Mexico: Recommendations for the Legal Discharge of Wastewater to Rivers, Lakes, and Subsoil

Most economic activities require the discharge of wastewater. While in some cases it is possible to discharge into sewage systems, in others, wastewater must be discharged into rivers, lakes, or directly into the subsoil, either because there is no sewage infrastructure or because the authorities that operate the sewage system do not allow it.

Unfortunately, poor management of wastewater discharges has caused some rivers and lakes to display high levels of contamination. For example, in 2021, the National Water Commission (“CONAGUA”) monitored 788 rivers and lakes throughout the country, and about 300 reported some kind of contamination.

Water pollution is a concern for everyone, as it leads to a number of environmental and social conflicts. As a result, CONAGUA has imposed sanctions and made it mandatory for those who generate discharges to remediate such discharges.

In this regard, those who discharge wastewater into rivers, lakes, and subsoil should consider the following recommendations to ensure that their wastewater discharge complies with the applicable environmental regulations:

1. Hold a wastewater discharge permit issued by CONAGUA. A wastewater discharge permit shall be obtained before discharging wastewater into rivers, lakes, or subsoil. Furthermore, the irrigation of green areas with wastewater is considered a discharge to the subsoil. Wastewater discharges without this permit may result in the imposition of fines and the shutdown of the activities that cause the discharge.
2. Avoid polluting discharges. It is necessary to have a water treatment plant in optimal conditions so that the wastewater to be discharged complies with the parameters established in NOM-001-SEMARNAT-1996. It is important to note that in March 2023, NOM-001-SEMARNAT-2021, which establishes stricter quality parameters, will enter into force.
3. Submit declarations in the DECLARAGUA system and, if applicable, pay fees. Holders of a discharge permit shall inform CONAGUA of the quality and quantity of the wastewater discharged and pay the corresponding fees. If the holder evidences that the substances in its wastewater discharges are within the maximum permissible limits established in the applicable official Mexican standard, it will be exempted from paying fees. For this purpose, the holder shall periodically carry out an analysis of its wastewater discharges.
4. Ensure that the laboratory issuing the analyses is authorized by CONAGUA and accredited by the Mexican Accreditation Entity. The analysis mentioned above shall be carried out by a laboratory authorized by CONAGUA and accredited by the Mexican Accreditation Entity (“EMA”). If the laboratory lacks these certifications, the analyses will be invalid, and the exemption to the payment of fees cannot be requested.
5. Do not exceed the permitted volume of wastewater discharge. Discharging more water than authorized, even if it is not contaminated, could result in the imposition of sanctions.
6. Apply for a discharge permit based on the forecast and estimates of the wastewater intended to be discharged. In case of discrepancies in the declarations made, CONAGUA may require payment of fees for the total volume permitted (regardless of whether a lower volume was actually discharged).
7. Avoid diluting wastewater discharges. This is considered a serious infraction that may result in the total shutdown of the facility. In addition, CONAGUA may require payment of fees for the total volume established in the permit.
8. Request for an extension of the permit at least 6 months prior to the end of its term. Unlike other authorizations that allow requesting an extension at any time prior to its expiration, permit extensions must be requested at least 6 months before the end of its term.
9. Obtain a concession title to use shoreline areas of rivers or lakes. The river or lake shore is considered a federal zone under the jurisdiction of CONAGUA. If the holder of a discharge permit intends to develop discharge facilities (such as ramps or pipelines) in this area, it shall obtain a concession title from CONAGUA.

Conservation of rivers, lakes, and groundwater is essential to ensure ecological balance. Furthermore, this will preserve the water supply for human consumption and economic activities. In this regard, wastewater discharges into these ecosystems shall be carried out responsibly and in full compliance with environmental regulations.

Authors

Vicente Grau | Partner | vgrau@s-s.mx

Claudia Rodríguez | Partner | crodriguez@s-s.mx

Heriberto Garza | Partner | hgarza@s-s.mx

David González Vega | Associate | david.gonzalez@s-s.mx