HEREDIA, Costa Rica – Some rivers in Costa Rica are among the most polluted in Central America after decades of contamination – sewage, runoff from plantations and industry – but the Tárcoles River takes the grand prize.
The Tárcoles River pollution is predominantly sewage and fecal contamination, which can cause vomiting, diarrhea, and infections in humans exposed to the water, according to a report issued by the Laboratorio Nacional de Aguas del Instituto de Acueductos y Alcantarillados – National Water Laboratory.
“It’s kind of depressing,” said Fabian Delgado, an employee and graduate of Universidad Nacional in Heredia. “It feels like shit.”
Delgado is in the process of getting a degree in environmental management from Universidad Nacional in Heredia. He takes water samples from around Heredia, and lives close to the Tárcoles, which crosses through some of the country’s most populated areas. He says the data he collects may help the Costa Rican government find viable solutions to river contamination.
In 1994, an agreement was reached between about 100 coffee plantations and MINAE – the Ministry of the Environment and Energy – with a goal to lower pollution and contaminant runoff into the rivers. In 1997, MINAE shut down mining projects in northern Guanacaste to try to prevent sediments from polluting the river further.
This had a positive impact, but the problem persisted.
“We protect all of our rivers by law,” said Carlos Roverssi, the Costa Rican Minister of Communication. “We have a lot of work to do. The Tárcoles is very contaminated.”
The San José Environmental Improvement Project was approved in 2006 and aims to “improve worsening water quality of urban rivers and waterways,” according to the project website. As part of the plan, treated water will be discharged into the Tárcoles River with no expected negative impacts.
Bert Kohlmann, Ph.D., teaches an introduction course to natural sciences at EARTH University. To stop the pollution of the rivers, Kohlmann said, Costa Rica must build sewage treatment plants and stop draining everything – sewage, pesticides, heavy metals – into the rivers.
“It (the Tárcoles) is the worst case in the country,” Kohlmann said. “The great majority is sewage. Unsafe for humans.”
Unsafe for animals, too. The river pollution is significant enough to draw the attention of researchers concerned about the health of American Crocodiles in the Tárcoles. Some crocodiles living in the river have gone blind – a sort of ocular disease that can be caused by trauma or infection. According to a report issued by the Hollings Marine Laboratory at the Medical University of South Carolina, pollution in the river may not be causing the disease, but the researchers did not rule out the possibility.
EARTH University’s Kohlmann points to development as a cause of the continuing problem of river pollution.
“All we do is create more and more problems,” Kohlmann said. “It’s the consequences of developing cities and industry.”
Acciona Agua, a Spanish company, won a bid in 2012 to build a water treatment plant in San José. The project, which will cost more than $45 million, will be Costa Rica’s biggest treatment plant upon completion. The treatment plant is a key part of the San José Environmental Improvement Project, according to the Acciona Agua website.
Felix Rojas, a researcher and professor of environmental sciences at Universidad Nacional, studies and observes the Rio Virillo. The Virillo River runs through residential and commercial areas near San José and Heredia and ends when it meets the Tárcoles, dumping all of its own pollution into the Tárcoles.
“We monitor that river’s pollution. The problem is that industry is actually the smallest contributor to the pollution,” Rojas said. “Houses are the biggest contributor.”
Rojas explained that a lot of Costa Rica’s industries are required to monitor the amount of organic waste they dump into the river or be fined by the government. But it is the illegal connection of residential sewage tanks to rain water collectors that discharge into the river that cause the main problem, Rojas said.
“If you don’t monitor, you don’t know how bad it is,” Rojas said. “You need data for legislation. Our goal is to generate data so decision makers can make decisions on solutions.”
Rojas suggested that smaller municipal treatment plants would accomplish more to reduce the river pollution. He said that the geography of Costa Rica would make it difficult for a larger plant to receive sewage from farther away for water treatment.
Hope remains for the Tárcoles, Rojas said. He explained that rivers have the ability to “auto regenerate” or to become cleaner over time. But it is not an overnight process and cannot occur while large amounts of pollutants are still being added to the river.
“It would take education to make a difference,” said Fabian Delgado.