Liquid waste at an agave plantation.
Credit: Courtesy of José Hernández
Tequila Leaves Environmental Hangover
By Emilio Godoy
The environmental impact of tequila production is only recently being recognized by the industry, say observers.
MEXICO CITY, Aug 3 (Tierramérica).- Tequila, deeply absorbed into the national identity of Mexico, accompanies all types of family celebrations and national holidays. But many are unaware of the bitter taste the tequila industry leaves in the water and soil.
This liquor, which is about 38 percent alcohol (76 proof), comes from the fermentation and distillation of sugars from the blue agave (Agave tequilana Weber), a plant with thick pointed leaves radiating out from a central point. It is native to Mexico.
Among the more than 200 agave varieties in this country, blue agave is the best for making tequila. Its Latin name refers to the German botanist, Franz Weber, who classified it in 1902.
The agave is grown in 180 municipalities in the western states of Jalisco, Nayarit and Michoacán, the central state of Guanajuato, and in Tamaulipas, in the east. This is the territory of the Tequila Denomination of Origin, established by the government in December 1974 to validate the legal status and quality of this liquor.
Mexico has 118 tequila factories and 715 brands. In Jalisco alone, considered the birthplace of tequila, the industry employs 38,000 people. From January to April, the factories produced 48 million liters, with about 40 million to be sold in Mexico and the rest for export.
But the tequila tradition and the business have environmental costs, particularly for water and soil.
To obtain one liter of tequila requires an input of at least 10 liters of water. However, the negative effect does not lie in the volume of water, "but rather the fact that the water is unlikely to be treated and will be discharged as industrial waste, in the ground and into streams and rivers. They are contaminated waters that contaminate more water," José Hernández, a researcher with the University of Guadalajara and member of the Mexican Academy of Sciences, told Tierramérica.
For every liter of tequila bottled, the process generates five kilograms of agave pulp and seven to 10 liters of distillation waste, or "vinaza".
"The vinazas are acidic, they have an oil that makes the soil impermeable, and are hot when they are dumped. The acid is not recommended for agriculture; it should be neutralized. The oil makes the soil hard so it is useless for farming. And where the ground cracks, the vinaza filters into underground water sources," explained Hernández.
The indigenous peoples who lived in the region before the arrival of the Spanish Conquistadors revered the agave for its many benefits. The plant represented Mayahuel, the Nahuatl goddess of fertility, whose 400 breasts fed an equal number of children.
As a distilled beverage, tequila emerged in the 16th century from the combination of the native raw material and a European fermentation process.
Eight years after planting, the blue agave is ready for harvest. Its leaves are removed in order to extract the "piña", or heart of the plant, from the ground.
The pineapple-shaped hearts are set to bake 50 to 72 hours in brick ovens or steel tanks. The hearts soften and release the sugars used for fermentation.
In the fermentation process, the sugars are mixed with leavening, converting them into alcohol. The liquid is distilled twice, generally in stills made of copper or steel. The result is tequila, which can then be aged in oak barrels - "añejo" on the bottle's label indicates it has been aged.
In 1996, the Secretariat (ministry) of Environment and Natural Resources introduced standards for the degree of toxicity permitted in the waste and vinaza, which were to be adopted by the tequila industry in 2000. But none of the distilleries comply with all of the rules.
According to the standards, one liter of vinaza can generate no more than 150 milligrams of "biochemical oxygen demand" (BOD), a measurement of the quantity of the gas consumed in the biodegradation of the organic material in the water.
But each liter of vinaza emits about 25,000 milligrams of BOD, an indicator that permits measurements of water contamination.
According to the Jalisco State Environment Secretariat, only one of the 67 tequila factories there heeds the law on discharge of waste into rivers and lakes.
In 2007, the authorities conducted 197 inspections, found irregularities at 51 distilleries, and shut down two of them.
Due to increased tequila consumption within Mexico and abroad, the cultivation of blue agave has expanded to other regions.
"They are growing in a protected forest, invading several hectares, where it has replaced the encino trees," said Adriana Hernández, an activist with the non-governmental Save the Forest Committee, dedicated to protecting El Nixticuil forest.
El Nixticuil, declared a protected area in December 2005, extends across 1,850 hectares in the Jalisco municipality of Zapopán, 550 km from the Mexican capital.
The tequila industry has taken slow steps towards recognizing its polluting responsibilities. Some distilleries are neutralizing the acidity of the wastewater, and cool down the vinaza before discharging it, and produce compost from the agave pulp.
In 2010, two vinaza treatment plants are slated to begin operating.
In Hernández's opinion, there is no single solution to the environment problem. "The most common now is composting. In addition, they are trying to remove the oil coming from the cooked agave before distilling so that the vinaza is more environmentally friendly," said the researcher.
* IPS correspondent.