Mexico has more than its fair share of polluted waterways. Nearly 70% of Mexican rivers have some type of harmful contamination.
Grupo México, the largest mining company in Mexico, has been implicated in 120 environmental damaging instances since 2000. On July 9, 2019, the company dumped 3,000 liters of sulfuric acid into that water in Guaymas, Sonora. In 2014, a subsidiary of Grupo México was responsible for a spill of 40,000 cubic meters of copper sulfate acid solution which affected the drinking water of more than 22,000 people.
However, Grupo México is not the only company contaminating the water supply. A few days after this incident, 2,000 cubic meters of water were polluted with cyanide in the town of El Oro, Durango. This time the culprit was a ProyectoMagistrals mine.
On July 21, a huge wave of toxic foam formed in the irrigation canal near the Valsequillo dam in Puebla. It was created by the mixture of pollutants, including lead, cadmium, solvents, paints and engine oil, that had been dumped into it combined with household organic waste.
The Santiago River in Jalisco is another toxic water source. The heavy metal contamination caused by farm and factory dumping has caused a range of illnesses including kidney disease and cancer among local residents. In fact, the water is so toxic, that an 8-year-old boy died of arsenic poisoning in 2008 after falling in the river.
Up to 1/4 of all children born to lakeside communities in the state of Hidalgo have birth defects attributed to the polluted water. Sewage from Mexico City is pumped directly into the water reservoir.
According to the Organization for Economic Cooperation and Development (OECD), most regions of Mexico have strongly or excessively contaminated drinking water. Up to one-third of gastrointestinal problems in the country are the result of feces-contaminated drinking water. In Oaxaca, 54 of every 100,000 inhabitants die because of bad water. Some experts estimate that more than 12 million people in Mexico lack drinkable water, especially in rural areas.
Unfortunately, water contaminated with toxic chemicals is not safe to drink even after being boiled or disinfected, which does kill certain bacteria and parasites.
Water that is safe to drink should be clear and have no odors. You may be able to pinpoint a problem if your water appears, smells or tastes differently.
If your water is causing your fixtures and sinks to blacken, it may contain hydrogen sulfide or manganese. If there are blue/green stains on your sink, there might be some corrosion from copper, brass or another metal piping. Reddish-brown water comes from corroded iron. Mexico often uses copper or metal tubing to run water to rural communities, so be on the lookout for those stains.
If your water is cloudy, it might have dirt, sand or clay in it. It may also be methane gas making it milky. Foamy water might have detergents or sewage in it. If the water leaves white deposits behind, it might be contaminated with calcium or magnesium. Yellow water could have organic soil run-off or vegetation residue in it or it may be chromium-6, a cancer-causing chemical.
Smells also indicate there might be something wrong with your water supply. If your water smells like bleach, it might contain chlorine or chloramines. Chlorine byproducts include trihalomethanes (THMs) which increase cancer occurrences and are linked to kidney problems and haloacetic acids (HAAs), another cancer-causing chemical that causes skin irritation as well. Low levels of chlorine in your drinking water will increase the risk of exposure to giardia, a parasite that causes nausea, cramps, and diarrhea.
Musty smelling water may contain organic matter. Gas and oily smelling water might be contaminated with gasoline or other semivolatile compounds. A rotten egg smell often indicates hydrogen sulfide. When hydrogen sulfide comes into contact with certain bacteria, it becomes sulfate which causes diarrhea and dehydration.
Fishy smelling water might indicate an excess of barium or cadmium. Barium in large doses can increase blood pressure, provoke muscle weakness and cause kidney, liver or heart damage. Cadmium also is harmful and may cause bone, liver or kidney damage.
You may be able to taste some pollutants. If the water leaves grit in your mouth, sediment might be the cause. A metallic taste could mean iron, copper, lead, manganese, sodium chloride or sulfates. If the water is contaminated with pesticides or other semivolatile compounds, it might have a sharp chemical taste.
Some chemicals can not be seen, smelled or tasted in your water, but still cause illness or death. If you have a rash of sudden deaths among different animal species in your area, water contamination might be the cause.
A water filtration system can eliminate many volatile organic chemicals, some pesticides, hydrogen sulfide, radon gas, and mercury. Water distillation can remove some pesticides, heavy metals, radium, nitrate, fluoride and salt. Reverse osmosis will remove radium calcium, sulfate, magnesium, nitrate, potassium, fluoride, phosphorous and boron. It also helps to filter out detergents, some pesticides, and chemicals.
Anion or cation exchange, also known as water softening, removes radium, barium and some chemicals. It can eliminate dissolved manganese and iron in low concentrations. Anion exchange units will rid the water of fluoride and nitrate as well but cation won’t. Mechanical filtration can filter our insoluble iron and manganese, dirt and sediment.
Chlorination eliminates bacteria, hydrogen sulfide, dissolved iron, and manganese when used in conjunction with an activated carbon filter. Ultraviolet radiation can handle bacteria and other microbiological contaminants. Ozonation removes some pesticides, bacteria, hydrogen sulfide, dissolved iron, and taste, odor or color-producing chemicals. An oxidizing filter such as a greensand or zeolite filter can rid the water from iron, manganese, hydrogen sulfide and some chemicals.
If you are concerned about your water, you can test it yourself using an at-home kit or send it to a lab for analysis. Merieux Nutrisciences Mexico and SGS Mexico are two companies that provide water testing services. You may also want to check with your local CONAGUA or El Sistema Municipal de Agua Potable y Alcantarillado offices for a list of other testing agencies.
It also bears mentioning that most Mexicans drink bottled water rather than tap water. Santorini/Epura owned by Pepsi, Bonafont owned by Danone, and Ciel owned by Coca-Cola are the most popular bottled water brands, although there are other water purification companies throughout Mexico. Despite claims to pure water, studies have shown a disagreeable amount of contaminants in bottled water samples. Then there’s the possibility that the garrafón just might allow BPAs to leech into the water. Bisphenol A has been linked to prostate and breast cancer, heart disease, diabetes, asthma, and cognitive problems.
More recently, small garrafón (water cooler jug) refill centers have sprung up. Using these setups, you could refill your own glass garrafón and eliminate the worry over leeched chemicals. However, I have yet to ascertain where the water that is being sold comes from. It does cost half the price of a garrafón of water from one of those big-name companies, but I just can’t be sure that it’s filtered at all.
Some rural communities have their own manantial (underground spring) which supplies water for the area. The increase in pesticide use among farmers over recent years has polluted even many of these sites.
With water purity so uncertain, it would be in your best interest to have your drinking water tested regularly