Faced with the shortage, authorities are seeking to extract more liquid from the subsoil; However, almost 60% of the wells in the country have contaminants, which translates into diseases and a purification challenge.
Due to the water crisis that the country is experiencing, the responsible authorities have opted for greater extraction from underground sources, water that almost 60% contains toxic substances, such as heavy metals, which threatens the health of the inhabitants if it is not made drinkable properly. appropriate form.
Arsenic, cadmium, chromium, fluorine, mercury, nitrogen, lead, and fecal coliforms contaminate wells in states such as Coahuila, Durango, Baja California, Campeche, Tamaulipas, Zacatecas, Michoacán and Sonora, mainly, according to data from Conagua.
Of the 775 monitoring points that it reported in 2022, 302 are on a red traffic light, which indicates a high presence of contaminants, while 144 are on yellow. In total, Conagua data show 446 underground points with contamination levels higher than what is allowed in drinking water, which represents 57.5% of the total.
In recent weeks, given the water shortage in the Metropolitan Area of the Valley of Mexico, the capital government reported that the city will be supplied with liquid extracted in Hidalgo. Meanwhile, in 2022, when Nuevo León experienced a similar crisis, Conagua itself reported that it would seek to drill more wells to provide liquid to the residents of that entity.
However, specialists warn about the risk of overexploiting aquifers and depending on water with high levels of contaminants, instead of creating a comprehensive plan to reduce the volume allocated to areas such as agriculture, which represents 76% of consumption. in the country—recover rainwater, and treat and reuse wastewater.
BLIND CONSUMPTION
Francisco Bustamante, president of the Water in Mexico association, warns about the quality of the resource used in Mexico, given that the fact that it comes from a well does not guarantee its safety.
80% of the water supply for human consumption comes from wells, but many times, since it is from a well, they say: ‘It doesn’t need anything, the water is already filtered, I just give it chlorination and that’s it.’ It is not true, and that is where we have to see where we stand. We have to be aware that all supply sources must be reviewed by Standard 127 and, if they do not comply with any of the characteristics, they must implement processes to remove heavy metals, chemicals, fertilizers, coliforms, in such a way that we can have access to good quality water,” he highlights.
The Official Mexican Standard NOM-127-SSA1-2021 establishes the permissible quality limits that water must meet for human use and consumption.
The truth is that, in most cases, when it comes to wells, the only thing they give (to the water) is a little chlorination to kill bacteria, a disinfection, and then it goes to your house, that’s what “It’s really happening,” he warns.
He warns that, in addition to the risk of land subsidence and greater damage from earthquakes, drilling new wells implies very high attention to purification.
OVEREXPLOITATION, THE CAUSE
Miguel Salas, a member of the Water Advisory Council in Durango, explains that the contamination of wells occurs mainly due to the overexploitation of aquifers, which leads to drilling at depths where there is a greater concentration of elements such as arsenic, fluorine, and lead.
This contamination of the wells with elements that are harmful to health of course has repercussions for the users who receive this water of non-standard quality and who, in the end, will have diseases that must be attended to by the health sector, which It will also require a budget for that,” he warns.
To avoid risks of illness in the population that consumes well water, given the lack of resources to opt for bottled water, the specialist calls on governments to ensure that the liquid collected in dams stops being a priority for the countryside and, Instead, it is delivered to the population, once made drinkable. At the same time, invest in the treatment of wastewater from cities, so that it can be sent to the countryside – the sector that consumes the most nationwide – and that it is used efficiently through technical irrigation, thus releasing significant volumes.
URGENT WATER MANAGEMENT
For Francisco Bustamante, the solution to the water crisis is not in drilling more wells, but in effectively managing the use of water and guaranteeing its quality.
This can no longer be left. We have to attack water management, first in the loss through leaks; In water treatment, only 40% is treated; in the purification of water, well, conscientiously, with Standard 127, and that it is certified by Conagua, and if the operating organizations do not comply with the standard, they are really sanctioned,” he considers.
It also recommends implementing incentives for the industry to invest in water treatment and reuse.
HEAVY METALS THREATEN YOUR HEALTH
Among the main contaminants in groundwater sources are heavy metals that, in high concentrations or prolonged exposure, can cause serious health effects.
One of these is chromium, which, although it is an essential nutritional element, at high levels is linked to cases of cancer, such as those recorded in an entire community, in Hinkley, California, in the 1990s.
In Mexico, Conagua reports only one well with dangerous levels of chromium—the Xoxtla 1 site, in the municipality of Coronango, Puebla, part of the Balsas basin, which is considered unsuitable as a Source of Drinking Water Supply (FAAP). )—; However, it omits results on this parameter in 35 of the monitored points.
Arsenic is one of the most common metals in the wells, tanks and springs monitored by Conagua. Of the 775 sites monitored in total, the agency alerts high levels of this metal in 155 (20%), which it classifies as not suitable as FAAP, while over 120 more do not present results.
