Water Mains Replacement
As part of our investment programme we are committed to replacing 70 Kilometres of problematic mains each year for the next 5 years, costing approximately 8 million pounds per annum. Many of the mains that are recommended for replacement have been in service for a very long time.
Before a main is recommended for replacement we have a dedicated team who monitor performance of the mains, including frequency of bursts and taking pipe samples for analysis which give a clear defined picture of the serviceability and life of the main.
By replacing our water mains we not only improve the quality of our service to our customers but this action will assist in reducing costly underground leakage and potential disruption to customers due to frequent bursts.
We use specialist contractors to work in residential areas. As part of their contractual obligations they are expected to keep disruption to a minimum whilst completing the job as cost effectively as possible.
In order to achieve our goal of 70 Kilometres of replacement per annum our contractors use some of the latest low dig technology available. In doing so, this reduces the amount of disruption caused to pedestrians and vehicles passing through our works.
Replacement Methods
Pipe Cracking
This method used the latest equipment available to crack the existing main and pull through a new plastic main reducing the need for long lengths of trenches being open. The aim is to excavate a pit every 100 metres and pull through a coil of new pipe reconnecting the service pipes to the new main or replacing if necessary.
Slip Lining
This method is very similar to pipe bursting but we reduce the size of the new main and insert this into the old main in 100 metre lengths.
Directional Drilling
This method is used when we cannot use the existing pipe because of close proximity to other utilities apparatus. We use a rotating head that cuts through the ground creating a void which we can pull a new pipe through without excavating a trench in 100 metre lengths. The only drawback is that we can potentially cause damage to other utilities apparatus so we have to do several trial holes to ensure we have a clear run which tends to be in a more rural environment.
Open Cut
This is the traditional method of excavating a trench for the whole of the length of pipe that is to be replaced. This is the slowest, most expensive and disruptive to pedestrians and vehicles that may pass through our works.
All mains replacement works have to be co-ordinated with the Local Authority Highways Department who advise when we can work and also advise of how we control traffic throughout the duration of work scheme.