European Action Plan Theme Pollution prevention, detection and mitigation
Contents
Theme rationale
Pollution is defined as the state of water when it contains a large amount of foreign materials so that it is no longer fit for its intended use, whether it is drinkwater, cold water for the cooling of engines, or clean water for tourism. This topic, which is of utmost importance for the European commission and national governments due to a number of events which occurred in the last years, covers a broad scope of knowledge including chemical processes of pollutants synthesis, hydraulic transport of compounds, biological impacts on human health or ecosystems, socio-economic consequences of a pollution event and engineering techniques for the mitigation of pollutions. The issue of observing the state of pollution and improving water quality near coastal zones has been addressed in different ways in most coastal countries, through regulations and the organisation of alert and protection systems.
However, in spite of the great efforts which have been made in the past years to reduce the number of accidental pollutions and the impacts of chronic pollutions in coastal zones, one cannot but notice a large step still has to be taken in order to improve the understanding of sources and consequences of pollution and to create better warning procedures and reliable tools to mitigate the impacts of pollution.
Theme objectives
A bad water quality endangers human activities in the coastal zones as well as the environment. Diverse source of pollution threaten the water quality and may be sorted in mostly two types:
- accidental pollutions which occur after some catastrophic events, are unpredictable and may have a huge impact on water quality, but mostly on a short-term basis, and of which examples are ship accidents and industrial accidents with their environmental impacts due to oil spill or chemical pollution;
- chronic pollutions due to regular human activities: discharge of oil and paintings from ships, harbour runoff containing a mixture of contaminants (oils, oil emulsifiers, solvents, detergents, bleach), ship's passages and dredging operations which increase the suspended solids contents in water and involving sediments likely to hold heavy metals and organic micro-pollutants, diffuse land-based pollution resulting from agriculture, industry and urban settlement, regular discharge of wastewater from coastal outfalls.
According to the type of pollution, different measures have to be taken to mitigate their impacts and improve their management. For accidental pollutions, the critical point is how the consequences of the accident are being dealt with, first based on an adapted alert system in order to inform authorities and allow them to take decisions while pollutants are still concentrated in a limited territory, then by making tools to evaluate in real-time the evolution of the pollution state and finally be developing and giving access to new technologies and tools for mitigating the impacts of the pollution. For chronic pollutions, which are well known and can be studied and understood by scientists, the development of observatories may help to identify the most threatened areas and establish priorities for their mitigation. Further analysis can be carried out to find the pollution source and the tools to reduce the pollution level include adaptation techniques as well as strong regulations from local or national governments.
Based on what was was agreed by scientists and practitionners in the first Encore meetings, theme 4 is focused on two main unresolved issues:
- Observation and monitoring of pollution: the purpose is first to improve the observation systems and the sharing of information regarding priority substances defined by the EU and the program OSPAR. Pollutants have to be characterized, along with their impacts on biotopes and human health. Sources of chronic pollutions also have to be investigated. This goes through a preliminary diagnosis of pollution state in European coastal seas. A transnational approach has to be adopted since a release of pollutants in a national coast may often have impacts on neighbour countries. In order to target the most endangered sites, a map of pollutants loads (which is different from pollutants amount as it includes a measure of vulnerability) may be drawn from the results of the monitoring system.
- Improvement of risk management with respect to the ecosystems: risk management is an important part of pollution mitigation. A decision making process has to be set up to assess sanitary impacts of pollution. Vulnerability indexes and sensitivity maps may then be established. Impacts of pollution, including non-direct consequences, for instance on the food chain, can be predicted and evaluated. Since this major goal needs knowledge related to multiple domains and support from users, public and practitionners have to be involved in all the steps of the process, which leads to the necessity of a strong participation process.
In order to reach this goals, theme 4 wishes to create a global understanding of the underlying physical and chemical processes related to water quality and pollution by offering scientists, practitionners and decision makers a way to share their points of view on the topic. The aim is to develop networking between stakeholders, engineers, scientists and legislators working in the field of coastal pollution. These actions should lead to develop guidance on analytical methods to assess the pollution state, guidance on the behaviours of pollutants and contaminants and their interaction on a long-term basis, to develop a decision making process to help reduce the level and impacts of pollution.
State of the art conclusions
Maritime pollution and water quality are highly shifting topics and techniques and policies related to them are in constant evolution, gradually integrating new aspects when major events occur through the world sometimes resulting in human or ecological losses but always involving a progressive awareness of the threats and vulnerabilities and feeding the improvement of mitigation techniques and prevention policies.
