Phase 2 Investigation
If your Phase 1 Preliminary Risk Assessment (desk study) identifies potential contamination, a Phase 2 Site Investigation is required. This intrusive investigation confirms the presence, type, and extent of contamination, and assesses risks to human health and the environment.
We recommend preparing a detailed Scope of Works outlining the investigation approach, contaminants of concern, and sampling methods. For planning condition discharge, it's advisable to obtain approval for both the Phase 1 Environmental Report and the Scope of Works from the local authority before starting the Phase 2 investigation to avoid any subsequent delays or additional costs.
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Typical Phase 2 Investigation components can include:
Before beginning, we help you prepare a Scope of Works for approval - aligning with planning and regulatory expectations from the start.
These methods allow us to assess the type, extent, and location of any contamination, ensuring your development can proceed safely.
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Ground Gas Monitoring or Vapour Monitoring
For methane, carbon dioxide, and hydrogen sulphide and volatiles
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Soil & groundwater sampling
Trial pits and boreholes using hand augers, excavators and rigs
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Laboratory Analysis
Including soil, water, gas and vapour by accredited labs
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Reporting
Refining the conceptual model and risk assessment and recommendations for remediation or further action
How much investigation is needed?
The scope of your Phase 2 contaminated land investigation depends on; site size; suspected contaminants; proposed land use; Phase 1 findings.
We use the Phase 1 report to target areas of concern, reducing unnecessary testing and delays.
Some investigations may take just a day, while others (e.g., ground gas monitoring) may require multiple site visits over several weeks.
We always balance regulatory compliance with cost-effectiveness.


What if contamination is found?
Working with you we will prepare a cost-effective remediation strategy after considering:
- Proposed end use, residential, commercial, allotments.
- Can the contamination be left in place and encapsulated?
- Can site levels or layout be changed to minimize costs?
- Can further testing minimise the area requiring remediation?
- The optimal remedial solution for the contaminants on your site.
This will be followed by a Phase 4 verification report after the site has been remediated.
Get a no obligation Phase 2 quoteWhy Choose Go Contaminated Land Solutions?
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20+ Years in Property
Expertise you can trust. Our managing director has decades of experience in contaminated land issues.
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Targeted, efficient investigations
Site specific and cost effective so we don’t waste time or money on what you don’t need.
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Regulatory Compliance
Our reports are in full compliance with UK planning and environmental regulations
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Top resources
We use MCERTS-accredited labs and high-spec equipment (e.g., GFM436 gas analyser, RAE PID)
Frequently asked questions
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What contaminants are tested in a Phase 2 Site Investigation?
Clearly this depends on the phase 1 findings, however typical contaminants include:
- Petroleum hydrocarbons (from oil, diesel, petrol)
- Heavy metals (lead, arsenic, cadmium)
- Polycyclic aromatic hydrocarbons (PAHs) Byproducts of forest fires, volcanic eruptions, burning of fossil fuels, vehicle emissions, and even cooking methods like grilling and frying.
- Volatile organic compounds (VOCs)
- Asbestos in soil
- Ground gases (methane, carbon dioxide, hydrogen sulphide)
Tests are selected based on the site history and Phase 1 findings. Additional testing maybe be required depending on what the results have found eg, if asbestos is identified quantification will be required.
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Will a Phase 2 Investigation cause delay?
Yes, if not planned properly. Talk to us at the earliest possible stage. We advise agreeing the Scope of Works with the Environmental Health Officer (EHO) before starting the investigation. This ensures the Phase 2 report should meet local authority requirements thereby avoiding unnecessary delays or additional costs.
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Do I always need a Phase 1 before a Phase 2?
Yes, a Phase 1 Preliminary Risk Assessment is required first. It evaluates the current and historical uses of the site and surrounding area, geology and hydrogeology and develops a conceptual model and risk assessment crucial to a cost-effective targeted phase 2 investigation. A Phase 2 is triggered if potential contamination risk to sensitive receptors is identified in the Phase 1.
In a few cases a site investigation may be required without phase 1 if contamination has already been found or any incidences such as oil spill has occurred.
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Who reviews or approves a Phase 2 report?
Approval typically comes from:
- Your local authority (e.g. Environmental Health or Contaminated Land Officer)
- The Environment Agency (for sensitive or permitted sites)
- Warranty providers, lenders, or funding bodies as required
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Is a Phase 3 remediation Strategy always needed after a Phase 2?
No: A Remediation Strategy is only needed if contamination levels exceed acceptable limits for the intended use of the site.
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What information do you need to price a Phase 2 site investigation?
We need a site location plan, existing and proposed site plans as well as the phase 1 desktop study report to prepare a fee.
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Do I need Waste Acceptance Criteria (WAC) testing at Phase 2?
While not an essential part of a phase 2 they will be required for removal of any potentially contaminated spoil. WAC tests determine the appropriate landfill category for wastes, including soils, based on acceptance criteria for inert, stable-non-reactive hazardous, and hazardous landfills. Providing as much information as possible should enable your groundworker to reduce the unknowns allowance and provide more accurate costings.
If contamination is known or the site’s history (e.g., petrol station) suggests likely remediation, conducting WAC tests alongside initial investigation potentially saves time and money.
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Can a Geotechnical report be part of a phase 2 site investigation?
Yes, a geotechnical report can often be done alongside a Phase 2 site investigation dependant on the project scope and specific site conditions.
Since Phase 2 investigations typically involve detailed soil and groundwater sampling, combining geotechnical testing can be efficient. This approach can save time and reduce costs by coordinating fieldwork and lab testing.