Event Duration Monitoring

EDM Monitors are installed in the network at CSOs or on a sewage treatment works in the overflow chambers where a discharge would start. These monitors continuously watch the level of wastewater in the chamber. A discharge event is considered to have begun when the level reaches the height that it would spill over an overflow wall.
All monitors operate within accuracy bands and both environmental and site working conditions can influence the accuracy levels– this allows us to work with industry experts to develop a better understanding of accuracy levels.
Our monitors take readings of the water level either every 2 minutes or every 15 minutes depending on the Environment Agency classification of the receiving watercourse. Every data point captured at or above the overflow level would count towards the total time that a discharge was occurring at that location.