Contaminated Land: Engage Geo-Environmental Consultants

Developing contaminated land: engage experts to satisfy planning conditions

Contaminated land refers to areas of soil, sediment or groundwater that have been polluted by substances considered harmful due to industrial activities, natural sources, or other human interventions. These contaminants may be chemical, biological, or radioactive and can pose a risk of significant harm to human health and the environment if not managed effectively.

The UK’s regulations surrounding contaminated land and environmental damage must be complied with to enable sustainable development. This is especially relevant as the National Planning Policy Framework (NPPF) encourages the redevelopment of brownfield sites. Geo-environmental consultants are experts in advising on polluted land issues and creating a contaminated land strategy to make a site safe for re use.

Statutory definition of contaminated land

The Environmental Protection Act 1990 defines contaminated land as land where significant harm is being caused or where there is a significant possibility of such harm being caused to human health, protected species or controlled waters.

The legal definition is contained in Section 78A of the Act as land where substances in, on or under the land are causing or have the significant possibility of causing significant harm to human health or protected species or significant pollution of controlled waters.

The British Geological Survey provided guidance to the Department for Environment, Food & Rural Affairs between 2011-2012 on what normal levels of contaminant concentrations are in English soils. The information supports the Act’s revised part iia Contaminated Land Statutory Guidance.

Who is responsible for contaminated land?

Ensuring that development on contaminated land is safe is the legal duty of the developer, landowner or both. According to the Planning Portal: “Where a site is affected by contamination or land stability issues, responsibility for securing a safe development rests with the developer and/or landowner” (Paragraph 197, NPPF).

This highlights the importance of understanding, assessing, and remediating contamination risks before commencing any development project. Voluntary remediation at an early stage can prevent issues down the line with most sites.

The legal framework for contaminated land

In England and Wales, the management of contaminated land is governed by part iia of the Environmental Protection Act 1990. Under this legislation, local authorities are required to:

• Identify land which may be contaminated and inspect potentially contaminated land sites.
• Determine whether a site may pose a significant risk to human or environmental health.
• Ensure appropriate remediation measures are taken.

Land is classified into four categories based on risk levels:

• Category 1: High risk requiring immediate action.
• Category 2: Evidence of potential risk requiring remediation.
• Category 3: Low or uncertain risk; regulatory action may not be required.
• Category 4: No risk or acceptable levels of risk.

Land contamination can arise from previous land uses including:

• Industrial activities: Historical industrial operations such as factories, mines, and landfills often leave behind substances like heavy metals, radioactive substances, oils, and organic compounds.
• Natural sources: Underlying rock formations can sometimes release contaminants into soil such as radon gas or heavy metals.
• Agricultural practices: Pesticides, fertilisers, and waste disposal can introduce pollutants into the land or cause pollution of controlled waters.
• Brownfield land: Previously developed areas might harbour residual contaminants from prior use.

Why is land contamination a concern?

New development on a contaminated site can create significant risk to human health and future occupants by exposing the contamination. The development work may disturb radioactive contaminated land or create pollutant linkage – new pathways for the contamination – and introduce new receptors that can be adversely affected by contamination such as a person, protected species, surface water or controlled waters.

The risks posed by contaminated land depend on three key elements:

1. Source: The presence of contaminants at harmful concentrations.
2. Pathway: A means for the contaminants to reach humans or the environment, such as via ingestion, inhalation, or skin contact.
3. Receptor: The individuals, ecosystems, or environments exposed to the contaminants.

If one of these elements is missing, the risk is significantly reduced. For example, heavily contaminated land that is inaccessible to the public poses minimal threat.

Risk assessment on contaminated land

A contaminated land find may not indicate an unacceptable risk. Exploration of historic uses of the site will clarify the significance of risk to the proposed development. A land contamination assessment will provide the facts needed to decide the way ahead.

While this report is important, it rarely completely stalls a development. A public register may hold information on contaminated land sites in the relevant area.

Human health and environmental health could be harmed by a failure to follow statutory guidance and deal correctly with a contamination issue on affected land. For example, when managing protected species, significant pollution with be a major factor in any local planning authority decision making process.

Contaminated land and the planning process

The NPPF emphasises sustainable development and encourages the remediation of contaminated land to make it free from the possibility of such harm that may result from contamination and safe to develop.

Where contamination is suspected on a development site, from radioactive substances to pollutant linkage, the risks must be understood and mitigated before the planning authority will grant consent.

Developers are required to provide sufficient information for such sites: a land contamination assessment will prove that any contamination has been thoroughly investigated, that the proposed scheme will not present unacceptable risks and that any remediation is workable.

