Wednesday will be an historic day for the metro area. The day will see the inauguration of the Los Tajos sewage treatment plant.
Although the event is just the first step in treating area sewage, the significance is major. Less raw human waste will be flowing into the Río Grande de Tarcoles to be transported to the Gulf of Nicoya to end up on the country’s supposedly pristine beaches.
News reports have called the lack of treatment Costa Rica’s dirty little secret. Abel Pacheco, when he was president, joked that Río Tarcoles crocodiles are nourished by the Metro Area effluent, although he was more graphic.
The treatment plant is in La Carpio, a section of La Uruca west of the San José downtown.
Initially the plant will handle sewage from parts of Tibás, Moravia, Goicoechea and San José, accepting flow from the collector lines along the ríos Rivera and Torres. Eventually as more lines are built and improved the plant will serve slightly more than a million persons. The estimate is for 220 kilometers of lines to be installed or renovated, some 136 miles.
The condition of much of the collector lines is shocking. At some points the lines have rusted out conveniently over a river or stream. The raw sewage pours directly into the waterways. There is ground water infiltration, too, that greatly adds to the flow during rainy weather.
Many residents who do not live in the central city have installed septic tanks. Many overflow. Other residents and some industries, too, simply run their sewer line to the nearest waterway.
The project is being done by the Instituto Costarricense de Acueductos y Alcantarillados, which has stressed the health hazards of the current system.
One big job is a 1,787-meter (5,863-foot) tunnel that will carry sewage underground to the plant.
The state company known as AyA plans to tackle the substandard and aging sewer lines that service 700,000 persons. Then the sewer lines will be expanded to reach homes that are not now connected to the network.
Eventually Alajuelita, Vásquez de Coronado, Montes de Oca, Curridabat, La Unión and Escazú also will be connected to the plant.
Plans call for servicing at least part of 11 cantons.
Like most sewer systems, the AyA project takes advantage of the downhill grade to the treatment plant. The sewer lines are being improved and installed parallel to the rivers that run through the Metro area, including the María Aguilar and Tiribí.
The entire project has been estimated at $362 million.
The ceremony Thursday will include President Luis Guillermo Solís and other dignitaries.