Determination of risk

1 CLARINET Problem Catalogue Draft – October 2000. Venice Prepared by the Federal Environment Agency – Austria. The following Problem Catalogue has been structured on a Risk based Site Management approach according to the CLARINET Conceptual Paper. RISK A. Determination of Risk A.I Technical and Scientifical Issues a) Samples Sampling strategies did not evolve substantially and uniformly in European countries so that new methods have to be implemented improved and compared. Sampling methods • Strategic sampling techniques on landfills and industrial sites are not systematically standardised proceedings. • Sampling strategies are not always harmonised at the national level so that divergent approaches can be observed thus leading to different interpretation of investigation results • Sampling methods do often not fit to specific hazard situation on a specific site. In choosing sampling methods in risk assessment campaigns, there is little experience in balancing costs against risk (uncertainties). • Generally for the purpose of risk assessment, investigations focus only on pollutant’s concentrations but not on the total amount of pollutants on a site. This would be a very important information in helping to find the best available and adapted remediation scheme for the specific site, as clean-up costs are directly depending on the quantities of hazardous substances present in the underground. Sample preparation • Specific and proven methods for sampling, transporting samples to laboratory, conserving and processing samples are not standardised in all countries. Results of several environmental investigations over Europe are hard to be compared with international guidelines due to divergent sampling strategies and techniques through the countries. Special analytic • Analytical techniques helping to distinguish specific pollutants present in low concentrations in the groundwater are not generally standardised. It is in that way important, as pollutants can have various hazardous effects on the environment and human health by very low concentrations. b) Pollutant fate and transport Natural environmental effects, bioavailability, transport and fate of pollutants in the underground are complicated processes which have to be studied further. 2 Pollutant transport processes • Detection of leachate pollution and transfer of contaminants from the unsaturated zone to groundwater are not enough studied and investigated under field conditions e.g. in pilot experiments, clear concept for such processes are generally missing. • There is no clear evidence on how fare transport models can be used in investigation campaigns and how efficient they can be, depending on site conditions. Therefore mathematical verifications of models should be carried out under field conditions in order to improve their efficiency. • Site investigations should be done in a way that enable to see the evolution in time of contamination plume. Interactions between pollutants and its surrounding media are not well understood. Prediction of possible evolution of a contamination plume is still very difficult to carry out. • There is little knowledge in some countries on contaminant’s behaviour in multiphase transport processes. Especially efficient methods for non aqueous phase liquids detection are missing. Pollutant bioavailability • Modified methodology for assessing differences in bioavailability among different soils, taking abiotic and biotic aspects into account are not yet available. This is an important point to determinate bioavailability of contaminants for soil organisms. This kind of assessment would represent a tool for developing specific remedial or monitoring actions which would take in account the natural biodegradation of soil pollutants. • Bioavailability of pollutants to humans is a complex and yet not enough understood problem as pollutants are available through a variety of media (groundwater, soil, air, plants) • Effective methods for the estimation of pollutant bioavailability for human are often missing. This would be an important view in order to come to a more precise risk assessment. • Objective and methodological investigation methods, assessing negative effects of contaminated sites on agricultural crops, cattle, house animals and plants in gardens are not standardised procedures. Such investigation methods would be an important tool to help setting clean-up target values. • The transfer mechanisms of pollutants from soil to plant are yet not completely understood. Studies in laboratory and on field experiemtns are missing. Pollutant degradation and modification • Specific investigation tools for appreciation of soil pollutant partitioning and speciation are difficult to be implemented. • It is difficult to estimate precisely the role of pollutant fractions in soils (immobile, mobilisable and mobile) in assessing their impact on soil ecosystems and plants. Precise and selective risk assessment on sites on which several pollutants are present are hardly possible. • There is no sufficient understanding of the behaviour of groundwater pollution (long term transport, attenuation, adverse effects on local conditions) in heterogeneous media. A specific planning system taking several natural environmental effects (biodegradation, dilution, dispersion) as well as human activities (tunnel building, chemical input in soil etc ) in account, is missing. 