The General Environment Law (Law 64-00) was enacted on August 18, 2000 and dictates that the governing body on environmental and natural resource policy is the Ministry of Environment and Natural Resources. This law provides, in Article 38, the environmental assessment process in order to prevent, control, and mitigate potential impacts on the environment and natural resources caused by different projects and activities.

The environmental assessment process is required for all projects, installations or schemes, both private and state owned. One of its instruments is the Environmental Impact Study, a process of technical and multidisciplinary study that is conducted on the physical, biological, and socioeconomic environment where a project will be installed or run.

The professionals who perform Environmental Impact Studies come from various disciplines and their characteristics and fields of knowledge will depend on the nature of the study. The consultants who undertake these assessments must be duly registered with the Ministry of Environment and Natural Resources.

The purpose of the study is to identify, predict, and describe the effects, positive or negative, from installing or running activities.

To perform an Environmental Impact Study one must begin with what is known as the baseline, which is simply the description of the situation at the time the study was conducted, before the influence of any external interventions. From the baseline,  all environmental variables are considered and the effect that the possible interventions would have on the environment is assessed, estimating the positive and negative changes potentially introduced by them.

It should be noted that something known as the zero variant, alternative zero or project zero is also considered within the protocol of the Environmental Impact Study. This is the option of doing nothing, based on the environmental impacts of the project to be implemented.

After the study is conducted, it must be submitted to the Ministry of Environment and Natural Resources, who will in turn issue an approving verdict or may order additional studies