Environmental Due Diligence

They are always willing to work to whatever timescales have been laid out for them.

Tammy BrantleyHead of HSE, Certas Energy

Environmental Due Diligence is an essential part of any land transaction as it highlights potential liability costs associated with environmental risks. OHES is able to offer Environmental Due Diligence surveys as part of our EnviroContruct Toolbox product designed to support land acquisition, planning and development or as a standalone service

We frequently carry out specialist Environmental Due Diligence Surveys on sites as part of site acquisition or divestment to provide estimates for potential environmental liabilities associated with land contamination and areas of regulatory non-compliance. The service can include information review and processing (e.g. data room inspection, Phase I Surveys), environmental investigation (Phase II Investigations) and remediation.

OHES also carry out Environmental Due Diligence services during lease transactions; either pre-lease (e.g. Baseline Surveys), lease renewal or on lease completion where we can assist in developing a site exit strategy with our Clients.

Our team has extensive experience of providing Environmental Due Diligence services to the UK Fuel Oil Industry having carried out surveys for both single and multiple site transactions. OHES has strong relationships with many of the major independent UK fuel oil providers having carried out environmental surveys on over 250 fuel oil depots, terminals and petrol filling stations as well as other commercial and industrial sites.

Without doubt, a significant area of strength is our ability to be responsive. We are frequently asked to perform environmental due diligence surveys and submit reports with very tight deadlines usually at the very final stage of a major acquisition. We are trusted advisors to our clients during this often confidential process and we add great value through our ability to resource these projects with high calibre staff who appreciate the urgency of the situation and the commercial significance of the information and opinion we provide.

With decades of collective experience gained from providing advice to the fuel/oil, property and industrial sectors and a pro-active and innovative approach, OHES possesses the dedication, skills and tools to deliver the advice you need to balance and minimise your environmental risks and optimise the value of your project.

Understanding the environmental and associated cost implications of a property investment are fundamental in enabling informed investment decisions and ensuring a successful transaction for purchasers, vendors and funding partners.

Environmental due diligence is required in order to:

  • Limit environmental liabilities and associated costs.
  • Provide a competitive advantage by fully understanding and reducing risk, cost and timescales.
  • Protect corporate brand and reputation.
  • Provide opportunities to enhance value and maximise the return on capital.
  • Provide details to reduce future environmental liabilities.

Our rapid response due diligence services includes:

  • Phase 1 and Phase II environmental assessments.
  • Provision of initial advice and environmental reviews.
  • Peer reviews of third party reports.
  • Data room assessments.
  • Completion of baseline and lease closure assessments.
  • Provision of practical remediation advice, where necessary.
  • Project management and cost control of third party environmental works.

As well as identifying and mitigating environmental risk our parent company is able to insure against environmental liabilities.

Case Studies

Environmental Due Diligence - Fuel Depot Portfolio, Scotland


In late 2009 OHES were instructed to carry out Phase II site investigations on eleven fuel oil storage depots in Scotland as part of pre-acquisition works. These investigations were required to advise our client on potential environmental liabilities associated with the sites.

Completed Works

OHES collated full Phase 1 desk study data and produced full Risk Assessments / Method Statements prior to commencing site works. Drilling works on all sites were rapidly mobilised in response to client instructions. In-depth information on ground conditions, potential contamination issues relating to site processes, surrounding land use and site history were reported to the client. OHES provided clear site specific recommendations for further assessment and remediation where appropriate, giving invaluable expert advice and feasible options prior to acquisition.


All site investigation work and reporting was completed with a 4 week turnaround to ensure that the deal could be progressed with confidence. OHES were able to provide a professional discreet approach at all stages and rapid project completion.

Environmental Due Diligence - Oil Depot, Cranbrook


A Phase II environmental investigation was required prior to leasing a fuel oil storage and distribution depot in Kent, in order to identify any environmental liabilities associated with potential soil and groundwater contamination at the site. The works were planned to establish the potential for the site to be contaminated, to enable a conceptual site model to be developed and provide scope for any required remediation works in addition to providing ongoing pollution prevention recommendations.

Completed Works

OHES carried out a desk top study to include information on environmental setting, site history and other relevant data prior to carrying out the intrusive site investigation. An on-site inspection walkover, drilling of boreholes, soil sampling and analysis and subsequent risk assessment and reporting were carried out. Following the site investigation, two rounds of groundwater monitoring and samplingwere undertaken to obtain information on risks to controlled waters from on-site activities.


OHES provided a comprehensive Environmental Investigation Report summarising the findings of the survey along with recommendations for remediation requirements and the associated costs. Our unrivalled experience of working in thefuel oil sector allowed us to provide practical proposals for remediation and improvement works to help reduce environmental risk at the depot.

Environmental Due Diligence - Petrol Filling Station, Isle Of Man


OHES received instructions to complete Phase II environmental due diligence surveys at two petrol filling stations on the Isle of Man prior to acquisition. Due to urgent requirements, all works had to be carried out within a tight time scale without compromising the quality or detail of the reports.

Completed Works

The work included a comprehensive desk-top review of information relating to environmental setting, site history and depot operations. Intrusive site investigations were carried out at both sites to obtain data on ground conditions including any potential exisiting fuel oil contamination. Further details on the sites' infrastructure and operations were obtained from the Petroleum Licensing Authority and the Isle of Man Government in order to produce a thorough review. OHES liaised closely with site staff representatives to ensure that disruption to site operations was kept to a minimum during the investigation works.


The desk studies and site works were all successfully completed within a tight timescale, with final reports delivered to the satisfaction of the client ahead of the original agreed deadline.