3 A.II Risk Assessment a) Risk assessment methods are not adapted to site heterogeneity (pollutant variety, complexity of ecosystems and geology) • Efficient risk assessments are difficult to be carried out in case of the presence on site of a multitude of pollutants, pollutant fractions and pollution sources. New methods have to be developed and implemented. • Rapid pollution detection and a risk evaluation methods for multiple potential pollution sources are not systematically available. • Specific procedures for risk assessment are not applied systematically. Risk assessments are not carried out in function of specific site conditions thus leading to unnecessary investigations (cost efficiency decreases) or uncomplete assessment (risk is underestimated). • The impact of pollutants on soil ecosystems is not predictable in detail and has to be assessed further by developing new investigation methods. b) Monitoring of pollutant emissions are not developed enough in order to enable an efficient risk estimation • Assessment and monitoring of smells is too expensive and time consuming. New and efficient methods are missing. • Risk assessment methods for indoor air pollution caused by contaminated soils or groundwater have to be developed. • A better control of emissions from dumping and industrial wastes, as well as mining waste deposits has to be guarantied. Pollution by heavy metals and organic compounds are still difficult to assess and to monitor in a way to enable an efficient risk estimation. Emission of nitrates due to the excessive use of fertilisers are difficult to be estimated at the regional scale. Their effects on point source pollution are still not enough investigated. A.III Special geographical and geological conditions • Combined risk assessment approaches for radionuclides and heavy metals/arsenic in former uranium mining regions are not yet implemented. Exposure assumptions have to be improved and methods for the combined assessment of deterministic and stochastic effects from both source have to be developed. The evaluation of combinatory effects of radiation and heavy metals has to be improved. • Special site conditions give rise to various types of problems e.g. investigation plan, risk assessment and remediation planning. • Contaminated land in fractured rocks and karstic areas are still a main problem concerning the spreading of contaminants in such heterogeneous geological structures. • Overexploitation of coastal aquifers is at the origin of several soil pollution in the vicinity of the sea. Interactions between seawater and groundwater are yet not clearly understood and give rise to additional problems in risk assessment studies. 4 B. Management of Risk B.I. Managing ecological risks is a fundamental conflict as their accurate evaluation is still very difficult thus giving rise to uncertainties a) Interpretation uncertainties of pollutant fate in the underground are still very high as natural phenomenon occurring in those ecosystems (soil, aquifer) are highly complex. • There exist some models to estimate leaching from the unsaturated zone towards groundwater, from very simple to very complex. It is not very clear how to tackle the leaching problem during the different phases of soil investigation (from screening to more quantitative approach). It is not clear in every case whether or not it is accurate to use databases to describe site conditions. The model’s values their implementation on different levels of accuracy, and their related expends are not easy to be determined or estimated. Efficient cost estimation and comparison methods for various investigation procedures are missing. • Tools to find out the best available risk assessment strategy with regard to site specific conditions as well as to uncertainties are missing • The multiple effects of contaminated soils on ecosystems are not well enough investigated with regard to the complexity of those ecosystems. Ecosystems adapt and react very differently to pollution. This natural capacity of ecosystems has not been studied enough yet as field experiments are lacking. • Risk-based approaches are not improved sufficiently. The remaining risk uncertainties have to be minimised in order to enable better application of fitness- for-use assessments in real life decision making, in particular in human exposure models. b) The accuracy and representativity of observation methods (sampling and measurement methods) have to be improved further • Sampling methods do generally not fit to specific hazard situation on a specific site. In choosing sampling methods in risk assessment campaigns, there is little experience in balancing costs against risk. • Considering risk management approaches, it is notable that guideline as well as investigation and intervention values do not always fit to site specific conditions. Those values are too often differing with the reality of local conditions and pollutant’s specific environmental impact on site. • In urban environment, multiple pollution sources are hard to be assessed, as pollution plumes get mixed and diluted. Integrated risk assessment for multiple sources have to be improved. • There is a great difficulty in estimating the spatial origin of soil/groundwater contamination in combination with complex underground storage tanks systems upgrading and filling station networks. Efficient monitoring methods to locate the origin of those contamination are missing. B.II. The link between risk management and land-use planning has to be improved. Specific Decision Support Systems are missing 5 • Risk based fitness for use approaches are still very difficult to implement on site. This is mainly due to the high uncertainties of pollutants quantitative estimates. In particular the confidence in the human exposure models should be improved. • Tools for helping to choose the best available (adjusted) clean-up strategies are missing. • Methods to find out the most cost-effective remedial strategies and technologies with regard to risk have to be developed and improved. • Practise oriented concepts for contaminated land clean-up are too rarely applied. Assessments of technical and socio-economic feasibility of different clean-up solutions with regard to future uses of contaminated land are not systematically available. • Decision tools for engineers and more specially for decision making authorities are sometimes lacking so that there is no