Challenge
The water operator had established District Metered Areas (DMAs) as a crucial component of their water loss management strategy. However, ensuring the effectiveness of these DMAs required verifying their hydraulic isolation from the rest of the network. The operator needed to confirm that boundary valves were fully closed and did not allow water to pass between DMAs, which could compromise their ability to monitor and manage water loss accurately. Additionally, recent water mains augmentation near the boundary had raised concerns about potential cross-connections.
Solution
Aqua Analytics was engaged to conduct a series of zero-pressure tests (ZPTs) across four adjacent DMAs. This involved a comprehensive approach to validate DMA integrity:
- Zero Pressure Test Design: Aqua Analytics developed a detailed test plan, strategically selecting locations for pressure monitoring and identifying potential areas for cross-connections or valve leakage.
- Nighttime Operations and Monitoring: Aqua Analytics conducted the ZPTs during nighttime hours to minimise customer disruption. Ovarro XiLog pressure monitoring IoT devices were installed at key points within the network, providing real-time data on pressure fluctuations and enabling the team to monitor network performance during the tests. The XiLog devices transmitted data at one-minute intervals via 4G, allowing for continuous monitoring and analysis by the project team. Access to the data was also provided to the client via a secure cloud server.
- Boundary Valve Assessment: The tests focused on confirming the full closure of boundary valves, a critical factor in ensuring DMA isolation. Any valves found to be leaking or partially closed were addressed to maintain hydraulic independence.
- Data Analysis and Reporting: Aqua Analytics analysed the collected data to assess the integrity of each DMA's hydraulic isolation. A detailed report was provided to the client, including recommendations for remedial actions, such as valve repairs or replacements.
Results
- Confirmed DMA Isolation: The zero pressure tests successfully confirmed the hydraulic isolation of most of the tested DMAs, validating their effectiveness for water loss management purposes.
- Identification of Undiscovered Valves: The project uncovered additional valves that were not fully isolated, allowing the client to address these issues and further improve DMA integrity. The client had a strong identification system for boundary valves and undertook these works as a priority.
- Enhanced Network Understanding: The real-time pressure monitoring data provided valuable insights into the network's behaviour during the ZPTs. This ensured that the field team, at various locations at night, could all see the same data in real time.
Client Benefits
- Improved DMA Performance: By verifying the hydraulic isolation of DMAs and addressing any identified issues, the client could optimise their water loss management strategies and have improved confidence in the data coming into their central event management system.
- Reduced Non-Revenue Water: The project contributed to a reduction in non-revenue water, leading to cost savings and improved resource management.
- Increased Operational Efficiency:The accurate assessment of DMAs allowed the client to focus their leak detection and repair efforts more effectively, maximising efficiency.
- Enhanced Network Resilience: By addressing valve issues and improving DMA isolation, the client increased the resilience of their network to leaks and other disruptions.
Conclusion
Aqua Analytics’ zero pressure testing project played a vital role in ensuring the effectiveness of the water operator’s DMA strategy. By confirming hydraulic isolation and providing actionable insights, the project empowered the client to proactively manage water loss, improve network efficiency, and ensure a reliable water supply. Clients should undertake ZPTs regularly to ensure boundary valves are not compromised by third parties or in the ordinary operation of their business.
