AAcid mine drainage (AMD) or Acid Rock Drainage (ARD) is a common problem when mining sulphide ores. This acid water often contains heavy metals, including aluminium (Al), cadmium (Cd), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), nickel (Ni), and zinc (Zn). AMD is typically treated using lime [Ca(OH)2] to precipitate metals, followed by solid/liquid separation to produce a clear, non-toxic effluent. Envirobay has extensive experience in the high-density sludge process (HDS), the standard in the industry. The sizing, process design, equipment selection, control philosophy, start-up (commissioning), and training are key services provided by Envirobay.

In some cases where an HDS plant is not the optimal choice, pond treatment, batch pit treatment, or conventional lime treatment plants can also be designed to meet the needs of the site.