The present paper shows an innovative methodology for the detection of potentially contaminated routes through a varied analysis depending on the occurrence and frequency in a specific place. One of the tools used is the Geographic Information System (GIS), which was used for the analysis and identification of industrial routes from which pollutants potentially harmful to health are derived. These industries are classified according to the pollutants whose emissions and effluents vary according to the economic line of business; they were also classified according to the number of people working in them. To calculate the area susceptible to contamination and the population exposed, the main roads (canals, tributary rivers) affected by these discharges were located. The case study is the José Antonio Alzate dam, one of the most important dams in Mexico, which is going through one of the worst stages in its history due to the excessive amount of toxic waste discharged into the José Antonio Alzate river and some tributaries. In the present paper were identified qualitatively and quantitatively 567 industries whose activities directly affect approximately 2.5% of the population, as well as the polluting routes.