use sodium hypochlorite. See the appendix for tetrachloroethylene+trichloroethylene and total trihalomethanes.
Perfluoroalkyl or PFAS substances are synthetic chemical compounds origin. Their molecules have at least one fluorine atom. The most common PFAS family substances are PFOS and PFOA. These are used to manufacture impermeable and non-stick materials and produce detergents, paints, and pesticides.
In chemical analysis, sampling is the set of operations needed to prepare a sample i.e. a quantity of substance or a part of a material that must then be analysed. Samples must be representative of the entire substance or material which they are collected from.
The water aggressiveness index defines the propensity of water to attack and solubilise certain minerals contained in rock, soil or building materials. Aggressive waters generally have low salt content, low alkalinity and a free carbon dioxide content defined as 'aggressive'. Aggressiveness can cause deterioration of cement and thus damage cement fibre pipes, consequently releasing asbestos fibres into the water. The lower the aggressiveness rating value, the higher the aggressiveness of the water. Aggressiveness values lower than 12 indicate waters that generally corrode cement structures.
The World Health Organisation is the UN agency that focuses on health matters. It was founded on 7 April 1948 and is based in Geneva. The WHO’s goal is to ensure that all populations have the highest possible level of health, meaning a condition of complete physical, mental, and social well-being and not only the absence of illness or infirmity.
