Rapid Design and Deployment of Real-Time Control for CSO Compliance: Lessons for US Utilities from a UK Case Study

Purpose: This presentation aims to share recent advancements in real-time decision support systems (RT-DSS) for combined sewer overflow (CSO) compliance driven by new technology and changing regulatory drivers. It focuses on lessons learned for US utilities from tightening CSO regulations in the UK, particularly in the rapid deployment of a city-wide Smart Network system in Newcastle, UK. Benefits of Presentation: The learning objectives include an understanding of common implementation steps for RT-DSS (sensor network, modeling, control, and forecasting), novel project delivery methods, and a comparison of CSO regulations and utility organization in the US and UK. Background: Recently, the UK has tightened CSO regulations at a rapid pace. To meet these regulations, Northumbrian Water Limited, a UK-based utility, decided to explore the use of RT-DSS to reduce the volume and number of CSO occurrences in a sewer system serving a large city with approximately 1 million population, 5,600 miles of sewers, a single 165 MGD treatment facility, and about 300 CSO discharge points. An RT-DSS uses a combination of over 900 sensors to determine the real-time state of critical assets, a digital twin to forecast future scenarios, and an optimization algorithm to determine the optimal control strategy to mitigate overflows. This case study will present the life cycle of a machine-learning powered planning and design of the RT-DSS including sensor placement, network constraint analysis, control locations, and cost-benefit analysis. It also shows how a combination of low-level regional control logic and high-level global strategy optimization are used to deliver an operator-friendly yet highly optimal and robust control system. The Smart Network system is expected to reduce the volume of spills by 284,000 m3 per storm event and reduced the cost of achieving this reduction by 94%. Status of Completion: The Northumbrian Water Limited case study on the Newcastle upon Tyne system is ongoing. More than 800 monitors have been deployed, and one real-time control site, Browns Point Sewage Pump Station, has been implemented and is dynamically balancing flow between Howdon Sewage Treatment Works and the 19,000 m3 Storm Tunnel. Five additional sites will be live by the end of Q1, 2025, and the system will have a total of up to 31 control sites online by the end of 2026. The web-based platform used by operators for control strategy recommendations is already in use. Conclusion: Real-time control can provide quick wins for utilities on a tight timeline to meet regulatory requirements. Longer term, RT-DSS can provide sustained improvements when coupled with new green and gray infrastructure projects.