By Jesus Aguado
Thousands of liters of wastewater run through pipes that are supposed to carry it toward SAPASMA’s Planta Tratadora de Aguas Residuales (Treatment Plant for Residual Waters) located along the railroad tracks near San Miguel Viejo. However, the system has not worked properly since its inception.
SAPASMA—Sistema de Agua Potable y Alcantarillado (System of Potable Waters and Sewerage) has a department of Cultura de Agua (Water Culture), which is responsible for providing talks and workshops in schools, and bringing students to the plant to inform them about the treatment of residual waters produced by the residents of San Miguel de Allende. What they fail to tell them is what happens to untreated water.
One does not need to be an expert to realize, when visiting the lower elevations of San Miguel that thousands of liters of water flow into the reservoir Presa Allende. Some 100 meters from the perimeter of the Planta Tratadora there is a pipe from which comes clear water with a strong smell of chlorine—this is treated water. The water from this pipe is combined with untreated water of the Cachinches arroyo, and flows toward San Miguel Viejo and from there goes into the reservoir.
Some distance from the plant, at a higher elevation, there is a channel with mixed waters where a 10-inch concrete tube has been placed. Vehicles drive over this tube and splash dirty water when passing.
This is not all. When one nears the plant at the north end, there are various channels of gray water visible. In this area, there is a series of intricate channels and gates diverting the water toward cultivation fields. When we were there, we could see alfalfa fields, and neighbors told us that they had seen this water used to irrigate corn, beans, and squash fields. All this water used for irrigation is untreated.
Whose fault is this? Atención spoke with one of the farmers of San Miguel Viejo, who told us that the neighbors (who are not part of the community) are complaining because the water is not treated.
“They complain because we irrigate with dirty water, but they have never come to give us solutions. We want them to come and tell us how to do it. Let them dig a well for us or treat the water. But they complain and don’t give us solutions.”
The 15- year-old structure needs renovation
David Jiménez, director of SAPASMA, recalled that the Planta Tratadora first began to operate on February 12, 2005. He explained that at that time the plant was treating 100 percent of the water in San Miguel. He accepts that the system is currently overtaxed and needs reengineering. The cost for this would be 200 million pesos. If this work were to be done, all the water could be treated before releasing it toward the reservoir, and that would then eliminate fines from Comisión Nacional de Agua (National Water Commission)—CONAGUA.
In San Miguel, SAPASMA collects 18 thousand liters of water per minute—at least within the urban areas—and of this, 80 percent is runoff. When it reaches the railroad bridge over Cachinches arroyo, part of it is directed toward the plant, and the rest is discharged into the channel that takes it to the reservoir. It is from this area that the farmers divert untreated water into irrigation channels leading to their fields.
Jiménez addressed the issue of the farmers using the dirty water in their fields. He explained that the system provides for the water to be taken into a federal irrigation channel since this is where CONAGUA requires it to be directed, and water that is untreated is then fined. In 2019 a total of 2,600,000 pesos were paid in fines.
“The water they take (the farmers) is in the area of the railway bridge, but the responsibility is with CONAGUA and not with the municipality,” stated Jiménez. Neighbors of Mirador also say that there ought to be wetlands—as had been suggested 15 years ago. Regarding this, Jiménez said, “They are not being created because large parcels of land are needed for it, and [land in] San Miguel is very expensive. We would have to buy a great number of lots that we don’t have. It would be very costly to buy them. There is a great deal of technology, but we need a lot of land to treat all the water. If the owners would sell their land, it would be very expensive. It’s not just a matter of money; it also has to do with availability of land.”
Private transport takes treated water to Club de Golf Malanquin, and public administration uses it to irrigate parks and gardens.
Jiménez said that reengineering the Planta Tratadora would clean all the water that currently arrives to the lower elevations of San Miguel. He stated that an executive project is being created so that resources for the funds (200 million pesos) can be found. He hopes to have the necessary work permits for the project and to begin the work this year, if possible.
A visit to the plant
During our tour of the treatment plant, we asked municipal workers, including director Denia Guadalupe Gonzalez, to tell us about the mechanics and function of the treatment plant. Everyone refused to grant us an interview including Gonzalez, who would not even grant us five minutes of her time, stating that she was on her way to a sampling event. When I said that I would be willing to do the tour on my own time, one of the helpers (who asked to remain anonymous) told us that this would not be possible because it’s a private area. We asked to be shown official documents that indicate that this is indeed a privately funded space or that it has been made private. Once we recorded this on video, he allowed us to continue our work.
The plant is located in the lower area of Los Frailes, and the collection unit is one-and-a-half kilometers from there, along the Las Cachinchesarroyo. According to Jiménez, in the area where the arroyo discharges, all kinds of garbage have been found, from clothing to dead piglets. That is why when the water—in quantities of 120 liters per second—arrives at the treatment plant, it goes through various filtering processes to eliminate slime and solid matter. Around 20 tons of this matter is collected monthly and then is taken to the sanitary landfill, according to workers in the filtering unit.
Once the solids have been eliminated, the water passes through a canal into which microorganisms—vorticella—are introduced that eliminate all organic contaminants. Once the water settles, chlorine is added, and at that point it is given CONAGUA’s safety index of 003 that indicates it is safe for direct contact with skin but is not potable. This treated water is then dumped back into the arroyo, where it combines with untreated water—which is what we observed during our visit.
In the city, SAPASMA operates water treatment plants in La Vista 1 and 2, at La Paz, La Esmeralda, and at Los Rodríguez. Ventanas has its own private water treatment plant.