Phase 2 Site Investigation

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Call us on: 0800 772 0053
E: info@dbsenvironmental.co.uk
A well designed Phase 2 intrusive site investigation tells you more about the risks posed by a development site or its surroundings, and helps to further define potential in ground risks.

It allows you to identify and quantify risks, to refine your sites Conceptual Site Model established at Phase 1, and to help you meet your legal requirement to work and build safely.

An effective Phase 2 site investigation is often a condition of planning permission, and we work with agencies and local authorities to deliver the data they require about your site to the proper standards.

Contaminated land risks are not always linked to obvious, large-scale industrial processes. Even residential gardens can have contaminants present as a result of the historical practice in the UK of using coal fire ash, or practices such as purchasing foul lime from the local town gas works (a production waste containing cyanide) as soil improver for growing vegetables etc. This is why your LPA will require at least a Phase 1 report, and an initial risk assessment when considering planning applications for a change of land use. These reports do not always necessarily lead to the Phase 2 requirements discussed here.

DBS has designed and managed intrusive investigations for both small and large residential schemes, and large industrial and commercial properties. We have worked to clear filling stations and underground fuel tanks, enabled the re-use of MOD land and other high risk industrial sites, mitigated the effects of landfill and generally made land safe where there is a risk from contaminants, ground gas and other pollutants.

We have also designed and managed site investigations to support Local Authorities strategically with their obligations under Part 2A of the Environmental Protection Act 1990. The general strategy is the same, but rather than addressing potential risks for future development, Part 2A work typically involves identifying existing risks to receptors including human health as a result of historic contamination present in the ground.

A Phase 2 investigation is often designed to obtain both environmental and geotechnical data/information (often referred to as a geoenvironmental investigation) in one phase of works.
  • We work with local planning authorities to determine the information they need, then apply our technical and scientific expertise to providing high standards of data aligned with British Standards, guidelines and legislation.

  • A Phase 2 investigation gives you the knowledge you need to plan – whether that means the reassurance that work can proceed, or to provide the data needed to design a remediation plan to make land safe, and to provide information to allow foundation solutions to be designed.

  • We'll help manage and reduce risk – a key consideration for planning permission
Our investigations are carried out in accordance with BS 10175:2011+A1:2013 "Investigation of Potentially Contaminated Sites – Code of Practice" and BS 5930:1999 "Code of Practice for Site Investigations". Our investigations also conform to BS EN ISO 14668-1, BS EN ISO 14668-2, BS EN ISO 14689-1, 2003 and CLR11 Model Procedures for the Management of Land Contamination guidance.

Phase 2 Site investigation Techniques

We offer a range of services, including
  • Boreholes (cable percussion, rotary, terrier rig);
  • Probe drilling for coal measures (including obtaining Coal Authority permits);
  • Trial pits;
  • Soil logging to BS and Eurocodes standards;
  • Soil sampling and chemical analysis;
  • Groundwater monitoring, sampling and chemistry;
  • Ground gas monitoring;
  • Vapour monitoring;
  • Geotechnical appraisal;
  • Rock logging;
  • Risk assessment;
  • Interpretative reporting with confirmation that development can proceed without further work as all potential source-pathway-receptor linkages for human health, controlled waters and property are fully understood, or
  • Recommendations for further work to plug data gaps, remediation or detailed quantitative risk assessment (DQRA), if required.
We use fully accredited national labs accredited for MCERTS and ISO 17025 for all of our sampling analysis requirements, and all testing on site follows our in house Quality Assurance procedures for the taking and packing of samples, and delivery protocols to the testing laboratory.

The Phase 2 process is completed with a report containing detailed information about soil analysis, water, gas monitoring and geotechnical data. It is an opportunity to update the Conceptual Site Model created in Phase 1 and to further refine potential pollutant linkages. The risk assessment process is progressed with real data, allowing a generic quantitative risk assessment (GQRA) to be completed for your site. It will include an interpretative report related to the specific goals and challenges of your project.

We can also assist with surveys for sites that have the potential for radionuclide impact from operations such as luminising activities from MOD land.

Due the nature of our work, interpretative reports presenting the findings of site investigation and risk assessment can be very technical, we make sure that we liaise with clients in non technical language to get the main findings of our work across to them, and we provide a non technical summary in all of our reports that captures the main findings and what they mean in a language that can be understood.