If you are involved in the planning, funding, design, construction or maintenance of infiltration systems and wish to use infiltration drainage as a method to control and dispose of stormwater, this manual is essential reading. It presents good practice for the design, construction and maintenance of infiltration systems for the on-site control and disposal of stormwater runoff from small-scale residential or commercial development upstream of an area with existing sewers. It discusses the advantages and disadvantages of such systems and gives you information to help you decide whether, in given circumstances, infiltration techniques are appropriate. The manual provides information that should enable users to conduct field tests and relate the data to the design, and also to design a range of types of infiltration system. Guidance on pollution prevention is included. More detailed information from the research project is contained in CIRIA Project Reports 21-25.