Drinking water and sanitation

All processes intended to render sewage sludge in compliance with environmental standards, land use regulations or other applicable quality standards for recycling or reuse. Primary, secondary and tertiary treatment is usually distinguished. These treatments not only reduce the volume of residues, but also stabilize and transform them into environmentally acceptable components and useful by-products. Tertiary treatment includes, for example, chemical conditioning, disinfection, pressure filtration, vacuum filtration, centrifugation and incineration. It is possible to classify wastewater treatment and sludge treatment in different categories, namely secondary treatment for wastewater and tertiary treatment for sewage sludge.

Treatment of (urban) wastewater which treats carbon suspended solids more advanced than primary treatment, according to a process by a process usually involving a biological treatment with secondary settlement or any other process resulting in a BOD reduction of at least 70% and COD of at least 75%. This treatment is required for agglomerations of over 2000 population equivalents.

Private individual system to evacuate domestic or other waste waters where there is no collecting system of municipal waste water or where the latter is not justified either because it does not affect the environment, or because the cost would be excessive.

All facilities for the collecting and treatment of urban wastewater. These systems are often managed by public authorities or semi-public associations.

Water volume lost during its conveyance between the abstraction point and a point of use (due to leak or evaporation) or between the place of use and a place of reuse.