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HESI provides a full range of Environmental Services to do with contaminated land, from a Phased Risk Assessments right the way through to 'muck away' Classification.


For a quick overview download our Contaminated Land Guide.

Below is a quick overview of how a Phased Risk Assessment would proceed Prior to any works being undertaken on a development site, consultation will be made with the developer such that any specific requirements of the Local Council or relevant authorities can be assessed and answered within any early correspondence. Additionally, the protocols for the site investigation will be agreed with the Local Council for the site investigation procedure. On completion of this, the site investigation will be undertaken as follows :-


(Approximate Time Scale = 2-4 weeks to complete)

A Phase One Land Assessment involves research into the history of the site and surrounding area such that the potential contamination can be identified from historical and ongoing source. A walk over survey of the site is also undertaken to assess the condition of the site. Additional information relating to the geological condition of the site will be made for the purpose of designing the site investigation for foundation requirements. At the instruction of the developer to undertake the site investigation, a brief overview assessment will be made of the desk top study data by ourselves taking into account the proposed development, geology and site conditions such that site work time can be booked to minimise delays. Therefore, on completion of desktop study, the physical investigation can be undertaken quickly. The exact locations of the physical investigation will be given within the data recovered from the desktop study.


(Approximate Time Scales = 3 weeks to complete)

The Phase Two Land Assessment is undertaken through the information gained from the Phase One report where the design of the site investigation will be undertaken. This will involve the development of the proposed locations to investigate, depth of subsoil to be investigated, sampling procedures and requirement for standpipes to assess groundwater or land gas. On completion of this and taking into account the information recovered from the desktop study, a range of samples will be sent to the analytical chemist for analysis. The results of this testing will then be further assessed to determine the site specific remedial target values of the particular contaminants based on the proposed development and a remedial plan designed.


(Approximate Time Scales = 1 week to complete)

The Remedial Strategy combines all the data previously recovered relating to the site and formats the data in an easy to understand document for approval by the Local Authority. This will discuss and detail the most appropriate method of remediating the development site including the timescale's to undertake the works and health and safety procedures required in order to complete the works.


(Approximate Time Scales = Ongoing)

When the site investigation procedure has been completed and a remedial strategy has been designed and can be undertaken on the site, validation sampling may form part of the remedial process in order to limit the areas of contamination. Herts & Essex Site Investigations will provide ongoing care and consultation for the developer, such that we are on hand to deal with correspondence from relevant authorities, visit the site for further sampling or consultation, and provide a duty of care to the developer throughout the remedial process. Additionally, the validation of the site may incorporate the monitoring of land gas or water levels within the site and as such, further site visits may be required.

HESI strive to ensure a good working relationship with both the developer and the site operatives working within the development site. As such, once a report has been completed, we arrange a site meeting between ourselves and the site agent/operatives such that we can go through the site investigation report and ensure the workforce are fully aware of the impact of the contamination within the site and exactly what remedial measures are required. With this completed, the development of the site can progress with a limited potential for unforeseen problems to arise.

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