The treatment site of the Central Basin Acid Mine Drainage (AMD) plant has been significantly affected by the recent increased rainfall in Gauteng, the Trans-Caledon Tunnel Authority (TCTA) said on Monday. TCTA, on behalf of the Department of Water and Sanitation (DWS), operates and maintains three AMD plants within three basins, namely Central Basin in Germiston, Eastern Basin in Springs and Western Basin in Randfontein.