Ariel Pérez Castellón is Bolivian environmental lawyer and was part of the AIDA’s Freshwater Preservation Program. He received a law degree from the Universidad Católica de Bolivia and specialized in metropolitan environmental management and oil & natural gas law at the University of Buenos Aires. He is a professor of environmental and hydrocarbons law. Over the past 15 years, he has worked at national and international NGOs and as an independent researcher on issues related to extractive industries, the rights of indigenous peoples, and good governance in public policy in Bolivia and Argentina and on regional projects in Andean countries.