Guidance

Contaminated land and groundwater: generic developed principles

Published 1 December 2021

Applies to England

The release of radioactive material can lead to contaminated land and groundwater, which can also act as a pathway to the spread of radioactivity into the wider environment. In this document we describe how operators should act to minimise the contamination of land and groundwater and how they should clean this up, where present – contaminated land developed principals (CLDPs).

There are two sets of principles for radioactively contaminated land and groundwater. One set are general principles that apply to most sites. The other set apply only to sites that we are regulating under Part 2A of the Environmental Protection Act 1990, as modified by the Environment Act 1995, and other legislation. These regulations for radioactive contaminated land do not apply on nuclear licensed sites.

The principles related to our role in regulating radioactive wastes produced during the characterisation and remediation of radioactively contaminated land on all sites are in the document Radioactive substances management: generic developed principles.

General principles

These are the general principles that apply to most sites.

CLDP1 – prevention of contamination

The best available techniques should be used to prevent and where that is not practicable minimise radioactive contamination of land and groundwater, whilst allowing permitted disposals of radioactive wastes.

Considerations

Facilities should be designed, operated and decommissioned so that there is no radioactive contamination of land or groundwater under normal conditions.

Facilities should also be designed, operated and decommissioned using the best available techniques to minimise the probability of contamination occurring, and the extent of contamination, under fault conditions.

Operators should locate and stop, or if that is not practicable minimise, leaks of radioactive substances to land or groundwater as soon as possible, and take measures to prevent recurrences. On-going leaks that cannot be stopped should be monitored or otherwise assessed.

Operators should take measures to prevent the spread of contamination and monitor their effectiveness.

We should establish whether the source of radioactive contamination, or the dispersion of radioactive contamination, constitutes an unauthorised discharge under the Regulations and act accordingly.

Permitted disposals are those that are permitted under the regulations or do not require permitting (for example, because they are exempt from permitting requirements).

CLDP2 – strategy for radioactively contaminated land and groundwater

Each site should have a strategy for the detection and management of radioactively contaminated land and groundwater.

Considerations

This principle applies to all nuclear-licensed sites and all other sites where it is known or suspected that there is radioactively contaminated land or groundwater (or both).

The strategy should include the detection, characterisation, short-term control and monitoring of radioactively contaminated land and groundwater, as well as their long-term management. It should cover the site and land and groundwater adjacent to it.

The contaminated land strategy should be integrated with other relevant site strategies (for example, those for decommissioning and for waste management on nuclear-licensed sites).

Stakeholder views should be taken into account in developing, updating and refining the contaminated land strategy.

The strategy should include non-radioactive contamination of land and groundwater, if there is any such contamination present on the site.

Strategy development should be informed by an environmental assessment and optimisation process in which alternatives are systematically evaluated and compared in terms of their impacts on people and the environment, their financial costs and other factors.

The end-state for the site (or the end-states for each area within the site) should be described in the strategy, with any interim states that are envisaged. The end-states should have been derived taking into account stakeholder views.

The strategy should specify that radioactively contaminated land will be remediated to appropriate standards before any new facilities are constructed on or close to it.

It should be shown how plans for the long-term management of each contaminated area will be developed and implemented.

The strategy should set out the record-keeping arrangements to be used throughout the process of managing contaminated land.

CLDP3 – approach to management of radioactively contaminated land and groundwater

The approach to the management of radioactively contaminated land and groundwater should have regard to the guidance developed for the SAFEGROUNDS learning network.

Considerations

Operators should have regard to the SAFEGROUNDS guidance when carrying out:

• site characterisation
• prioritisation of contaminated areas
• identification and evaluation of management options for areas
• implementation and validation of management options
• record-keeping

There should be appropriate stakeholder involvement throughout the process of managing the radioactively contaminated land and groundwater.

There should be appropriate monitoring throughout the implementation of management options and at the end to validate that the end-state has been achieved. Thereafter there should be no need for monitoring unless the end-state is an interim one and further remediation is envisaged to be needed at a later date.

Principles for regulating under Part 2A

The principles in this section stem from the Statutory Guidance on Part 2A, to which reference should be made for further details. It should be noted that groundwater is included in the Part 2A regime as a pathway for radionuclides to move through the environment but not as an environmental receptor in its own right (we cannot regulate radioactively contaminated groundwater in itself under Part 2A).

CLDP4 – justification and optimisation of interventions under Part 2A

All interventions that are part of the remediation of radioactive contaminated land should be justified and optimised.

Considerations

Remediation in this context should be taken to include all the activities involved in assessing the condition of the contaminated land, as well as operations and actions to prevent, minimise, remedy or mitigate the harm caused by contamination. It also includes subsequent inspections to keep the condition of the land under review.

