Dan Balteanu

The long term fate and environmental significance of contaminant metals released by the January and March 2000 mining tailings dam failures in Maramureş County, upper Tisa Basin, Romania

In January and March 2000 two tailings dam failures in Maramures County, northwest Romania, resulted in the release of 200,000 m3 of contaminated water and 40,000 tonnes of tailings into tributaries of the Tisa River, a major tributary of the Danube. The high concentrations of cyanide and contaminant metals released by these dam failures resulted in pollution and fish deaths not only in Romania, but also downstream in the Tisa and Danube rivers within Hungary, Serbia and Bulgaria. Following these accidents, a research programme was initiated in northwest Romania to establish metal levels in rivers affected by the tailings dam failures and to compare these to metal values in river systems contaminated by historic mining and industrial activity. In July 2000, 65 surface water, 65 river sediment and 45 floodplain sediment samples were collected from trunk streams and principal tributaries of the Lapus/Somes rivers (affected by the January 2000 spill) and the Viseu/Tisa rivers (affected by the March 2000 Novat spill) down to the Hungarian and Ukrainian borders, respectively. Sample analyses for Pb, Zn Cu and Cd show that metal contamination in surface water and river sediment decreases rapidly downstream away from presently active mines and tailings ponds. Concentrations of heavy metals in water and sediment leaving Romania, and entering Hungary and the Ukraine, generally fall below EC imperative and Dutch intervention values, respectively. However, Zn, Cu and Cd concentrations in river sediments approach or exceed intervention values at the Romanian border. The results of this survey are compared with earlier surveys to ascertain the long-term fate and environmental significance of contaminant metals released by mine tailings dam failures in Maramures County.

The solid state partitioning of contaminant metals and As in river channel sediments of the mining affected Tisa drainage basin, northwestern Romania and eastern Hungary

The solid state partitioning of metals and As in river channel sediments has been investigated along an 828 km study reach comprising the rivers Lapus, Somes and Tisa, using a 4-stage sequential extraction procedure (SEP) that identified 4 chemical phases: (1) exchangeable, (2) Fe and Mn oxides, (3) organic matter/sulphides and (4) residual. Peak total concentrations of As (240 mg kg−1), Cd (95 mg kg−1), Cu (24,500 mg kg−1) and Pb (21,100 mg kg−1) were found in the River Lapus immediately downstream of Băiuţ base-metal mine, with Zn concentrations (23,000 mg kg−1) peaking 2 km further downstream. Contaminant metals and As within samples close to Băiuţ mine were largely bound to sulphides (>92%). Ten km downstream from Băiuţ mine, however, Cd and Zn were found to be environmentally significant due to their strong association with the exchangeable phase (73 and 47%, respectively). Lead was found to be predominantly associated with Fe and Mn oxides (71%), but concentrations in the residual phase were relatively high in the upper Tisa. Copper was more evenly distributed between the 4 phases than the other 4 elements analysed. Elevated metal and As concentrations were found in the rivers Lapus and Somes downstream of polluted tributaries, but sites on the River Tisa had total metal concentrations below Dutch guideline values. The implications of the river sediment metal partitioning results on the environment are considered in light of Cd and Zn ‘exchangeable hotspots’ at sites on the Lapus and Somes Rivers.

Environmental and socioeconomic assessment of impacts by mining activities—a case study in the Certej River catchment, Western Carpathians, Romania

