Parallel to the development of our civilisation there has been an increase in the accumulation of contaminants in our environment. Industrial revolution led through the rise of the living standard to the production and use of more and more harmful substances, as well as to their escape into the environment and to growing piles of waste. Several decades of uncontrolled contaminant-emission had resulted in the pollution of environment indicated by an increase of shallow groundwater pollution cases in the 1960s. Governments had to reconsider soil- and water protection policies and the responsibility for the protection of the environment.
The elaboration of soil- and water protection strategies in accordance with environmental objectives, as well as the preparation and use of the necessary legal and technical regulations was already started in the developed European countries and the USA in the 1970s. However, the seriousness of the problem became obvious only in the 80s when environmental damages of great extent endangering human health and the environment were brought to light.
In connection with the elimination of the damage countries were faced with a series of problems that gave rise to social debates: the question of liability, the financing of expensive remediation works, land use and the loss of value in the case of properties – none of which have been solved until now.
These problems arise especially in the case of long-standing pollutions caused by meanwhile abandoned activities where the generally acknowledged “polluter pays principle” cannot often be enforced, particularly when the polluter cannot be found or unambiguously identified or when liability becomes forfeited thus enabling its repudiation based on the Civil Code. In more and more countries the problem is dealt with at national level by the establishment of remediation programs. In some countries like Germany, the Netherlands, Denmark and the USA these government-level programs have been in operation since the mid 1980s. In other developed European countries their preparation and introduction is in progress.
In the USA the program aimed at the remediation of abandoned contaminated sites was incorporated in law (Superfund Program). In other countries environmental acts and other special pieces of legislation support remediation programs.
Separate funds originating mostly from taxes on products and waste, environmental charges/contributions and fines are allocated for the financing of remedial activities. Other ways of financing are found and established, like the co-operation with the industrial-economical sector (Denmark, Germany, France) or the involvement and contribution of a wider range of society through the establishment of different types of compensation.
The EU also supports member states’ remediation activities, the preparation and execution of programs by establishing special and separate funds; Spain, Portugal, Greece and Ireland for example received financial support for the implementation of environmental, remediation and transport programs from the Cohesion Funds of the EU.
At the same time European organisations and the EU aim at an increased taking of responsibility of member states in the field of environmental protection.
In 1995 member states of the Council of Europe – except some countries, f. e. Great Britain - signed the treaty on environmental liability.
The so-called Green Paper prepared by the European Commission on civil liability recommends the introduction of a strict system of environmental liability in all member states with special supplements of compensation.
The Council of Europe has drawn up the general principles of soil protection in the European Soil Charter in 1972 defining soil as common heritage and as an easily destructed, non-renewable natural resource. The Charter furthermore laid down the principle of multifunctional soil protection stating that soils should be preserved in a status adequate to perform all functions of land use for present and future land users.
The above principle has become part of the European countries’, the US’ and the Canadian soil protection and cleaning policies.
The other, also acknowledged principle in the field of remediation is the principle of sustainable development to ensure equal quality of life and environment, as well as equal possibilities of environmental use for the next generations.
Several European countries consider groundwater as a resource of strategic importance, the protection of which is first among priorities.
Strategic goals of groundwater protection and the draft of the action program according to which action programs to ensure the protection of groundwaters should be put into force by 2000 were approved by the EU in 1991.
In practice however, economic reasons and land use purposes also play a role – though to a different extent - in the achievement of these common goals as the key question, i. e. to what extent soil should be cleaned, has direct effects on remediation costs, the possibilities of land use and the price of the area.
From this point of view there are two different types of thinking. On one side are countries, where there is a close link between the aims of remediation and land use, and the connection of remediation to the national water and soil protection policy is rather loose (f. e. Germany). In these countries soil cleaning is carried out acc. to land use and vulnerability.
The other side includes countries where remediation forms an integral part of the general water and soil protection policy and land use does not play a direct role in the determination of the extent of soil cleaning (f. e. the Netherlands). There has been an advance in the approach of the two sides recently.
Some countries like Denmark – backed by 12 years of experience in remediation - are changing over from their previous “idealistic” approach, pursuant to which all contaminated areas must be cleaned according to the principle of multifunctionality, to more pragmatic views. At present they already tolerate only partly cleaned or contaminated areas if further spreading of the contamination can be excluded and surveillance is ensured. In the field of water protection emphasis is put on the designation and increased protection of groundwater resources of special importance. Therefore the main goal is the elimination of dangerous pollution sources in these areas.
One important question related to remediation is how to classify contaminated areas, how to determine priorities and the related criteria of quality and priority. In this field there are also differences in opinion with the “Dutch list” on one end and the “US approach” on the other.
The first approach is based upon standardized limit values of contaminant-concentrations that are used to determine the necessity of remediation (intervention) and the extent of cleaning (target value). Risk assessment is applied to determine the priority of the intervention and to select the adequate cleaning technology in the later work phases (the Netherlands).
In the USA on the other hand the single case approach is emphasised, where priorities are determined separately for each area based on special types of risk assessment and under consideration of the relevant remediation targets.
Also in this field there has been some advance in the different views recently. Countries are tending towards the approach to consider limit values in the first phases of remediation, in the course of the site investigation and preliminary assessment of pollution, whereas specific risk assessment is used in the course of detailed investigations, as part of the later decision making process to determine the method and technology of intervention.
It is to emphasise however that the protection of human health is the most important goal in every country being of absolute priority in the case of direct danger.
Remediation is carried out based on the so-called priority lists. Reduced risk assessment methods – adequate for the priority ranking of pollutions sources and polluted sites - based on uniform evaluation principles are used to prepare the lists in several countries. The weighting of risk factors expressed in points form the basis of reduced risk assessment methods. There are however differences in the details of the methods applied in the different countries, i. e. in the selection of parameters for evaluation, the weighting of risk factors and the algorithms of calculation.
Initial phase of remediation is the survey and inventory of pollution sources and polluted sites in every country. Putting it into practice there are differences between the countries’ methods depending upon the requirements of classification. In some countries survey is combined with the investigation of pollution (soil and water sampling), in other countries information already available is used only.
The strategic implementation of remediation programs is directed and controlled by ministries in charge of environmental protection, while execution generally takes place at regional level.
Between 1978 and 1991 the EU published several directives and recommendations affecting directly or indirectly the field of water and soil protection and supporting the harmonization of the member states’ national legislation. Since 1996 EU directives and recommendations have set the course and target for the single phases of remediation.
Countries acknowledge common goals and keep to directives, but practical implementation of remediation changes from country to country reflecting social, political and economical characteristics.
In Europe the Netherlands, Germany and Denmark are holding the first place in remediation and the USA have also great experience. Several European countries (out of which a short description will follow later on France’s, Great Britain’s, Finland’s, Norway’s and Spain’s remediation practice) took over the experiences of the above-mentioned countries to form an own remediation strategy.