Contaminated land in London: navigating planning requirements

What you need to know about contaminated land in London

Contaminated land can result from historic industrial activities, waste disposal, or other land uses that have left harmful substances in the soil or water. Managing contaminated land to protect public health, the environment, and London’s long-term growth is a key policy for the Greater London Authority (GLA).

With such a densely populated city as London, ensuring the safe transformation of contaminated land into useful and sustainable spaces is vital. Here’s an overview of London’s contaminated land strategy.

Contaminated land plays a strategic role in redevelopment

The GLA oversees Greater London, which includes 32 boroughs and the City of London. Its policies on contaminated land align with broader city-wide goals for sustainable development and regeneration. Under the National Planning Policy Framework (NPPF), contaminated land is a material consideration in the planning process, meaning that it must be addressed when land is redeveloped. The GLA ensures that local borough councils implement robust policies to identify, assess, and remediate land formally determined as contaminated. Details of contaminated land across the capital are held in a contaminated land register.

Key principles of the GLA’s contaminated land strategy

Protecting public health and the environment

Land must be safe for its intended use, whether it’s residential, commercial, or recreational. Contaminated land can pose risks to human health, such as through exposure to toxic chemicals, and harm ecosystems if left unaddressed. Legal notice must be given regarding contaminated land, and policies focus on reducing these risks to create a safer London across its many local authorities.

Encouraging sustainable land use

London has limited space for development, so brownfield land (previously developed land) is a key focus for new use such as housing and infrastructure projects. The GLA’s strategy is to see a scaled increase in the development of contaminated land sites to optimise land for new property construction and protect valuable green spaces. By transforming brownfield sites into usable areas, the city can address human health and environmental risks from contamination and support its growing population.

Prioritising accountability for contaminated land

This policy aligns with Part 2a the Environmental Protection Act 1990, which places the responsibility for remediation on those who caused the contamination (the “polluter pays” principle) or, if they cannot be identified, the current landowners. This contaminated land strategy ensures that those accountable bear the cost of clean-up, minimising the financial burden on taxpayers.

Integrating contaminated land management into planning

Local authorities must ensure that any planning applications for potentially contaminated land sites include the relevant environmental information and remediation plans. Developers are required to submit environmental reports for large sites and small, that assess risks and outline measures to make the site safe for its proposed new use. Planning applications made to local authorities must include appropriate measures to prevent the activation or spread of contamination to ensure that redevelopment is both responsible and safe.

A guide to managing contaminated land in the planning process

Planning and Risk Assessment

Before granting permission for development on potentially contaminated land or brownfield sites, local authorities must ensure risks are assessed and managed via an environmental search. A contaminated land risk assessment will demonstrate that:

• The site has been properly investigated.
• The proposed development is safe.
• If land contamination is identified, clean-up plans are practical and achievable.

Steps in Land Contamination Risk Management

The correct steps to take are outlined in the Environment Agency’s Land contamination risk management (LCRM) – GOV.UK) guidelines:

1. Desk study: a geo-environmental consultant reviews historical maps and records to reveal details of potential contamination.
2. Site walkover: an environmental search will be carried out on-site to look for visible contamination signs. Adjacent properties will also be investigated as part of the contaminated land enquiries.
3. Testing: soil and water samples are analysed for harmful substances.
4. Risk analysis: possible impacts on people, wildlife, and the environment are assessed.

If environmental reports reveal details of risks from contaminated land, a remediation plan is created and submitted to the relevant local authorities.

The role of a geo-environmental consultant

A qualified consultant handles:

• Site investigations: identifying contamination sources and risks.
• Risk assessments: evaluating the seriousness of the contamination.
• Remediation plans: suggesting methods such as soil treatment or containment.
• Legal compliance: ensuring all environmental reports meet regulations.
• Monitoring: overseeing the clean-up and confirming the site is safe.
• Engaging a qualified geo-environmental consultant will enable a planning application to be submitted, speed up the planning process and reduce the chance of objections to a scheme.

Legal Framework

Part 2a of the Environmental Protection Act 1990 defines contaminated land as any area where harmful substances in, on, or under the ground could impact human health, the environment or water sources. Local authorities must:

• Inspect potentially contaminated land sites.
• Assess health and environmental risks.
• Enforce clean-up actions if needed.

Risk categories for contaminated land are:

• Category 1: High risk, immediate action required.
• Category 2: Moderate risk, clean-up needed.
• Category 3: Low or uncertain risk, may not require action.
• Category 4: No significant risk, no action required.

Clean-up options for land determined as contaminated

• Excavation and removal: replace contaminated soil with clean soil.
• Soil treatment: use physical, chemical, or biological methods to neutralise contaminants.
• Capping: cover the area with clean soil or concrete to prevent exposure.
• Groundwater treatment: clean contaminated water either on-site or off-site.

By following these steps, risks from contaminated land can be managed effectively in the planning process, enabling safe and sustainable development.

Why managing contaminated land is vital to London

As well as being a regulatory condition as noted in Part 2a of the Environmental Protection Act, managing contaminated land is a way to create opportunities. Cleaning up polluted land can lead to successful planning applications for housing, parks, schools, and businesses, contributing to London’s vibrant urban fabric. It also helps to reduce environmental inequalities, as some of the most contaminated sites are often located in disadvantaged areas.

By turning challenges into opportunities through the planning process, contaminated land can be developed into spaces that benefit everyone. If you would like further information please contact Arbtech’s specialist consultants via the contact details at the top of this page.