A Spanish construction firm has been selected to install the first three kilometers of sewer line for the valley project.
The firm is a familiar one, Fomento de Construcciones y Contratas, S.A., known by its initials FCC. The company said that it will have 10 months to build the line which will connect to the Los Tajos treatment plant, which also is under construction.
The new sewer will be on the north bank of the Río Torres and will be the main line for future sewerage in that watershed.
In all there are watersheds of five rivers that will be drained into the new sewer plant as part of the $344 million project.
The plant is expected to serve the cantons of San José, Tibás, Moravia, Vásquez de Coronado, Goicoechea, Montes de Oca, Curridabat, Desamparados, Escazú, Alajuelita and La Unión. Users are estimated to be some 65 percent of the population of the Central Valley.
The sewer plant project is not without criticism. Residents nearby in the la Carpio section of La Uruca are not happy with the location.
Environmentalists also have voiced their concern because the $45 million plant will only provide primary treatment for sewage at first. The partly treated water would be dumped into the nearby Río Tiribí, one environmentalist said in an internet mailing. He urged the construction of smaller packaged treatment plants at locations around the Central Valley instead of one big plant. He claimed the plant would be overwhelmed at times by sewage.
Juan Manuel Sánchez, a civil engineer with the Instituto Costarricense de Acueductos y Alcantarillados, said the sewer system should be completed by May 2019. The complicated installation calls for 350 kilometers of sewers in San José as well as a tunnel.
The treatment plant is set to become the biggest of its kind in Central America with a capacity of 12 cubic meters per second. Government officials are optimistic that it will clear waterways and basins and provide immediate ecological benefits.
For a country that prides itself on maintaining a level of environmental purity, its polluted waterways run like scars over the idealized public image. Sánchez said that many rivers flowing through the Central Valley are badly contaminated and in need of a massive cleaning.
“At this moment the rivers are considered to be the most polluted in all of Central America,” he said via phone interview. “The idea is to stop the waste waters flowing to the rivers, like they are today without any treatment.”
The entire treatment plan includes two removal phases. The first phase will clean up to 80 percent of the pollution in the waste water coming from 1.1 million residents. The next step will remove nearly 95 percent of all remaining contaminants and should bring the source number up to 1.6 million people, Sánchez said.
Acueductos y Alcantarillados estimates that right now only 4 percent of San José’s waste water is properly treated. But following the second phase of operations, the majority of the population’s waste water is expected to go through the treatment process, Sánchez said.
“It’s definitely going to improve the environment immediately,” he said. “There are four main rivers near San José and all of them are polluted. Right now there’s no biodiversity in any of the rivers.”
One of the major waterways is the Río Grande de Tárcoles, which begins in the Cordillera Central and empties west into the Gulf of Nicoya. Though it is near a substantial part of the population and houses a lot of iconic Costa Rican wildlife like crocodiles, it is considered the region’s most polluted river. All of the Central Valley’s rivers drain into it.