Utilities need guidance related to appropriate flushing velocities in order to achieve a balance between water quality improvements, demand for O&M resources and water conservation. The objective of this project was to determine the range of flushing velocities required to dislodge and remove various accumulated materials from water distribution mains based on site-specific conditions.Twelve utilities from 3 countries (USA, UK, Australia) participated in this study.Research Partner: KIWAOriginally published by AwwaRF for its subscribers in 2003 This publication can be purchased and downloaded...

Sudden valve closures can create rapid changes in water velocity that result in transient pressure conditions. Pressure transients can travel throughout a distribution system and cause low or negative pressures. Contamination may occur if a leak or air-vacuum valve is submerged and a low pressure wave passes through the pipeline. Pressure transients may be initiated by regular water distribution system operations. Therefore, pressure transients may occur frequently in certain water distribution systems. The objectives of this project were to verify that low and negative pressure transients...