Drainage for land treatment sites must be evaluated with respect to the purpose the system is meant to achieve. Off-site drainage controls the flow of storm runoff onto the site or groundwater incursion into the soil within the site. On-site drainage is employed for a variety of reasons. These two areas of drainage control must be designed as a system to obtain the desired effluent quality from the land treatment system. Surface drainage techniques often used for the control of water include diversions, random surface drains, waterways, and ditches. Subsurface drainage is generally accomplished through the use of drain piping with materials such as plastic, clay, and concrete. These techniques will generally make up the drainage system. The objectives of drainage systems as they relate to land treatment sites are discussed, including some flexible operating patterns which can be incorporated through the use of on-site drainage. (Author/BB)