Established 2004

Ruddlesden geotechnical

Ruddlesden geotechnical provides ground investigation, geotechnical consultancy and contamination assessment services.

Based in Exeter, but covering the whole of the UK, albeit primarily concentrated in the South West, Ruddlesden geotechnical was formed in 2004.

Ruddlesden geotechnical works on behalf of a wide client base, including local, regional and national housing developers, housing associations, commercial developers, building contractors, structural and civil engineers, architects, building consultants, quantity surveyors, local authorities and private individuals.

Development projects range from single dwellings and extensions to large housing estates, multi-storey flats, offices, industrial units, roads, slopes, schools, hospitals and basements.

The services and projects listed on this web-site provide an indication of those undertaken by Ruddlesden geotechnical, but others are carried out. If your requirement is not readily identifiable on this web-site, please contact us as we may still be able to help you.

  • AGS
  • Constructionline
  • CSCS
  • SMAS
  • ECFC trust
  • Latest news

    14 May 2026

    MSc Student to Help with BRE 365 Soakaway Project

    At Ruddlesden geotechnical, we often provide work experience to university students over the summer. This pleases both parties, as it provides them with invaluable industrial experience and a bit of pocket money, and helps us cover staff holidays, as well acting as an extended job interview, should a suitable vacancy arise in the future.This summer, we are particularly looking forward to welcoming Bailey, from the University of Portsmouth, who will be doing his MSc dissertation with us. He will be working and extending on an on-going project of ours. He will be reviewing all of our soakaway testing data and correlating this with the published geology, and then asking the question, and potentially providing the answer: does BRE soakaway testing need to be carried out in certain geologies?We have been reliably informed that he is a GIS whizz and are hopeful that he is what the project needs to take it to the next level.

    MSc Student to Help with BRE 365 Soakaway Project
    MSc Student to Help with BRE 365 Soakaway Project
  • Recent projects

    Supervision of Contamination Remediation of Former Petrol Filling Station

    Ruddlesden geotechnical recently supervised the contamination remediation works for residential development of a former petrol filling station site in Exeter. Ruddlesden supervised the excavation of the underground fuel storage tanks, pipelines and interceptors, as well as grossly contaminated soils. Validation testing of the resultant excavations was subsequently undertaken, to demonstrate that no unacceptable levels of contamination remained in the ground. Groundwater quality monitoring in borehole installations was also undertaken before, during and after the remedial works, to assess the risks to controlled waters and a betterment of groundwater quality. Close liaison throughout the works with the local authority and Environment Agency, ensured that the regulators were satisfied with the works and all the relevant planning conditions were discharged.

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  • Recent projects

    Bioaccessibility Testing Negates Remediation

    The chemical laboratory test results obtained as part of a Phase 2 contamination investigation for a proposed residential development in South Devon indicated elevated levels of arsenic to be present in natural soils. A generic qualitative risk assessment (GQRA) showed that all the recorded levels of arsenic exceeded the generic assessment criteria (GAC), indicating that remediation or further assessment was required. Based on the conceptual site model (CSM), as no significantly elevated levels of contamination were expected, but given the underlying geology naturally elevated levels of metals and metalloids may be present, it was considered that further assessment should be undertaken instead of remediation. A detailed quantitative risk assessment (DQRA) was therefore carried out, including additional bioaccessibilitytesting, as the GAC to which the recorded levels of arsenic were initially compared assumes that 100% of the arsenic is bioaccessible, whereas naturally occurring elements are typically not 100% bioaccessible. The bioaccessibility test is a laboratory test that simulates conditions in the gastrointestinal tract to assess the human bioaccessibility of potentially harmful elements by ingestion. As the ingestion pathway is the primary migration pathway for arsenic, the bioaccessibility significantly affects the assessment criteria. The results of the bioaccessibility testing were incorporated into the CLEA, in which the end users were also modified, as the proposed development was for a residential care home rather than a standard residential land use, to produce a site-specific assessment criterion, which was greater than all of the recorded levels of arsenic. It was therefore concluded that the recorded levels of arsenic were not likely to be harmful to end users, given the proposed end use, and that no remediation was necessary. Carrying out this further testing and detailed quantitative risk assessment (DQRA) avoided the need to carry out unnecessary remediation.

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