As shown by the analysis, main pollutants which have to be taken care of in Europe include chemical compounds, such as nitrates and phosphates with their effects on eutrophication or anoxya of coastal areas, heavy metals which accumulates in organisms and have strong impacts on their health, oil resulting from regular sailing activities, biological compounds like hormones (endocrine disruptive compounds) and physical processes, for instance the intrusion of saltwater in coastal aquifers resulting on their being improper for drinkwater.
A lot of initiatives have been carried all over Europe and have led to the development of measurement tools, mitigation techniques, and analytical models to help predict the fate of these pollutants. Transport and dissemination models are implemented by universities, but only seldom used for operational goals. Observation and measurement techniques exist but their use has not become common yet. Risk analysis methods have also been developed and tested on specific areas. Nevertheless, all these actions are local initiatives which could benefit from being shared at a European level.
In the same time, while catastrophic events helped to raise the awareness of pollution consequences, national governments followed by the European commission began dealing with the problem by elaborating recommendations and establishing new laws to regulate human activites, based on current scientific studies. Good examples of these first regulations are the Water framework directive, the marine strategy directive and the new greenpaper for a EU maritime policy. Those policies still have to demonstrate their efficiency for water quality management.
As a conclusion, the state of the art elaborated by theme 4 members points that work still has to be done to improve knowledge and practice for three major unresolved issues:
- observation and monitoring of pollution;
- risk management;
- analysis of the fate and impacts of pollutants.
Objectives of the actions plan
Since there is some cross-over between theme Water quality and other scientific-related topics of the Encora project (adaptation to climate change, restoration of biodiversity in coastal zones, effects of development on coastal habitats), most of the discussions between theme 4 participants at the Paris conference did not deal with physical processes but addressed the current state of pollution in European countries and techniques which can be applied to mitigate the impacts of chronic pollutions.
To launch the discussions, participants were asked to do a small presentation on a specific topic of water pollution based on their field of knowledge, their own experience and their national context. Three issues were thus identified:
- Sediments contamination: this includes the transformation of contaminants trapped in sediments and the fate of pollutants during dredging. One major source of pollution is the human activities resulting of contaminants deposition in sediments, in river or harbours. During dredging, these sediments with their pollutants may contaminate natural biotopes and threaten wildlife.
- Physical processes: although this field is commonly thought as well understood, one has to admit that no reliable operational tool or system has been implemented to predict in real time the fate of a pollutant, for example to estimate the dissemination of petrol after an oil slick. A nice example would be the Prestige oil slick in 2002, for which no model was able to predict on which coastal area oil would settle. However decision making processes would benefit a lot of those systems. Other processes, like saltwater intrusion in coastal aquifers, starts to be taken into account but mitigation techniques have yet to be discovered.
- Impacts of pollutants: many presentations dealt with the impact of pollutants on human health or on ecosystems. Eutrophication and anoxya result from high concentrations of contaminants and are a real threat to biological organisms and, in some cases, for economic activities relying on these products. Numerous examples of polluted waters were given and analysed, from eutrophication near Portugal coasts to anoxya in the Baltic sea.
Agreed final actions plans
As a result of the discussions between theme 4 participants, the following tables show the two issues which were considered of utmost importance. There are still knowledge gaps in these fields which have to be bridged and a particular effort has to be made by decision makers to take these issues into account in the next actions plans.
| The fate and impacts of contaminated sediments | |
| Development of ship traffic, bigger ships
Increased risk of indirect impacts due to dredging and change in dynamics Lack of appropriate knowledge to support regulations | |
| Better understanding of interactions between pollutants, sediments and bottom water, including integrated assessment of ecological and socio-economic impacts leading to harmonisation of regulations | |
| Scoping exercise of different regulations in Europe, and of current state of contaminated sediments, inventory of quantity and quality of contaminated sediments in Europe
Fundamental research and coupled transport-biogeochemical modelling Data acquisition with full scale experiments Development of an appropriate ecosystem health index Involvment of local practitioners : port authorities, dredging companies, fishermen |
| Quality of nearshore and transitional waters | |
| Pressure of human activities in the coastal zones, including coastal watershed
Climate change | |
| Understanding and forecasting of transport and mixing of pollutants in nearshore waters
Interaction between groundwater and sea water Alterations in biogeochemical processes and nutrient and oxygen conditions Assessment of forcing factors controlling biodiversity and ecosystems functioning Socio-economic evaluation of impacts | |
| Fundamental research about transport and mixing processes at different spatial and temporal scales
Use of remote sensing and modelling tools for forecast and scenario analysis Optimizing design of observation and monitoring networks for surface and groundwater Integrated assessment of nearshore and transitional waters (eutrophication and anoxia, biological and chemical pollutants) Conceptual tools and protocols for long term assessment of impacts of pollution on ecosystems Development of sensitivity index and sensitivity and vulnerability maps |
Preliminary work before Paris conference
| Dredging of contaminated sediments.
