Nairobi/Paris, July 2001 - UNEP DTIE and International Commission on Large Dams (ICOLD) has published "TAILINGS DAMS: RISK OF DANGEROUS OCCURRENCES - Lessons learnt from practical experiences ICOLD Bulletin 121." The Bulletin analyses the causes of 221 tailings dams accidents and failures, and offers examples of effective remedial measures.

Knowledge about the factors that control the behaviour of tailings dams has improved greatly during the past 20 years as have the consequences and public perception of tailings dam failures, causing managers and owners to become more aware of the risks involved in the construction of impoundments. Many factors influence the behaviour of tailings impoundments. Accidents and other incidents are often the result of inadequate site investigation, design, construction, operation, or monitoring of the impoundment, or a combination of these.

The purpose of this Bulletin is to discuss some of these failures and see what lessons can be learnt from them, to identify improvements that would reduce the occurrence of these failures. It is intended to give general advice that can be of help to all those connected in any way with tailings dams and waste lagoons - government officials concerned with regulations, planning officials concerned about the requirements needed for planning permission, and those concerned about the continuing stability of existing tailings dams.

The Bulletin covers the following key issues:

• Pre-Requisites for Safe Tailings Dams

• Overview of Dam and Tailings Dam Incidents

• Common Reasons for Faulty Behaviour

• Risk Management (Risk assessment, risk management, and risk contingency plan)

• Lessons Learnt from This Study

• Safety Management

• Conclusions and Recommendations

• Lessons Learned: Implications for Policy – A UNEP View

• Tailings Dams – Incident Case Records

If the recommendations given in these guidelines were to be implemented, the risk of a failure or dangerous occurrence with a tailings dam and impoundment would be greatly reduced. UNEP is pleased to collaborate in producing this publication which is a sequel to ICOLD Bulletin 106. We hope that all readers will benefit from TAILINGS DAMS: RISK OF DANGEROUS OCCURRENCES.