Few of the region’s wastewater treatment plants function on a regular basis. As a result, the region’s water sources are reportedly highly contaminated and worsening (Iracheta Cenecorta, 2012). The Puebla-Tlaxcala metropolitan zone is no exception to this trend, and there is also evidence to suggest that urban sprawl may be a more prominent phenomenon in Puebla-Tlaxcala than in other metropolitan zones in Mexico.