A vízminöség és szabályozása

Translated title of the contribution: Water quality and its management

L. Somlyódy, B. Hock

Research output: Contribution to journalArticle

Abstract

Changes and management of water quality are decisive areas of water management, and also of the concern of the public. In the past decades several studies and papers were dealing with the quality of surface- and subsurface water in Hungary. Less favourable is the case with pollutant discharges (emissions) and the literature on the strategic questions of the future of water quality can be considered a very modest one. The joint discussion of these three fields is seldom needed and made. An attempt to do this is made in this study. This task is rendered very timely by Hungary's accession procedure: we must make an "inventory" and answer the question "how to step forward". Evaluation of the water quality of streams was based on the data of 239 monitoring sites and on four water quality constituents (CODp, TP, Total coliform count, chlorophyll-a). Aggregated water quality classes were defined for 23 regions of the country. We have calculated for a given parameter the average value of the classes identified (classes 1-5) for all stations of the region, not weighed with flow. The thus obtained areal-averaged water quality is shown in Figure 1. This regional data processing indicates well that the heaviest water quality problems are related to bacterial conditions and to nutrient loads. The shallow lake mostly endangered by eutrophication is Lake Balaton. The deterministic algal growth limiting parameter is phosphorus. Before the reduction of nutrient loads chlorophyll-a exceeded sometimes 200 mg/m3. The elements of an overall water quality management strategy, that have already been implemented, have decreased the external phosphorus load of the lake by about 40%. The conditions of subsurface waters were characterised with the help of the most widely used drinking water treatment technologies (Figure 2.), in conformity with the presently valid Hungarian standard and the EU guidelines. According to these guidelines the water quality class is defined by the level of complexity of the water treatment technology applied. For near-surface ground-waters it may be stated that they are heavily polluted and cannot be used for drinking water supply. A characteristic "by-product" of the present economic situation of larger region is the increasing number of accidental pollution events and their increasing severity. They stem from technological failures, improper storage and handling of wastes and also from carelessness. These lead to incidents such as the catastrophic cyanide accident and heavy metal pollution incidents (of Rumanian origin) of the year 2000. These incidents were by orders of magnitude higher than any other accident observed in Hungary before and can only be compared to the case of the Sandoz accident of the River Rhine. In respect to emissions it can be stated that the majority of the estimated total CODd load of 177 kt/year falls into the Danube Basin 75%). 80% of this is discharged directly into the Danube and within this 80% is the pollutant load of Budapest. In the Tisza River Basin the loads are more uniformly distributed. The ratio is 50-50% for the Tisza and its tributary rivers. Entrance and exit COD loads of the country and of the River Tisza are shown in Table III. In respect to nutrients we may state that in 1992 the total TN and TP emission discharges were 85 kt/year and 17 kt/year, respectively. Of the nitrogen diffuse (agricultural) sources accounted for 60-70%, while this ratio was only 30-40% for phosphorus. Karstic areas and areas without surface or near surface water tight layers render the underlying subsurface waters vulnerable to surface pollution. Exploration of the sources ( of about 2000 sites) of pollution of existing and future subsurface drinking water abstraction sites are under way and remedial actions are being planned. Water quality shows an improving tendency in the past 15 years. Annual mean values of certain selected stations are shown in Figure 5. Water quality improvement can be explained by various reasons: (a) Waste water treatment was intensified in Germany, Austria and also in Pozsony/Bratislava; (b) Industrial technologies were modernised (in Germany and Austria and also in the cellulose industry of East-Slovakia); (c) Economic recession and transition; (d) Spreading of "environmentally friendly" products. In estimating the expectable future trends of water quality we have tried to assess the impact of both Hungarian and foreign waste water discharges. On the basis of this assessment we may only state that the quality of water will likely be deteriorating, but will be better than that of the eighties of the past century. Due to the downstream-country character of Hungary, we have not much influence on these changes. The Water Framework Directive of the European Union, approved on the 14th of September, 2000, requests the co-ordinated preparation and implementation of basin-wide action programmes for entire river catchments (thus for the whole of the River Danube catchment), disregarding political borders. This imposes several tasks on Hungary, especially in the field of water quality management. The present Hungarian regulations do not comply with the requirements of the Framework Directive. The presently valid laws involve certain elements, which fit into this directive, but the basic institutions of the directive do not have appropriate weight. Compliance with the Framework Directive will require the review and modification of several Hungarian legislations and it also basically affects the bilateral agreements of Hungary with her neighbouring countries. We must also duly consider the proposals and guidelines on water quality of the Danube Convention, as well.

Original languageHungarian
Pages (from-to)486-524
Number of pages39
JournalVizugyi Kozlemenyek
Issue number3-4
Publication statusPublished - Dec 1 2000

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ASJC Scopus subject areas

  • Water Science and Technology

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