Background, aim and scopeIn the region of the Apuseni Mountains, part of the Western Carpathians in Romania, metal mining activities have a long-standing tradition. These mining industries created a clearly beneficial economic development in the region. But their activities also caused impairments to the environment, such as acid mine drainage (AMD) resulting in long-lasting heavy metal pollution of waters and sediments. The study, established in the context of the ESTROM programme, investigated the impact of metal mining activities both from environmental and socioeconomic perspectives and tried to incorporate the results of the two approaches into an integrated proposition for mitigation of mining-related issues.Study siteThe small Certej catchment, situated in the Southern Apuseni Mountains, covers an area of 78xa0km2. About 4,500 inhabitants are living in the basin, in which metal mining was the main economic sector. An open pit and several abandoned underground mines are producing heavy metal-loaded acidic water that is discharged untreated into the main river. The solid wastes of mineral processing plants were deposited in several dumps and tailings impoundment embodying the acidic water-producing mineral pyrite.MethodsThe natural science team collected samples from surface waters, drinking water from dug wells and from groundwater. Filtered and total heavy metals, both after enrichment, and major cations were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES). Major anions in waters, measured by ion chromatography, alkalinity and acidity were determined by titration. Solid samples were taken from river sediments and from the largest tailings dam. The latter were characterised by X-ray fluorescence and X-ray diffraction. Heavy metals in sediments were analysed after digestion. Simultaneously, the socioeconomic team performed a household survey to evaluate the perception of people related to the river and drinking water pollution by way of a logistic regression analysis.Results and discussionThe inputs of acid mine waters drastically increased filtered heavy metal concentrations in the Certej River, e.g. Zn up to 130xa0mg L−1, Fe 100xa0mg L−1, Cu 2.9xa0mg L−1, Cd 1.4xa0mgL−1 as well as those of SO4 up to 2.2xa0g L−1. In addition, river water became acidic with pH values of pH 3. Concentrations of pollutant decreased slightly downstream due to dilution by waters from tributaries. Metal concentrations measured at headwater stations reflect background values. They fell in the range of the environmental quality standards proposed in the EU Water Framework Directive for dissolved heavy metals. The outflow of the large tailing impoundment and the groundwater downstream from two tailings dams exhibited the first sign of AMD, but they still had alkalinity.Most dug wells analysed delivered a drinking water that exhibited no sign of AMD pollution, although these wells were a distance of 7 to 25xa0m from the contaminated river. It seems that the Certej River does not infiltrate significantly into the groundwater.Pyrite was identified as the main sulphide mineral in the tailings dam that produces acidity and with calcite representing the AMD-neutralising mineral. The acid–base accounting proved that the potential acid-neutralising capacity in the solid phases would not be sufficient to prevent the production of acidic water in the future. Therefore, the open pits and mine waste deposits have to be seen as the sources for AMD at the present time, with a high long-term potential to produce even more AMD in the future.The socioeconomic study showed that mining provided the major source of income. Over 45% of the households were partly or completely reliant on financial compensations as a result of mine closure. Unemployment was considered by the majority of the interviewed persons as the main cause of social problems in the area. The estimation of the explanatory factors by the logistic regression analysis revealed that education, household income, pollution conditions during the last years and familiarity with environmental problems were the main predictors influencing peoples’ opinion concerning whether the main river is strongly polluted. This model enabled one to predict correctly 77% of the observations reported. For the drinking water quality model, three predictors were relevant and they explained 66% of the observations.ConclusionsCoupling the findings from the natural science and socioeconomic approaches, we may conclude that the impact of mining on the Certej River water is high, while drinking water in wells is not significantly affected. The perceptions of the respondents to pollution were to a large extent consistent with the measured results.Recommendations and perspectivesThe results of the study can be used by various stakeholders, mainly the mining company and local municipalities, in order to integrate them in their post-mining measures, thereby making them aware of the potential long-term impact of mining on the environment and on human health as well as on the local economy.

Sulfide oxidation and acid mine drainage formation within two active tailings impoundments in the Golden Quadrangle of the Apuseni Mountains, Romania

Sulfidic mine tailings have to be classified as one of the major source of hazardous materials leading to water contamination. This study highlights the processes leading to sulfide oxidation and acid mine drainage (AMD) formation in the active stage of two tailings impoundments located in the southern part of the Apuseni Mountains, in Romania, a well-known region for its long-term gold-silver and metal mining activity. Sampling was undertaken when both impoundments were still in operation in order to assess their actual stage of oxidation and long-term behavior in terms of the potential for acid mine drainage generation. Both tailings have high potential for AMD formation (2.5 and 3.7 wt.% of pyrite equivalent, respectively) with lesser amount of carbonates (5.6 and 3.6 wt.% of calcite equivalent) as neutralization potential (ABA=-55.6 and -85.1 tCaCO(3)/1000 t ) and showed clear signs of sulfide oxidation yet during operation. Sequential extraction results indicate a stronger enrichment and mobility of elements in the oxidized tailings: Fe as Fe(III) oxy-hydroxides and oxides (transformation from sulfide minerals, leaching in oxidation zone), Ca mainly in water soluble and exchangeable form where gypsum and calcite are dissolved and higher mobility of Cu for Ribita and Pb for Mialu. Two processes leading to the formation of mine drainage at this stage could be highlighted (1) a neutral Fe(II) plume forming in the impoundment with ferrihydrite precipitation at its outcrop and (2) acid mine drainage seeping in the unsaturated zone of the active dam, leading to the formation of schwertmannite at its outcrop.

