Water Quality in the Yucatan Peninsula.

In Mexico’s Yucatan Peninsula, the environment is an unfavorable one. The fractured limestone shelf contains nearly all of the peninsula’s water within in it. Thin soils and a flat landscape allow for rain and contaminants to quickly percolate down into the water table. Scarce surface waters appear as cenotes (sinkholes) across most of the peninsula and as wetlands in the Holbox fracture zone. Local people have become reliant on the tourist industry which thrives on the cenote, coastal, and archeological wonders of the Yucatan. Both the community and tourist populations draw their drinking water from the same fresh water lens. Contributions to that lens are thought to vary greatly between these two different populations. This research investigates the difference in fecal coliforms, water chemistry, and the presence of antibiotics in the water. The waters investigated include drinking water, cenotes, beach water, groundwater well fields, and sewage treatment effluent. Tests were conducted using both inexpensive and expensive equipment in order to find a reliable and an affordable protocol for local water quality monitoring. Fecal coliforms were found at acceptable levels in most drinking water, but were abundant in ocean water. The water chemistry yielded unexpectedly high concentrations of rubidium and lithium in several locations. While no antibiotics were found in the field, we were able to show that the formally milk-based test works in freshwater, though not in salt water. Based on the data collected, it can be concluded that theses highly impacted waters deserve further investigation, possibly to be conducted with user-friendly and affordable methods.