Mains rehabilitation schemes

Many, many kilometres of water mains are forecast to be replaced in the next AMP period.  Works will be undertaken in busy urban areas where the success of the particular engineering process to be used to replace the main will depend upon the accurate location of the underground assets.  Using traditional hand dug trial holes throughout the survey area prior to the work being undertaken in order to collect information about existing utilities brings to the project a host of issues including:

• Traffic management / congestion
• Manual trial holes are restricted to 1.2m in depth
• Noise and other environmental concerns
• Information is limited in scope and is relatively expensive to collect

Most recently our work on the Dublin Water Mains Rehabilitation project won us a Highly Commended award from the United Kingdom Society for Trenchless Technology. 

We tailored our approach to provide the client with sufficiently accurate utility information that allowed the project design team to choose not only the best route but also the most cost effective engineering solution.  To allow the client maximum flexibility we gave an indicative schedule of rates for a range of our services so that they could estimate themselves the cost of the collection of information.  Once the best design had been agreed we worked with the digging crews to mark out the utilities on the ground to aid in safe digging practices. 

The benefits for the client were:

• A dramatic reduction in the disruption that manual trial holes had been causing a densely populated and heavily used area of the City,
• Our processes provided the designers with far more information that the trial holes had done previously and were 60% cheaper meaning better designs that cost less!
• Cost savings from reduced site revisits to investigate potential utility conflicts
• An improved Health and Safety record as a result of using non-intrusive methods of working rather than using men with machines and shovels to collect information.

For these reasons the use of non-intrusive utility location and mapping techniques holds many benefits for water company clients.  Whilst the area of the proposed works may at first appear large, our guidance on the strategic focus of electronic trial holes, slit trenches and junction surveys can bring relatively inexpensive accurate information to the design team. 

Link to pdf of Dublin slit trench
Link to pdf of Dublin junction survey