Last reviewed 26 June 2014

One of the requirements set out in the Industrial Emissions Directive is for those sites that have the capacity to pollute or contaminate soil and groundwater to have a “baseline report”. This report details the pollution status of the site before operations commence, and can be used for comparison when activities at the site eventually cease. In her article, Dr Lisa Bushby summarises the stages of preparing a baseline report.


Directive 2010/75/EU on industrial emissions (IED) applies an integrated environmental approach to the regulation of certain industrial activities (Part A activities). Where the activity involves the use, production or release of relevant hazardous substances, and having regard to the possibility of soil and groundwater contamination at the site of the installation, under Article 22(2), operators are required to submit a baseline report.

Its purpose is to clearly outline a series of actions that are fully reproducible at site cessation and set out the current results so that a quantified comparison can later be made.

Stage 1: Identify hazardous substances

Stage 1 involves creating a list of the hazardous substances that are used, produced or released within the installation boundary either as raw materials, products, intermediates, by-products, emissions or waste. The chemical constituents of products and the relative proportion of the largest constituent chemicals of mixtures or compounds should be included.

Stage 2: Identify relevant substances

Stage 2 involves deciding whether these substances are relevant. This means that each substance should be considered and those that are incapable of contaminating soil or groundwater discarded. This decision must be justified and recorded.

To determine relevancy, consider each substance’s chemical and physical properties (eg from its safety data sheet or from the classification and labelling inventory), such as its:

  • composition

  • physical state (solid, liquid, gas, nanoform)

  • solubility

  • toxicity

  • mobility

  • persistence.

Where a group of substances display similar characteristics they may be considered together provided justification for the grouping is noted.

Stage 3: Create a risk profile

Stage 3 creates a risk profile for each relevant substance to determine whether circumstances exist which may result in the release of the substance in sufficient quantities to represent a real pollution risk, either as a result of a single emission event or as a result of accumulation from multiple emissions.

Specific issues to be considered include:

  • quantities of substance in relation to its environmental effects

  • the location of the substance on site, eg where it is delivered, stored, used, moved, emitted

  • control measures in place to minimise the risk of soil or groundwater contamination, eg bunds, handling procedures.

A physical inspection of the site should be undertaken to verify the integrity and efficiency of the measures to prevent releases occurring. This should involve looking for signs of chemical attack on surfaces in the vicinity of potential emission points.

To create the risk profile, the circumstances (such as accidents/incidents, drips during delivery, planned emissions) under which an emission to soil or groundwater may occur and the likelihood of such emissions should be described along with a list of which substances may be emitted to the environment.

Stage 4: Detail the site history

Available data and information sources should be accessed to detail the site history.

List the former uses of the site from green field to development of the proposed installation and identify whether these uses are likely to have involved any of the relevant hazardous substances identified in stage 2. If so, where were they likely to have been handled, what is the likelihood of emissions to soil/groundwater having occurred and what remediation, if any, has been undertaken?

For installations that are operational at the time of producing a baseline report, consider:

  • location, nature and extent of accidents, incidents or direct discharges made historically (permitted or otherwise) that might have caused a release of relevant hazardous substances to soil or groundwater

  • what changes or improvements have been made to the process, chemicals handled, storage locations, disposal methods, etc and why

  • do maintenance records show good current and historic integrity of drains, tanks, bunds, pipelines, etc

  • details of site investigations undertaken previously and remedial works carried out

  • physical inspection data gathered during stage 3 to provide emission information, eg the presence of staining, evidence of corrosion, presence of new surfacing.

Stage 5: Examine the environmental setting

Stage 5 determines where hazardous substances may go if released and where they should be looked for.

Where available, site-specific data should be used. In its absence, reference data, qualitative/subjective assessments and inferred or extrapolated data should be used. In each case, the source of the data should be identified; where this is not site-specific, justification for the use of the selected data and margins of error should be recorded.

Consider the site’s:

  • topology and the type of ground surface (concrete, open ground, etc) in the vicinity of each emission point (the surface type and gradient can be shown on a site plan that also identifies the location of bunded compounds, pits, etc)

  • geology: describe the soil and rock strata beneath the site; identify whether groundwaters are present or are likely to be present in each of the strata, and, where known, indicate the hydraulic gradient (a simple summary of the data, rather than a full geotechnical description, is sufficient for the report)

  • direction of groundwater flow (indicate how each water body might be affected by emissions from the site)

  • other potential migration pathways, such as drains and service channels which may act as migration routes for hazardous substances

  • environmental aspects, eg particular habitats, species, protected areas

  • surrounding land use, especially those up gradient which may handle the same or similar substances and may cause pollution to migrate onto the site.

