This dissertation aims to explore the gap between the theory and practice of an integrated approach in pollution control, mainly through two case studies in the UK. The best practicable environmental option (BPEO), best available techniques not entailing excessive cost (BATNEEC), and the best available techniques (BAT) are the central pillars in IPC/IPPC. The operators should apply them to achieve a high level of environment protection taken as a whole. Whilst they are recognized as good concepts in theory, they incurred lots of arguments within the regulated companies. The main complaints are that too much effort has been spent on justifying the extent of pollution prevented, reduced or rendered harmless, rather than instigating the improvement. In reality, the integrated approach in pollution control is an extremely complex issue, needing more time to develop its infrastructures. From the research findings, three recommendations are given for the future development: firstly, more efficient use of information; secondary, more incentive credits in statutory permit conditions; and lastly more emphasis on the integration of resources to take more advantages of one-stop-shop.