Contaminated soil is that whose characteristics have been negatively altered by the presence of dangerous chemical components from human activity, in such a concentration that it poses an unacceptable risk to human health or the environment.[1]​.

The establishment of the list of activities likely to cause contamination in the soil, as well as the adoption of criteria and standards for the declaration of contaminated soils, has been carried out by Royal Decree.[2]​.

The owners of the activities included in said list will be obliged to send to the competent body of the autonomous community a preliminary situation report for each of the lands in which said activity is carried out. Once the preliminary situation report has been examined, the corresponding autonomous community may obtain more detailed complementary reports from the owner of the activity or the owner of the land. Likewise, they will be obliged to periodically send situation reports to the competent body.

The owners of land on which any potentially polluting activity has been carried out in the past will be required to submit a status report when requesting a license or authorization for the establishment of any activity different from potentially polluting activities or that involves a change in [[land use]].

The declaration of contaminated soil must be made in accordance with the criteria and standards and through an express resolution.

Taking into consideration the information received in the previously indicated reports, as well as other available sources of information, the competent environmental body of the autonomous community will declare a soil as contaminated for the corresponding uses.

The generic reference levels that will be used for the evaluation of soil contamination by certain substances are included in the regulations. The substances that will be evaluated are those established in the chemical characterization"), which will especially take into consideration previous activities that may have contaminated it.

The declaration of a soil as contaminated will require the carrying out of the necessary actions to proceed with its environmental recovery.

Contaminated soils will lose this condition when all decontamination actions are carried out on them or this has been declared by administrative resolution.