In terms of pollution migration onto the site at the time of surrender of the permit it is for the operator to demonstrate that they have not caused pollution while operating. It is therefore important to know if adjacent properties could be a source of the same or similar pollutants.

Stage 6: Describe the site conceptually

The results of stages 3–5 can then be used to describe the site making links between sources of emissions, the pathways by which pollution may move and the receptors likely to be affected. The nature and complexity of conceptual site models will vary by site and by the activity or activities undertaken.

A conceptual site model is a representation that sets out both the existing levels of pollution and possible future pollution sources for a given area of land.

Alternatively, it may be preferable to produce more detailed individual models for each area of concern at the installation. For example, a conceptual model of the area around a tank, could indicate the construction of the bund, the direction of slope of the ground, whether fill points are inside or outside the bund, the type of surfacing around the area, and the underlying geology and water table.

Stage 7: Collect any additional data

If any additional information needs to be collected to allow a quantified assessment of soil and groundwater pollution by relevant hazardous substances, it should be collected now through site investigation.

The details of such investigation should be clarified with the Competent Authority who will be able to assist in selecting the most appropriate sampling strategy.

Selected sampling strategies should provide sufficient confidence that measurements and samples taken accurately reflect the actual level of contamination by relevant hazardous substances so as to enable a determination of the current state and condition of the soil and groundwater. When the site is assessed at the definitive cessation of activities, it will be necessary to use the same approach and either the same methods or methods which have been shown to produce comparable analytical performance.

Sampling strategies should:

  • be focused on identified relevant hazardous substances and their hazardous degradation products

  • take into account the hydrogeological and hydraulic conditions of the site: suitable upstream/downstream measuring points must be reviewed prior to their establishment on the site of the installation

  • recognise the impact of natural and process-related influencing factors on the samples taken and the sampling strategy (place and method), contaminant linkage, heterogeneity of the pollutant distribution in the soil or in the groundwater, the handling of the sample between the time of obtaining it and its measurement and the measurements taken within the laboratory.

Clear mapping and marking of the sampling points is a pre-requisite.

Stage 8: Produce the report

The purpose of this stage is to summarise the information that has so far been collected and to produce a report that identifies the state of soil and groundwater contamination by relevant hazardous substances.

The baseline report itself should provide an accurate and clear description about:

  • what data has been used to establish the state of the soil and groundwater

  • the methods that have been used to sample and analyse the substrata

  • how the results have been verified, statistically or methodologically.

So as to ensure, at final cessation, a valid quantified comparison can be made, the baseline report should:

  • be presented in a logical and structured format

  • contain sufficient information to establish the scope and impact of the current activity or activities covered by the permit, including the dates of all relevant soil and groundwater measurements

  • provide a clear and accurate description of the approaches used and the results obtained by the assessment as well as the location of any intrusive works, wells, boreholes and other sampling points in accordance with a standardised geographic referencing system

  • provide a clear description of the analytical techniques used to establish the concentrations of hazardous substances in soil and groundwater with reference, where appropriate, to national or international standards used as well as any guidance provided by Member States that existed at the time of the investigation

  • state the scientific uncertainties and limitations of the approach taken in preparing the report

  • include all technical data.

Where a baseline report is not required

A baseline report will not be required where it is apparent that owing to the quantities of the hazardous substances used, produced or released at the installation, or due to the soil and groundwater characteristics of the site there is no significant possibility for contamination of soil or groundwater.

In case of existing installations, where measures are taken which make it impossible in practice that contamination of soil or groundwater occurs, a baseline report is also not required.

However, if it is considered that a baseline report is not required, a record of such a decision, including the reasons for the decision, is still required to be made by the operator and will be further assessed and held by the Competent Authority.


Every site is unique, so variation in the type, depth and presentation of baseline reports between different activities covered by the IED is anticipated and acceptable. The key is to gather accurate and reliable information on the current status of the site in relation to the presence of hazardous substances so that at the time activities at the site cease, an accurate assessment can be made.