ABSTRACT
The discharge of stormwater runoff and combined sewer overflows (CSOs) has resulted in contamination problems that have often prevented the attainment of water quality standards in many receiving waters. The contaminants found in stormwater and CSOs include bacteria, solids, BOD, nutrients, metals, pesticides, and other potentially toxic constituents. This chapter provides information on stormwater runoff and combined sewer overflows. It includes current status; characteristics, impacts, and management of stormwater runoffs; and characteristics, impacts, and management of CSOs. The quantity of stormwater runoff from urban areas is determined for design of storm sewers. The runoff is dependent upon the size of the area, topography, and rainfall. The US Environmental Protection Agency developed the Stormwater Management Model (SWMM) over an extended period of time. This model has substantial capabilities beyond simple stormwater modeling. The information is introduced in the form of unit hyetographs of different subareas and characteristics of subareas.
