1. Developing an environmental monitoring programme
Source: gov.uk (2025-04-03)

How to define the objectives for your programme and think about what is proportionate and sustainable, along with health, safety, welfare and quality considerations.

Use objective-based environmental monitoring

The objectives of an environmental monitoring programme should be clearly defined. Monitoring of different exposure pathways should be clearly linked to at least one objective.

The following objectives are presented for use in underpinning an environmental monitoring programme.

Objective A - Assess total representative person dose

Note: A representative person is defined as an individual receiving a dose that is representative of the more highly exposed individuals in the population. This term is equivalent to and replaces the previous concept of the ‘average member of the representative person’ (ICRP, 2006) (https://www.icrp.org/publication.asp?id=ICRP%20Publication%20101a).

This objective can be used to demonstrate that radioactive waste disposals into the environment from permitted operations are not exceeding the public dose limit or dose constraints. It can also be used to support demonstration that best available techniques (BAT) are being used to minimise radiological impacts to the public and to the environment.

Note: Managing Radioactive Substances and Nuclear Decommissioning: UK policy framework (https://assets.publishing.service.gov.uk/media/6632371769098ded31fca7c1/managing-radioactive-substances-and-nuclear-decommissioning-uk-policy-framework.pdf) provides a summary of international guidelines, regulations and obligations and also the UK’s approach to managing radioactive substances.

This objective is required for a monitoring programme at a site where the dose to the representative person is assessed to be >0.01 millisievert per year (mSv/y) for discharges at permit limits from all permitted release routes. The assessment is known as a prospective dose assessment. There is guidance available for the assessment of public doses (https://www.gov.uk/government/publications/assessment-of-prospective-public-doses-from-authorised-discharges).

Once adequate monitoring data become available, these may be used to assess dose by a retrospective assessment. Results from this assessment, alongside information about the site’s current and future discharges, can be used to decide if this objective is still needed.

If needed, the objective should be assigned to monitoring of exposure pathways which contribute doses >0.001mSv/y to the total dose.

Note – an exposure pathway is the route in the environment through which people or wildlife may become exposed to radioactivity or radiation. For example, inhalation of radionuclides in air, drinking of water containing radionuclides, external radiation from walking over sediments containing radionuclides.

Objective B - Assess total impact on wildlife and ecosystems

This objective addresses the site’s impact from disposals to the environment on wildlife and ecosystems. It can also be used to support demonstration that BAT are being used to minimise radiological impacts on wildlife.

The objective should be used for a monitoring programme at a site where the dose to wildlife, from a prospective assessment, is assessed to be >10 microgray per hour (µGy/h) (annual average) for discharges at permit limits from all permitted release routes.

Once adequate monitoring data become available, these may be used to assess the dose by a retrospective assessment. Results from this assessment, alongside information about the site’s current and future discharges, can be used to decide if this objective is still needed.

If needed, the objective should be assigned to monitoring of exposure pathways which contribute doses >1µGy/h (annual average) to the total dose.

Objective C - Provide assurance

This objective is to provide information that can be used to assure regulators that the impacts of discharges are as expected. Once assured the regulators can provide assurance to interested parties, including members of the public.

The need to provide assurance to interested parties will be dependent upon ongoing and emerging concerns. The use of this objective for the monitoring of different exposure pathways should be proportionate to the scale of the concerns and the potential impact.

During decommissioning this objective will remain important to provide information on the outcome of decommissioning tasks and impacts of unmanned sites, but it may best be achieved through process monitoring, triggering targeted environmental monitoring.

Objective D - Check or complementary monitoring

This objective allows comparison of results between monitoring programmes to achieve consistency of results. The purpose is to identify any sampling, monitoring or analytical problems and allow investigations to take place.

This objective should be used by all sites which have a routine environmental radiological monitoring programme.