help for them to choose between available technologies for remedial actions, while considering socio-economic aspects of contaminated land redevelopment. • For land rehabilitation and planning purposes, the risk analysis has to cope with the technical and socio-economic feasibility of different soil remediation actions and final uses. A flexible but specific Decision Support System would be the tool for different experts to co-operate in planning, and for quantitative environmental analyses, such as risk assessment, to be properly integrated in the decision making. • Risk assessment and risk management are not systematically integrated in all brownfield redevelopment plans on a long time scale. It is too often forgotten that former contaminated sites can still represent a threat for the environment in the future. • Eco-social aspects of risk acceptance are not taken in account brownfield sites recycling plans. • Risk based management of specific contaminated sites are not enough planed in relation with management schemes of water quality at a basin scale, especially when different sources of pollution discharge in the same aquifer. • The use of multiphase transport models as a tool for clean-up planning is yet not a standardised method of procedure. • The public expectations are not systematically integrated in the site management concepts on a contaminated site. C. Risk Reduction/ Monitoring C.I Existing methods to be improved a) Ex-Situ Proceeding optimisation. Laboratory and field experiments are lacking • The development of separation and treatment technologies for different kinds of waste and soil pollution is not very advanced. • Concepts for handling excavated soils are not carried out in the most efficient way and have to be developed. It is generally the case that excavated soils are transported to special deposit plants. 6 Sustainable remediation solutions are lacking • Transporting excavated soil on other disposal sites is not a long term solution and should be replaced by alternative sustainable solutions. • Reuse of contaminated soil material is not systematically taken into consideration. b) In-Situ/On-Site Duration of clean-up procedures is often too long • Combination and optimisation of different treatment methods has not been very much experienced and would help to shorten clean-up treatment duration. Proceeding optimisation. Laboratory and field experiments are lacking • Groundwater denitrification technologies have yet not reached a very high standard level. Neither laboratory nor field scale improvement experiments of those technologies are sufficiently carried out. In-situ as much as on-site technologies have to be developed. • Physio-chemical techniques are not well enough developed and should be tested and implemented in a greater extend on contaminated sites. • Gentle remediation techniques (biochemical and physio-chemical) are not improved enough. Site heterogeneity is difficult to handle • Clean-up techniques of fine grain sized compact soils contaminated with highly volatile hydrocarbons are not always efficient so that they should be improved. • The use of bioremediation techniques is severely limited by environment agency and owner of contaminated sites because this method leads to an uncompleted removal of the pollutants (non bio-available pollutants). • There is not enough experience in on-site remediation techniques of groundwater contaminated by municipal disposal sites at different layers and levels. • On-site treatments for low permeable soils are not well developed. • There is a lack of experience in the evaluation of the efficiency of in-situ bioremediation technologies in heterogeneous systems. Sustainable remediation solutions are lacking • Remediation techniques focused on resource optimisation are not enough developed yet. Verification methods for clean-up success have to be improved • In-Situ remediation technologies are too often left aside due to remaining uncertainties on their efficiency. • There is a lack of experience in the evaluation of the efficiency of in-situ bioremediation technologies in heterogeneous systems. • Efficient evaluation methods for long term efficiency of enclosure systems and permeable reactive barriers are missing. c) Monitoring Verification methods for clean-up success have to be developed and improved • There are no standardised monitoring methods for verifying soil and groundwater quality in the vicinity of contaminated sites. 7 • There is insufficient knowledge regarding natural attenuation processes in groundwater systems at contaminated sites. • Cost effective monitoring strategies concerning possibilities and limits of natural attenuation are not existing yet and have to be developed. Proceeding optimisation. Laboratory and field experiments are lacking • An efficient monitoring system for the geochemical and ecological conditions throughout the river catchment areas, regarding the threat of pollution caused by mining sites is often missing. An important issue is the evaluation of the governing transport and attenuation processes on a large areal scale. • Monitoring methods for characterisation of emissions from anthropogenic sources, industrial activities and their mixing with seawater have to be improved. • There are no rapid pollution detection methods concerning the leakage of fuels from underground storage tanks. Site heterogeneity is difficult to handle • The variability of groundwater pollution is not well known. A better understanding of the problem might be possible with the development of a permanent monitoring system giving information on the evolution of groundwater pollution on the long time scale. C.II Choice for new concepts Proceeding optimisation. Laboratory and field experiments are lacking • Demonstration sites for clean-up technologies are not available in sufficient number. These sites would allow to observe pollutant’s behaviour in different