Event Duration Monitoring

What is Event Duration Monitoring?

  • The rollout of our real time monitors have influenced an acceleration in the improvements we can make along the sewage network. We are continually striving to improve our performance and are committed to playing a leading role in improving river quality in our region.
  • 100% of our sites have monitors installed as of December 2022.
  • Event Duration Monitoring is the collection of data about storm overflow events. This is measured by the number of discharge events (spills) at each overflow point and the number of hours an overflow discharged for. This data is totalised for each discharge point annually and submitted to the Environment Agency (EA) by the end of February each year.
  • Every year the EA collects Event Duration Monitoring (EDM) data from all companies, providing greater transparency around the frequency and duration of spills from all storm overflows - both those on the network through combined sewer overflows (CSOs)and at the start of sewage treatment works.