Monitoring is also necessary to verify that discharges and emissions conform with the conditions of permits and/or do not cause undue damage to receiving environments.In order to provide reliable results, monitoring must be carried out in accordance with established procedures. The results must be recorded in a set way, and the data analysed with valid statistical methods. Standard methods, calibrated equipment and trained personnel are at the heart of a monitoring programme.Audits, also sometimes called "cleaner production assessments", and monitoring are a part of the overall management systems that companies are increasingly using to more systematically plan, maintain and improve their environmental policy objectives and targets. The recent adoption of ISO 14001 has given further impetus to the use of such formal management systems.This manual is relevant to most industries. Within the limited space available, procedures are given for the stages and steps required to carry out systematic monitoring programmes. The manual demonstrates how monitoring programmes can be implemented by companies, whether ‘in house’ or by special monitoring organizations.The manual complements the previously published UNEP/UNIDO Audit Reduction Manual for Industrial Emissions and Wastes. It is designed for use by a range of professionals, including plant managers, technical staff, monitoring teams and government agencies. UNEP and UNIDO welcome feedback from these and other users, for incorporation in future editions.After the introduction in Chapter 1, Chapter 2 describes the basic steps; further details are given in Appendix D, and the analytical procedures are detailed in Appendix E. Training and cost procedures are dealt with in Chapter 3. The four case studies given in Chapter 4 illustrate monitoring programmes of different levels of complexity and cost. The procedures and information given in Chapter 2 were applied to all the case studies of processing plants.