environmental conditions under application of various clean-up measures. • Innovative technologies (various technologies) for the remediation of sites contaminated by heavy metals have to be developed. • Practical application of phytoremediation technologies and their combination with other in-situ clean up methods for contaminated soils have to be further developed and improved. Sustainable remediation solutions are lacking • Sustainable techniques for the treatment of persistent pollutants as MTBE (Methyl Tertiary Butyl Ether) are not available. • Integrative concepts considering technical aspects (site remediation and site improvement for construction) for reintegration of rehabilitated sites into the economic cycle have to be developed in order to be more cost efficient with regard to the rehabilitation of abandoned sites. Reliability of remediation techniques is not optimal • Clean-up designs are not always adapted to the specific site conditions, especially with regard to security and health protection. SITE 8 A. A few contaminated sites present particular problems to contaminated land management schemes due to the specific nature of contaminants • A combined risk assessment approach for radionuclides and heavy metals/arsenic in former uranium mining sites is necessary. • The treatment of mining wastes is still causing technical problems. Especially sulphates and heavy metals represent particular harm for the environment. • The continuous raising amounts of mining wastes represent a major problem to environmental authorities as the behaviour in the environment of released dangerous acids and heavy metals is not sufficiently understood. • Special measures for the treatment of abandoned mining sites in sub-arctic areas have to be found. The use of explosives on mining sites led to emissions of nitrogen and petroleum products thus resulting in additional threat for the environment. • Investigation and rehabilitation of creosote on impregnating installation and gasworks has to be improved. • Characterisation and assessments of industrial landfills polluted with heavy metals, solvents, water soluble metals and hydrocarbons, aromatic compounds and PAH are still difficult and would need to be verified and improved. • The use of lignite in energy production is a main source for contamination problems for which adapted investigation and remediation techniques have to be developed and improved. • There is little knowledge on the behaviour of heavy metal solvents in the underground. Risk assessment is difficult to be carried out for such hazardous substances. B. A few contaminated sites present particular problems to contaminated land management schemes due to the type of activity on the site and/or site specific conditions • Large scale problems: contamination of groundwater caused by farming and zootechnic activities are difficult to be assessed. • Characterisation and remediation of a large number of abandoned uncontrolled and illegal waste landfills are difficult to be carried out because of the high variety of harmful substances present on such sites. • Industrially contaminated sites in coastal areas are under the influence of seawater thus leading to interactions on contaminated groundwater. Risk assessment in such areas is therefore very difficult. New specific investigation and assessment methods have to be adapted to such special conditions. • Estimating the influence of rising groundwater tables in urban areas where there is land contamination is still a difficult procedure. Reliable investigation techniques are missing. • Mining sites represent an important source of local soil pollution; the main threat is surface and groundwater contamination. The transport of pollutants on such sites is very much influenced by modification of the soil/underground structure thus making risk assessment even more difficult. 9 • Pollution of surface water caused by contaminated sediments as well as the spreading of contaminants by sediment transfer in harbours (especially metal- organic compounds) is at the origin of numerous problems for investigations and risk assessments. Surface water pollution caused by desorption from contaminated sediments is mostly either ignored or overestimated and leads to inadequate remediation measures. Therefore, better methods for the quantitative assessment of surface water pollution caused by contaminated sediments is highly needed. MANAGEMENT A. Administration A.I Legislative Framework a) Harmonisation of acts and guidelines • There is no harmonised concept for handling excavated soil. Conflicts do exist between waste management acts and soil protection acts through Europe. In several countries the actual laws regulating the soil remediation are not soil oriented but concern the waste management. • The compliance of groundwater and soil quality standards with risk based procedure for land rehabilitation is not always guaranteed. • Comparison studies E.U. wide on the toxicological criteria used for the setting of soil standards are missing. • There are no technical guidelines for the risk oriented characterisation of contaminated sites. In some countries the risk assessment approach in estimating site specific remedial targets doesn’t fit to the latest national standards. A homogenous European regulation for the risk oriented characterisation of contaminated sites seems to be necessary. • Standards values should be differentiated for different geological layers and for different regions. b) Technical, economic and legislative tools for the redevelopment of contaminated sites are missed by decision makers and planners • Concepts to avoid the increasing consumption of land by recycling brownfield sites have to be developed. • Ecological balance aspects are missing in the legislative framework on brownfield rehabilitation. • Integrative concepts for reintegration of rehabilitated sites into the economic cycle have to be developed. • Although immense surfaces are registered as derelict land through Europe, green-land consumption is still growing every year. The threat that industrialised and highly urbanised countries will be faced with land planning problems in cities is great. Management tools taking care of derelict land surfaces are missing for decision makers. 