Waste rock materials from mining, mineral processing and related operations, which contain sulphide minerals such as pyrite, have the potential to be the source of acidic contamination in the environment. Such contamination is termed acid rock drainage (ARD). The testing of waste materials can be carried out to provide data so that ARD can be predicted and controlled and to facilitate the implementation of cost effective waste management practices. Numerous laboratory and field test procedures to assess or predict generation of ARD are in use, or have been proposed. This Manual gives background information on ARD generation and its prediction and provides a guide to the components necessary for carrying out and implementing a prediction program. Detailed descriptions of recommended prediction procedures are provided. Alternative procedures are also presented. For each prediction method, the objectives, test principles, equipment and reagent requirements, test procedure, interpretation and reporting of results, advantages and disadvantages, are described. A selected bibliography and list of references is included. The development of new test procedures and revisions to existing procedures is ongoing. The Manual is designed to allow the inclusion of revisions and updates to registered subscribers