ABSTRACT Critical events such as the disruption of the Fundão tailings dam, considered the biggest technological disaster in Brazil and the biggest of its category in the world, test the responsiveness of organizations in charge of protecting the environment. In the process of assign liability for damage, lawsuits initially proposed were replaced by settlements negotiated between companies, state agencies and the Public Prosecution Service, which previously have stipulated amounts for mitigation actions and environmental compensation. The economic valuation of environmental damage, despite being a tool capable of assisting in the quantification of environmental compensation, has not yet been adequately used in the initiatives to hold the Fundão dam case accountable. Preliminary diagnoses of the disaster have not sufficiently detailed the estimated economic values for environmental and socioeconomic repair, nor have they distinguished between the repairable damage and the irreparable ones that must be compensated. Due to the lack of clear definition of who is responsible for the economic valuation of environmental damage, Brazilian environmental protection institutions have not developed standardized procedures for this purpose, except in an incipient, experimental or particular way for certain types of damage. The implementation of civil liability settlements based on inaccurate diagnoses and values can compromise their effectiveness and perpetuate, without compensation, the damage to Brazilian environmental heritage.