Back to school for Phase SI

Earlier this year Phase Site Investigations was asked to carry out a utility tracing survey at a site where a school was being rebuilt. The client had come across unexpected buried services during excavation work at another school site and wanted to see whether a non-intrusive survey could minimise the risk of this happening again.

Phase undertook a detailed utility tracing survey using a combination of radio frequency location (RFL) and ground penetrating radar (GPR) and were able to locate metallic and non-metallic apparatus. The routes of apparatus shown on record drawings were accurately confirmed (in some cases the plans were more than 10 m out compared to the true position of the services) and significant amounts of ‘unrecorded’ apparatus were also identified. Thus significantly reducing the risk that services would be struck during excavation work at this school.

Our survey identified the routes of electric and communication cables, gas and water pipes (including plastic water pipes) and provided information on drainage connectivity and pipe diameters. Field drains were located under the playing fields and several other possible buried obstructions were also identified.

The information that we provided was of use not only in avoiding striking the existing services, providing health and safety and cost benefits, but it was also of benefit in designing the new infrastructure as some utility routes could be reused.

The client was so pleased with the survey results that utility tracing surveys were rolled out across a further five schools that were due for rebuilding. Phase was also able to provide a full topographic survey at one of the sites and established a survey control network at another.