Progress in management of contaminated sites

In EEA member countries, it is estimated that potentially polluting activities have occurred at about three million sites[1]. National estimates show that more than 8% (or nearly 250000 sites) are contaminated and need to be remediated (Fig. 1 Overview of progress in the management of contaminated sites in Europe).

These estimates have increased considerably over the past years, due to progress in investigation, monitoring and data collection, and this trend is expected to continue in the future. According to projections based on the analysis of the changes observed in the last five years, the total number of contaminated sites needing remediation may increase by more than 50% by 2025. Moreover, remediation is progressing relatively slowly: in the last thirty years, only just over 80000 sites have been cleaned-up in the countries where data on remediated sites are available (This covers about 70% of the area of the EEA and collaborating countries).

Losses of contaminants during industrial and commercial operations, municipal and industrial waste treatment, oil extraction and production; and inadequate storage are the main sources of soil contamination in Europe (Fig. 2 Overview of activities causing soil contamination in Europe).

The range of contaminants found in the investigated sites varies from country to country. However, overall estimates identify heavy metals and mineral oil as the main soil contaminants in Europe. These estimates are based on the frequency with which a specific contaminant is reported to be the most important in the investigated sites. Other contaminants include polycyclic aromatic hydrocarbons (PAH), aromatic hydrocarbons (BTEX), phenols and chlorinated hydrocarbons (CHC) (see Fig. 3 Overview of contaminants affecting soil in Europe). Mineral oil and heavy metals are reported as the most relevant contaminants for groundwater.

A considerable amount of private and public money has already been spent on remediation activities. However, this is relatively small compared to the total estimated costs. Annual expenditure on the management of contaminated sites is on average about 2% of the estimated overall management costs in the countries for which such estimates are available.

Although most of the countries in Europe have legislative instruments which apply the "polluter-pays" principle to the management of contaminated sites, large sums of public money are provided to fund remediation activities (Fig. 4 Estimated allocation of public and private expenditure for the management of contaminated sites). This is due to the limited applicability of the principle in the case of the remediation of historical contamination, as many of the legally responsible polluters either no longer exist, cannot be identified or are insolvent. This is a common trend across Europe. On average, approximately 35% of total expenditure in the surveyed countries derives from public budgets. This ranges from a maximum of 100% of public funds employed in the Czech Republic, FYR of Macedonia and Spain to a minimum of about 7% in France, where a large proportion of funds comes from the private sector. However, it must be taken into account that only rough data on public expenditures is widely available and information on private expenditures is patchy.

Annual national expenditure for the management of contaminated sites are on average about 12 EUR per capita, with a range of approximately 0.2 to more than 20 EUR per capita in the reporting countries. This corresponds to an average of 0.7 per mille of the national Gross Domestic Product (Fig. 7 Annual national expenditure for the management of contaminated sites per unit of GDP).  The largest portion of expenditure is employed for remediation measures (nearly 60% of the total expenditures) and site investigations (about 40% of total expenditures). It should be noted that, the number of sites to be investigated is much higher than the number of remediated sites (see Fig. 1 Overview of progress in the management of contaminated sites in Europe). At the EU level, the rehabilitation of industrial sites has been funded through the framework of the Structural Funds using a total budget of 2.250 billion EUR for the EU25 in the period 2005-2013[2].

Annual management expenditure has been almost constant in the period 2000 - 2006, but varies considerably from country to country. There is, in fact, a 100-fold difference in annual expenditures per capita across Europe. This difference does not necessarily reflect a different level of awareness of the problem in the countries, but may be due to the different environmental standards applied, as well as the specific local conditions and the degree of industrialisation. However, comparisons must be made with caution, due to lack of data of the costs borne by the private sector.

