Project Appreciation and Objectives
Service reservoirs are a critical part of the infrastructure for the supply of safe drinking water; loss of integrity may lead to leakage and/or ingress and contamination. Regular inspection is required which can be disruptive and costly. Current approaches may involve a drop test, or require the reservoir to be taken out of service for man entry and visual inspection, or a remotely operated vehicle may be used while the reservoir remains in service. These approaches require careful planning, can be difficult to implement, are costly or limited in the quantity and quality of information they provide. There is a need for improved techniques to assess service reservoir integrity.
Methods that might be used, including: discrete or linear hydrophone technology for leak detection; permanently installed structural condition monitoring; 3D scanning sonar and radar; ground probing radar; microwave aquametery and time domain reflectometry; and novel approaches to gas and water tracing. This two phase project will:
- Identify and evaluate new and alternative solutions in use in other sectors, for service reservoir inspection which meet the industry's current and future needs.
- Independently validate selected techniques, identify implementation routes, and define short term benefits and further development needs.
Benefits to Clients
- Reduced risk of asset failure through the ability to undertake quicker, lower cost, more frequent inspection.
- Reduced disruption to supply through the use of technologies which do not require the service reservoir to be taken out of service.
- Informed decision making on future approaches to service reservoir inspection.
The work programme is divided into two phases:
Phase 1: review the regulatory requirements, current approaches and techniques for service reservoir inspection. Define the monitoring requirements and undertake a desk-based technical review of potential new techniques.
Phase 2: by agreement, validate those techniques identified as most achievable and cost-beneficial using a combination of laboratory testing and site trials.
Phase 1 - A technical requirements specification for service reservoir inspection and a review of potential new techniques with recommendations for Phase 2 actions.
Phase 2 - Results of the testing work, defined strategies for implementation and recommendations for further work that may be required for full benefits realisation (e.g. training or design modifications).
WRc has undertaken a number of projects on optimising, repair and maintenance of service reservoirs and produced manuals on condition grading of structures for asset management purposes. Monitoring and technology projects of specific interest are:
- Portfolio project developing new methods for the inspection of sewage rising mains, CP371 (2009 - 2011).
- The WRc Instrument User Group, CP378 (2008 - 2011).