2. Using water means practically agreeing to pollute it

In any industrial activity, water comes into contact with gases, solids and liquids, which it dissolves or carries away in the form of more or less finely dispersed suspended matter. In reality, most processes generate either continuous or discontinuous discharges of pollutants, which include all by-products and losses of raw materials that cannot be recovered or recycled. The nature and composition of discharges vary widely from one industry to another, as does their impact on the natural environment (surface water and/or groundwater), as shown in the table 1 .