Paraguay opens new wastewater treatment plant in San Lorenzo

This is an automated translation of the original release published in Spanish

Statement from the Ministry of Public Works and Communications of Paraguay

With the presence of the Head of State, Mario Abdo Benítez, the Minister of Public Works and Communications, Ing. Rodolfo Segovia and other national and local authorities, the Wastewater Treatment Plant (PTAR) of the city of San Lorenzo was inaugurated this morning, in Central department.

This work completes the delivery of two of the three WWTPs provided for in the Comprehensive Sanitation Program for the Bay and Metropolitan Area of Asunción, executed by the Ministry of Public Works and Communications (MOPC). The first one, located in Varadero, in operation since March 2021, and the one in Bella Vista, whose completion is expected for the first quarter of 2023. Both are located in Asunción.

In this case, it is the first in the country to carry out the comprehensive treatment of sewage effluents. Its design and technology allow complete filtering and purification of the waste collected through the sanitary sewerage network, directly benefiting 120,000 residents of this city, although -indirectly - it will positively impact the lives of some 600,000 people.

In addition, its commissioning will have a positive impact on the entire basin of the emblematic Ypacaraí lake - seriously affected by pollution - of which it is a part, as a tributary of the Yuquyry river.

The sanitation infrastructure in the university city includes, in addition to the WWTP, four pumping stations, the rehabilitation of 24 kilometers of sanitary sewerage pipes, and the installation of 110 kilometers of new pipes.

The total investment in the works amounts to G. 156,032 million. This figure includes the renovation and expansion of the sanitary sewerage network, the construction of the WWTP, as well as the resettlement of a group of 40 families, who occupied the property where it is located. Under the responsibility of the San Lorenzo Sanitary Consortium and supervised by the Nippon Koei Lac Consortium, the works were financed with a loan from the Inter-American Development Bank (IDB).

TREATMENT PROCESS

The cycle starts with a pre-treatment phase - or preliminary treatment - during which the solid waste is filtered through a mechanized system of bars, which will retain it. Next, the sand and fats are removed, in a separation process carried out in the desander/degreaser.

Once free of these elements, the sewage effluents receive a treatment to process the organic matter, through anaerobic reactors, biological filters and decanters. Once this phase is over, they will be subjected to disinfection, before being discharged into the San Lorenzo river.

As a result of all of the above, the surrounding environmental conditions will also improve, as well as the health and quality of life indicators of the people residing in the area of influence of the works.

The new WWTP replaces the previously existing one, where the sewage effluent purification process was carried out through oxidation or stabilization ponds. The system was composed of three lagoons, arranged in series. The first one, called facultative, and the other two, maturation.

The old plant was built in 1978 and had the capacity to provide service to some 7,000 homes. However, in light of the number of household connections identified, it served a total of 25,000. These data show a level of capacity totally exceeded, the consequence of which was the permanent collapse of the records of the city's sewage networks.

SAN LORENZO WWTP

-Beneficiaries 120,000 people.

-Improves the quality of life of a total of 600,000 residents, directly and indirectly.

-Investment: G. 156,032 million.

-Includes 4 pumping stations.

-The rehabilitation of 24 km of sanitary sewerage pipes.

-The installation of 110 km of new pipes.