The Austrian strategy of sustainable development (BMLFUW 2007) refers to a reduction target of 1 hectare sealed soil per day - to be reached by 2010 - but current trends are far above this. If the three-year period 2007-2009 is compared with the previous period 2004-2007, only the Provinces Vorarlberg, Salzburg and Vienna show lower consumption rates in the second period.
(When interpreting trends based on regional information uncertainty and time-lag of data used has to be expressly mentioned.)
Diffuse contamination. Soil surveys of four heavy metals - mercury, lead, cadmium and copper - showed increased lead and cadmium concentrations in topsoil in the Northern and Southern Limestone Alps. (see Maps of the distribution of heavy metal contents in topsoil). This may be attributed both to local sources of pollution and to long-range trans-boundary air pollution.
Lead enrichment is particularly relevant in grassland and forest soils - in the latter due to the high filtering effect of the vegetation cover. In such sites, the guidance values for lead established by the Austrian Standard (ÖNORM 2004a) were exceeded in more than 5% and 3% of the monitored sites respectively.
Cadmium concentrations exceeded the guidance value in 5% of the monitoring sites in forests and 6% in grassland areas.
Copper and mercury pollution only occurs in restricted areas such as those surrounding industrial sites that process copper ore and in areas with intensive animal husbandry (BORIS 2009). The latter is due to the application of high amounts of pig manure with high copper content - the result of copper-enriched ready-made feed. Other sources of copper are sewage sludge, compost and pesticides containing copper. About 2% of the forests and grasslands monitored exceeded the guidance value for copper (Umweltbundesamt 2007).
Persistent Organic Pollutants (POPs) contamination was found in a limited number of sites. Pollution mainly occurs in urban areas and around industries, but can also derive from long-range transboundary air pollution. Emissions of POPs have been substantially reduced in the past years, but a systematic survey of results is not available. For this and other reasons, such as the low mobility of these pollutants and newly marketed chemical products, the importance of the problem may increase in the future (Umweltbundesamt, 2004 and 2007b).
Contamination from local sources. In Austria, a distinction is made between contamination generated before 1989 and new contamination. This paper discusses historic contamination only.
(According to the legal definition historically contaminated sites are either former waste deposits or industrial sites, which - on the basis of a risk assessment - pose a significant threat to human health and the environment. In this context the surface, the subsoil, and in particular the underlying groundwater body are considered.)
As of January 2009, 248 areas appear in the Register of Contaminated Sites on the basis of investigations and risk assessments. These either need to be secured or require remediation measures - 97 of these sites have already been secured or remediated. Securing or clean-up measures are already underway for 92 of the remaining 151 contaminated sites (Umweltbundesamt 2009c).
There are an estimated total of 72,000 potentially polluted sites of which 74% have already been identified. The number of contaminated sites is estimated to amount to 2,050 sites, of which 17% have been identified and about 9% remediated (BMFLUW 2007, Umweltbundesamt 2009c).
Salinisation is of minor importance in Austria. According to a survey carried out in the period 1958-1970 (agricultural soil mapping), the areas affected amounted to just 2,500 ha. In addition, soda-containing soils are estimated to cover 2,000 ha. In these areas, strict rules for agricultural production apply.
To date, salinisation only occurs on a very small scale in eastern areas and is generally characterised by a negative water balance, salt-sensitive soils, a low groundwater table and salty groundwater. Future changes in climate and inappropriate land management practices could induce more salinisation of soils.
Erosion by water could potentially affect about 13% of agricultural land or more than 5% of Austria's territory. The spatial distribution of potential erosion risk is very heterogeneous. The most affected areas include the productive southeast and northeast plains and hills, the Alpine foreland and the Carinthian basin (Strauss and Klaghofer, 2006).
Information on wind erosion is scarce, although it has been observed in the lowlands of eastern Austria since the 18th century. Areas at risk are typically those with sandy soils and, in the dry season, some areas covered with black soils (chernozems). In the past, some protective measures, such as reforestation of lowlands, were carried out - today, new windbreaks are planted annually, increasing the areas protected by several thousand hectares a year. Early recognition of the problem and measures adopted have resulted in the stabilisation of erosion in these areas. (Strauss and Klaghofer, 2006).