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On Nov. 5, 2021, approval of Mexico’s National Contaminated Sites Remediation Program for 2021-2024 was published in the Federal Official Gazette. The program aims to help fulfill the Mexican government’s commitments made in the Stockholm and Minamata International Convention agreements. In addition, it will assist the Sustainable Development section of the General Axis II. The “Social Policy” of the National Development Plan 2019-2024 states Mexico’s commitment to promoting sustainable development and to meeting the needs of the current generation without compromising the ability of future generations to meet their own needs.

Basis for Program Creation

Article 4 of the Constitution of the United Mexican States establishes : “Every person has the right to a healthy environment for his or her development and well-being. The State shall guarantee respect for this right. Environmental damage and deterioration will generate responsibility for whoever causes it in terms of the law.” 

Contaminated Sites and Their Sources

The program is brought about as a means to address the existence of contaminated sites within Mexican territoryis.  The term “contaminated site” is defined by the General Law for the Prevention and Integral Management of Wastes (LGPGIR in Spanish) as the place, space, soil, body of water, facility, or any combination of these that has been contaminated with materials or wastes that, due to their quantities and characteristics, may represent a risk to human health, living organisms, and the use of goods or property of persons.

The program specifically states that site contamination in Mexico has been caused by various anthropogenic activities, including:

1. Mining activities have generated large quantities of tailings (i.e., the resultant waste stream after the commodity of value is extracted from the ore material) and byproduct formed in smelting, welding, and other metallurgical and combustion processes from impurities in the metals or ores being treated, much of which was improperly disposed of before Mexico implemented environmental regulations.  These waste products leach into the ground, contaminating nearby soil and water.

2. Hydrocarbon sector activities. Pollution from hydrocarbons and other potentially toxic substances has damaged soil and bodies of water.

3. Agricultural activities. The use of agrochemicals and inadequate environmental practices in agricultural activities has impacted not only the soil in treated areas but also rivers, lagoons, and coastal areas.

4. Industrial activities. Consumer-good production has generated sources of pollution due to improper handling of hazardous materials and other types of waste.

5. Service facilities. Gasoline service stations, vehicle repair shops, railroad stations and facilities, bus terminals, and airports, among others, have generated soil and groundwater contamination due to leaks in containers of hazardous materials, continuous spills of lubricants, organic solvents, or other substances, as well as inadequate handling practices.

6. Wastewater use for irrigation of agricultural fields. The use of such wastewater for irrigation of agricultural crops can contaminate soils and crops with chemical residues from industrial and municipal discharges.

7. Landfill/irregular waste disposal. Urban solid waste mixes with hazardous waste and is not properly disposed of, leading to soil contamination.

Impact on Public Well-Being

Soil and water contamination negatively impacts people and the environment. According to the United Nations Environment Program (2017), contaminants in soil degrade soil biodiversity, can reduce agricultural productivity, and can cause disease and death in humans and wildlife.

The Food and Agriculture Organization of the United Nations (FAO, 2018) points out that soil contamination causes a chain reaction—decreased biodiversity in the soil reduces the amount of organic matter and the soil’s capacity to act as a filter. Groundwater and water stored in the soil also become contaminated, causing an imbalance of nutrients in the soil.

Information on Contaminated Sites in Mexico

The Ministry of Environment and Natural Resources (SEMARNAT in Spanish) keeps a National Inventory of Contaminated Sites (INSC) with information on sites that have been studied and characterized as contaminated. The inventory is maintained according to the LGPGIR and its regulations.

Information on contaminated sites can be obtained via requests for remediation proposals submitted to both the SEMARNAT General Directory of Integrated Management of Hazardous Materials and Activities (DGGIMAR) and the Industrial Management Unit (UGI) of the National Agency for Industrial Safety and Environmental Protection in the Hydrocarbons Sector (ASEA). According to the INSC, as of December 2018, there were 913 contaminated sites in Mexico (756 in rural areas and 157 in urban areas). To date, the contaminated sites that could affect indigenous communities in Mexico are not identified.

Remediation of Contaminated Sites

Contaminated sites are subject to remediation – a set of measures  that aim to eliminate or reduce pollutants to safe levels for the health of both humans and the environment, or to prevent the dispersion of pollutants in the environment without modifying them. Those responsible for the remediation of a site contaminated with hazardous materials or wastes are:

1. Individuals or legal entities that, directly or indirectly, pollute a site or cause damage or harm to the environment;

2. Persons responsible for activities related to the generation and handling of hazardous materials and wastes that have resulted in site contamination; and

3. Owners or possessors of private property and holders of a concession title in areas where soils are contaminated.

SEMARNAT may take part in remediating a site contaminated with hazardous materials or wastes that represent a risk to human health and the environment in the following circumstances:

1. A contaminated site is declared abandoned;

2. A space is expropriated for public use;

3. A remediation declaration is issued by the federal government;

4. The site is owned by a federal entity or a municipality;

5. Remediation has been ordered by federal mandate or through an international arbitration award.

Priority Objectives

SEMARNAT, through DGGIMAR, intends to promote actions that support the remediation of contaminated sites, prioritizing the following objectives:

1. Improve the National Inventory of Contaminated Sites;

2. Promote remediation actions at contaminated sites to contribute to the well-being of the population;

3. Strengthen the regulatory framework for remediation of contaminated sites.

Promotion of Remediation Actions at Contaminated Sites

To improve the process of obtaining approval and complete remediation programs, a proposal will be prepared by the interested party or the person responsible for remediating that identifies the reasons why remediation efforts have been stalled in the past.

Further, those responsible for remediation will be encouraged by the government or competent authority to obtain the necessary authorizations. In addition, a program that considers inspection visits to monitor contaminated sites will be established by PROFEPA or ASEA, as will conformity assessment through third-party agencies (verification units and testing laboratories).

Vision for the Future

With these new goals, the current administration reaffirms its commitment to providing the general public with reliable and updated information on contaminated sites, fully identifying which sites are contaminated, incorporating them into the INSC, and differentiating them from those that have been cleaned. This process will indicate which sites should be prioritized during remediation projects, in accordance with the LGPGIR. There will also be an updated inventory by 2024.

These changes should allow the INSC to have more reliable, detailed, and precise information by 2040; to understand the  pollution trends at the national level; and  fully identify the pollutants that are most recurrent, how they are distributed, and their impact on soil and water.

* Special thanks to Daniela Cobo˘ for her assistance with this GT Alert.
˘ Not admitted to practice law.