Site investigations – often referred to as Phase 2 geo-environmental investigations – are an essential component of any land development process, informing the ultimate foundation solutions and any remediation relating to land contamination.
A phase 2 site investigation is the second stage of a phased assessment of ground conditions, sometimes required for planning permission and almost always for scheme design. A Phase 2 investigation usually follows a Phase 1 Desk Study, where potential sources of contamination and challenging ground conditions may have been identified, and the risks require further assessment.
A Phase 2 Site Investigation will physically inspect the condition of the soil, groundwater and surface water that may have been impacted by sources of contamination and/or are of geotechnical importance. The most common methods of investigation include:
- Trial pitting
- Window sampling
- Cable Percussive drilling
- Rotary drilling
- Foundation pitting
However, the ever-increasing need and desire to develop on inner-urban sites presents significant challenges in conducting these site investigations in order to inform scheme design. Certain aspects of the site need to be considered when undertaking ground investigations, these include:
Site access – restricted site access will influence the types of investigation rigs and machinery that can be used. It is also influenced by the impact it can have either on adjacent properties, or people in the area and is an issue for both residential and commercial projects.
Utilities – developers will need to ensure that existing site information is obtained, and utilities clearance surveys carried out to determine the position, extent and capacity of existing high pressure gas mains, water mains and electricity cables. Utilities pose high risk health and safety concerns and must be determined before intrusive site investigations are carried out.
Active sites – sites can often already be occupied and active, therefore careful consideration will be required in sequencing investigation activities in order to protect site users and the public from potential harm.
Unexploded ordnance (UXO) – UXO’s must be considered for sites located in areas which were heavily bombed during wartime. If UXO risks are not managed efficiently, there could be a risk of loss of life or injury to personnel, and a costly delay to construction or operational activities.
If you are planning to develop on a complex site, ensuring your site investigations are planned in advance with an experienced geo-environmental consultant is crucial.
Call the REC geo-environmental team today on 0845 676 9303 or email firstname.lastname@example.org to discuss your next project.