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Groundwater Protection in Selected Countries

4. Groundwater Protection

4.1 Preventive measures

4.1.1 Well field protection areas

There are currently no direct provisions in legislation nor practice of defining an area in the immediate proximity of a well field for the purpose of protecting the well field.

4.1.2 Aquifer protection zones

The Hydrological Plans of Basins, 1998 is the theoretical instrument for implementing protection zones as defined in the Water Law. These zones are to be determined according to a schedule which depends on the number of people that the water supply serves:

> 15,000 people 10 years
2,000 – 15,000 20 years
< 2,000 not defined

Since these regulations are new, zones have not yet been defined and approved.

There are 12 Hydrological Plans made by the Drainage Basin Authorities and 4 additional plans prepared by certain autonomous regions. These Plans have been prepared prior to the preparation of a Nation Plan for Basins. A National Plan is currently under preparation by the Ministry and may result in the need for some revisions of the 16 basin plans mentioned above.

This National Basins Plan will not likely be specific in exactly how the zones are to be defined. In an example for the Guadalquivir plan, however, mention is made of a zone of 1-2 km radius, which is to be defined for certain water supply wells.

Following the delineation of zones, the major challenge of implementing certain restrictions within these zones will have to be met. This will be the responsibility of the municipalities, who will find it difficult or impossible to find the financial resources necessary to carry out these restrictions.

4.1.3 Mapping of vulnerability

Already in the 1980’s, a number of maps showing the vulnerability of groundwater have been prepared through contracts directly between the some of the Drainage Basin Authorities and the Instituto Tecnológico de Geominero de España. Maps for a total of 5 of the 9 basins in Spain have been prepared (Fernandez, 1999). The maps are on a scale of approximately 1:50,000. The two factors which have been used to determine the vulnerability are lithology and depth to water.

An additional study of various methods for determining vulnerability has been prepared in the region of Guadalquivir. Here, international methods such as DRASTIC and GOD were used.

4.2 Remediation of existing problems

4.2.1 Prioritising contaminated sites

The contaminated sites that are listed on the national inventory have only undergone a limited investigation. On the basis of this investigation, an initial risk assessment is made in order to place sites into one of three categories with respect to the acuteness of the problem: short term medium term and long term. Official de-listing of contaminated sites has not yet taken place.

Two motivating factors for remediation are aquifer contamination and the possibility of the site being urbanised after clean-up. The autonomous regions decide how to weight these factors. Due to the lack of financing, it is likely that the remediation of sites which have the possibility of being urbanised after clean-up will be most frequent.

To date, remediations have mostly involved capping of landfills and urbanisation of brownfields.

4.2.2 Criteria

The Waste Act of 1998 states that the government must set minimum clean-up criteria for contaminated soils. The current intention is to develop these soil criteria for 100-120 hazardous substances. The first criteria are expected to be set in the fall of 1999.

No groundwater or soil gas criteria have been set.

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