The problems of acidification of some environmental components by acid mine drainage (AMD) are well-known all over the world, mainly in the regions with developed mining industry and in the regions with abandoned mines. AMD production and its consequences can be found also in the spoil dump of pyritized hydroquartzite in the locality of Malý Šobov in the Banská Štiavnica region (central Slovakia). This paper presents the results of two-year soil moisture research, its distribution, regime in the AMD production in this locality. The seasonal soil moisture variability in the spoil dump corresponds with the AMD production intensity (in spring and autumn the spoil dump moisture of about 20 % and temperature create suitable conditions for the activity of autochthonous microflora). The space distribution of soil moisture identified the permeable zones in the spoil dump (where the primary process of pyrite decomposition is expected) and impermeable zones where water and AMD are retained. This knowledge could be useful in application of other remediation processes into the spoil dump.