A review of the different rehabilitation techniques available, their applicability to the assets (network, manholes, chambers, sewer rising mains, etc.) and the level of implementation within the industry. Applicability of different rehabilitation techniques must be considered in terms of performance depending on the existing sewer pipe material as part of the review.
A review of research into sewer rehabilitation techniques and implementation globally, e.g. evaluation projects and interpret findings into the effectiveness and longevity of these techniques.
Analysis of the performance of the rehabilitated assets including root cause analysis of subsequent failures where they have occurred. A statistically sound range of examples should be taken and analysed to help understand the impact of sewer rehabilitation on asset life and performance. The performance of different types of rehabilitations i.e. patch liners versus full length should be considered.
Project scope to include:
1. Review of the different current and emerging (from other geographies) rehabilitation techniques (e.g. sock liners, spray liners, cured in place patches (in terms of longevity, strength, resistance to ground water infiltration and ingress particularly the durability and performance of renovation methods and the success of installing against active infiltration), LED lamps and resins being developed for curing patches, liners, and formed in place PE pipes, etc.).
2. Project to consider the following:
· H2S (growing issue for utilities) and best practice to renovate or protect CP pipes and structures. Consider what happens to the affected structure after CIPP or coating is completed.
· Appropriate renovation of brick sewers and other problem pipe materials, such as PF which will become an increasing burden with the takeover of S105a sewers.
· Other replacement or upsizing systems to address network capacity issues through no-dig such as bursting or discreet MH to MH replacement systems. i.e. In2 and Snap-it etc.
· Understanding the short and long term impacts of rehabilitation on serviceability performance like blockages, root ingress, and infiltration reducing available capacity.
· Analysis of liner performance with respect to host pipe material and diameter, curing techniques.
· Analysis of general maintenance activities and impact on various rehab techniques (e.g. jetting operations resulting in shedding of inner foil lining of CIPP).
· Opex benefits, i.e. reduction of silt accumulation in lined sewers, saving on cleaning and tankering.
· Costs associated with serviceability impacts or the customer impact of these issues, and the benefits of the lining.
· Whole life costing of rehabilitation techniques.
· Review of accelerated aging testing on various rehabilitation techniques undertaken by the supply chain or academic material experts.
· Determine successes and failures modes of various technologies.
Review of utility Standards and identify if these are adhered to. Determine level of inspection/testing of installation applied by contractors. Identify the potential of developing a standard “sand box” type test so that random tests can be carried out on patch repairs in the field. The level of Quality Control implemented at installation stage may have a significant bearing on the effective life of any rehabilitation works and should be reviewed in the context of historical data.
Above points to include a minimum number of examples from each participating company.