Brownfield Reconnaissance

Brownfield sites typically require regenerative work before any new development can go ahead. Problems with unexpected hazards and missing, incomplete or unreliable records can lead to losses of time and money during the project cycle.

Clients are familiar with the need for utility plans, showing the location and depth of cables and pipes, but what about other obstructions and hazards on site?

Buried tanks, cellars and voids are just some of the many potential hazards that can exist on brownfield sites and if encountered unexpectedly pose a risk not only to the health and safety of those on site, but can lead to costly delays.

Working in consultation with Met Consultancy Group (Met) early in the project cycle can reduce the impact of these issues. Boreholes and trial pits provide for direct investigation of the sub-surface, but knowing where to place these can be a problem, and they are always likely to miss features. Using non-intrusive techniques to complement an intrusive site investigation allows the whole site to be assessed, rather than just a few point locations, and results in greater confidence and reduced delays.

Using a variety of geophysical techniques Met are able to produce plans that illustrate where buried obstructions exist on your site. Different methods can identify different ground properties. By combining the results of these survey methods an interpretation can be developed which provides information on what might exist beneath the ground.

This additional information can then be used to target specific features for investigation, either by further geophysics or intrusive works; to redesign projects to avoid costly exercises (e.g. archaeology or removal of insitu piles) or to provide information for structural design.

Ground penetrating radar, electromagnetic and magnetic techniques are most commonly used for reconnaissance surveys. These techniques allow for rapid ground coverage and quick turnaround of results. These techniques can usually cover around 2-3 hectares a day, and are hand-held or cart mounted systems, allowing them to cover a wide range of terrain.

Using non intrusive methods means there is limited use of intrusive techniques to ‘ground truth’ the results of the surveys. Interpretations can be developed for the whole site rather than having to extrapolate findings between isolated borehole and trial pit locations. In return, project team’s are better informed, safer project planning is undertaken and the risk of unexpected delays due to unforeseen ground conditions is reduced.