One system, not isolated points
The Yucatán aquifer covers around 165,000 km² and connects nearly every cenote on the Peninsula. There is no natural filter between the surface and the water millions of people use daily: the limestone lets whatever is poured above reach below — and travel from there.
What is documented
Here we separate what studies and media report from what Cenote Scout can verify itself: the latter is close to nothing, which is why every point below is sourced.
- Industrial pig farms: according to AMEK, up to 70% of cenotes in the Ring of Cenotes show direct contamination from waste filtering into the aquifer (faeces, antibiotics, nitrates).
- A Greenpeace México report (2018) found glyphosate — classified by the WHO as a possible carcinogen — in cenote water samples from the region.
- El Universal documented reports of more than 1,400 cenotes showing faecal contamination, linked to the lack of sanitation infrastructure in several inland municipalities.
- Unregulated tourism: solid waste, chemical sunscreen and trampling erosion at high-volume cenotes such as Suytun or Ik Kil, where carrying capacity has repeatedly been exceeded in high season.
- Tren Maya: scientists and activists flagged the risk of drilling support pillars directly into the limestone that holds up the cave system, with possible impact on structural integrity and groundwater flow.
Who is working on this
SEDUMA (Yucatán’s urban development and environment authority) runs a sanitation and integrated cenote management project. AMEK (Mexican Association for Karst Studies) documents the state of the Ring of Cenotes through scientific research. Communities such as Homún have built their own tourism rules — certified guides, set hours, visitor caps. National Geographic published a 2025 report on the risk facing Mexican cenotes, a sign of growing international media attention.
Tourism, done well, also protects
A cenote that generates recognised income for the local community is more likely to stay cared for than one with no visible economic value. The Homún–Cuzamá circuit, in the Ring of Cenotes, is a cited example of how community-run tourism creates real incentives to keep the water clean and the infrastructure sound.
It is also why Cenote Scout shows the reported crowding level on every page and suggests less-visited alternatives near saturated cenotes: spreading tourism out is not just a better visit, it is part of how a cenote stays protected.
How to visit responsibly →