PROPUESTA DEL INDICE DE CALIDAD DEL AGUA RESIDUAL PARA EL DISTRITO FEDERAL, UTILIZANDO UN MODELO ARITMETICO PONDERADO

Abstract

The use of water in Mexico City has become a problem derived from is shortage, causing what some specialists call “hydro stress”. The sewerage is the system of pipes through witch this residual water runs and this has been affected by the aggressiveness of the waste, carried by liquid. The damage provoked by the residual water is such that it seriously damages the sewer system, up to the point of destroying it completely. Treatment plants function with the purpose of returning used water to the water cycle, with the polluting charge possible. This gets almost impossible when the polluted charges excessive, due to this it is important that the people responsible of the use of water employ (the fix sores) guarantee that the residual waters are in condition that would facilitate the removal of pollution. Once this liquid waste has been incorporated to the treatment plants, begins the process of eliminating the pollution present in the water. The residual waters with a high level of pollution make it difficult and sometimes almost impossible to treat to the point that even the treatment plants go out of service to get preventive or in the worst cases corrective maintenance. It is a priority to have an instrument capable of informing, based on the waste water analysis from enterprise and on the pollution excess. This can only be achieved by means of a quality standard of the water that gets into the sewerage installations. On environmental matters, the rising of quality has a big development and acceptance, but in what concerns to water, the quality standard for water (ICA) is the only existent for area water (rivers, lakes, etc.) managed by CONAGUA. Although contaminated water should keep certain amount of quality to facilitate their treatment, sewer system has not changed, from being just the waste that is poured into the sewer. In this study is proposed the residual water quality standard (ICAR) based on the Mexican Official Norm, NOM-002-SEMARNAT-1996, using in its calculation 15 quality sub-standards, each one pondered by a degree of importance; with an interval from 0 to 100 units, and only gets in the data computing the waste that exceeds the environmental norm. With the ICAR obtained in can be inferred what are procedures to follow in an enterprise, that is, it can be deduced if it is necessary for an industry to adjust to manufacture practices, if it is needed a treatment water system or even the going on of a sewage treatment plant for their residual water. The ICAR constitutes by itself a tool that the environmental authority must use and supports the application of the measures for the control of the waste that is poured into the sewer system.