(*) related to the HUMAN USAGE subchapter 2 - Industry
Today water is used in many industrial processes: the washing of materials, the cooling of plants (questions e) or the dumping of wastes(questions c-d).
Industrial water consumption varies according to the kind of production (questions a-b), the level of efficiency of plants, the production processes and the amount of recycling. Water, which is used in production processes, can often be recycled: the percentage of recycled water in the paper and the chemical industry is quite high, while in other production processes, this percentage is almost zero.
Another negative side effect of industry is intake: oftentimes, industry diverts water to a degree that it deprives rivers of their minimum flow requirements needed to ensure environmental functionality.
A large quantity of water is necessary to produce all the things we use in everyday life: cars, paper, rice, oil, and cotton; these productive processes can create pollution problems related to both chemical and biological by-products and to heat (questions e). The alteration of temperature is in fact very dangerous for the life of the river ecosystems, because it damages the metabolism of flora and fauna and alters the chemical balance of water. Pollution arises from the dumping of industrial waste in the rivers (nitrogen and phosphorus from chemical industries and heavy metals from mining) (questions c-d). Every time water is diverted and returned to a river, it’s is inevitably altered. However, if alternations are not too dramatic, they can be absorbed and neutralized by the river by means of its natural capacity of self-purification. A well- functioning ecosystem is able to absorb changes, if they are not too severe, and recover its balance quickly. The capacity of self- purification is reduced or lost when a river has been stripped of its natural banks and consequently the necessary level of biodiversity.
(to deepen the understanding of this topic see : WATER QUALITY chapter of FYR Checklist)