Soil Environment Services

Soil Surveys, Soil Investigations, Site Investigations and Environmental Land Surveys

Petrochemical sites investigations

Contaminated land risk assessment


Risk assessment work can range from a contamination desk-top survey at a site through to detailed Phase 3 intrusive investigations involving drilling to depth. In all circumstances, the primary goal is to determine all the risks from contamination at a site but with a phased and economical approach. This work is undertaken for private home owners, developers and large organisations.


Our aim is to ensure your site is risk-assessed to the exact requirements of the local planning authority and the Environment Agency as quickly as possible. Our assessments are not off-the-shelf contaminated land surveys that can leave more questions than answers. We engage in dialogue immediately with the regulatory authorities and manage all the land contamination issues needed to gain your planning permission or assess any liabilities.


A typical assessment incorporates and evaluates the findings from a desk top investigation and a site survey. The desk top investigation includes information detailing the history of the site together with any previous reports or correspondence. Following this, a site visit is undertaken to inspect ground conditions, talk with appropriate persons and check on surrounding land uses.


The risk assessment is designed within the source/pathway/receptor framework for contaminated site investigation as outlined in CLR 11, Model Procedures for the Management of Land Contamination and carried out on-site with reference to BS10175, Investigation of Potentially Contaminated Sites – Code of Practice. This framework, in its broadest sense, outlines a dynamic methodology for assessing risk which focuses on a Conceptual Site Model (CSM), the ultimate aim being to pronounce a site suitable for use and if not, the numerical and/or qualitative value of any risk.


A conceptual site model (CSM) is developed with a view to examining the potential risks given the intended operations on, and future use of, the site. The CSM describes the significant parameters, characteristics and processes at the site which have relevance to the likely risk of contamination. An effective CSM requires good quality and relevant information which can then be used within the Contaminated Land Exposure Assessment model (CLEA) and/or for consideration with information from the Total Petroleum Hydrocarbon (TPH) working group recommendations or other approved risk assessment procedures and models such as RISC4.


Reporting will be in a format following the guidance documents recommendations, which in most cases will require separate sections on:


  • sources
  • pathways
  • receptors
  • conceptual site model
  • uncertainties
  • risk evaluation


Chemical spill assessment


If your site has experienced a known or suspected leak or spill, recently or sometime in the past, we can survey the site, take soil and water samples and test these for very specific chemicals or a general screen.


We work closely with you to minimise disruption and ensure you characterise the site such that any potential liabilities are fully understood.  This can also involve working closely with the Environment Agency or Local Authority.


Underground tank leak assessment


Underground tanks can be assessed by undertaking boreholes to depth around the tanks such that samples can be taken for analysis.  We can use ground penetrating radar initially if you are not sure of tank or pipework locations.


Any surface can easily be penetrated and carefully reinstated.


We would typically undertake about four boreholes to depths of about 4 to 5 m around an area.  If groundwater is present we would install borehole monitoring wells should this be needed.


Due diligence assessment for site closure or sale


We undertake this work to the same standard as a contaminated land risk assessment, even though the land may not be contaminated.


The aim is to produce a report which details any liabilities related to potential contamination such that all parties involved in a site transaction can be fully informed of risks.


Please contact us if you require this type of investigation.