Land Remediation

Brownfield site development can provide a competitive way to extend your estate – while breathing new life into underutilised land. With the right guidance and governance, decommissioned forecourts can become affordable housing. Disused industrial areas can be repurposed for renewable energy production. Existing sites can be re-designed to make them more efficient. And it goes on… 

Giving brownfield sites a second purpose supports the UK’s drive toward sustainable development – reusing existing infrastructure, conserving resources, and reducing the need for new construction. But is legacy land actually worth the investment? Restoring contaminated sites can be a confusing, costly, and unpredictable process, subject to a raft of complex compliance regulations and introducing abnormals not faced when developing other types of land.

Any possibility of land contamination triggers the need for a multi-tiered process of site characterisation, risk assessment (to human health and the wider environment), remediation and verification. The approach is set out in ‘land contamination risk management’ (LCRM) procedures which replaces CLR11. 

Whether you’re developing, selling, or buying potentially contaminated land, it’s essential that you understand the legal, financial and time implications that such sites can present, but also the opportunities to meet your business goals that they represent. Every site is unique, representing different challenges and opportunities, and a trusted environmental consultant will help you to minimise liabilities and maximise opportunities, by shaping the correct solution for the site and your business and, crucially, help define a commercially sound exit strategy, while ensuring full compliance.

In this article, we explain the legislation surrounding land remediation and its vital importance to businesses and individuals operating on brownfield sites or reclaimed land. 

Land contamination guidance and policy in the UK

In the UK, several pieces of legislation and policy influence how pollution issues are addressed. They provide a legal and policy framework for identifying and assessing contaminated land, determining liability for remediation, and ensuring sites are restored to a suitable standard. Key pieces include:

• Part 2A of the Environmental Protection Act 1990 holds local authorities legally accountable for identifying and remediating contaminated land that presents a significant risk to human health or the environment. The statutory guidance also requires anyone responsible for causing or knowingly permitting contamination to pay for remediation efforts.
• The Environment Act 2021 sets statutory targets across the priority areas of air quality, biodiversity, water, and waste. It also features a new target to reverse the decline in species abundance by the end of 2030. The Act also contains several principles including the polluter pays principle, the precautionary principle, the principle that environmental damage should be averted by preventative action, and the principle that environmental damage should as a priority be rectified at source. 
• The Water Environment Regulations 2017 outline rules for preventing water pollution and preserving water quality. They require that any contaminated land that could compromise surface or groundwater is adequately assessed and remediated – and that operators take all necessary steps to control pollutants.
• The Environmental Damage (Prevention and Remediation) (England) Regulations 2015 (and equivalents for other UK jurisdictions) set out a duty to report damage or “imminent threat”, to take all practicable steps to prevent the damage and further damage, and to suitably remediate damage. The regulations include concepts of primary, complementary and compensatory remediation.
• The Environmental Permitting Regulations control activities that could impact the environment or human health, such as treating, storing, or disposing of hazardous substances. They also require businesses that carry out potentially environmentally harmful activities to operate responsibly, hold an appropriate permit, and remediate land in the event of a pollution incident.
• Building Regulations ensure reasonable precautions are taken before construction to assess and prevent potential contamination to prevent harm to the structure’s occupants and users.
• The National Planning Policy Framework (paragraphs 174, 183, and 184) prevents developments from being adversely affected by unacceptable levels of soil, air, water, or noise pollution. Where possible, it requires developers to improve local environmental conditions and remediate contaminated land.

When does land contamination need to be considered?

The need for assessment and remediation of contamination is driven by five main scenarios:

1. Pollution Incident – There is a legal requirement to assess the extent of contamination and potential impact on human health, water sources, and the surrounding environment and remediate to suitable standards.
2. Land Development – Legal requirement to assess and potentially remediate land contamination as part of the planning process. This can either be limited to a desk study (where little or no contamination is likely) or potentially involving remediation to mitigate risks identified.
3. Property or Business Transaction – Under UK environmental law, property owners can be held liable for pollution that existed before acquisition so there is a requirement to understand what liabilities exist and if these will be transferred post-acquisition.
4. Environmental Permitting – Legal requirement for ongoing monitoring and to confirm that the site is left in a suitable condition (typically baseline levels) at permit surrender.
5. Operational Risk Management – Voluntary investigation of contamination levels to avoid regulatory intervention, understand and manage risks and boost environmental credentials.

Moreover, proper consideration of any environmental liabilities associated with these scenarios should consider how they might change in the future.

Working with an experienced and competent environmental advisor, the aim is to guide you through the process to minimise financial, reputational and environmental damage.

How should contaminated land be identified and dealt with?

Land contamination is dealt with through a process set out in LCRM and this aims to:

• Identify and assess if the land poses an unacceptable risk to human health, water supplies, soil, property, and ecosystems (including wildlife, animals, and wetlands).
• Determine suitable remediation options to manage the risk.
• Plan and carry out remediation.
• Ensure that remediation is effective.

There are three main stages within this process:

1. Site characterisation and risk assessment
2. Remediation options appraisal
3. Remediation and verification

Each step reduces uncertainty and reveals new information, helping to define the level of risk and the necessary measures to mitigate or eliminate it. Remediation isn’t always required, so it’s important to understand the limits of your obligations with every step.