In the case of cadmium, which, according to the World Health Organization (WHO), exerts toxic effects on the kidneys, as well as the skeletal and respiratory systems, and is classified as a human carcinogen, the agency does not report contamination in any well, but does not have data for 35 sites.
Meanwhile, the Commission indicates 10 points in Mexico contaminated with lead—which is one of the 10 most dangerous substances for health, according to the WHO—: Juan Domínguez Cota, in La Paz, BCS; The Huarache, in Lerdo, Durango; Metepec and Toluca wells, in Edomex; 77B Ejido El Palmar, in San Nicolás, Tamaulipas; P19C-6+350, in Acuña, Coahuila; Álvaro Obregón, in La Paz, BCS, and 1,3 and 4 GN, in Mulegé, also BCS.
Although none of the sites present contamination by mercury – toxic to the nervous and immune systems, the digestive system, the skin, the lungs, kidneys and eyes – there is no data regarding it in 87 wells.
In addition, 93 sites are not suitable for human consumption due to high concentrations of nitrate nitrogen, and 87 due to high levels of fluorides.
Although it is not a heavy metal, it is reported that 51 wells are contaminated by fecal coliforms, whose presence, according to the Ministry of the Environment and Natural Resources (Semarnat), is related to pathogens that are more difficult to detect, such as Salmonella, Shigella and Vibrio, which cause gastroenteritis, dysentery, typhoid, and cholera. In this area, 92 sites lack results.
Arsenic:
- Prolonged exposure through consumption of contaminated food and water can cause cancer and skin lesions. It has also been associated with cardiovascular diseases and diabetes.
Lead:
- It affects the central nervous system. Intoxication, no matter how mild, can cause brain damage. It is a greater risk for babies, young children and pregnant women.
Iron:
- It has no health effects but can negatively modify the taste of water and cause reddish-brown stains on clothing, dishes, utensils, glasses, dishwashers or plumbing fixtures.
Cadmium:
- It exerts toxic effects on the kidneys, as well as the skeletal and respiratory systems. It is classified as a human carcinogen.
Fecal coliforms:
Their presence represents bacteriological contamination.
Mercury:
- Toxic to the nervous and immune systems, the digestive system, the skin and lungs, kidneys and eyes.
Nitrogen from nitrates:
- Reduces the ability of red blood cells to carry oxygen.
Chrome:
- Although it is an essential nutritional element, high levels of chromium are linked to cancer. Conagua reports only one well with dangerous levels of chromium, but does not have data for 35 of the 775 it monitors.
Fluorides:
- It can cause skeletal and dental fluorosis, and prolonged exposure can cause renal, neurological, endothelial, gonadal, muscular and hepatic alterations.
Manganese:
- It can make water look bad, smell bad, or taste bad. At high levels in water it can affect health, especially neurological development in children.
CHEMICALS STRIKE THE LAGUNERA REGION
The problem of fluoride, arsenic, and heavy metals in water wells in the Laguna region of Durango and Coahuila is an old problem that both state and municipal administrations have not been able to solve for more than two decades.
José Gerardo Ruiz, an environmentalist, points out that, in Durango, there is a ban dating back to 1956 so that new wells are not drilled and the city is supplied with the 98 registered ones. However, around 50% of these are contaminated with arsenic and fluoride.
According to the study Chemical quality of water in an agricultural area of forage corn in the Comarca Lagunera, in the area, there are wells intended for agriculture with lead higher than the permitted limit at 1.208%, arsenic at 144% and cadmium at 780 percent. hundred.
This problem is related to the significant increase in cancer cases in the region, a situation that forced the authorities to launch the Healthy Water for the Lagoon project, whose objective is for the Lázaro Cárdenas and Francisco Zarco dams to provide water to the lagoon. population over the next 30 years, which will allow changing the water supply from wells to purified surface water.
Miguel Salas, a member of the Water Advisory Council in Durango, calls for this project to deliver quality liquid to the population and, once used and treated, go to agricultural producers, not the other way around so that the same water has an effective double use.
-Alma Gudiño
THEY REQUIRE ANALYZING THE HYDROCOLLOID WELLS
Given the presence of contaminants such as arsenic in the wells of the hydro-warm capital and municipalities such as Tepezalá, local deputy José de Jesús Altamira urged that the Ministry of Health carry out analyses of underground sources in the state.
We have had this situation for many years now, there are two main factors: the depletion of the wells, which no longer work, and the contamination; and I would put a third point: the geological faults in Aguascalientes, which generate leaks of contaminated water,” he told Excélsior.
The former director of the State Water Institute (Inagua) also warned about the presence of arsenic in the wells, which is due to the extraction at increasingly deeper depths and the mining past of the areas in which they drill.
He warned of damage to the health of residents in places like Calvillo. “For example, they had kidney problems, mainly in children, for 15 years or more,” she said.
Since 2019, the then-head of the state Health Secretariat, Sergio Velázquez García, warned about the danger of consuming tap water in Asientos, Calvillo and Tepezalá, due to the high concentrations of arsenic, cadmium and magnesium in the water.
-Karla Mendez
