Site Investigations

CDS offers a wide range of site investigation techniques to best suit the site, ground conditions and commercial objectives. Whether the works are related to cemeteries, crematoria, parks and open spaces, or other kinds of development, our team can design and undertake a site investigation that is fit for purpose.

Site Investigations are usually carried out in a phased approach in order to provide a bespoke solution for each site.

  • Phase 1 – Desk Study Assessment and Walkover Survey. The aim of phase 1 is to identify the potential geotechnical and contaminative risks which may impact the site based on the nature of the development. The assessment enables a specific plan of action to be designed for the for the next stage of works.
  • Phase 2 – Site Investigation Work. A targeted intrusive investigation is carried out using the information provided from Phase 1, enabling a cost efficient investigation to be undertaken ensuring potential risks can be highlighted and addressed.
  • Phase 3 – Production of remediation strategy. If Phase 2 works identify a significant risk of contamination, CDS will design a site specific remedial strategy to best deal with the identified contamination in the most cost and time efficient way.
  • Phase 4 – Remedial Works and Validation. Following the remediation strategy being agreed with the Local Authority, CDS can oversee and document the remedial action and provide the validation report required by the planning department, ensuring works are carried out as agreed to remove the risk to the environment and end users of the site.

CDS also offer a wide range of services including:

  • Geotechnical Site Investigations
  • Trial Pitting – A quick and useful way to identify soil conditions on site, assess the risk of contamination and to assess groundwater ingress and trench stability. Trial pitting requires access for a machine onto the site and can lead to significant disturbance of the site due to the scale of the excavation.
  • Windowless Sampling – A cost effective alternative where trial pitting is considered unsuitable. Windowless sampling is carried out using a small rubber tracked rig which drills a borehole approximately 100mm in diameter to depths of upto 5m bgl, and allows for the installation of groundwater and land gas monitoring wells.
  • Dynamic Probing – A rapid tool for a wide variety of geotechnical uses. Dynamic probing can be used to investigate the presence of below ground obstructions, old mine workings, solution features and sinkholes. Dynamic Probing can also be useful to investigate the depth to bedrock on cemetery sites to assess whether burial depths can be achieved.
  • Cable Percussive Boreholes – A tripod drilling rig, towed to site by a 4x4, is used to drill boreholes to depths greater than those reached by windowless sampling. Uses include pile design boreholes, with SPT’s, SPT(c), U100s, as well as drilling borehole soakaways, groundwater abstraction wells and enabling the installation of groundwater and land gas monitoring wells.
  • Rotary Drilling – A specialist rock drilling rig, which can core through rock and sample to enable accurate logging of the rock, or it can quickly drill open holes to target depths using down the hole hammer techniques.
  • Geoenvironmental Site Investigations
  • Contaminated Land Assessments - Assessment of the ground conditions on site using a variety of intrusive drilling and sampling techniques. Accurate and detailed soil logs are produced, and potential contaminated material sampled for laboratory analysis.
  • Land Gas Well Installation and Monitoring - Where a site contains deep made ground, pockets of highly organic natural soil or is in close proximity to a landfill site, the risk to a proposed development from land gases needs to be established. Land gas monitoring boreholes can be installed on site, and land gas monitoring undertaken in accordance with current guidance to assess the levels and impacts of land gases.
  • Groundwater Monitoring Well Installation, Monitoring and Sampling. Groundwater monitoring wells can be installed in boreholes to assess the depth to groundwater, which can impact the development of cemeteries and the construction of foundations and drainage features such as detention basins. The wells are monitored to assess variations in groundwater levels throughout the year and can be remotely monitored using dataloggers which can record levels every minute to provide a detailed assessment of changes. Where required, monitoring wells can also be purged to collect groundwater samples for contamination testing.
  • Drainage Assessments including Soakage Testing. Drainage of new and existing sites is an increasingly important aspect of all developments, with surface water flooding becoming increasingly common due to poorly maintained infrastructure and increasingly heavy rainfall events which overwhelm drainage systems. CDS carry out site specific surveys of drainage systems, and undertake soakage testing and devise new drainage strategies to prevent surface water flooding.