An experienced environmental partner will guide you through this process, identifying a suitable exit strategy to satisfy all relevant parties, then creating a cost-effective action plan and map of the most effective possible route through it. 

Stage 1 – Site Characterisation and Risk Assessment 

The first stage identifies the potential sources, pathways, and receptors of contamination at a particular site, initially through a desk based assessment and preliminary risk assessment, and if required, through intrusive site investigation (drilling boreholes, trial pits, soil and water sampling, etc). It then uses quantitative data to establish whether an unacceptable level of risk is present and to establish suitable site specific target levels (SSTLs), which set the standards the remediation programme should achieve.

Depending on the circumstances the target could be derived specifically for the site e.g. SSTL, or be based on a known benchmark e.g. pre-incident condition.  Increasingly – and particularly in operational or environmental permit scenarios – the pre-incident condition is taken to be the target level, which raises issues of suitable due diligence, e.g. when purchasing a site or starting a new operation.

Stage 2 – Remediation options appraisal

Reaching this stage means there is a requirement to remediate the site. The primary aim of options appraisal is to choose a compliant remediation plan that aligns contamination levels with a specific target, reduces environmental impact, and minimises costs.

There are three main steps that need to be followed: 

1. Identify feasible remediation options – Establish a shortlist of viable remediation options for evaluation. They must all be able to meet the remediation objectives and criteria set for the site.
2. Evaluate options – Pinpoint which option best tackles contaminants as they move from source to receptor. What are the pros, cons, and limitations of each solution? Consider technical suitability, practicality, cost, timescale and health & safety implications.
3. Select your final remediation option – Your final strategy could be a single option, multiple options, or a combined approach.

Ideally, your options appraisal should consider sustainability – specifically, the social, economic, and environmental impacts of your proposed clean-up process. The industry-led Sustainable Remediation Forum UK (SuRF-UK) has produced a framework for assessing the sustainability of soil and groundwater remediation.

Stage 3 – Remediation and verification

This stage involves delivering the chosen remediation option and verifying that it has been a success. There are four steps to follow: 

1. Develop a remediation strategy – A detailed specification of your chosen remediation option, confirmation of remediation target levels, and methods to measure success. It’s required before any remediation work can commence and should reflect the needs of all parties, including the site operator and environmental regulator.
2. Remediate – The process of reducing land contamination to acceptable risk levels. A remediation trial is often carried out to test selected methods in site-specific conditions.
3. Produce a verification report – The report delivers evidence that the remediation objectives have been achieved and the site-specific target levels (SSTLs) for contaminants have been met. Once approved by the appropriate authorities, the site may be signed off for its intended use. 
4. Conduct long-term monitoring and maintenance, if required – This step ensures remediation methods work over a prolonged period. It may involve routine sampling and analysis, ongoing water quality monitoring, or maintenance of remediation tools and technologies.

FOCUS: What should you look for in a remediation strategy?

• Clear, realistic and safely achievable objectives and targets
• Clear responsibilities and communication routes
• Technical specifications and sound science
• Transparent reporting and key milestones
• Verification plan and a contingency plan
• Clear programme of activities and an exit condition

Remediation techniques

The need for remediation is driven by the environmental risks that are associated with different source-pathway-receptor pollutant linkages. However, it is often not possible to manage the linkage by removing the receptor, for example a river is going to remain where it is. Therefore, successful remediation usually relies on removing the sources of contamination or breaking the pathways.

The choice of technique must be appropriate for the site conditions, constraints and the type of contamination present but, overall, the simplest solution is often the best. It should also be noted that the lowest cost solution is not always (or usually) the most effective solution, although cost-effectiveness does increase with scale.

Remediation techniques boil down to just a few principles, involving physical, chemical, biological and thermal factors. Common approaches are summarised in the table opposite, but it should be noted it is often beneficial to combine approaches to enhance effectiveness, for example adding heat to an air sparging process, planning monitored natural attenuation to reduce a soil excavation, or adding a filter of activated carbon to help ‘polish’ treated water.

There are a few simple watchouts to keep in mind when planning remediation activity:

• First remove gross contamination, for example a layer of oil floating on groundwater, otherwise your work area will re-pollute.
• Some approaches may require an environmental permit, for example, water discharges.
• Wastes including soil, liquids, vapours/gases or other materials, must be suitably contained and managed.
• Keep accurate records of all activities, including for waste materials, imported materials, monitoring work and observations.
• It is easy to fall into over complication and loss of pragmatism, the strategy must be simple, robust, and flexible to adapt to changing circumstances.
• More contact increases effectiveness, due simply to an increased surface area.

Partnering through to limit liabilities and maximise opportunities

Land contamination represents both complex challenges and abnormals as well as presenting opportunities. Navigating this with an experienced environmental consultant reduces risk, protects business interests, and ensures an intelligent, informed approach to developing, buying, or selling brownfield spaces. 

With expert guidance, it’s possible to balance the environmental, regulatory, and commercial requirements of contaminated sites – and turn brownfield land into lucrative opportunities. A suitable environmental partner will help you achieve your business objectives, whatever the scenario (development, acquisition, operations, permitting or incidents).