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Soil pollution


What regime governs liability for soil pollution (including the allocation, transfer and limitation of liability)?

As a general rule, the individual or entity accountable for the activities relating to the generation and management of materials which pollute soil is obliged to perform remediation activities. Brownfield proprietors and tenants are jointly obliged to perform remediation activities. However, the following exceptions apply:

  • in the case of brownfield abandonment or when the proprietors or tenants are unknown, the Secretariat of Environment and Natural Resources (SEMARNAT) undertakes remediation activities;
  • when contaminated land is subject to purchase, the involved parties may agree on who is liable to perform remediation activities. Any agreement regarding cleaning-up obligations must be authorised by SEMARNAT. When liability is not established, the alienating party is obliged to complete remediation; and
  • oil and gas tenders may operate sites with environmental passives. In this case – and after determining the extent of environmental passives through a baseline study – the contractor must organise the cleaning up and can then claim expenses through governmental royalties.

Due diligence

What environmental due diligence measures are recommended before concluding land transactions?

When conducting an environmental desk review, the performance of soil assessments or analysis is typically required. It is usually necessary to require Phase I and Phase II environmental site assessments before concluding a transaction, in order to evaluate the likelihood of soil pollution.


What remediation and clean-up measures are typically applied and how can remediation costs be recovered?

Cleaning up is accomplished through remediation programmes that include:

  • descriptive studies;
  • environmental evaluation and risk studies;
  • historical investigations; and
  • remediation proposals.

Remediation programmes must be authorised by SEMARNAT.

With regards to remediation costs recovery, liability scenarios must be accounted as follows:

  • The proprietors or tenants that performed the remediation actions on sites polluted by a third party are able to seek recovery through civil proceedings against said party.
  • In case of abandoned brownfields or of the proprietor or tenant being unaware, remediation actions performed by SEMARNAT are covered by taxation incomes.
  • If liability is set through an arrangement, an escrow agreement can be subscribed to cover remediation activities.
  • Baseline studies – which are performed as a result of tenders involving environmental passives – determine the probable costs of remediation. In this case, despite the contractor being bound to carry out remediation actions, remediation costs are deducted from governmental royalties.

Air pollution


How are air emissions regulated? What air quality standards and emission limits apply?

Air emissions are federally regulated by the General Law of Ecological Balance and Environmental Protection, which states that the Secretariat of Environment and Natural Resources (SEMARNAT) must provide the general guidelines for regulated subjects. The following stationary source industries are federally regulated:

  • chemical;
  • petroleum and petrochemical;
  • paint and ink;
  • automobile;
  • cellulous and paper;
  • metallurgical;
  • glass;
  • power generation;
  • asbestos;
  • cement and limestone quarry; and
  • the treatment of hazardous waste.

The obligations of operators are established in the Regulations on Emissions Registry and Pollutants Transfer.

As state governments have responsibilities in regulating this matter, air emissions from stationary sources aside from those listed above are locally regulated. Companies which create air emissions must obtain a licence from the corresponding local authority.

Air emission limits are established in Mexican Official Standards, which contain technical specifications for each type of air pollutant.


What are the consequences of non-compliance with air emissions regulations?

Consequences of non-compliance vary depending on the severity of the offence. The penalties for non-compliance include:

  • fines;
  • the temporary and permanent closure of facilities; and
  • licence cancellation.

Water pollution


What rules govern the discharge of wastewater and the protection of water resources?

The discharge of wastewater into bodies of water and soil and the protection of water resources are regulated by the National Waters Law and its regulations. The discharge of wastewater into sewage is locally regulated by state and municipal regulations. With regards to water control, the federal authorities issue the following:

  • concessions to use and consume national water (eg, water obtained from wells, water courses and reservoirs); and
  • permits to allow the discharge of water in areas under federal jurisdiction (eg, soil, seas and rivers).

Wastewater discharge permits contain dispositions to avoid water pollution.

The protection of water resources is primarily intended to avoid pollution and as a general rule, parties that contaminate water must restore its quality and bear the costs involved.


What are the consequences of non-compliance with water pollution regulations?

The consequences of non-compliance with water pollution regulations are dependent on the severity of the non-compliance but can include:

  • fines;
  • the temporary or permanent restriction of activities;
  • the cancellation of permits, concessions and assignations for water use; and
  • jail sentences.

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