Regional officials in the Mexican state of Quintana Roo are worried about the historically high contamination levels they’ve recently found in cenotes near Cancun. In the state’s northern region, 11 cenotes (or approximately 15% of those tested) now show poor water quality, according to recent routine testing by municipal officials.

Cenotes are a connected system of mineral-rich lagoons that developed over many centuries and are freshwater-filled sinkholes nourished by the subterranean rivers that permeate the area’s porous volcanic bedrock. Cenotes are a group of geologic phenomena that are exclusive to the Yucatan Peninsula. There are hundreds of them dispersed throughout the lush rainforest scenery of the Peninsula, luring travelers from all over the world who want to experience their serene, otherworldly beauty.

There are 71 of these subterranean and surface-level waterholes in the northern part of Quintana Roo, where Cancun is situated, along with other well-known tourist destinations like Costa Mujeres and Puerto Morelos. These waterholes are typically valued for their novelty as pristine natural plunge pools. The Laguna Chacmochuk (also known as Laguna Las Blancas), a significant coastal lagoon close to Costa Mujeres, just off the northern coast of Cancun, was found to have the most contaminated water, according to a recent study conducted by Quintana Roo’s General Directorate of Ecology, which was covered by The Cancun Sun. Within Cancun city center are the other 10 affected cenotes.
Officials claimed that poorly disposed wastewater, which seeps into these delicate lagoons through the water table, is to blame for the Records-High Contamination Levels Found in Cancun’s Cenotes impacting Chacmochuk and the other 10 cenotes in Cancun. On Isla Mujeres, an abandoned dump site creates leachate, a hazardous liquid contaminant that seeps into adjacent surface waters and seeps into groundwater from the combination of decomposing waste and rainfall. According to Claudia Cecilia Topete Martn, manager at AyMA Engineering and Environmental Consulting, the main pollutants are phosphorus, ammoniacal nitrogen, and the bacterium coliform, which is found in both human and animal feces.

The 71 cenotes in the region were regularly tested for water quality between 2020 and 2022, with study locations including Isla Mujeres, Benito Juárez, and Puerto Morelos. The cenotes in question may or may not be off-limits to visitors at the moment, but one of the study’s results will guide the local government’s action plan for preventing further water pollution. Topete Martn offered some of the most practical suggestions for preventing ongoing water pollution, such as:
— Extending the local sewage network’s coverage region
— Making sure that effective wastewater treatment methods are in place
— Making sure the drainage system in the region is properly maintained to stop leaks and spills
— Informing people about the water quality in the area and how to properly dispose of trash Authorities intend to examine 39 neighborhood water treatment facilities, 63 groundwater, lagoon, cenote, and coastline monitoring stations, a traffic light system for reporting on water quality, and up to 19 discharge sites to the Nichupté lagoon system as a result of the research.