GROUNDWATER PROTECTION*)

An effort to maintain sustainable development and environmentally sound management of groundwater resources in Indonesia

by : Soetrisno S.

2. Efforts

On the basis of legal and technical aspects which has to be taken based upon the hydrogeological knowledge of a respective area, efforts have been made to protect groundwater resources, both in quantity and quality, which are as follows:

1. To restrict the extraction of deep groundwater.

   Restricted of licenses for industrial use is issued based upon the binding technical recommendation given by the Directorate of Environmental Geology, in order to restore water level.

2. Adjustment of groundwater strata extraction.

   In areas where the hydrogeological condition permits, extraction from the deeper aquifers has to be conducted.

3. To undertake artificial recharge into aquifers.

   During rainy season water can be collected from the roofs and infiltrated into wells in order to increase the recharge into the shallow aquifers. However, infiltration wells can be built only in areas where the hydrogeological condition is favourable.

4. To work out a plan and regulation for extraction of deep groundwater.

   Based on the result of investigations in the past years, a mathematical model for several groundwater basins has been established. This model gives scenarios, with annual schemes of rational extraction of deep groundwater, putting forth the optimum allocation plan for extraction at certain periods for different areas and different layers of aquifers.

5. To set-up groundwater protection areas.

   Groundwater protection areas addressed to spatial planning of a certain area in order to protect both the quantity and quality of groundwater resources. To determine groundwater protection areas, beside hydrogeological condition, actual land use and existing infrastructure have to be considered.

In this respect environmental geology has a deterministic role, since it provides or is able to obtain key information on the main factors. These include the occurrence and size of economic deposits, soil types, building or construction materials and above all, the availability of groundwater and the conditions for its protection. It is therefore necessary to compile environmental geological data in order to make it available for planners.

In view to the dense population and requirements for intensive land use in urban areas in Indonesia, it appears impossible to apply protection measures for all occurrences of explorable groundwater. On the other hand, no regulations are available to specifically govern the groundwater protection areas as mentioned before. Law No. 24 of 1992 and Presidential Decree No. 32 of 1990 give only guidance to manage protection areas in general. However, recommendable measures for groundwater quality protection in the urban areas have been set-up.

The requirements of groundwater protection in regional planning and land use developments in the urban areas can be formulated (Wagner & Sukrisno, 1991).

• New residential and commercial areas are to be build outside groundwater protection areas, except adequate sewerage system has been installed and piped water supply is advisable.

• New or expansion of industrial areas should not occur within groundwater protection areas, except adequate waste water collection and treatment systems have been installed, preferably not in areas with restricted groundwater abstraction.

• Waste disposal sites are not to be built in groundwater protection areas.

• Traffic (roads, railways, airport) and exploitation of mineral resources in protection areas should be constructed only after detailed investigations.

• Deep excavations in protection areas are to be restricted or accompanied by protective measures.

• Conservation of present land use; preferably all presently forested areas and in protection areas with presently prevailing agricultural land use.

All the above steps have to be backed-up by government policy on industry. Industries which are consuming a lot of water and produce pollutant waste must be put on negative list for investment.