The Land Contamination Risk Assessment

Assessing contamination risks involves several stages as determined by a series of guidelines, namely the Environment Agency Land Contamination Risk Management rules, part 2a of the Environmental Protection Act 1990 and building regulations.

1. Desk study: A review of historical records, maps, and previous land uses to identify potential contamination sources.
2. Site investigation: An inspection strategy detailing signs of potential contamination or land instability on or around the proposed development site.
3. Soil and groundwater testing: Sampling and laboratory analysis to determine the presence and concentration of contaminants. Assistive technology may be used to help assess land affected by significant pollution.
4. Risk analysis: Evaluating the likelihood and potential impact of contaminants on receptors.

If risks are identified, a remediation plan must be developed and submitted to the local planning authority. This plan outlines the measures required to make the land affected by contamination safe for its intended use and for future occupants.

The role of geo-environmental expertise in contaminated land assessment

A competent geo-environmental consultant plays a crucial role in assessing and managing contaminated land. These specialists bring technical expertise to evaluate the geotechnical and environmental conditions of a site. Their responsibilities often include:

• Site investigations: Identifying the original source of contamination, pathways, and receptors via an inspection strategy.
• Assessing risk: Calculating risk levels by analysing data from contaminants.
• Remediation: Devising a contaminated land strategy using workable solutions to deal with contamination. This might involve treating or removing soil, or containment techniques, often using assistive technology.
• Regulatory compliance and legal implications: All assessments and remediation work must comply with statutory guidance, legal requirements and the enforcing authority’s planning conditions.
• Site monitoring and validation: Remediation techniques must be checked and verified to ensure that the site meets the required safety criteria and is suitable for use.

How to manage land contamination

By working closely with developers and the enforcing authority, geo-environmental consultants help ensure that contaminated land is safely redeveloped, reducing potential risks to health, the environment and future occupants of the site.

Engaging a competent person, as defined by the NPPF, to devise an inspection strategy detailing all the necessary information offers several benefits, including:

• Reducing the chance of objections to your scheme.
• Minimising delays by helping the planning authority to process your application efficiently.
• Enabling the planning authority to tailor its land contamination conditions: this should reduce requirements that are not necessary and the need for an environmental permit.
• Reducing the risk of delays caused by environmental searches revealing issues during a land sale, or a remediation notice being served.
• Protecting the health of future site occupants from contamination risks.
• Minimising the risk of future liabilities or legal implications related to land contamination.

Addressing land contamination through remediation

Remediation aims to reduce or eliminate risks associated with contaminated land. Remediation techniques frequently used include:

• Soil excavation and removal: Contaminated soil is removed and replaced.
• Treatment of soil: Contaminants are neutralised or removed through physical, chemical, or biological methods.
• Capping: A barrier, such as a layer of new soil or concrete, is placed over contaminated areas to prevent exposure and future land contamination.
• Groundwater treatment: Contaminated water is treated on-site or extracted for off-site treatment.

Why develop potentially contaminated land?

The National Planning Policy Framework (NPPF) focuses centrally on promoting sustainable development. To achieve this, it directs planning policies and decisions to prioritize building houses and other projects on suitable brownfield land. Ultimately, the NPPF dictates that the planning system must deliver viable, sustainable development.

The redevelopment of brownfield sites aligns with the UK’s commitment to reducing urban sprawl and preserving special sites and greenfield land. The Environment Agency prioritises the safe redevelopment of potentially polluted sites and wants to ensure that remediation is carried out correctly to leave the land in such a condition that it is safe for re use.

Future contamination prevention

With proper assessment and remediation, land affected by contamination can be transformed into safe, useable areas. While contaminated land can present challenges, it also offers opportunities for regeneration and sustainable development if a robust strategy is in place.

By understanding the sources, risks, and remediation options, developers, landowners, and local authorities can work together on a phased approach to remove the threat of pollution incidents and ensure safe and sustainable land use. The involvement of geo-environmental surveyors provides expertise to help negotiate regulations, ensuring that guidance in part iia of the Environmental Protection Act 1990 is complied with, as well guidelines from the Department for Environment, Food & Rural Affairs, the Environment Agency and Natural England.

With careful planning and collaboration, even the most challenging sites containing heavy metals can be made suitable for use again and successfully redeveloped, contributing to a cleaner and more sustainable future.

If you would like further guidance or a quote from a geo-environmental consultant, contact Arbtech’s expert team by filling in the quick quote form above.