Water resources of the Chunchucmil Maya

Chunchucmil, on the Yucatan Peninsula, was densely populated in the Maya La te Classic period (ca. A.D. 550-830), even though it depends principally on groundwater. In the 1990s, hydrologic investigations were conducted to det ermine whether groundwater could have met domestic and agricultural needs. The region's groundwater is near the surface and is influenced by sea-level fluctuations; however, geochemical analysis revealed that groundwater qual ity is not affected by mixing with seawater, The potential exists for high and spatially extensive nitrate contamination in this karstic area, yet wat er-quality analyses revealed only moderate levels of nitrate in the groundw ater. Agricultural limitations are imposed by chloride, total dissolved sol ids, and salinity, as indicated by electrical conductivity; domestic water use is limited by the presence of nitrate, sulfate, and chloride. Throughfl ow in the ring of cenotes (sinkholes) around the Chicxulub impact crater ma y explain the movement and spatial distribution of water-quality constituen ts in Chunchucmil's groundwater.