Normally, the operator’s programme is seen as the main programme and elements of the regulator’s independent environmental radiological monitoring programme provide a check on this. However, for foodstuffs in England and Wales, the Food Standards Agency’s (FSA) monitoring programme may be considered to be the main programme and elements of the operator’s provide a check on the FSA programme.

The elements of the programme assigned as check monitoring should also be designed for the same objective as the main programme to ensure the results can be compared.

Overall, comparisons should be taking place such that 1 to 10% of the main programme is being compared between programmes, taking account the number of locations and frequency of monitoring in the main programme.

Objective E - Assess background (very far field)

The objective is to provide information on background conditions against which to assess the impact of site operations.

This objective is generally satisfied by regulatory national monitoring programmes.

The objective should be assigned to monitoring locations which are beyond the range of the detectable impact of sources.

Objective F - Assess long-term trends (indicator)

Note – an indicator is the term used in relation to a sample type that is rapidly responsive to changing activity concentrations.

This objective provides information on changes to the environment over time.

If modelled or measured activity concentrations are close to background or the limit of detection, monitoring for this objective would be unlikely to be warranted.

The need for this objective will depend upon the observed or potential rate of change of environmental concentrations, for example due to variable discharge profile (such as batch processes), half-life of radionuclide and dynamic environmental processes.

The objective should be assigned to monitoring parts of the environment which accumulate or integrate radionuclides (such as seaweed, soil and sediment).

For decommissioning activities, consideration should be given to assessing changes to background in the near field, to understand impacts of the work.

Samples should be taken from the same locations using the same sampling techniques for a meaningful temporal comparison of the results to be made.

Objective G - Comply with international obligations

This objective is to gather information to comply with international requirements (for example OSPAR (https://www.ospar.org/work-areas/rsc)).

This objective should be assigned to monitoring programmes or elements of programmes which are required to comply with international agreements.

Objective H - Detect abnormal, fugitive, and non-permitted releases (indicator)

This objective is to provide an early indication of an abnormal release and to detect any unaccounted-for releases. These could be from fugitive emissions or from a process with an unexpected consequence.

The objective should be used where there is the potential for abnormal or fugitive releases.

This objective should be assigned to elements of the monitoring programme which are sensitive to change and have a rapid response so that they can provide a means of early detection of such an abnormal release.

Instrumentation to detect abnormal releases, on stacks for instance, may provide better early warning information and preclude the need for this objective, but such justifications should be recorded and subject to routine review.

Objective I - Understand or monitor behaviour of radionuclides in the environment

This is a wide-ranging objective looking at spatial distribution and temporal variations. This could be for model verification by comparing monitoring and modelled data.

This objective is likely to be applicable to sites with the largest environmental impact to ensure that the main source – pathway – receptor routes have been identified and the scientific basis of the programme remains acceptable and any constraints on the data are understood.

The objective should only be assigned to elements of the monitoring programme where there are detectable activity concentrations (that is results are greater than the limit of detection).

Sample types and locations will need to be selected to provide information on spatial distribution, extent of dispersion, re-concentration, and changes in environmental behaviour of radionuclides. They will also need to be compatible with models to allow model verification.

Design proportionate, optimised and complementary environmental monitoring programmes

The design and management of environmental monitoring programmes should be proportionate to the cost and to past, current, and future impacts of discharges on the public and the environment.

Programmes should be optimised to achieve the maximum number of objectives from a minimum number of samples, ensuring that sufficient monitoring data of an acceptable quality are collected for all the objectives to be achieved.

Programmes should be complementary, and the regulators should ensure that their programmes and those of the operator address all the appropriate monitoring objectives whilst avoiding unnecessary duplication.

Other considerations in determining the proportionality of the programme will be the type of environment (including how dynamic it is), the likely behaviour of radionuclides in that environment (including half-life) and current state of knowledge. For decommissioning work where contamination may be mobilised or released, and the views of interested parties may change on the need for surveillance and monitoring, the balance of what is proportionate should be reviewed.