Community Perception of Water Quality in a Mining-Affected Area: A Case Study for the Certej Catchment in the Apuseni Mountains in Romania

Mining-contaminated sites and the affected communities at risk are important issues on the agenda of both researchers and policy makers, particularly in the former communist block countries in Eastern Europe. Integrated analyses and expert based assessments concerning mining affected areas are important in providing solid policy guidelines for environmental and social risk management and mitigation. Based on a survey for 103 households conducted in a former mining site in the Certej Catchment of the Apuseni Mountains, western Romania, this study assesses local communities’ perceptions on the quality of water in their living area. Logistic regression was used to examine peoples’ perception on the quality of the main river water and of the drinking water based on several predictors relating to social and economic conditions. The results from the perception analysis were then compared with the measurements of heavy metal contamination of the main river and drinking water undertaken in the same study area. The findings indicate that perception and measurement results for the water quality in the Certej Catchment are convergent, suggesting an obvious risk that mining activities pose on the surface water. However, the perception on drinking water quality was little predicted by the regression model and does not seem to be so much related to mining as to other explanatory factors, such as special mineralogy of rock and soils or improper water treatment infrastructure, facts suggested by the measurements of the contaminants. Discussion about the implications of these joint findings for risk mitigation policies completes this article.

Heavy metals in potable groundwater of mining-affected river catchments, northwestern Romania.

Groundwater, accessed using wells and municipal springs, represents the major source of potable water for the human population outside of major urban areas in northwestern Romania, a region with a long history of metal mining and metallurgy. The magnitude and spatial distribution of metal contamination in private-supply groundwater was investigated in four mining-affected river catchments in Maramureş and Satu Mare Counties through the collection of 144 groundwater samples. Bedrock geology, pH and Eh were found to be important controls on the solubility of metals in groundwater. Peak metal concentrations were found to occur in the Lapuş catchment, where metal levels exceed Dutch target and intervention values in up to 49% and 14% of samples, respectively. A 700xa0m wide corridor in the Lapuş catchment on either side of the main river channel was identified in which peak Cd (31xa0μgxa0l−1), Cu (50xa0μgxa0l−1), Pb (50xa0μgxa0l−1) and Zn (3,000xa0μgxa0l−1) concentrations were found to occur. Given the generally similar bedrock geologies, lower metal levels in other catchments are believed to reflect differences in the magnitude of metal loading to the local environment from both metal mining and other industrial and municipal sources. Sampling of groundwater in northwestern Romania has indicated areas of potential concern for human health, where heavy metal concentrations exceed accepted environmental quality guidelines. The presence of elevated metal levels in groundwater also has implications for the implementation of the EU Water Framework Directive (WFD) and achieving ‘good’ status for groundwater in this part of the Danube River Basin District (RBD).

Primary Cause of Water Pollution in the Headwaters of River Cibin, Central Romania, With Special Reference to Sheep Overgrazing

Hydrological investigations were conducted through August into September 2003 and August 2004 on the River Cibin in the Danube drainage system on the northern slope of the Southern Carpathians, central Romania. The main purpose of the present paper is to clarify the actual circumstances of water pollution in the headwater basin due to human activity. The concentration of dissolved substances in the river water shows the maximum value at the uppermost observation point and decreases downstream due to dilution. Such a characteristic spatial change in river water quality is significantly affected by untreated household effluent and raw sewage from a settlement, which is located on the mountain ridge. During the summer season, a marked contamination of river water is found at some particular points where sheared wool is washed directly in the river channel. From the viewpoint of the primary factor affecting water quality, the river water in the watershed is clearly classified into four categories according to the difference in concentration and composition of the major dissolved substances. It is pointed out that the distinguishing features of water quality are consistent with the nature of both land use and water use.

