Septic tanks, cesspools and small sewage treatment works can cause odour, nuisance, health and pollution problems. There are some 800,000 such installations in England and Wales and several thousand of them are thought to cause problems every year. So how effective are existing control measures and why do problems occur? This book sets out to find the answers. It begins with an overview of the septic tanks and small sewage treatment plants available, how they work and the problems they cause. It goes on to describe the regulatory and administrative framework for control of their design, installation and use, and contains the results of a survey of practice and problems. The final section makes recommendations for improving the effectiveness of control measures.