ABSTRACT
A methodology was developed to assess the effectiveness of a variety of control options. The negative long term impacts of urban runoff discharges and combined sewer overflows (CSOs) have been widely documented over the past twenty years. Short term and long term impacts can have a negative impact on public water supply, recreational water use and aquatic species. The least cost for a particular level of service for a control option was determined from available cost data. In order to reduce these negative impacts, numerous control options have been proposed to reduce urban runoff and CSOs. Source control typically involves reducing urban runoff volumes entering a drainage system and includes such options as roof leader disconnection. A series of sensitivity analyses determined the circumstances under which other control options could be considered most cost-effective. In order to determine cost-effectiveness, the capital, operating and maintenance and land costs were estimated for each control option.
