All you need to know about contaminated land and planning permission
If you are planning to develop land or change its use, a contaminated land assessment may be required by the local planning authority. This requirement can seem daunting but understanding what it involves and why it’s necessary, will help you navigate the process smoothly.
You may also want a contaminated land assessment if you are contemplating buying land. Due diligence and site specific information is essential to evaluate possible risks and rewards. If a site is contaminated, remediation costs can be significant and impact a scheme’s viability: thorough site reconnaissance will identify unacceptable risks.
In this article, we’ll explain why a contaminated land risk assessment is important, how to arrange one, and the methods a geo-environmental consultant uses to complete the assessment. By the end, you’ll have a clear picture of how to handle this critical part of the planning process.
Why is a Contaminated Land Assessment required?
Developing brownfield land with a history of industrial use is a planning priority; such land must be considered before any greenfield sites. The brownfield first approach makes it harder to avoid areas with contamination and as people are more likely to take legal action over pollution issues, developers need to understand their responsibilities and follow the law.
A contaminated land assessment is often a crucial part of the planning process, ensuring that land is safe for its intended use. Local planning authorities require this assessment to comply with Environment Agency obligations. Here are some key reasons why a contaminated land investigation may be necessary:
- Identifying potential risks: Contaminated land can pose risks to human health, water supplies, and the wider environment. A land contamination assessment helps identify and manage these risks.
- Changing land use: If the land is being repurposed—for example, from industrial to residential use—it’s essential to confirm that it’s safe for the new use. It may also be relevant to make a risk assessment of the neighbouring land, for instance, there may be a sensitive site nearby such as a school.
- Historical land use: Sites with a history of industrial, agricultural, or waste disposal activities may have potentially hazardous residual contamination. The local planning authority will require a contaminated land assessment to identify potentially harmful substances.
- Legal obligations: Under UK planning regulations and the National Planning Policy Framework, LPAs are obligated to ensure that land is suitable for its intended use and does not pose a risk to people or the environment.
- Reducing future liabilities: Identifying and addressing risk from contaminated land early in the process can help prevent future legal or financial liabilities for developers or property owners.
- Signs of contaminated land: These may be evident from a site’s previous uses, for example at petrol stations, mines, factories or landfills where indicators include leaks, spills or underground tanks. Potentially hazardous contaminants may include ground gases, metals, oils, solvents, asbestos, radioactive substances and Japanese knotweed.
What is contaminated land?
Contaminated land is any area where harmful substances in, on, or under the ground could cause serious harm to people, property, the environment, or water sources in the surrounding area. This definition comes from part 2a of the Environmental Protection Act 1990. The National Planning Policy Framework also highlights the importance of ensuring that new developments don’t increase pollution or risks.
Who is responsible for managing contaminated land?
The “polluter pays” principle in the Environmental Protection Act 1990 states that the person or organisation responsible for the contamination must cover the clean-up costs. If they can’t be identified, the responsibility falls to the landowner or developer.
Local authorities oversee the clean-up process of contaminated sites. If the responsible parties fail to act or do not carry out the work correctly, the local authority can step in to remediate the land and recover the costs later.
How to obtain a Contaminated Land Assessment
Obtaining a contaminated land assessment involves a straightforward but detailed technical approach. These are the necessary steps:
- Engage a geo-environmental consultant: A qualified and experienced geo-environmental consultant will guide you through the process and ensure compliance with all relevant standards and regulations.
- Provide site information: Share all relevant information about the site, including its location, historical use, and proposed development plans. This information helps the consultant tailor the assessment to your needs.
- Determine the scope: Based on the site details, the consultant will determine the extent of the assessment. This usually involves a tiered approach, as explained below.
- Plan the Assessment: Once the scope is agreed upon, the consultant will plan the contaminated land assessment. This may include desktop research, site visits, sampling, and laboratory analysis.
- Receive the report: After completing site investigations, the consultant will provide a detailed risk management report. This report will highlight any contamination risks and outline recommendations to address them.
