About Dr. Mariana Tejado

Dr. Mariana Tejado is a Mexican environmental lawyer with over twenty years of experience in environmental law. Her expertise encompasses a wide range of fields, including environmental and natural resource issues, waste management, land use, corporate environmental regulation, environmental impact assessment, water resources management, air emissions, climate change, human rights, and various regulatory aspects of the Mexican energy sector.

During her tenure as Director of the Environmental Department at the National Human Rights Commission in Mexico, Mariana had the opportunity to issue recommendations to authorities at all three levels of government, advocating for the protection of the human right to a healthy environment, as well as the rights of indigenous peoples and communities. She has also served as an advisor and consultant to prestigious institutions such as the Commission for Environmental Cooperation of North America, the Inter-American Development Bank, and several Mexican government secretariats, including the Department of Environment.

Furthermore, Mariana Tejado has provided legal counsel at several firms, advising clients across diverse sectors such as energy, mining, tourism, food, chemicals, paper, livestock, transportation, and textiles, among others. With experience in both the private and public sectors, she offers a comprehensive understanding of Mexican regulations and has assisted numerous Mexican and international companies in navigating complex regulatory landscapes and ensuring compliance with social and environmental standards.

  • Providing legal services to an aerospace company based in California, USA, to regularize their Mexican factory in Tijuana, Mexico.
  • Participating in the legal strategy and being part of the third expert group that supported the Energy Association, the Mexican Wind Power Association, and more than 25 national and international energy organizations opposing electric reforms that negatively impact the environment.
  • Collaborating with Greenberg Traurig Law Firm (a multinational Law Firm founded in Miami, FL, USA) to represent and regularize (on environmental matters) a Korean company, in order to refinance their facility, marking the first issuance of covered and uncovered guaranteed notes by Korea Eximbank for $401 million in private placement.
  • Obtaining environmental and social authorizations, licenses, concessions, and permits from Mexican authorities for the construction of a hotel in Tulum, México.
  • Obtaining the Environmental Impact Authorization for the construction of a gas pipeline of Pemex.
  • Providing environmental legal services to international companies across various sectors, including beverage, brewing, energy, construction materials, renewable energy, and infrastructure, among others, to develop their projects in Mexico.
  • Due Diligences for solar and wind power plant projects.
  • Collaborating with international agencies such as the German Agency for International Cooperation GmbH and the Commission for Environmental Cooperation to provide legal advice on the issuance of guidelines or protocols.
  • Regularizing environmental aspects of solar and combined cycle projects in Oaxaca.
  • Applying the Ramsar Agreement and mangrove regulation for the construction of hotels in Mexico.
  • Obtaining permits from the National Agency of Industrial Safety and Environmental Protection for the Hydrocarbons Sector, for different gas pipelines.
  • Assisting in the development of projects needing to comply with indigenous regulation such as the Indigenous and Tribal Peoples Convention (No. 169) issued by the International Labor Organization.
  • Drafting recommendations for federal authorities (e.g., Ministry of Environment and Natural Resources or the National Water Commission) to comply with environmental regulation.
  • Issuing the first national precautionary measures for Mexican authorities.
  • Awarded with the Alfonso Caso medal for academic merit from UNAM (Mexico)

  • PhD – Institute of Legal Research at the National Autonomous University of Mexico – 2020 (México)
  • Master’s Degree – In Environmental Management and Audit from Miguel de Cervantes University – 2013 (Spain and México)
  • Epecialty in Environmental Law from the UNAM – 2010 (México)
  • J.D. Universidad Panamericana – 2005 (México)
  • Spanish (native)
  • English (fluent)
  • Affiliated to State Bar of Texas as Foreign Legal Consultant, certified by the Supreme Court of Texas
  • Illustrious and National Bar Association of Mexico
  • International Network on Climate Change, Energy and Human Rights
  • The World League of Environmental Lawyers.
  • She was accredited as an environmental legal expert by the Federal Judicial Council in 2017 and 2018.


  • Handbook of Mexican Environmental Regulation (2021), Institute of Legal Research at the National Autonomous University of Mexico
  • Soil Pollution by Hazardous Wastes and Their Regulation in Mexico (2014), Institute of Legal Research at the National Autonomous University of Mexico
  • Fracking and its Mexican Regulation: Its Social and Environmental Impacts (2022) Institute of Legal Research at the National Autonomous University of Mexico

Articles in Books

  • Article “A Holistic Vision of Sustainable Development in the Face of 21st Century Challenges” in the book “Readings on Environmental Law,” Universidad Externado de Colombia, 2023.
  • Article: “Water and Hydrogen Production from an Environmental Perspective” in the book “Water Law, Volume X,” Universidad Externado de Colombia Classification: Research Book, 2023.
  • Article: “The Relevance of Water Resources in Extractive Activities such as Hydraulic Fracturing. The Case of Latin America with Emphasis on Mexico” in the book “Water Law, Volume IX,” Universidad Externado de Colombia, 2022.
  • Article: “Mexican Regulation of Hydraulic Fracturing,” in the book Energy Development in Mexico in Light of Human Rights, IIJ-UNAM (2021).
  • Article: “COVID-19 as a Trigger for a Global Environmental Pact” in the book: The COVID-19 Health Emergency in Light of Climate Emergency. Challenges and Opportunities, Heinrich Böll Stiftung (2020).
  • Editor of and contributor to the book Mexico City: A Socio-Urban Non-Sustainable Space, UNAM (2014).
  • Editor of and contributor to the book Environmental Legislation in North America: Experiences and Best Practices for its Application and Jurisdictional Interpretation, CEC (2011).

Articles in Magazines:

  • “The Sciences and Environmental Protection from Institutions”, International Journal of Public Law, University of Monterrey, 2023 (under review).
  • Advocacy as a key element to achieve the Sustainable Development Goals”, Abogado Corporativo, Revista de Análisis Jurídico, ANADE, 2020.
  • “International Liability on Environmental Matters: The Trail Smelter Case,” Revista Iberoamericana de Derecho y Recursos Naturales, number 15, 2015.
  • “Geothermal Energy in Mexico: Derecho Ambiental y Ecología,” CEJA, number 72, September – October 2016.
  • From Teocintle to Transgenic Maize,” Foro Jurídico, Number 76, January 2
  • Some Implications of the Regulations of the Law for the Promotion and Development of Bioenergy,” CEJA, Year 6, number 33, October – November 200

Contribution as an expert respondent for the World Justice Project Rule of Law Index 2023.

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