It will be more appropriate to have a larger environmental monitoring programme where the dose from discharges to air and water are predicted to exceed 0.01 mSv/y from a prospective assessment (using discharge limits) to ensure that a realistic retrospective dose assessment can be performed.

Irrespective of dose, monitoring may still be required to satisfy objectives related to assessing background and long-term trends, complying with international obligations, detecting abnormal, fugitive, and non-permitted releases, understanding behaviour of radionuclides in the environment or be useful for check monitoring (objectives D, E, F, G, H, and I). Programmes covering decommissioning sites should also consider providing assurance (objective C).

Ensure sustainability for environmental monitoring programmes

Consideration should be given to environmental, social, and economic factors when developing an environmental monitoring programme. Examples of environmental, social and economic factors relevant to environmental monitoring programmes are outlined on this page. The benefits of the programme should exceed any impacts.

Note: The United Nations Sustainable Development Goals (SDGs) (https://www.un.org/sustainabledevelopment/sustainable-development-goals/) provide an overarching framework to consider these factors.

Environmental factors

In planning programmes environmental considerations should be at the core, including legal requirements (such as protection of habitat sites), being carbon conscious (target for carbon net-zero) and optimising the use of resources, both for responsible organisation’s actions and those of the supply chain.

Organisations should have an appropriate environmental management system, for example ISO 14001 (https://www.iso.org/standard/60857.html): Environmental management systems – requirements with guidance for use, and identify the environmental effects of their monitoring programmes and implement measures to minimise these environmental effects.

Sample sizes should be optimised to minimise the amount of material removed from the environment, particularly for wildlife.

Impact on wildlife and habitats

The sampling of living wildlife and habitats should be minimised as far as possible ensuring that any samples taken meet multiple objectives. Where samples are being taken as part of an independent monitoring programme by a regulatory body (for example the Food Standards Agency), the operator should not duplicate this sampling and should agree the sharing of data from the regulatory body. It is recognised this means the check or complementary monitoring objective could not be directly applied to samples of living wildlife.

Where sites have an objective which requires the monitoring of wildlife, if dead animals are found in the vicinity of the site the opportunity to monitor or analyse them should be considered, if potential health, safety and biosecurity risks (for example avian flu) can be mitigated.

Resource usage

Impacts from the use of resources should be minimised and things to consider are:
- use low or zero emission vehicles and well-planned monitoring trips to minimise transport emissions
- use products and materials that are socially and environmentally responsible throughout their life cycle
- minimise, with the aim of eliminating, the use of single use items (taking account of laboratory good practices and minimising cross contamination)
- use sustainable materials for sample containers where practicable
- use products and materials which contain re-manufactured, re-used and, or re-cycled content
- eliminate waste products and materials or where this is not possible use items that can be sustainably dealt with using the waste hierarchy
- keep analytical methods under review
- substitute for environmentally damaging reagents when alternatives available
- use sample preparation and radiochemical separation techniques which minimise energy and chemical use
- consider whether a different analytical technique could result in a more sustainable overall method, for example comparing ICP-MS with alpha spectrometry
Biosecurity

Procedures should be followed, and actions taken where necessary to address biosecurity to protect wildlife and farm animals from the spread of diseases (such as foot and mouth disease, fungal infections, avian flu).

Regular checks should be made to keep informed of new threats and check for appropriate mitigation measures and, for example, disinfectants to be used.

Invasive and non-native species

Be familiar with invasive and non-native species and take steps to minimise their spread.

Examples of invasive species of concern are Signal Crayfish, Japanese Knotweed, Hogweed, Giant Hogweed, Himalayan Balsam and Floating Pennywort.

Also, over fifty different freshwater species have already been found in UK lakes, rivers and other waterways, and the numbers of new arrivals is increasing rapidly. Information is available at the Non-native Species Secretariat’s (http://www.nonnativespecies.org/home/index.cfm) website.

