The need for strengthened national and international measures to prevent, control and reduce the release of hazardous substances into the aquatic environment and to abate eutrophication and acidification, as well as pollution of the marine environment, in particular coastal areas, from land-based sources.
Water resources in many shared systems are already heavily contaminated. Highly toxic substances are being found more and more, even in the international rivers, lakes and aquifers of developing countries.
The aquatic environment provides a basic resource for all kinds of ecosystems and human activities. Therefore, the sustainable use of such a vital resource is paramount. There is a need to prevent, control and reduce the pollution of waters, including transboundary waters, to ensure that water resources are used with the aim of ensuring integrated and sustainable management, in a reasonable and equitable way, as well as of protecting or restoring aquatic ecosystems at the local, national and transboundary levels. Water-quality objectives are an important supplementary instrument to prevent, control and reduce water pollution. The whole catchment area has to be considered the natural unit for water management. As most problems related to transboundary waters are common problems of water management at all levels, cooperation on the protection and use of transboundary waters, including the fair distribution of water resources, would also help to improve the management of internal waters.
"Transboundary waters" means any surface or ground waters which mark, cross or are located on boundaries between two or more states; wherever transboundary waters flow directly into the sea, these transboundary waters end at a straight line across their respective mouths between points on the low-water line of their banks.
Article 2(7) of the Draft Protocol on Water and Health (1999) to the Convention on the Protection and Use of Transboundary Watercourses and International Lakes (1992) states: "transboundary impact" means any significant adverse effect on the environment resulting from a change in the conditions of transboundary waters caused by a human activity, the physical origin of which is situated wholly or in part within an area under the jurisdiction of a Party to the Convention, within an area under the jurisdiction of another Party to the Convention. Such effects on the environment include effects on human health and safety, flora, fauna, soil, air, water, climate, landscape, and historical monuments or other physical structures or the interaction among these factors; they also include effects on the cultural heritage or socio-economic conditions resulting from alterations to those factors.
Many world leaders have realized that the very viability of the societies and economies of their countries is at stake and cooperative action has begun. International assistance has also been mobilized where national attempts to organize bilateral or multilateral cooperation or collaboration have been ineffective. Engaging qualified people and financing such studies, which are not revenue-producing, remain prime constraints, and not only for developing countries.
In 1985 in Bucharest, the Danube states adopted a declaration concerning cooperation in relation to problems of water management in the River Danube, particularly the protection of its waters against pollution. They agreed to pay special attention to the prevention of pollution by dangerous and radioactive substances, to gradually reduce the level of pollution, to monitor systematically the quality of the effluents discharged into the River Danube, to authorize the discharge of these effluents in accordance with their legislation and to verify compliance with these provisions within the framework of bilateral and multilateral cooperation in accordance with programmes and methods permitting comparable data to be obtained. The governments also agreed to inform each other about technical solutions for water purification, water quality analysis and research methods and national water quality standards. Danube water quality meetings would be held to compare results and evaluations and to deal with other questions. The end result is to "establish a consolidated water-economy balance of the River Danube".
The Environmental Programme for Europe recommends: (1) promoting water demand management, including the use of differentiated charge rates in accordance with the polluter-pays principle or the beneficiary/user-pays principle, and water-conservation measures; (2) minimizing to harmless levels discharges into transboundary waters from point and non-point sources likely to cause adverse transboundary impacts; (3) setting up compatible information systems that provide reliable data on the quality and quantity of surface waters and groundwaters as well as on consumption patterns; (4) implementing in a transboundary context and by way of agreements between riparian parties, sustainable water management schemes established by joint bodies in consultation with water users within the framework of existing agreements including the restoration of transboundary aquatic ecosystems and transboundary watercourses; and (5) establishing programmes for assessing quality and quantity in transboundary waters, and develop appropriate programmes for improving their quality, including the monitoring of pollution from point and diffuse sources and of the effectiveness of measures taken.
Article 3 of the Convention on the Protection and use of Transboundary Watercourses and International Lakes, 1992 requires parties to prevent, control and reduce transboundary impact, and develop, adopt, implement and, as far as possible, render compatible relevant legal, administrative, economic, financial and technical measures, in order to ensure, inter alia, that: (a) The emission of pollutants is prevented, controlled and reduced at source through the application of, inter alia, low- and non-waste technology; (b) Transboundary waters are protected against pollution from point sources through the prior licensing of waste-water discharges by the competent national authorities, and that the authorized discharges are monitored and controlled; (c) Limits for waste-water discharges stated in permits are based on the best available technology for discharges of hazardous substances; (d) Stricter requirements, even leading to prohibition in individual cases, are imposed when the quality of the receiving water or the ecosystem so requires; (e) At least biological treatment or equivalent processes are applied to municipal waste water, where necessary in a step-by-step approach; (f) Appropriate measures are taken, such as the application of the best available technology, in order to reduce nutrient inputs from industrial and municipal sources; (g) Appropriate measures and best environmental practices are developed and implemented for the reduction of inputs of nutrients and hazardous substances from diffuse sources, especially where the main sources are from agriculture; (h) Environmental impact assessment and other means of assessment are applied; (i) Sustainable water-resources management, including the application of the ecosystems approach, is promoted; (j) Contingency planning is developed; (k) Additional specific measures are taken to prevent the pollution of groundwaters; (l) The risk of accidental pollution is minimized.