Site Investigations

The United Kingdom has a huge legacy of industrial development spanning more than three centuries. This history of past land usage and re-usage has left behind hidden engineering problems and contaminants. Even sites that have lush vegetation can hid a legacy of industrial usage and the possibility of hazards to human occupants and the environment.

The introduction of key legislation in Part IIA of the Environmental Protection Act (1990) has instigated a regime to identify land potentially affected by contamination. Further legislation has been introduced; (as a requirement of the EU Landfill Directive) with the Landfill (England and Wales) Regulations 2002, reinforcing the requirements to properly investigate land and identify possible contamination.

The investigation of past land usage that may have been contaminative requires the adoption of a sophisticated risk assessment based approach. The risk assessment approach helps to reduce unnecessary waste and disposal to landfill, whilst at the same time ensuring that users of the land and the environment are protected.

Our Environmental engineers and scientists can identify possible contaminative sources and previous uses of the site. They will prepare site investigation and remediation strategies, working closely with our civil and structural engineers to devise a site specific engineering solutions.

A typical brownfield site strategy will include the following phases:

Phase 1: Desktop Study

This will involve a thorough investigation into current and previous land uses. We use available information including historical maps, local government resources and local knowledge to identify potential sources of contamination on the site.

Aspects that may affect the site, including coal mining, brine subsidence and landfill are identified in this report. Existing services, such as gas and electricity that may be affected by site development are also considered, if required.

Phase 2: Contaminated Land Investigation

A Phase 2 investigation determines the nature and extent of contamination present on a site. This is done through intrusive investigation and sampling techniques selected specifically for the identified site conditions.

Soil and water samples are analysed by approved laboratories. The results are then used to assess risk, toxicology and necessary remediation methods. A remediation strategy is devised, based on the proposed land use and receptors. All proposed ground investigations, soil/water testing and remediation proposals must be discussed and agreed with the local authority at each stage.

Phase 3: Remediation and Validation

Throughout the remediation, regular monitoring is conducted to ensure the works comply with the approved remediation strategy.

Imported or recycled material is tested to ensure suitability for its intended use, whether as fill or as part of an engineered remediation design. A validation report includes testing of remediated areas and evidence of disposal of waste to ensure the site is fit for its intended use.

Other environmental services provided by Thomas Consulting include landfill leachate monitoring, gas, water and soil testing and waste disposal advice.