Use ‘Check, Clean, Dry’ to prevent spread:
- check your equipment, boat, and clothing after leaving the water for mud, aquatic animals, or plant material, remove anything you find and leave it at the site
- clean everything thoroughly as soon as you can, using hot water if possible, paying attention to areas that are damp or hard to access
- dry everything for as long as you can before using elsewhere as some invasive plants and animals can survive for over two weeks in damp conditions.
Sites of Special Scientific interest and National Site Network sites

These sites are protected under law and any activities undertaken within them must comply with these protections.

Social factors

Concerns and expectations of interested parties should be actively considered in a transparent decision-making process to ensure the programme satisfies them, as far as reasonably practicable. The regulator would expect to see evidence that interested parties were involved in the decision making, with legitimate concerns addressed.

Access to, or across, private land for sampling and monitoring must only be undertaken by responsible parties with the landowner’s permission.

Economic factors

The impact on the local economy of the environmental monitoring programme should be considered where appropriate.

Balance benefits against health, safety, and welfare risks

The benefits of the programme should be balanced against health, safety and welfare requirements and elements with a potentially elevated risk only included if the risk can be reduced to an acceptable level.

Anyone conducting a monitoring programme needs to comply with the health, safety and welfare arrangements of their organisation and personnel should be competent and trained in relevant health, safety, and welfare issues.

In particular, risk assessments (generic and, or site specific) should be documented and in place and a dynamic risk assessment (at point of work) procedure employed.

Control measures should be used to eliminate or reduce the risk to an acceptable level before starting work. Control measures can be engineered, procedural, or personal protective equipment.

Accidents or near misses should be reported, as defined in organisations’ safety procedures, to allow lessons to be learnt and aid in the development of procedures and guidance to avoid future accidents.

Hazards to consider in risk assessments

Risk assessments will need to consider all the hazards likely to be encountered including, but not limited to:
- encountering hostile situations
- tides
- quicksand
- rock falls
- unexploded ordnance
- wildlife (such as snakes, bees)
- livestock
- electric fences
- slopes
- working near water
- contamination
- ionising radiation
- biological hazards
- weather (such as cold, sunstroke)
- uneven ground
- work at heights
- lone working
- driving
- railways or roads
- ground penetration and contact with electrical cables
- manual handling
- sampling equipment (such as cutting devices)
Handling contaminated items

Procedures should be defined for the appropriate action to be taken, if a discreet active item (such as a stone, plastic fragment, particle) or a localised area of contamination are identified. These will also need to address health and safety requirements and the responsibility for custody and detailed analytical requirements.

Welfare

Careful consideration should be given to the welfare of staff, particularly those carrying out monitoring in the environment. Long working days should be avoided and access to toilets, washing facilities planned.

Where possible, information on phone signal availability and the locations of local hospitals or medical facilities with accident and emergency services, in the areas visited, should be collated, and made available to staff undertaking the work.

Ensure appropriate quality standards are met

Programmes should satisfy or be compatible with international requirements or guidance where available.

Programmes should be undertaken to defined quality standards, for example ISO 9001 (https://www.iso.org/standard/62085.html): Quality management systems – requirements, ISO 14001 (https://www.iso.org/standard/60857.html): Environmental management systems – requirements with guidance for use and ISO 17025 (https://www.iso.org/standard/66912.html): General requirements for the competence of testing and calibration laboratories.

Organisations undertaking routine environmental radiological monitoring should work within a documented management system, such as ISO 9001 (https://www.iso.org/standard/62085.html), using suitable experienced and qualified personnel. Documented procedures should be available to cover all aspects of the work.

Performance criteria for the monitoring programme (uncertainty criteria, limit of detection, analysis turnaround) should be designed to allow the objectives to be met, whilst ensuring proportionality. Different objectives will have different performance criteria. For example, detecting abnormal releases, a relatively quick analytical turnaround will be important, but a higher detection limit may be acceptable.

