Previous analysis for the treatment of sewage in the city of Santiago de Chile

The need for flow measurement in order to calculate the size of treatment plants was required for the construction of the sewage treatment plants of Empresa Metropolitana de Obras Sanitarias (EMOS SA) in Santiago de Chile. Systematic sewage measurement starts with this activity In this work measurement is not the most relevant factor, but the issues confronted in order to start with the area of systematic measurement of sewage flow and the difficulties to be overcome in order to undertake these operations. For this purpose it is necessary first to solve different problems such as: to create at EMOS SA this area of work, elaborate inventories of the existing industrial discharges and the flows discharged, detect industries with their own sources, verify the consistency of the drawings of the existing networks, validate site measurements with potable water records, define correctly the boundaries of the tributary areas, dispose of the physical facilities and staff for the undertaking of the work, and finally from the flow differences detected to organise the measures which will explain them. Along with the latter, the following may be redefined: coefficients of absorption, population average consumptio- n and other factors which are currently used for hydraulic studies and calculations. By confronting this with reality, it will be possible to modify the coefficients which have compensated the lack of more complete studies.