- Submit to the local planning authority: Submit the completed report to the planning authority as part of your planning application. The local planning authority will review the site specific information and may impose planning conditions based on the report’s recommendations.
The Contaminated Land Assessment process
Geo-environmental consultants follow a structured approach to carry out a contaminated land assessment. This typically involves three key phases:
Phase 1: Preliminary Risk Assessment (desk study)
- The first step is to gather and review existing information about the current site conditions. This phase helps identify potential sources of contamination and assess the initial risk level. Key activities include:
- Historical research: Reviewing historical maps, planning records and past uses of the site to identify any potentially contaminating activities.
- Environmental data review: Examining environmental data, such as geological records, hydrology, and proximity to sensitive receptors (e.g., watercourses or residential areas).
- Site walkover: Conducting a visual inspection of the site to assess ground conditions, land quality, and identify potential signs of contamination, such as stained soil, chemical drums, unusual vegetation patterns or contaminant linkages.
At the end of Phase 1, the consultant will prepare a preliminary risk assessment report outlining any potential contamination risks. If significant levels of contamination are identified, further site investigations may be recommended.
Phase 2: Intrusive site investigation
If the preliminary risk assessment identifies potential issues, a more refined risk assessment is carried out. This phase involves:
- Soil sampling: Collecting soil samples from various locations and depths on the site to test for contaminants such as heavy metals, hydrocarbons, or asbestos.
- Groundwater sampling: Where applicable, testing groundwater for pollutants to assess risks to water supplies.
- Laboratory analysis: Sending samples to accredited laboratories for analysis to determine the type and concentration of contaminants.
- Monitoring: Installing equipment to monitor gas emissions or surface water quality over time, if necessary.
The results of the Phase 2 contaminated land investigation will help identify whether contamination levels exceed safe thresholds and what remediation measures may be required.
Phase 3: Remediation and validation
If contamination is confirmed, the next step is to address it. The consultant will prepare a remediation strategy, which may include:
- Excavation and removal: Removing contaminated soil or materials from the site.
- Treatment: Using physical, chemical, or biological methods to neutralise or contain contaminants.
- Containment: Installing barriers or protective layers to prevent contaminants from spreading.
Once remediation is complete, a validation report is prepared to confirm that the site is safe for its intended use. This report is submitted to the LPA for approval.
Benefits of a Contaminated Land Assessment
A contaminated land assessment offers several advantages for developers and property owners, as it:
- Ensures compliance: Helps meet planning and environmental regulations, reducing the risk of planning delays.
- Protects health and safety: Ensures that the site is safe for future users and the surrounding community.
- Reduces liabilities: Identifies and mitigates risks early, preventing costly issues in the future.
- Supports planning approval: Provides the LPA with the information needed to approve a planning application.
- Increases property value: Demonstrates due diligence, making the property more attractive to buyers or investors.
Choosing the right consultant
Selecting the right geo-environmental consultancy that offers a range of contaminated land services is essential to ensure a thorough and reliable contaminated land risk assessment. Look for a consultant with:
- Relevant qualifications: Ensure they are experienced in contaminated land assessments and accredited by professional bodies such as the Society of Brownfield Risk Assessment (SoBRA) or similar organisations.
- Local knowledge: A consultant familiar with local geology, environmental conditions, and local planning requirements will provide a more accurate and efficient service.
- Strong communication skills: Choose a consultant who explains the process clearly and keeps you informed at every stage.
To summarise:
A contaminated land assessment may seem like an additional hurdle in the planning process, but it’s a vital step to ensure safety, compliance, and long-term value for your project. By engaging a qualified geo-environmental consultant and following the outlined process, you can identify any unacceptable risk and keep your development on track.
If you’re preparing a planning application or have been asked to provide a contaminated land assessment, act early to avoid delays. With the right approach and expert guidance, you can turn this requirement into a valuable part of your project’s success.