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Hazardous Waste Mexico Prepares Final Rule to Regulate Oil Sector Waste Containment in Salt Domes

    MEXICO CITY–The Mexican Environment Ministry (SEMARNAT) is preparing to publish a final regulation setting criteria for the disposal of hazardous waste–especially from extractive industries–in salt dome caverns, a move designed to enable construction of new waste containment facilities.

    The draft regulation (PROY-NOM-145-SEMARNAT-2003) would allow waste materials from the oil industry defined as hazardous (under rule NOM-052-SEMARNAT-1993) to be confined in salt domes. The materials may include rocky waste produced in the perforation of oil wells, separation muds, sediments from hydrocarbon storage tanks, used oils, waste oils, and other oily muds and hydrocarbon sediments.

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

    “The standard was designed to facilitate compliance with the new law for the prevention and management of waste,” which should take effect in April, Ramón Torres, SEMARNAT director of energy and extractive activities, told BNA Feb. 18 (26 INER 1045, 10/22/03 ). “It is a technical standard that provides the last link in the legal chain.”
    Regulation Clarifies Law
    The proposed implementing regulation gives technical clarity to waste law, laying out precise requirements and environmental criteria for selecting, constructing, operating, and closing waste containment sites in pre-existing cavities in salt domes, Torres explained.

    A draft of the regulation was published Nov. 28 in the Diario Oficial, Mexico’s official journal. The government is now reviewing comments on the draft received before the end of January. The comments must receive a formal response before the final regulation may be issued.

    Torres said NOM-145 would benefit waste generators such as Petróleos Mexicanos (Pemex), Mexico’s state petroleum monopoly, which currently must export rocky waste produced in the southeast of the country to the United States.

    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 standard, as it is close to the Coatzacoalcos port on the Gulf and Mexico’s main oil drilling operations.
    Containment Criteria, Procedures
    The criteria include geological, topographical, climactic, and social provisions.

    According to the draft, salt domes to be used for containing waste must be at least 1,000 meters thick in three dimensions; the site must be at least 20 meters below the beds of rivers with an average annual flow above 100 cubic meters; and ground-level installations at the site must not be constructed in natural protected areas nor in urban zones.

    “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 [those regarding] the qualities of the treated wastes to be confined,” Torres said.

    The waste must have a pH not less than 4 and not more than 10, humidity not above 5 percent, and it must be able to withstand pressure of over 50 pounds per square inch.

    The standard will also establish 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 if they register changes that indicate presence of pollutants, the operations must be suspended immediately, and the National Water Commission must be informed.
    Regulations Meet Industry Request
    According to Torres, Pemex and the Federal Electricity Commission–both major producers of hazardous waste–as well as private investor groups had approached SEMARNAT asking for specific technical standards for the disposal of these wastes.

    “Pemex especially wanted this standard, as it is Mexico’s most important generator of waste that, according to the current law NOM-052, is defined as hazardous,” Torres said. “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,” he said.

    Nongovernmental organizations, however, criticized the draft standard, saying it will give preferential treatment to Pemex and that it contradicts current environmental legislation and promotes unsustainable waste management practices.

    “The draft text lacks technical, legal, or scientific bases for the preferential treatment it gives to waste from the petroleum industry,” said Alejandra Serrano of Mexico’s Center for Environmental Law Feb. 13.
    Environmentalists Note Oversights
    Serrano said the draft text contains a number of errors and oversights. For example, it does not refer to the need (established in Mexico’s General Law for Ecological Balance and Environmental Protection) to take seismic conditions into account when considering such sites. It also does not establish an adequate minimum distance between these containment sites and population centers, or between the sites and nearby aquifers.

    The subministry for environmental regulation, which was responsible for developing the standard, is currently analyzing observations received in the 60-day public comment period that concluded at the end of January.

    The Center for Environmental Law presented written objections, as did the Presencia Ciudadana and an ecologist named Gabriel Quadri. By Feb. 18 they still had not received a written reply to their comments, although they were invited to discuss their concerns with Mexico’s undersecretary for environmental regulation, although a date for the meeting has not been set.

    The regulation cannot be issued in its final version and published in the Diario Oficial until each of those commenting on the proposal has received a written response. It will then go into effect 60 days after publication.

    “We have received 88 different observations from 11 different groups or individuals,” Torres said. The committee will convene again soon, probably in March, to reply to these observations.
    Some Waste Not to Be Permitted
    Most of the objections relate to the first annex to the norm, Torres said, which lists the waste products that may not be confined in salt caverns, especially the prohibition of wastes produced by the metallurgy and mining industries. Other wastes that cannot be confined in salt dome caverns are persistent organic compounds such as PCBs, hexachloride compounds and material polluted by them that have concentrations of above 50 parts per million, biological-infectious hazardous waste, municipal solid wastes, and radioactive waste.

    Torres said that, since this list is already established in the new law, which went into effect Jan. 9, there is no need to include it as an annex to the standard, so one option the committee will consider is to omit the list altogether.

    Another option would be to explain in more detail why these substances are not permitted for confinement in salt caverns. For example, there are no existing studies as to whether certain waste products from the metal and mining industries could be confined safely together, and such studies would be very expensive to undertake, SEMARNAT Director for Soils and Waste Alma Escamilla said Feb. 18.

    Other objections call for more precision in the regulations, Torres said. With regard to the distance between these sites and population centers, he said, this is established in the general law, so it does not need to be mentioned in the standard.
    Development of Draft
    Torres said work began on drafting the standard at the end of 2001. A work group consisting of government, industry representatives, and academics first met to discuss the draft in August 2002. They produced an early draft in May 2003 after meeting 16 times.

    Participants included representatives of Mexico’s Energy Ministry, SEMARNAT, the National Water Commission, the industry association CANAINTRA, Petróleos Mexicanos, and several engineering institutions. No nongovernmental organizations took part in the discussions.

    The draft regulation is available in Spanish at