Many water and port managers face the continuous effort of dredging in order to maintain the required water depth. Europe-wide, the volume of dredged material is very roughly estimated at 200 million cubic metres per year. Maintenance dredging is mainly to keep waterways (e.g. ports and navigation channels) at a defined depth to ensure safe navigation, and remediation dredging is to solve environmental problems of contaminated sediments. Sediment contamination mainly leads to problems in maintenance dredging because given standards or regulations do not allow the free disposal in the aquatic system. | |
* Dredging is mainly done in the coastal or marine environment. While international guidance has existed for many years to minimise the ecological effects of dredging and open water disposal, European legislation for handling dredged material is complex, because dredged material is at the borderline of water, soil and waste policies. European legislation affects the management of dredged sediments in upland areas, like the waste legislation, especially the EU Landfill Directive, and possibly the Habitats Directive, but do not deal adequately with sediment.
Tools currently available:
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* the existing contamination of sediment may exceed the relevant quality targets and may lead to a widespread distribution of contaminants in coastal and marine waters with a correspondingly widely increased sediment contamination level
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* Development of, joint methods and strategies at European scale for sediment and dredged material management that link to the EU WFD and to pilot projects
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| The deterioration of the groundwater in coastal zones due to saltwater intrusion | |
| Human activities in the coastal areas have been intensified in the last decades. This led to the increase of the water demand in the coastal zone. In many cases this demand is covered by increasing the groundwater quantity pumped out from the coastal aquifers. Increased pumping enhances saltwater intrusion.
Further, increased human activities in the coastal zone increase the sources of groundwater pollution. Land derived groundwater discharges into the sea transporting pollutants such as nutrients, organics, bacteria etc, into the near shore environment. The impact on the ecosystem depends on the magnitude of SGD, on the mixing intensity of SGD in the near shore sea and on the exchange rate between the near shore sea and the open ocean. The problems to be solved are (a) to develop efficient tools for monitoring and control of saltwater intrusion into the coastal aquifers and (b) to develop tools for determining the impact of submarine groundwater discharge on the near shore environment.
In coastal areas, in which observation wells exist, decision makers can, based on the monitoring results, predict the development of the saltwater intrusion process in space and time using existing appropriate methods. If the predictions show that saltwater intrusion threatens production wells, the technique of artificial groundwater recharge can be used in order to reduce the salt water invasion. In cases that fresh water is not available for groundwater recharge, the use of sufficiently treated wastewater has been proposed. This procedure can fail in cases that observation networks have not been appropriately planned. It is not unusual that saltwater intrusion is recognized through too high salinities in the pumped groundwater. Further, not in all cases fresh or treated water is available for discharge. | |
| The anticipated breakthrough is the development of methods for efficient planning of monitoring well networks, so that the dynamic of the saltwater intrusion process can be safely monitored. A further breakthrough is the development of methods to prevent saltwater intrusion in cases that no water is available for groundwater recharge. Such a method is the formation of barriers by the crystallization of gypsum injected in the aquifer, which has been proposed in the last years, but it is not yet mature for field applications. | |
| This breakthrough can be achieved (i) by performing numerical investigations for heterogeneous aquifers in order to develop criteria for the optimal planning of groundwater observation wells, (ii) by analyzing the behavior of existing observation networks in coastal aquifers along the European coast and (iii) by applying the criteria of optimal planning in new installations.
Concerning the prevention of saltwater intrusion a breakthrough can be achieved by developing the method of gypsum injection to a mature technique performing real scale experiments. |
| The transfer of land derived pollutants into the near shore seawater by submarine groundwater discharge (SGD) | |
| Human activities in the coastal areas have been intensified in the last decades. This led to the increase of the water demand in the coastal zone. In many cases this demand is covered by increasing the groundwater quantity pumped out from the coastal aquifers. Increased pumping enhances saltwater intrusion.