Justification in this context means that the reduction in radiation detriment and any other benefits of the intervention should outweigh its financial costs, societal costs and any other adverse impacts – that the intervention should do more good than harm.

Optimisation in this context means ensuring that the form, scale and duration of the intervention maximises the net benefit – that the intervention option chosen is the one that will do the most good. Only justified intervention options should be assessed and compared in optimisation exercises.

The factors that should be considered in justification determinations and in comparing intervention options include: the human radiation exposures and health detriments averted, financial costs, social benefits (for example, reduction in anxiety), social costs (for example, the disruption caused by limiting access to property), adverse effects on the environment (for example, heavy traffic, radioactive and non-radioactive risks to air, water, soil, plants and animals), radiation exposures of remediation workers, and the generation, transport and disposal of wastes.

A range of stakeholders should be consulted during justification and optimisation, particularly to understand and take into account their views on the relative importance of the benefits, costs and other attributes of intervention options.

Assessments of radiation doses and health risks to people should be carried out to provide input to justification and optimisation.

The assessments should be for the land in its current use, including any temporary use, and any foreseeable future use that would not require new or amended planning permission.

All reasonable remediation options should be considered, including, where appropriate, the option of doing nothing beyond further site characterisation.

Doses and risks to individuals and populations should be assessed. The individuals to be considered are those who would incur the highest doses and those who would be at most risk. The time period used in collective dose calculations should be at most 500 years.

The level of detail in assessments should be commensurate with the level of risks to people and the conditions at the site, in particular the number and nature of exposure pathways.

Assessments should be based on sound scientific data.

Assessments should include an analysis of how uncertainties in key parameters and assumptions affect their results. This need not be fully quantitative nor entail complex calculations.

At any site where both radioactive and non-radioactive contamination are present one integrated remediation strategy to deal with all contaminated land should be developed and implemented.

Only justified interventions for radioactive contaminated land should be considered when developing site-wide remediation strategies.

The effects of the interventions for radioactive contaminated land on the significant pollution linkages for non-radioactively contaminated land should be assessed and taken into account in strategy development.

The factors to be included when comparing alternative strategies are as given above for justification and optimisation, with the addition of health detriments to the public and workers from non-radioactive contaminants.

A range of stakeholders should be consulted during comparisons of alternative strategies, particularly to understand and take into account their views on the relative importance of the benefits, costs and other attributes of remediation options.

Radioactive contaminated land should be characterised in enough detail to provide the information required to select and implement remediation options and strategies.

Site characterisation should provide the information needed to determine whether intervention is justified, identify the optimum intervention option and plan and implement the selected option.

The information required includes concentrations of key radionuclides in soil and groundwater and the physical and chemical forms of these radionuclides.

Characterisation should focus on the significant pollution linkages.

CLDP5 – remediation objectives under Part 2A

Remediation objectives should be set for each specific site and should be based on the remediation option or strategy selected for that site.

Considerations

The minimum requirement is that remediation should make land suitable for its current use – that it should no longer be ‘radioactive contaminated land’ in the Part 2A sense, subject to justification considerations.

In cases where it is decided that the best course of action is to redevelop the site, the minimum requirement is that the land in its new use should not give rise to doses above the constraint for practices (0.3 mSv/yr).

There should be consistency between remediation objectives for similar types of site in similar situations.

There should be monitoring on and around sites during remediation but not subsequently (unless there is a possibility that further remediation will be required).

Monitoring should be carried out during remediation to ensure compliance with procedures and regulations and to detect any unexpected radioactivity levels.

Monitoring should not usually be carried out after remediation. The exception is when potential changes in pollutants, pathways or receptors that are part of significant pollution linkages have been identified that would, if they occurred, make the land ‘radioactive contaminated land’ again and hence necessitate further remediation.

Remediation plans should be reviewed in the light of new information and modified if necessary.

Remediation plans should be reviewed in the light of monitoring results to determine whether they continue to be appropriate or whether they need to be modified. Several reviews of plans may be required during the course of remediation.

Plans should also be reviewed if significant new scientific or technical information becomes available during their implementation.

Modifications to remediation plans should be approved prior to implementation.

Surveys should be carried out to verify that remedial measures have been implemented as planned.

The main aim of verification surveys should be to determine whether the objectives of remediation have been met, including whether all remedial measures have been implemented appropriately.

The surveys should also assess compliance with other regulations and procedures.

Plans for verification surveys should be made prior to the start of remediation and modified if necessary as remediation proceeds.

Where appropriate, verification surveys should be done by an organisation that is independent of those which planned and carried out remediation.

Records should be kept of all the information gathered and decisions made during the selection, implementation and verification of remediation options and strategies.

Owners of sites should arrange for detailed records to be kept and passed on to new owners when sites are sold.

Records should be in a form that will enable information to be accessed easily in the future and that will last as long as necessary.