In addition to the degree and extent of the contamination, environmental standards, local site conditions and applied technologies are the main cost components. The link between environmental merit and invested budgets is highly dependent on national regulations and the way they are implemented. Costs are highly related to the different remediation targets and local site conditions. Stringent measures aiming at the removal of the sources of contamination usually tend to cause large investments (such as in Austria) whereas 'fit-for-use'-approaches, aiming at revitalising a site for a not very sensitive use, such as industrial use, are much less cost-intensive or may even require only land use restrictions (such as in the United Kingdom). An analysis of the costs per site covering seven countries and three regions shows that:

• the average unitary costs for the investigation of a (potentially) contaminated site range between 500 and 50000 EUR, with the exception of Austria, where the average costs are in the range of 50000 - 500000 EUR in approximately 90% of the sites. Investigation costs lower than 500 EUR per site as well as costs beyond 500000 EUR are not commonly reported;
• the costs for the application of risk-reduction measures range from 500 - 50000 EUR per site. However, in Austria and the FYR of Macedonia, remediation expenses range between 50000 and 500000 EUR in 55% and 44% of the sites respectively. In Slovakia and the Czech Republic the costs of remediation vary between 500000 and 5 million EUR in 17% and 19% of the sites respectively. With the exception of Austria, remediation costs exceeding 5 million EUR per site are rarely reported. By contrast, only the Czech Republic and the FYR of Macedonia reported costs are less than 500 EUR in a significant number of sites (respectively 17% and 13% of all remediations).

Due to economic and logistical reasons, the management of contaminated sites follows a tiered approach with increased efforts and expenses at each step. In Europe, initial steps in the sequence such as preliminary investigations are far advanced, whereas final steps such as detailed investigation and remediation are progressing slowly.

Based on information from national inventories, the progress in the management of contaminated sites varies significantly across Europe, depending on the different national management approaches and legal requirements. In most of the countries for which data are available, site identification activities are generally advanced. As a result of preliminary surveys, just over 60% of the sites have already been confirmed as potentially contaminated and need to be submitted for detailed investigations. Detailed investigations and remediation activities are generally progressing slowly. More is being learned on the size of the problem but the speed of the clean-up is slow (see Fig. 1 Overview of progress in the management of contaminated sites in Europe).

Nevertheless, progress in the remediation of sites has been observed. In the countries for which comparable figures on remediation are available, the number of cleaned-up sites has increased by more than 150% on average between 2001 and 2006, with increases in individual countries ranging from approximately 30% (Austria, Italy) to around 600% (Belgium, Norway). By contrast, the total number of sites awaiting remediation has grown by about 40% on average in the same period, while the estimates on the number of sites where potentially polluting activities have taken place have more than doubled. This progress is due not only to improvements in investigation, data collection and reporting, but also to the increasing experience in the risk assessment. As long as observed trends continue in the future, more efforts will be needed to solve the problem of historical contamination by 2050.

Most cases of contamination are a legacy from the past. However, current activities may still cause soil contamination. In the United Kingdom, for example, more than 2% of the estimated total contaminated sites are classified as newly created contaminated land[3][4]. In the future, the implementation of the EU and national legislative and regulatory frameworks already in place (e.g. Landfill Directive, Integrated Pollution Prevention and Control Directive, Water Framework Directive, Environmental Liability Directive) should result in the more efficient prevention of releases of contaminants into the environment, and into soil in particular. As a consequence, most of the efforts for remediation are expected to be concentrated on historical contamination.

Inventories or registers of contaminated sites represent an important tool for the effective management of soil contamination from local sources. This is recognised in the proposal for a Soil Framework Directive, published by the European Commission in September 2006 which requires the establishment of national inventories of contaminated sites in the EU.

According to available data, there is already a good basis for fulfilling this requirement. In fact, as of 2006, inventories or registers have been established in 24 EEA and collaborating countries. The registers are kept at the national level in 20 countries, while regional inventories exist in more than 55% of the 28 countries covered by the survey. In some countries, localised inventories have also been established to cover specific areas and activities. In Belgium, Germany, Switzerland and the United Kingdom, registers are kept only at regional or local level. Only three countries have no registers (namely Cyprus, Malta and Turkey[5]), while Greece only reported local inventories.

In all countries, inventories take into account both historical and new contamination (the latter with some restrictions), potentially polluting activities (abandoned and in operation), potentially contaminated sites and contaminated sites. Almost all inventories include industrial, commercial and waste disposal sites. Harbours, pipelines, airports, nuclear operations, accidents are registered in approximately 50% of the countries. For each site, most of the registers provide information on the exact location, site characteristics, local conditions, environmental impacts (in terms of risks to environmental media) and progress in the management of the site.

In all the surveyed countries, soil and groundwater are reported to be by far the most important media investigated. Investigation of surface water, sediments, waste and indoor air are less common (with the exception in Austria, where soil gas and indoor air are investigated in 60% and 20% of all sites respectively).

