Roberto Rojo is not proud to say he was up to his neck in sewage. Since he began exploring Playa del Carmen’s cenotes in Quintana Roo in 2018, the biologist has discovered that many have become true cesspools. The memory of entering Yaxché, the largest cave in his city, in 2019 is engraved on him: “It is a crystal palace, because the stalactites and stalagmites are made of crystallized limestone rock. It’s beautiful,” he says in the present tense, as if reading a story to a child. “But suddenly the smell of drains starts, and the stalactites turn black, viscous, because colonies of bacteria are growing on them. Paradise turns into a nightmare. Then we see the pipe right on the cave ceiling and the excrement starts falling down in front of us.”
The horror story illustrates the deep problem that the Yucatan Peninsula has with the treatment of its sewage. On the outskirts of Cancun, Playa del Carmen or Tulum, entire neighborhoods are growing at the speed of light, but the infrastructure needed to keep up with this unbridled population growth hasn’t kept up. From eco-chic hotels to popular neighborhoods, the Riviera Maya’s lack of connection to the public drainage system has prompted many to throw their rubbish straight into the caves and cenotes beneath their feet. At best, they have septic tanks which, when filled, are taken to sewage treatment plants, which themselves are inadequate and precarious. The result is an aquifer that is becoming more and more polluted by the day, in which traces of the bacterium E. coli, but also of caffeine, Viagra or cocaine have been detected.
The discovery of this drug in the aquifer does not seem to surprise those who have studied water quality in the Yucatan Peninsula. Because “everything that a person eats is excreted in the urine and faeces, especially when it comes to components that the body cannot absorb,” explains Alejandro López from the organization Centinelas del Agua, which has been campaigning for the centinelas del agua for years Protection of the Maya Aquifer Deploys . And Tulum has become an international party destination in recent years. A quick Google search will bring up dozens of results for electronic music raves in the jungle or cenotes for ’til dawn fun. There, drug use is skyrocketing, as evidenced by the growing presence of drug cartels in the region.
A Marine vehicle drives through Tulum’s Main Street last February.Teresa de Miguel
The hydrogeologist Patricia Beddows came across the drug more by accident. In 2011, he led a United Nations-funded study aimed at analyzing contaminant levels in the Riviera Maya’s groundwater to try to understand the impact of tourism and real estate development in the region. To do this, the Northwestern University researcher went in search of components that do not easily decompose in the environment. The result was startling: shampoo, toothpaste, Viagra, ibuprofen, cocaine… a long list of products of human origin confirming that the city’s effluents reached the aquifer, the main source of fresh water in the Yucatan Peninsula, the country’s largest water reserve .
“We chose the Riviera Maya because it has one of the fastest growth rates on the planet and anything that happens inland can affect the Caribbean Sea, where the Mesoamerican reef system is located,” says Beddows of Evanston, Illinois. The head of the environmental sciences course at the university not only sounded the alarm, but also suggested solutions: improving and expanding the sewage treatment plants in the region, stopping the feeding of residues into the aquifer or preserving the mangroves on the coast, which serve as a natural filter. A decade later, the situation not only appears not to have been addressed, but has significantly deteriorated.
Data from the National Water Commission confirms this: while in 2006 53.3% of the water on the Yucatan Peninsula was of excellent quality and 0% was polluted, in 2020 the situation took a 180 degree turn: 2.2% was excellent and 48, 9% were contaminated. Given expectations for population and tourism growth in the region, things don’t seem to be getting any better: a new international airport is being built in Tulum to accommodate more visitors, and the government of Andrés Manuel López Obrador is advancing with its controversial Mayan train It will cover the entire peninsula. There are other ingredients in the cocktail of poor water quality, such as the proliferation of pig farms and large-scale expansions of monoculture crops that use massive amounts of pesticides.
A key to understanding all of this is the karstic nature of the peninsula. The soil is limestone, very porous, which allows all the impurities that are on the surface to get into the aquifer. In addition, this underground basin is made up of thousands of kilometers of interconnected rivers that flow into the sea, so everything that happens inland sooner or later ends up in the turquoise waters of the Caribbean Sea. That worries biologist Marisol Rueda of the organization Healthy Reefs for Healthy People. For them, cocaine is just an anecdote, because the most dangerous thing is the nutrients that get into the sewage and are the preferred food of the macroalgae that proliferate on the Riviera Maya coast. These algae prevent the growth of corals, which, unlike them, need crystal clear water to thrive.
“All discharges should go through an appropriate treatment plant and be returned to the aquifer already treated. What is the problem? The fact that there are too few sewage treatment plants, that the existing ones don’t work properly and don’t have sufficient quality standards for the water that we have here, that’s clear, transparent,” explains Rueda. His organization and many other environmental groups in the peninsula campaigned for more than a decade for Mexico’s sanitation legislation, NOM001, to recognize the fragility of the karst system and raise standards in these types of areas. The changes were approved last March, and the biologist hopes things will improve with it.
Guillermo D. Christy is more skeptical. As a consultant on water treatment issues in Playa del Carmen, the expert confirms that the agency is permissive and, as in so many other matters in the country, corruption creeps in to make compliance with the law more difficult. “In addition, politicians don’t want to build sewage treatment plants because you can’t see them. They prefer to build roads, because people see that, they give them votes.” The blame doesn’t lie solely with the authorities. In recent years, especially in Tulum, there has been an overgrowth of small hotels and real estate developments “selling all the wonders people want to hear but then failing to follow the rules.” The big hotels in the Riviera Maya have their own sewage treatment plants, but controlling the endless number of small developments that are sprawling is far more complicated, says D. Christy.
Contaminated water in a cave under Playa del Carmen in Quintana Roo in 2019. Héctor Cahúm
Although the most polluted cenotes are found in cities, data shows that even those visited by tourists are beginning to exceed the levels permitted for recreational use. In its water quality analysis for the month of June, the Tulum Federal Commission on Sanitary Hazards Protection (Cofepris) found high levels of E. coli bacteria in three cenotes in the community. “We are turning these sacred places into sewers for the Mayans,” regrets Roberto Rojo. With his organization Cenotes Urbanos, he has mapped 85 of the 300 cenotes that exist underground in Playa del Carmen to demand that the authorities preserve them and not allow the discharge of sewage.
Despite the unpleasant findings he has witnessed since the project began four years ago – such as the drainage of a poultry house in a cave, complete with feathers and blood – the biologist does not lose hope. The group already has more than 400 volunteers who go every Sunday to map caves and every Monday to clean them. They organize storytelling, meditation and yoga classes, but above all lectures to sensitize the population to the problem and its solution. The day we speak, emotion overwhelms him. Last Monday, while cleaning in a cenote, he dragged himself into the mud because he saw something that caught his attention: a painted vessel in perfect condition. He sent a photo to the National Institute of Anthropology and History (INAH) and they confirmed it was a preclastic pot. “We can achieve that. And much more”.
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