Further, increased human activities in the coastal zone increase the sources of groundwater pollution. Land derived groundwater discharges into the sea transporting pollutants such as nutrients, organics, bacteria etc, into the near shore environment. The impact on the ecosystem depends on the magnitude of SGD, on the mixing intensity of SGD in the near shore sea and on the exchange rate between the near shore sea and the open ocean. The problems to be solved are (a) to develop efficient tools for monitoring and control of saltwater intrusion into the coastal aquifers and (b) to develop tools for determining the impact of submarine groundwater discharge on the near shore environment.
Decision makers have to determine the magnitude of submarine groundwater discharge and the intensity of mixing in the near shore sea area. Except of some indirect indicators of submarine groundwater discharge and some information about its probable relatively wide range, no simple methods exist to determine the magnitude of submarine groundwater discharge. The same is valid for the intensity of mixing in the near shore sea. The lag of simple methods can lead the decision makers to ignore an eventually important process or to waste valuable resources on an unimportant issue. | |
| The anticipated breakthrough is the development of simple methods to determine the relationship between SGD-rate and exchange rate between the sear shore sea and the open ocean in areas of interest. | |
| A breakthrough can be achieved by investigating the reliability of SGD estimations based on groundwater models calibrated using groundwater level data, which are available in many cases. This is much simpler compared to measurements at the sea bottom or to estimations based on radium isotopes. |
| Distribution and short-time transformation of coastal zone bottom sediments | |
| Distribution of the bottom sediments within the coastal areas are characterized by fast transformation due to different extremely active natural and anthropogenic processes. Accordingly, the distribution of pollutants concentrated in specific sediment types can also rapidly be changed. | |
| Evaluation and prognosis of the sediment load, balance of transboundary sediment flows, detection and mapping of high sedimentation rate areas, as potential concentrators and possible sources of secondary contamination. | |
| Litho-facial differentiation, mapping of bottom sediment distribution, analysis of the maps of bottom sediments and remote-sensing data. |
| Eutrophication and anoxya in coastal areas | |
| Presence of zones of eutrophication in coastal waters due to nutrients, in a lot of European countries. Eutrophication is a major issue in the Water framework directive, and has to be evaluated in transitional waters, coastal waters, and inland waters. | |
* Need to update drivers of pollution: price of oil may become a major driver with the increasing production of biofuels
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| Address all drivers at the same time: is building UWWT plants the only answer? What about CAP and farming practices? |
| Operational hydrodynamic and turbulent mixing models and observation systems | |
| Need of numerical tools to predict the fate of contaminants in coastal and transitional waters | |
* Comprehensive suite of coupled hydrodynamic-numerical and ecosystems models and to build a MMFS (marine management and forecast system) for different temporal and spatial scales of marine pollution (including wastewater, brine effluents, chemicals, oil spill,...)
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* Develop an observatory for monitoring the state of solid-splinters-based pollution and use it for operational forecast of transport based on long-term and high-scale numerical models
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List of participants
| Alice Newton | CIMA-Center for Marine and Environmental Research, Portugal |
| Doris Schiedek | Baltic Sea Research Institute Warnemünde, Germany |
| Hervé Thébault | Institut de radioprotection et de sûreté nucléaire, France |
| Evgeniy Yakushev | Southern Branch of Shirshov Institute of Oceanology, RAS, Ukraine |
| François Hissel | Centre d'études techniques maritimes et fluviales, France |
| Vassilios Kaleris | Department of Civil Engineering, University of Patras, Greece |
| Maurizio Brocchini | Istituto di Idraulica e Infrastrutture Viarie, Università Politecnica delle Marche, Italy |
| Philippe Sergent | Centre d'études techniques maritimes et fluviales, France |
| Renata Archetti | Università di Bologna, Italy |
| Roberta Guerra | Interdepartmental Research Centre for Environmental Science, University of Bologna, Italy |
| Andreas Rummel | Istituto di Idraulica e Infrastrutture Viarie, Università Politecnica delle Marche, Italy |
| Anabela Oliveira | Estuaries and Coastal Zones Division, Hydraulics and Environment Department, National Civil Engineering Laboratory, Portugal |
| Norbert Theobald | Federal Maritime and Hydrographic agency, Germany |
| Abdellatif Ouahsine | Université de technologie de Compiègne, France |
| Loïc Kerambrun | Centre de documentation, de recherche et d'expérimentation sur les pollutions accidentelles des eaux, France |
| Elena Nesterova | A.P.Karpinsky Russian Research Geological Institute (VSEGEI), Russia |