Note: Detection limit is defined in ISO 11929 (https://www.iso.org/standard/69579.html): ‘Determination of the characteristic limits (decision threshold detection limit and limits of coverage interval) for measurements of ionizing radiation – Fundamentals and application – Part 1: Elementary applications – as the “smallest true value of the measurand that is detectable, with a given probability of error, by the measuring method”.

Sampling

An audit trail of all samples should be maintained from the point of collection to final analysis, this can be achieved using a robust chain of custody.

Samples should be transported to and stored in the laboratory in a secure manner under storage conditions that minimise or eliminate loss or change of the principal constituents under investigation.

Samples should be retained to enable future analysis. Minimum retention periods should be agreed with the regulator.

Sample preparation

Sample preparation should ensure that a homogeneous sub-sample is taken for analysis.

For example, drying and hand mixing of soils or sediments prior to sub-sampling should be acceptable for gamma spectroscopy where a relatively large sub-sample is used (such as 500g). However, drying, grinding, and sieving prior to sub-sampling should be carried out where a small sub-sample (such as 5g) is to be taken for radiochemical analysis.

Analysis

Methods should meet the requirements of any relevant international standards, British Standards, Monitoring Certification Scheme (MCERTS), for example Radioanalytical testing for environmental and waste waters (https://www.gov.uk/government/publications/mcerts-radioanalytical-testing-of-environmental-and-waste-waters), where in scope, or other nationally recognised standards.

The analytical methods should be adequately validated and controlled such that they are or could be accredited by the United Kingdom Accreditation Scheme (UKAS) (or equivalent) under BS EN ISO/IEC 17025:2017 General requirements for the competence of testing and calibration laboratories (ISO 17025 (https://www.iso.org/standard/66912.html)).

Particular attention should be paid to the requirements on method validation, instrument calibration and performance testing.

Analytical laboratories should participate in national or international (such as NPL or IAEA) inter-laboratory comparison exercises (for example annually) to assist in quality assurance. Where possible, inter-comparisons should be chosen which relate not only to relevant radionuclides, but also relevant sample types.

Suitably qualified and experienced personnel

The experience, training and technical competence of personnel assigned to do the monitoring will directly affect the quality of the data being obtained. Hence only suitably qualified and experienced people (SQEP) should carry out the monitoring, sampling, analysis and data assessment and reporting.

Continued competence should be assessed by internal audit and formal SQEP reviews where appropriate.

The degree of experience and qualifications required will be matched to the complexity of the analysis being undertaken and level of uncertainty that is acceptable on a result, which will be influenced by whether the site is assessed as lower or higher impact site.

Role profiles defining the required level of education and experience should be produced. The required training and qualifications should be determined to be in accordance with the procedures to be undertaken.

Training

Training should take the form of studying and understanding the techniques and procedures, with on-the-job training to gain experience.

The training should be documented with evidence of competence required before a person’s competence is signed off. This may include independently collecting integrity-assured and traceable samples or conducting a field measurement with the results falling within acceptable quality control limits.

Re-training or refresher training should be required if work has not been undertaken for a period greater than 12 months. Where the sampling period is greater than 12 months (for example for annual samples) a previously trained and competent person may follow a written procedure to take those samples.

Training should be documented, and training records kept and maintained.

Measurement uncertainty

The measurement methods should be reviewed to identify all potential sources of uncertainty.

The significant sources of uncertainty should be quantified, and the uncertainty components combined at the 95th percentile level of confidence.

The measurement uncertainty should be reported with the measurement result.

The generally accepted approach to evaluating and expressing uncertainties in measurements undertaken by testing and calibration laboratories is given in the ISO/IEC Guide 98-3:2008: Guide to the Expression of Uncertainty in Measurement (https://www.iso.org/standard/50461.html). As this is a complex document, NPL has produced a guidance note Estimating uncertainties in testing (https://eprintspublications.npl.co.uk/2022/) presenting principles and guidance for this.