Allotments: duty to prepare a food growing strategy - guidance for local authorities

Annex C - Contaminated Land

When identifying land for food growing, it should be borne in mind that most land has been exposed to centuries of human activity, along with the proximity to industrial processes and traffic exhaust pollutants from busy roads, these activities will all impact on soil quality. This may result in the presence of a variety of contaminants in the soil such as heavy metals, polyaromatic hydrocarbons, asbestos and persistent organic pollutants. Food growers are subject to a much higher level of exposure to potential contamination in the soil than other site users, predominantly through contact with soil, ingestion and inhalation of soil/dust and ingestion of produce. In deciding whether the soil is suitable (or can be made suitable) for food-growing it is therefore necessary to undertake an environmental risk assessment.

If it does not form part of the site assessment process, an environmental risk assessment for food-growing should identify likely chemical, biological and physical hazards and evaluate how they might impact on the health of people who will be using the proposed site and upon the surrounding environment.

In determining the feasibility of designing a site for food-growing it will be necessary to gather information about the land to get an idea of the work that might be required to make it suitable for food-growing. The local authority's environmental health team or contaminated land officer (CLO) should be contacted at the earliest opportunity when a potential site is identified for food-growing; they will be able to offer guidance and may be able to provide additional support.

CLOs have collated a significant amount of land quality information as part of their duties under Part IIA of the Environmental Protection Act 1990 to identify potentially contaminated land within the local authority area. An environmental information request (EIR) can be sent to the local authority for any relevant environmental information held about a site (this may incur a small charge).

As part of the environmental risk assessment, it is likely that ground investigations involving soil sampling and laboratory chemical analysis will be required. Soil contaminant concentration limits will be dependent on the nature of food growing activity proposed. To ensure a proportionate response to findings it is essential that the investigation and environmental risk assessment be carried out by a competent expert.

Allow enough time and considerations for health and safety regulations when investigating a site. It is typical to investigate a site in a phased approach and depending on the findings, it may be more investigations are required to inform the site design and remediation approach.

The CLO will be able to provide advice throughout the environmental risk assessment process. There are numerous standards, codes of practice and guidance documents available; the CLO will be able to direct you to the appropriate publications.

Contaminants might be identified but the concentrations may not present an unacceptable risk ( i.e. below soil assessment criteria) and food-growing can proceed without any other actions.

In the event that the ground is found to be contaminated at unacceptable concentrations, steps will need to be taken to make the site safe for food-growing. There will be a variety of possible intervention solutions from contamination removal to raised beds. The site may not be suitable for the type of food-growing that is proposed and an alternative approach might be to change the type of food-growing activities or have zoned areas e.g. wild areas where food-growing is not appropriate. It will also be important to consider management of other possible issues such as non-native invasive plants, protected habitats and waste soil. Liaison with the CLO is strongly advised to ensure that the proposed remedial measures are acceptable to the regulatory authorities.

Best practice in food-growing and site management should be followed so as not to inadvertently contaminate food-growing soil.

The CLO has a regulatory role under Part IIA of the Environmental Protection Act 1990 ("Part 2A") to inspect their areas periodically to identify contaminated land and enforce remedial actions where there is unacceptable risk of harm to human health or the wider environment, or risk of pollution to the water environment. If food-growing activities commence without consideration of these risks and elevated contaminant concentrations are confirmed above tolerable limits it is likely that
food-growing activities would need to cease until all necessary works are carried out.

CLOs do not wish to prevent food-growing activity from taking place and will provide as much assistance as they can. They will provide guidance throughout the assessment process and may be able to advise on proportionate sustainable remediation solutions that will make the site safe for food-growing.

Landowners should undertake an environmental risk assessment before making
land available to communities for food-growing. Local authorities should allocate funding for sites they wish to make available for food-growing so this work can be carried out.

The Grow-Your-Own-Working-Group's Guide for growing on land which may be contaminated^[78] and Scottish Allotments and Gardens Society's Allotment Site Design Guide^[79] both contain useful guidance on the potential problems with contaminated land and how to deal with it.