have denied any proposed municipal plan for urban development. The town has a large pool of rain water catchment for the Valley of Mexico, the soil is not contaminated by industry. The people have an attachment to the land and the natural environment. As a semi-rural municipality in proximity to the Mexico City metropolis, Cerro Mesa Ahumada is a well-preserved natural area with many species of flora and fauna that are no longer possible to see in neighboring municipalities. In addition, Tequixquiac is one of the metropolitan municipalities of Mexico City where the environmental footprint is moderate. The impact of industrial and urban activities is lower than in other municipalities in the state. However, a major environmental problem that residents face is over the Tequixquiac Tunnel, opened during the government of former president Porfirio Díaz. The tunnel has been a locus of infection and waste gases given off by sewage from residential, commercial, industrial, and hospital areas of Mexico City. Tequixquiac Tunnel causes debate among the locals, the Comición Nacional del Agua (National Water Commission), and different levels of government. Continuing to build the extension of the tunnel on the Gran Canal would bring a million-dollar water project to the area. Wastewater is used to support agriculture, and the land filters the water as it is decanted into the ground. The water also contributes to a number of underground streams vital to the ecological balance of the area. Restricting the water supply for agricultural use would increase land speculation and force ejidatarios to sell their land for housing development. This would leave a great ecological impact on the country, since this region and others in the Midwest serve as buffer areas for rain water filtration, buffer zones between Mexico City and less urbanized land, and regulators for the temperature of the Valley of Mexico. Communication and transport Many paths and road in Teotlalpan had been built by the Aztec people to control the area, including an old road connecting the mythic Tula Xicocotlán with Texcoco Valley, crossing Tequixquiac. During the Spanish conquest and colonial period, this road was used for merchant traffic including freight of stone, silver, gold, lime, fruits, corn, wood, wine and furnitures. The Spanish built the camino real () from Tepotzotlán to Actopan, connecting with Camino Real de Tierra Adentro, crossing by Coyotepec, Huehuetoca, Tequixquiac, Tlapanaloya, Hueypoxtla, Apaxco, Santa Maria Ajoloapan, Ajacuba, Tezontlale, Ixcuincuilapilco, San Agustín, Tecama,