CEC Releases Molymex II factual record

The Molymex II submission (SEM-00-005) was filed with the CEC on 6 April 2000, by Academia Sonorense de Derechos Humanos, A.C. and Domingo Gutierrez Mendevil. The CEC Council instructed the Secretariat to prepare a factual record on 17 May 2002.

The factual record presents facts on whether Mexico is failing to effectively enforce the General Law on Ecological Balance and Environmental Protection (Ley General del Equilibrio Ecológico y la Protección al Ambiente—LGEEPA) and Mexican Official Standard NOM-022-SSA1/1993 ("NOM-022") with respect to the operation of the molybdenum production plant by Molymex. The factual record reaches no conclusion on whether Mexico is failing to effectively enforce its environmental law.

Molymex S.A. de C.V. operated a molybdenum roaster and other facilities in Cumpas until 1991. On 5 January 1995, Molymex resumed operations under an operating permit issued on 11 February 1994. The authorized annual production for the plant was increased from 7,500 tons to 50,400 tons with the expansion project authorized in January 1999. As of the resumption of operations by Molymex in 1995, several Cumpas and Hermosillo residents and civic organizations accused the company of violating environmental law and causing contamination that allegedly affected the health of the residents of the Municipality of Cumpas.

The submission asserts that Mexican environmental authorities are failing to effectively enforce the environmental impact law in the case of Molymex by allowing it to operate without an environmental impact authorization (EIA). The environmental authority asserts that the EIA procedure was not applicable because the obligation to perform an EIA was incorporated into Mexican law in 1982, it is of a purely preventive nature, and its retroactive enforcement would be unconstitutional. Mexico further states that it has effectively enforced the environmental impact law, since Molymex's expansion project of 1998 underwent an EIA and an authorization was issued for it. As detailed in this factual record, the environmental authority's arguments for not requiring Molymex to obtain an environmental impact authorization involve legal issues not yet resolved by the Mexican courts.

Another of the submission's allegations is that Mexico is failing to enforce LGEEPA Article 112 by failing to establish the zone in which polluting industrial facilities may be sited in Cumpas, Sonora, applying criteria for the prevention of environmental contamination as prescribed by that article. The municipality of Cumpas issued a land use permit to Molymex on 5 October 1998. According to the municipality, that permit and the furnace marked on the map included in the Cumpas Municipal Development Plan 1998–2000 establish the zone in which polluting facilities may be sited as required by LGEEPA Article 112.

The third matter to which this factual record refers is the effective enforcement of NOM-022, which establishes the ambient air SO₂ standard for the protection of public health. The submission asserts that in the first amendment to its Operating Plan, Molymex was authorized to exceed that standard. Mexico asserts that the standard set out in NOM-022 and the stack emission limits established in the Operating Plan are separate issues, and that Molymex did not exceed the applicable standard.

As of 31 December 2001, the 6-hour average limit for SO₂ stack emissions is 650 ppmv. Prior to that date, the Molymex roasting process operated with authorization under various Operating Plans and their amendments but with no enforceable limit for SO₂ emissions. As to concentration of SO₂ as an air pollutant, for the protection of health, NOM-022 provides that ambient SO₂ concentrations shall not exceed a 24-hour maximum of 0.13 ppm more than once a year and an annual arithmetic mean of 0.03 ppm. This NOM has been in force since Molymex resumed operations on 5 January 1995. Moreover, since 17 June 1997, Molymex has been subject to the maximum concentration levels set out in its contingency plan: alert phase, 1-hour average of 0.600 ppm SO₂; alarm phase, 5-hour average of 0.400 ppm; and emergency phase, 24-hour average of 0.130 ppm. The independent experts consulted by the Secretariat concluded that it is possible that ambient air SO₂ concentrations exceeded the NOM-022 standard even though the concentration at the stack did not exceed the 650 ppmv limit, because this latter value is a 6-hour average.

Molymex measures sulfur dioxide in the roaster's stack emissions with a continuous monitor that has operated since early August 2001. The graphs of averages provided to the Secretariat show levels below the limits. As regards ambient concentrations, Molymex has been operating a continuous monitoring system for ambient SO₂ in the vicinity of the plant since October 1994. Mexico asserts that at the monitoring stations installed by Molymex from 1994 to 2000, there was no day in which the SO₂ limit of 0.13 ppm as a 24-hour average was exceeded, and that during this same period the annual arithmetic mean of 0.03 ppm SO₂ set by NOM-022 was not exceeded. In the opinion of the independent experts consulted by the Secretariat in this regard, it cannot be stated with certainty from the data contained in the monthly reports of continuous perimeter monitoring of SO₂ in the vicinity of the Molymex plant that the NOM-022 standards were not exceeded. The information does not support this assertion primarily because the data were collected with detectors whose detection capacity is insufficient (0-0.500 ppm, recording greater concentrations as being equal to 0.500 ppm) and because there are blank records and negative data in the reports.

SO₂ may cause respiratory diseases, particularly in children, the elderly, and asthmatics, and may worsen pulmonary and heart problems. High SO₂ concentrations, even for very short periods, can be particularly problematic for asthma sufferers. Ambient levels around 1 ppm for periods as short as 10 minutes may affect healthy individuals engaging in vigorous outdoor activity. The principal effect of SO₂ in the environment is the formation of acid rain, which causes damage to forests, crops, houses, and buildings and contributes to the acidification of soils, rivers and lakes. Coprodemac and several Cumpas residents assert that Molymex has caused harm to the health of persons and animals, and to the environment in the vicinity of the plant. The information gathered for this factual record did not enable the Secretariat to confirm the alleged negative health and environmental effects, although all studies conducted in this context recommended further research and continuous monitoring.

Molymex has obtained various certificates and awards relating to environmental protection, including a Clean Industry Certificate from Profepa and ISO 14001 certification for its environmental management system, both in 2002. The company calculates that 55 percent of the US $40 million it invested in the Cumpas plant since 1994 was devoted to environmental protection infrastructure.

This is the tenth factual record prepared by the CEC Secretariat. Factual records provide information that may assist submitters, a NAFTA country, and other interested members of the public in taking any action they deem appropriate in regard to the matters addressed.

The CEC was established under the NAAEC to address environmental issues in North America from a continental perspective, with a particular focus on those arising in the context of liberalized trade. The CEC Council, the organization's governing body, is composed of the top environment officials of Canada, Mexico and the United States.