Optimization of Rancagua, Machalí and Graneros Sewage Treatment Plant

Description: The Project corresponds to the optimization of the Sewage Treatment Plant (PTAS) of Rancagua, Machalí and Graneros and has the objective of expanding the treatment capacity of the PTAS, considering the demand of the population served by the year 2030, which is estimated at 501,649 inhabitants. For this, it is necessary to modify the original project "Sewage treatment plant Rancagua, Machalí and Graneros" qualified environmentally friendly through the RE No. 37/2001 of the Regional Environmental Commission of the Region of Libertador General Bernardo O'Higgins . The following modifications were made to the original project, presented through Declarations of Environmental Impact and Consultations of Relevance to the SEIA, resolved through the resolutions and letters indicated. Project "Sewage Treatment Plant of Rancagua, Machalí and Graneros" associated with the incorporation of sludge from the PTAS of Peumo and Malloa to the PTAS Rancagua, Machalí and Graneros. Qualified environmentally friendly through RE N ° 36/2003. Project "Modification of the Sewage Treatment Plant Project of Rancagua, Machalí and Graneros" associated with the reception of Riles from mobile discharges in the PTAS Rancagua, Machalí and Graneros. Qualified environmentally friendly through RE N ° 66/2004. Pertinence query associated with the modification of the project by the RCA review process. Resolved by Letter N ° 263/2012 that indicates that it does not constitute a change of consideration that must enter the SEIA. Pertinence consultation associated with the incorporation into the sludge line of a third band filter and a mud lining system, replacing the drying court as a sludge stabilization system. Resolved by Letter N ° 384/2012 that indicates that it does not constitute a change of consideration that merits its entry into the SEIA. Consultation of Relevance "Construction of Odor Treatment System of the PTAS of Rancagua-Machalí-Graneros". Resolved by means of RE N ° 188/2015, it resolves that the project does not necessarily require entering the SEIA. Currently the Sewage Treatment Plant consists of a preliminary treatment, followed by a secondary treatment of activated sludge, consisting of three aerated reactors and three settlers, with recirculation and sludge purge, and finally a contact chamber for the disinfection of the effluent. . The effluent from the plant is discharged to Estero La Cadena in compliance with the limits established in Table Nº1 of DS No. 90/2000 MINSEGPRES, emission standard for the regulation of pollutants associated with discharges of liquid waste to bodies of surface water . On the other hand, the sludge generated in the system goes through a process of aerobic digestion and mechanical dehydration, to finally be whitewashed. The mud lime system has an exclusive odor treatment system. It should be clarified that the PTAS of Rancagua, has two systems of limed mud. The first and just mentioned, which has its own odor control system, is exclusive to whitewash sludge generated in the PTAS of Rancagua, and the second, described below, to whitewash the sludge from other PTAS of Essbio SA, located in the Region of Libertador General Bernardo O'Higgins. In fact, within the PTAS precinct, there is also the Rancagua Glazed Warehouse, a facility built to treat sludge from the Coinco, Coltauco, Nancagua, Santa Cruz and Requínoa PTAS sludges, which has not yet started operations. This project was presented through a Relevance Consultation, resolved through SR No. 146/2015, which indicated that it did not require mandatory entry to the SEIA. The Liming Warehouse is currently connected to the odor treatment system of the PTAS, treatment of odors that was designed to treat both the units of the PTAS of Rancagua, as the whitewashing shed, so it became part of the project