Several techniques are available for the reduction of the risks caused by soil contamination. In the reporting countries, there is a balance in the application of innovative in situ (on-site) and ex situ (off-site) techniques. A significant high percentage of the most-frequently applied techniques can be defined as traditional (Fig. 8 Remediation technologies - Other soil treatments) such as the so-called "dig and dump" techniques and the containment of the contaminated area. This reflects the fact that contaminated soil is frequently treated as waste to be disposed of rather than a valuable resource to be cleaned and reused. In Ireland, for example, contaminated soil was reported as the largest single hazardous waste type generated in 2004, accounting for more than 45 per cent of the total reported volumes.[6]

National reports indicate that heavy metals and mineral oil are the most frequent soil contaminants at investigated sites (Fig. 3 Overview of contaminants affecting soil and groundwater in Europe), while mineral oil and chlorinated hydrocarbons are the most frequent contaminants found in groundwater.

The risks to human health and the environment vary considerably with the specific contaminant, the site specific conditions and exposure of the receptors. In fact, the risks are determined by the physical -chemical properties of the contaminants such as: solubility, mobility, volatility, sorption capacity, persistence etc; the pathways to potential receptors (e.g. the existence of an impermeable layer, the permeability and thickness of the unsaturated zone etc.) as well as the exposure of the receptors (e.g. humans or animals). Therefore, the assessment of the impacts of contamination has to be evaluated on a case-by-case basis.

The protection of groundwater resources and the exposure of humans via drinking water from ground sources are reported by far as the most important motives for the application of risk-reduction measures. The protection of the soil per se has a relatively low importance (this is only reported in Hungary in 10% of all remediated sites). This may be due to the lack of specific regulations covering the soil media, but also due to the wider dispersion of contaminants in groundwater compared to soil. Relatively low priority, with a few exceptions is assigned to the remediation of sites where exposure to the contaminants comes from surface water, soil gas and the food chain. Only in very few cases are remediation activities reported to be triggered by the protection of ecosystems, e.g. in Croatia and the Czech Republic, and the loss of biodiversity (Croatia, Malta).

An assessment of the impacts of the above mentioned contaminants in soil and groundwater would require a detailed knowledge of the local situation in each site (e.g. type and amount of contaminants, hydro-geological conditions, land use, receptors, etc.) and therefore cannot be carried out at European level. An assessment focussing on problem areas of soil contamination in Europe, based on national data and a common methodology, would be a feasible alternative. This work is currently at an early stage and the limited results of recent data collections do not allow conclusions to be made which can be validated at European level. The limited response is mainly motivated by the lack of resources and by restrictions in reporting site-specific information which is seen as politically-sensitive in the absence of legally-binding obligations.

Nevertheless, the results of preliminary analysis, covering 33 problem areas in three countries (Austria, Hungary and Italy) show that these areas have several factors in common which influence to a lesser or greater degree the progress being made towards solving the problem. These factors do not always seem to include the size of the affected land, which may vary from less than 1 km² to more than 1000 km² in the analysed problem areas. Other factors include:

• nature and complexity of the activities which have been identified as sources of soil contamination.  Industrial and commercial activities are the sources most frequently reported;
• nature and complexity of contamination: the main contaminants identified include heavy metals, the BTEX group (benzene, toluene, ethylbenzene, and xylenes), polycyclic aromatic hydrocarbons, chlorinated hydrocarbons and other inorganic compounds, as well as asbestos and mineral oil. The presence of these contaminants makes the remediation particularly difficult and costly;
• nature and complexity of the impacts: the presence of several impacted or threatened receptors, including land uses, has been reported in most of the problem areas. This is seen as a major factor in determining the problem. The main receptors include groundwater (seen mainly as a drinking water source), and urban and industrial land uses. The impacts of contamination on surface waters, coastal areas and food safety are also seen as relevant. By contrast, the impacts on ecosystems seem not to be considered to be of high priority for remediation;
• complexity of management and liability issues: the presence in the area of many site owners is frequently reported;
• limited progress achieved in remediation: in general the investigation and implementation of remedial activities proceed at a fast pace in all the areas analysed, while the rate of completion of remedial actions is still low.