As part of the closing strategy of the UM La Zanja, owned by Compañía de Minas Buenaventura, Amphos 21 develops innovative hydrogeochemical studies as support to different lines of research aimed at identifying and supporting the sustainable activities of mine closure. For this, studies were developed with a clear focus on the operation’s water cycle and their interactions with the mining components (waste faciliies, open pits), which integrate the concept of enhanced soils for their potential use as coverage and integral restitution of the environment.