Scenarios of Land Cover Change and Landslide Susceptibility: An Example from the Buzau Subcarpathians, Romania

Since 1990 the Subcarpathians in Buzau County, Romania have witnessed substantial socioeconomic changes and resulting changes in the land cover. Influenced by the interplay of poor economic conditions, land ownership reforms, and institutional difficulties, these changes have been difficult to manage, resulting in a dispersal of built-up areas. Even though, the spatial extent of land cover changes has not reached critical levels as similar areas in the Carpathians, our analysis suggests that in the future the area might experience more extreme land cover changes. Moreover, the litho-structural traits and the high relief energy of the Romanian Subcarpathians favored the occurrence of various types of mass movements, imposing different levels of risk to people, buildings and infrastructure. Increase of human influence in form of expansion of built-up areas in the area could therefore result in slope instability and changes in the temporal and spatial patterns of hydro-meteorological hazards. This study shows, that possible future changes in land cover will not have a major influence on hazards, however risk might increase due to the increased value and number of elements at risk.

Fostering Community Outreach Activities for Environmental Sustainability Through a Cross-Border Academic Research Partnership

The focal aim of this study is to provide a general framework of the role of an academic research partnership in fostering community outreach activities to improve environmental sustainability through developing tailored science-society interfaces. The paper seeks to present an overview of the EU Romania—Bulgaria Cross Border Cooperation Programme project entitled “Romanian—Bulgarian cross-border joint natural and technological hazards assessment in the Danube floodplain. The Calafat-Vidin—Turnu Măgurele-Nikopole sector (ROBUHAZ-DUN)” and, particularly, the research collaboration, scientific outcomes and dissemination activities carried out during the 18 month project. The aim of the paper is to offer an example of how to promote environmental sustainability to community members in a rural transboundary area in order to respond to their needs in terms of hazard assessment and mitigation, but also to increase knowledge and awareness of disaster risk reduction, climate change and environment sustainability. A special attention was paid to the main scientific and informative products (promotional materials, maps, posters, guidebooks, university course, reports) which were used as support materials for the dissemination activities undertaken throughout the project in terms of raising awareness and informative campaigns in schools, meetings with local authorities, joint round tables, media events, summer school etc. These activities were aimed at bridging the gap between the academic research and local communities in an area prone to natural and human-induced hazards in order to support environmental sustainability through disaster risk reduction education.

Economic Losses for Rural Land Value Due to Landslides

A high dynamic environment is typically interested by changes affecting the natural processes and their related consequences. Landslides do not only alter the landscape, but substantially affect human activities. When it comes to natural hazards, landslides have been acknowledged as one of the main causes of human casualties or damage to assets. Furthermore, economic losses to rural lands are also significant, despite often being underestimated, especially in rural areas. In territories not densely populated, the main productive activities are in fact often based on the agricultural and pastoral resources. We intend to propose a methodology that helps to investigate the potential loss of value (expressed in EUR) of lands usually exploited for economic profit in rural areas. We test the method on two case studies, belonging to different European Countries with very different economical assets and geological, geomorphological and other environmental conditions. The first study area is situated in the Southern Italian Apennines, in the Molise region, while the second area is located in Buzau County, a region belonging to the Romanian Curvature Carpathians and Subcarpathians Our analysis is focused not only on the actual situation, represented by the past and present landslides, but also on potential future scenarios for 2050. The scenarios foresee future similar socio-economical and technological activities, with no major changes expected. The loss estimation is based on the presence of landslides affecting the rural lands, but it also considers both a present and future landslide susceptibility scenario. This procedure allowed the estimation of the economic losses in the two case-study areas, highlighting how the same natural processes might result in different economic consequences. Following our approach, the results highlight that for the Italian case study there is a loss of 10,45% for 2007 and 9,90% for 2050 of the total land value as concerns landslides susceptibility. In the Romanian case study, on the other hand, the loss corresponds to 29,60% and 29,81% for 2010 and 2050, respectively. In addition, the proposed procedure could be considered a valuable methodological approach to assess landslide-induced economic losses, and be effectively used during spatial planning activities, aimed at supporting decision