Unexpected failures on trunk mains and critical sewers can cost an individual Utility tens of millions of pounds in third-part damage. Added to this are direct costs of repair / restoring serviceability and indirect costs (loss of image, customer dissatisfaction / traffic disruption plus diffuse social / environmental costs). Each large Water Utility has between 2 - 6 of these high-profiles failures each year.
Unfortunately, real costs of failure are hard to quantify; the Sewer Rehabilitation Manual (SRM) methodology uses 1970's traffic conditions and there is no single, consistent method to assess criticality (impact of failure) of both sewers and water mains. Consequently, it's difficult to justify preventative maintenance and uncertainty in targeting these 'super critical' assets means of effective use of budgets is compromised.
This project will:
- Examine cost elements to determine criticality of trunk mains and critical sewers and identify an effective methodology for combining / comparing these cost elements.
- Detail a methodology for quantifying overall criticality of trunk mains / critical sewers.
- Explore extending the method to cover variable impact events e.g. sewer flooding.
- Knowledge and methodology to support a more robust basis for estimating asset criticality and targeting / prioritising preventative maintenance.
- Reduced risk of failure of critical sewers and trunk mains.
- Understanding regulatory implications of updating existing models and improved awareness of serviceability / environmental impacts of critical asset failures.