10 • Scientific proven tools for identifying the responsible parties for contamination are missing. Those tools are necessary to help the authorities to enforce the polluter- pays-principle for land remediation in particular in the brownfields situation. • The implementation of in-situ physio-chemical techniques often hurt the local authority’s sanction. Getting special permission from those authorities is often very time consuming. Administrative ways should be shortcut. • Regulation tools (acts, guidelines) for implementation of ecological quality standards are lacking or have to be reviewed • Legislative tools for investigations and criminal action measures on contaminated sites have to be improved c) Financial and legal guaranties for investors are missing • There exist a legal and also economic problem between brownfields and greenland redevelopment. There is a competition between greenlands and brownfields as the economical and legal risks are higher for investors by buying brownfields. A.II Structural organisation Co-operation strategies among different institutional levels are not improved • The management and co-ordination efficiency of public control authorities is not organised very efficiently, new organisation models have to be developed and harmonised. • Efficient management systems of public funds among different institutional levels are necessary for implementing effective and specific remediation measures. The problem is more specifically to get the right amount of money at the right place at the right time in order to keep the clean-up schedule to other needs of society especially in the case of brownfield redevelopment. • Contaminated land management skills of local administrators can’t be considered as sufficient in many countries considering the complexity of the problems. Scientific, legislative as well as administrative basics should be part of an education program. B. Communication B.I Public Relations a) The public concerned by a contaminated site is not enough involved in the process of site management • Public acceptance of remedial objectives and future land planing, technical remedial measures, adverse environmental side effects, nuisances e.g. noise pollution is not considered enough by planning rehabilitation measures on a contaminated site. b) The general public is not well informed about the risk associated to contaminated sites in general [...]... remediation technologies are not available An overview of the situation concerning brownfields and regulatory and financial framework is not existing in many member states - the dimension of brownfield problems is not known yet Problems in the redevelopment of brownfields: - lack of site-specific information on the environmental condition of land - absence of mechanisms that foster the alliance among stakeholders... for redevelopment of formerly contaminated land are often not available 11 • • • • Socio-economic rehabilitation plans of several industrial areas are missing Many of the national interest sites through Europe represent abandoned industrial contaminated land to be redeveloped In these areas integrative concepts for reintegration of rehabilitated sites into the economic cycle are often missing It can... research on environmental risk issues and general public information on risk perception is not enough developed Specific educational and national research programs are still lacking Estimations on how the environmental risk perception is understood by the general public are lacking There is no feed-back from the public towards the contaminated land managers Public’s perception of risk is not integrated... reluctant for buying brownfield sites The economical and legal risks are not predictable C.II Cost efficiency • • Instruments that enable objective estimates of risks, costs and benefits for cleaning-up contaminated sites have to be developed and optimised There is no tool available for the assessment of technical and socio-economic feasibility of different clean-up solutions according to land use 12 ... is not integrated in contaminated land management schemes B.II Dissemination of information and database availability concerning contaminated land is not sufficient in all countries a) Information flow from more experiencd countries to lower experienced countries should be improved • An international platform for the exchange of information between countries, specialised organisations, private companies... of rehabilitated sites into the economic cycle are often missing It can be summarised that this issue is linked to the problems of decreased industrial production and unemployment The regions concerned are missing new economic activities Effective methods for cost sharing of groundwater clean-up among different site and problem owners on intensively industrialised areas are lacking The general legal... mechanisms that foster the alliance among stakeholders B.III Links between field work and laboratory experiments Relation between engineering offices / cleaning companies and research institutes • Structures for information exchange between experimental level of upcoming technologies and their application on field are missing Information exchanges have to be improved in order to assure efficient investment . has been structured on a Risk based Site Management approach according to the CLARINET Conceptual Paper. RISK A. Determination of Risk A.I Technical and. ecosystems and geology) • Efficient risk assessments are difficult to be carried out in case of the presence on site of a multitude of pollutants, pollutant fractions