Toxic disposal dilemma: Pemex targets salt domes as waste confinement centers.

Since late 2003, Mexico's government has made public its interest in improving waste management capabilities.

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In practice this means not only dealing more efficiently with municipal waste--encouraging companies and households to separate garbage, using new technologies to save more space when compacting such waste, for example--but also increasing the number of hazardous waste confinement centers in Mexico.

The only waste confinement center operating at the moment is in Mina, in the northern industrial state of Nuevo Leon. Mexico produces approximately 8 million tons of hazardous waste per year and according to a government report "there is a deficit in infrastructure for confinement of hazardous wastes."

Last November, Environment Secretary Alberto Cardenas said up to seven new hazardous waste containment sites are needed in Mexico over the next three years.

Official Environment Secretariat (Semarnat) policy for 2004--which takes into account that the lack of such containment sites creates a risk that wastes will be disposed of improperly--includes plans for the development of hazardous waste confinement centers. These would be built and operated by private companies but with significant government oversight.

Another factor propelling policy is that exports of these wastes such as polychlorinated biphenyls (PCBs)--harmful mixtures of chlorinated compounds that build up in the environment--and waste from oil drilling are costly to industry, which has lobbied successfully for new legal initiatives under a new law.

ENVIRONMENTALISTS OBJECT

On Jan. 9, a new waste management law went into effect, one of its aims being to promote "economically feasible" management of hazardous wastes and to spur growth of infrastructure for waste from treatment plants to containers.

Three days earlier, Semarnat proposed a new regulation that reduced the minimum required distance of hazardous waste disposal sites from population centers, from 25km to 500 meters, and from highways (from 500m to 100m). In May, Semarnart received congressional approval of a law that would permit the disposal of waste in salt dome caverns, a move designed to increase facilities for the disposal of waste, especially waste produced by the drilling industry.

Environmental groups protested both initiatives, pointing out that no NGOs participated in discussions for either draft regulation.

Greenpeace de Mexico was especially vocal, with spokeswoman Cecilia Navarro saying, "Semarnat wants to convert Mexico into a graveyard for toxic waste."

Mexico's Center for Environmental Law (Cemda), Presencia Ciudadana and other groups presented written objections to Semarnat.

"This standard contradicts current environmental legislation, since it promotes non-sustainable practices in the management of hazardous waste," said Alejandra Serrano, a lawyer with Cemda.

"The draft text lacks technical, legal or scientific bases for the preferential treatment it gives to waste from the petroleum industry," she said. "It was clearly designed to favor Pemex, which participated in the standard's design."

Despite the opposition, the regulation was passed into law in May.

RESOLUTION CLEARLY NEEDED

Two major producers of hazardous waste in Mexico are Pemex and the Federal Electricity Commission (CFE).

Ramon Carlos Torres Flores, director of Energy and Extractive Activities in Semarnat, said in March--when the Secretariat was in the process of responding to public comments about NOM-145--that both Pemex and the CFE, as well as private investor groups have long been asking Semarnat for new technical rules permitting the disposal of these wastes. Initial approval for work on a standard to confine waste in Mexico's salt dome caverns was granted at the end of 2001.

"Pemex especially wanted this regulation, as it is Mexico's most important generator of waste that, according to the current law NOM-052, is defined as hazardous," Torres said.

Waste products from the oil industry currently defined in Mexico as hazardous under NOM-052 include rocky materials produced in the perforation of oil wells, API separation muds, sediments from hydrocarbon storage tanks, used oils, waste oils, and other oily muds and hydrocarbon sediments. The new regulation (NOM-145-Semarnat-2003) allows the above waste materials from the oil industry to be confined in salt domes.

"Pemex estimates that in 2002, it produced nearly 400,000 tons of waste currently defined as hazardous. More than half of these were oil-impregnated rocks that are produced when digging offshore oil wells," the official explained.

Just over a year ago in May 2003, President Fox unveiled two multibillion-dollar projects for Pemex, the development of the Chicontepec field, northeast of Mexico City, and the Marine Platform Building Program, which will build 47 offshore platforms, 111 miles of pipeline, and facilities to develop the Ku-Maloob-Zaap complex in the Gulf of Mexico, and the Lankahuasa natural gas find and other light crude projects.

The plans are going ahead. This June 21, ICA Fluor announced it has signed four separate contracts with Pemex, each for the fabrication of an offshore drilling platform to be installed in the northeast region of Campeche Bay in the Gulf of Mexico. The platforms, scheduled for completion in August 2005, will help increase the oil production in the sea field of Ku-Maloob-Zaap, to replace production from the Cantarell Field.

Pemex, in a phase of increasing production--with plans to increase crude oil production to 4 million barrels per day (from 3.8 in 2003) by 2006--clearly needed an answer to Mexico's waste disposal dilemma.

SALT CAVERNS SEEN AS ANSWER

The government estimates that 74 percent of Mexico's hazardous waste is dumped illegally, constituting a major source of water and air pollution and a threat to human health.

Salt caverns can be created in underground salt formations as chambers for product storage or waste disposal. For more than five decades, they have been widely used to store hydrocarbon products.

Since the 80s, concerns over costs, and environmental effects, of land disposal and incineration have led to interest--in Canada, England and Holland, for example--in using salt caverns for waste disposal. Proponents argue they are hermetically sealed by thick walls of salt, which guarantees their safety.

NOM-145 specifies geological, topographical, climactic and social restrictions on the use of salt caverns for waste storage. For example, the salt dome to be used for the cavity must be at least 1,000 meters thick in 3 dimensions, the site must be 20 meters below riverbeds with an average annual flow above 100 cubic meters, and the ground level installations of the site must not be constructed in Natural Protected Areas nor in zones classified as urban.

"The three most important criteria to be established by NOM-145 are those that prevent the movement of fluids produced in the operation of the waste confinement site to aquifers, that state dominant winds must not be directed toward nearby populations, and the qualities of the treated wastes to be confined," Torres said.

The standard also establishes procedures for monitoring adjacent aquifers and soils. Water quality must be monitored before construction and at monthly intervals when the site is in operation.

If physical chemical characteristics of aquifers differ from those before the site existed, or register changes that indicate presence of polluting elements, the operations must be suspended immediately and the National Water Commission (CNA) must be informed.

Mexico has three important salt formations, in the states of Veracruz, Tamaulipas and Chihuahua. It is likely that the Veracruz formation would be the first to be developed for the waste containment sites allowed by the new regulation, since it is close to the Gulf Coast and Mexico's main oil drilling operations.

For more information on waste storage in underground salt domes, see "UIC" (Underground Injection Control) in: http://www.epa.gov/safewater

Barbara Kastelein is a Mexico City-based freelance writer.