The objective of this research project was to sample groundwater from touristic to non-touristic wells and sinkholes along the Riviera Maya region, to determine the occurrence, source and extent of the fecal contamination, and link this information to the predominantly touristic activity of this zone. The Escherichia coli (E. coli)  is one of the most common bio-indicators to asses the bacteriological water quality its presence is related with pathogenic health problems associated to anthropogenic influence such as leaks from septic tanks, untreated wastewater. Despite the limitations and problems associated with the detection of fecal bacteria, this bio-indicator is still present in several water policies around the world. The study zone was located at Puerto Morelos Quintana Roo, where seven groundwater samples were collected from sinkholes and wells. The results reveal that fecal contamination in groundwater at the touristic and non-touristic sampled sites is occurring. However the detection of the Vibrio spp. and the determination of caffeine makes evident that only in the touristic sites the extent of the contamination implies a human source. The others sources of bacteriological contamination can be linked to the type of coastal ecosystems presented along the area of study.