GC Alert | Official mexican standard nom-001- semarnat-2021, which sets forth the maximum tolerable limits of pollutants in wastewaters discharged into receiving national water bodies.

On March 11th, 2022, the Ministry of Environment and Natural Resources (“SEMARNAT”) published in the Official Gazette of the Federation the Official Mexican Standard NOM001-SEMARNAT-2021, which sets the maximum tolerable limits for pollutants in wastewaters discharged into receiving national water bodies (“NOM-001”).

Amendments made to NOM-001 range from strictly formal to substantially technical matters. It is important to mention that national receiving bodies, such as streams, canals, drains, reservoirs, lakes, lagoons, rivers, and Mexican marine areas will be impacted by the regulation of NOM-001.

The main differences of NOM-001 with respect to the previous version published in 1997 are:

1. The maximum permissible limits of pollutants in wastewater discharged are strengthened and stricter. Similarly, the maximum temperature allowed for discharges is modified, that is, reduced from 40°C to 35°C in all receiving bodies.

2. The receiving bodies classification is modified and to a large extent eliminates the focus on subsequent uses; this is in order to improve the management and protection of receiving bodies.

3. Specific discharge conditions will be required in wetlands and karstic ecosystems due to their vulnerability.

4. Inclusion of parameters of True Color and Acute Toxicity.

5. Inclusion of a compliance assessment procedure for the issuance of an opinion of conformity, which may be carried out by PROFEPA, CONAGUA, or a Verifying Unit.

6. It sets out the obligation to place equipment and material to collect samples at discharge points in order to improve sampling practices. This will in turn facilitate internal verification, as well as that of the environmental authority.

The entry into force of the new NOM-001 is set as of March 11th, 2023, that is, 365 days after its publication in the Official Gazette of the Federation.

In addition, the general permissible limits will come into effect on April 3rd, 2023. On the other hand, the parameters of water toxicity and true color, as well as the regulatory appendix related to sampling ports will be enforceable only until the fourth year of the publication of NOM-001, that is, March 11th, 2026.

We urge our clients and other interested parties who are permit holders of discharges to national assets to continue complying with the “NOM-001-SEMARNAT-1996, published January 6th, 1997, until the recently published NOM-001 enters into force.

Although NOM-001 will take a year to enter into force, we strongly suggest that holders of discharge permits begin the legal, technical, and economic analysis regarding adjustments required to comply with the new parameters set forth

At Gonzalez Calvillo, we remain at your service to resolve any questions in relation to the above.

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About Gonzalez Calvillo

For over 30 years, Gonzalez Calvillo has been at the forefront of the legal market in Mexico as a full-service leading law firm due to its transactional core and expertise in a wide range of practice areas. The firm is recognized for its ability to build cross-disciplinary teams for the most complex legal challenges and long track record of successfully providing groundbreaking business and regulatory advice to high-profile domestic and international companies. Often described as a pioneer of the Mexican legal services industry, the firm is known for its commitment to do things differently, bespoke solutions, and creating transformational legal changes that enable clients to achieve their objectives.

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