Case study

Northumbrian Water Limited provides water and wastewater services to 2.6 million people in North East England, trading as Northumbrian Water, and water services to 1.7 million people in the South East, trading as Essex & Suffolk Water. The company owns, maintains, and operates 41,000km of water mains and sewers, just over 500 treatment plants, nearly 400 water storage sites, and more than 1000 pumping stations.

At key locations, NWL uses 1,500 Combined Sewer Overflows (CSOs) which drain both foul and surface water flows to manage storm water. They needed an alarm management system which would allow them to provide clear prioritisation of alarms allowing targeted operational intervention to mitigate potential pollution events, as they were unable to differentiate easily between rises in levels due to increased rainfall and rises caused by blockages or other problems. This was leading to an increase in false alarms, engineers call outs, and pollution incidents.

NWL identified rainfall radar data as the key to their problem. The Met Office were able to provide rain intensity data at 15 minute intervals covering the whole of NWL’s operation. C3 global were then able to produce a Sewer Information Dashboard (SID), which was able to remotely monitor the operation of the entire sewerage network, bring in the weather data and run it alongside the alarm management tool and provide a real time, web based analysis of high level alarms in the sewerage network across the whole of the NWL area. The system would be able to identify and differentiate between normal and dry weather overflows and allow NWL to optimise their resources more efficiently to solve CSO problems.

Using the information from SID, NWL where able to target operations to reduce pollution and improve environmental performance, develop an understanding of the performance and operation of individual drainage networks and their response to rainfall, move from a reactive to a proactive approach as they were able to respond to incidents faster and more effectively, and preventing incidents occurring in the first place. By using C3 globals technology, SID has contributed to over 50% reduction in pollution incidents to date, improved levels of customer service, and has improved operational and maintenance regimes resulting in enhanced financial performance. As more information on rainfall data and sewerage system performance is built up using SID, NWL will be able to target capital improvement schemes to provide best value for money for customers and reduce pollution still further.