Cuban sugar mill poses explosive risk

One of the main industrial sugar refining complexes in the province of Matanzas, in the west of Cuba, has been blamed for an underground build-up of methane gas and other violations of environmental law that are putting thousands of families in the area at risk.

The case came to light after it was reported in an extensive article in the daily newspaper Juventud Rebelde - the press in Cuba is a government monopoly - which included the testimonies of many residents and experts, who confirm the threat posed by the pollution caused by the Jesús Rabí agroindustrial complex in Calimete, a municipality in Matanzas with a population of 30,000.

According to the experts, the company's refinery and distillery both discharge their untreated waste into the same ditch, contaminating the groundwater. "This is improper waste disposal, and the main problem is the distillery," a source in the Sugar Ministry told IPS in Latin America.

When they leak down into the subsoil, the waste products create underground pockets of methane, a colourless gas that is inflammable when mixed with air. The methane is produced by anaerobic digestion (in the absence of oxygen) by methanogenic bacteria that break down vegetable material.

"At the start of the rainy season when the groundwater level rises, the water reaches the gas pockets and compresses the methane, which is forced up to the surface," chemical engineer Manuel Pereira told the newspaper.

And Jorge Luis Bregio, a government official in Calimete who used to work for the Jesús Rabí company, said that when the weather was cold, methane gas accumulated inside the roof spaces of houses, "as if it were in a fume hood." The gas came up between the floor tiles, through chinks in walls and floors, or into courtyards through tiny cracks in the ground, he said.

"I knew of a person who went into a cave, and was almost asphyxiated by the presence of methane gas before he was brought out," Alberto Pino, who lives 10 kilometres away from the Jesús Rabí complex, told IPS by telephone.

Other residents of Matanzas said on Tuesday that they had not yet obtained a copy of Juventud Rebelde, but that they were keen on reading the article.

The Sunday, May 7 edition of Juventud Rebelde reported the testimony of María del Carmen Herrera, who suffered serious burns on her arms, back and legs from a fire in her bathroom. During a blackout, she attempted to light her way with a cigarette lighter, and the gas caused an explosion.

In the past, some people used the gas emerging from pits in the ground to improvise open air cooking fires. "Nowadays it seems that the methane is going elsewhere, because of the ditch they dug at the complex, but we do not know who will be harmed in future. The Calimete area has a lot of caves," said Raimundo Rodríguez, another local resident.

"Methane is highly dangerous and can cause explosions. In fact, there have been explosions at other times and places," an expert in the field, who wished to remain anonymous, told IPS.

Oscar Santalla, an expert, told the newspaper that for the past several years, because of "technical shortcomings," the distillery waste has been very acidic, and when added to the sugar mill waste, it cannot be used for "fertigation", a technique combining fertilisation and irrigation which would boost sugarcane yields and curtail pollutants.

In fertigation, liquid wastes from the refinery, distillery wastes and the must from cultivating torula yeast (Candida utilis) are applied directly to crops.

Esperanza Valdés, director of the National Centre for Environmental Management for the sugar industry and its derivatives, confirmed that the Jesús Rabí complex and seven other sugar agribusinesses have been given financing for fertigation projects, which make good use of their industrial waste.

The director-general of the complex, Tomás Zamora, whom IPS was unable to contact