Groundwater Protection in Selected Countries
4. Groundwater Protection
In the following sections, measures which are used in Austria for the protection of groundwater are given. To improve the overview, these measures are divided into measures which can be utilised to prevent contamination from happening (prevention) and measures which are used to tackle existing contamination problems (remediation).
4.1 PreventionPreventive measures are centred around the definition of wellhead protection zones and aquifer protection zones and pollution from diffuse sources as described below.
4.1.1 Wellhead protection zonesIn addition to a physical protection area on a smaller scale, protection zones around individual supply wells are usually set. These protection zones are declared by the local authorities under the Water Act. The size and shape of this protection zone are related to the catchment area of the well and a period of 60 days of groundwater flow. Originally, this was meant as a sanitary protective area. The authorities can define restrictions for current and future land-use within a wellhead protection zone.
4.1.2 Conservation areasThe Water Act also defines so-called conservation areas with the aim to protect water resources on a larger scale and to guarantee future water supply in general. The size and the shape of a conservation areas which has groundwater of importance for present and future water supply can be determined by special studies or can focus on river basins.
Conservation area declaration
Under the Water Act, a conservation area can be declared by federal authorities as well as by local authorities. Within this declaration, restrictions for current and future land-use can be defined. The declaration of a conservation area usually instructs the local authorities to give special consideration to water protection with respect to industrial operations and urban development.
Mapping
Since a declaration of a conservation area must include the delineation of its borders, there is a map for every conservation area. In addition, a general map of conservation areas in Austria is available.
4.1.3 Environmental challenges from diffuse sources of pollution
Quality of groundwater in porous media is endangered by both diffuse and point sources. In order to assess pollutants from diffuse sources, a Groundwater Threshold Value Ordinance has been issued. The threshold values in this ordinance were determined in accordance with the precautionary principle and are below (60 %) or equal to the drinking water standards. If these threshold values are exceeded in more than 25 % of the sampling sites within a groundwater body over a longer period, the provincial authorities have to co-ordinate remediation measures.
4.1.4 Mapping of vulnerability
A mapping of groundwater resources according to vulnerability has not taken place so far.
4.2 Remediation
4.2.1 Prioritising contaminated sites
Priority classes
Any site which threatens the groundwater or the environment in general must be declared as contaminated and listed in the Register of Contaminated Sites. This national inventory distinguishes between three classes of priorities which are described below. Since it is the intent of ALSAG to finance or fund remediation projects, the classification is a means to qualify environmental risks and to determine the urgency of financing and remediation of individual projects. Groundwater protection strategy and the targets of the Austrian Water Act are integrated in the overall process of risk assessment and prioritising.
The Act on the Clean-Up of Contaminated Sites (ASLAG) mentions five general aspects (e.g. actual and future spreading of contaminants; threatened objects and current use) for setting priorities. According to these aspects, contaminated sites are prioritised on a national scale by placement into one of the following three classes (simplified):
Class I (highest priority):
 | Actual groundwater contamination with significant emissions of pollutants. |
| Actual or potential contamination of public drinking water supplies, specially protected groundwater resources, or large areas. Risk of rapid spreading of pollution. |
Class II:
| Actual groundwater pollution with significant emissions of pollutants. |
| Groundwater resources polluted by a small area and the possibility of a further future spreading of the pollution is low. |
| No special protection of the local groundwater resource. |
| No future damages to drinking water wells expected. |
Class III (lowest priority):
| No actual pollution of groundwater or pollution of a groundwater resource of low flow rate and a low emission rate for pollutants. |
| No special protection of the local groundwater resource, no future damages to public water supply wells expected. |
Priority class proposal
Classifying a contaminated site requires a risk assessment and a proposal of a specific priority class by the Federal Environmental Agency. The risk assessment has to describe risks according to four receptors (groundwater, surface water, soil, air). The proposal of a priority class is an expert judgement, which includes the results of a scoring procedure. The threats a contaminated site poses to the four receptors of concern are judged and scored autonomously. The proposal must pass a public hearing of a political commission and comments of the local authorities.
At the end of 1998, the Register on Contaminated Sites contained 145 contaminated sites. A total of 110 of these sites has been prioritised. 34 sites have been assigned to priority class 1, 47 sites to priority class 2 and 29 sites to priority class 3. At these sites, receptors which were threatened are as follows:
| groundwater - 140 sites |
| surface water – 10 sites |
| gas (landfill gas) – 10 sites |
| soil (land use) – 9 sites |
Groundwater conservation zones, groundwater protection zones, affected wells and drinking water plants are all taken into account during the prioritising of contaminated sites. The actual practice of prioritising is in line with the intentions of the Federal Environment Agency since is carried out at a national level by the Agency itself. Nevertheless, difficulties are often experienced in initiating an urgent clean-up on short notice. This is due to the current legislation, which makes it possible for polluters to delay legal proceedings and also due to the fact that the regulations for the financial compensation of clean-ups driven by the authorities are not adequate.
4.2.2 CriteriaCurrent criteria
There is no federal law for soil protection. The Act on the Clean-up of Contaminated Sites (ALSAG) focuses on the funding of remediations. There are hardly any regulations defining targets or criteria for assessment and remediation within this act. Criteria for assessment and remediation are therefore basically driven by corresponding legislation such as the Water Act. This act sets out the targets for groundwater protection, as it generally demands the preservation of drinking water quality. Therefore, all contaminated sites must currently be cleaned up to an extent at which groundwater quality is returned to drinking water standards and at which no significant pollution of the soil remains.
Future criteria
Since the Water Act is dominated by the precautionary principle, there is an ongoing discussion to introduce the repair principle as a second approach with regard to contaminated sites. There are three possible targets or levels for the remediation of contaminated sites (ÖNORM S 2088-1):
| natural quality of groundwater |
| quality which allows for the multifunctional and sustainable use of groundwater |
| restoration with regard to current and future use |
Table 4.1 gives an overview of criteria as they relate to the three mentioned remediation targets.
Table 4.1.
Remediation targets and their criteria for clean-up.
Remediation |
Leachate or |
Downgradient |
Natural quality |
should meet drinking water standards |
Should meet a value of 60% of the drinking water standards |
Mulitfunctional use |
should not release significant amounts of pollutants to groundwater |
Should meet drinking water standards |
Current and future Use |
- |
Should not release significant amounts of pollutants to groundwater |
It is planned to include these targets in future legislation for contaminated sites. This
will require introducing "alternate concentration limits" for pore water and to
define "release of significant amounts" for both pore water and groundwater.
Types of criteria
In the Water Act there is no differentiation between "intervention values" and "target values" for the clean-up. In general, groundwater and pore water should meet drinking water standards. With respect to specially protected groundwater resources, the criteria for groundwater can be lowered to 60 % of the drinking water standard.
The ÖNORM S 2088-1 differentiates between "trigger values" and "intervention values". "Trigger values" mark concentration limits demanding further investigation and assessment whereas "Intervention Values" mark concentration limits which usually demand remediation activities. The derivation of "clean-up values" can take place site-specifically within the range between "trigger values" and "intervention values". The criteria set out in the ÖNORM S 2088-1 are included in Appendix 1.
4.3 CostsThere are no data available on the total costs of the management of the groundwater resources nor on the costs of land-use restrictions.