Impacts of Urban and Industrial Development on Groundwater, Bandung, West Java, Indonesia^*)

by : Soetrisno S.^**)

 

Abstract

Urban and industrial development in Bandung has changed the land usage. For nearly three decades, thousand hectares of technical irrigated paddy fields and dry crop land in the Bandung basin have been converted to the housing complexes, business districts, and industrial areas.

The land use conversion has an impacts on groundwater recharge, both its quantity and quality. In another side the urban and industrial development effected to the total of groundwater usage, since groundwater is still a mayor resources for water supply.

Abstraction of deep groundwater which is recorded to be 10.5 M m³ in 1970 has rapidly increased to 66.9 M m³ in 1995.

Continous lowering of the piezometric head of 2 - 4 m/year in the industrial center during the last five years has considerably changed the flow of groundwater system, in which vertical downward leakage occur almost in the entire of the basin.

Poor drainage and sewerage system in heavy populated area, unproper waste disposal sites and untreated indutrial waste water has led the deterioration of quality of shallow groundwater in the Bandung basin.

Efforts have been made to keep groundwater sustainable with strictly applied of spatial planning to reduce groundwater usage by increasing surface water, reallocation of industries, which mostly textile industry to the nearby of surface water resources and promoted shallow recharged wells.

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*) Paper presented at Groundwater and Land-Use Planning, Fremantle, Western Australia, 16 - 18 September 1996.

Background

Bandung is the capital of West Java Province and has a population about 2.5 million (1995), is surrounded by several medium sized towns which formed the Greater Bandung, and has total population about 3.5 million.

The Greater Bandung lies in the catchment area of the upper Citarum river and is surrounded by range of hills and volcanoes, some of which are still active, formed the inter-montane basin, and has an area of about 2250 km². The central part of the basin, where most of which occupied by urban and industrial areas, is a plain measuring 40 km East-West and 30 km North-South (Fig. 1).

The mean annual precipitation in the basin, depending on the altitude, is between 1900 - 2200 mm. In the western part of the basin the mean annual prcipitation is about 1500 mm/a and in the higher parts of the volcanoes about 3500 mm/a.

The traditional economic basis of the Greater Bandung area is agriculture, intensive irrigatied rice farming in the floodplain and rain-fed cultivation of vegetables in the hills. However, due to rapid urbanisation, conforming to the growth of industries, and rise in its population, the economic basis has shifted to industry and services. This affected to the land use of the area from open land or rain-fed and irrigated paddy field to housing complexes, business districts, and industrial areas. Comparing between the land use map of 1971 and actual situation, it is estimated that for nearly three decades, thousands hectares of land in the Greater Bandung has changed its usage.

This land use conversion certainly has an impact on groundwater recharge. In another side the urban and industrial development have increased the demand of water supply, where most of which relied on groundwater resources.

This paper attempts to discuss impacts of both urban and industrial development on groundwater, and efforts to overcome or minimize the impacts, in order to keep the groundwater resosurces in Bandung sustainable.

 

Hydrogeologic Features

On the basis of its hyraulic characteristic and its depth, the multi layer aquifers configuration of the Bandung basin may be simplified into two systems :

Shallow aquifers : unconfined, a few meters to around 40 m below the surface, commonly exploitable by dug wells or driven wells, highly vulnerable to pollution.

Deep aquifers : semi to confined, more than 40 m to 250 m below surface, exploitable by bore holes, low to moderate vulnerability to pollution.

Litology aquifers comprise of volcanic products from the volcanic complexes which bordered this basin and lake sediments, were deposited while the central part of the basin was a lake.

The most prominent aquifer is Cibeureum aquifer comprises mainly of arenaceous tuff and volcanic breccias of young volcanic deposits, the depth of the aquifer varies between 50 and 150 m below the ground surface. Its permeability is moderate to high in coarse materials and lava flows, which is average between 111 and 877 m²/day.

Due to its high productivity, the Cibeureum aquifer is the most aquifer in the basin which is intensively exploited, primarily by textile industries.

The other aquifers are Cikapundung aquifer consists of old volcanic deposits and Kosambi aquifer, its lithologic composition is mostly fine materials of lake deposits. Both aquifers have low to medium productivity, 112 to 150 m²/day, therefore are not so exploitable as the Cikapundung aquifer.

Groundwater flow across the elevation of 1000 m above mean sea level (amsl) to the basin is calculated about 107 million m³/year (Schmidt and Tirtomihardjo, 1991), where about 70 % of which coming from the north.

The northern area of the basin which is situated at elevations between 1050 and 1300 amsl, based on the natural stable isotope content of groundwater in the basin, is considered as the main recharge area of the groundwater exploited in the basin (Geyh, 1990).

Natural groundwater quality in the basin is charecterized by its low salinity (electrical conductivity < 500 uS/cm) on the mountain slopes, and increased to moderate values (500 - 1000 uS/cm) towards the lower parts of the basin. Predominance HCO₃ (45 - 90 meq%), low content of SO₄ (< 20 meq%), and high concentrations of Fe (exceeding 1 mg/l) which occur practically in all areas of the basin, are considered typical for the hydrogeologic condition prevailing in the Bandung basin.

 

Groundwater Usage

Since the early development of the city of Bandung, in late of 19^th century, groundwater resources played an important role in supplying water demand. Following the industrial era in 1970’s, Bandung became a great urban area which attracted people to migrate from rural area nearby to Bandung city. In that time groundwater abstraction was 10.5 m³/year, which number of wells was recorded less than 300. This affected to the rapid growth of population, which is recorded 3 - 4 % per annum in 1990. In other sector, industry become a major sector of economic growth in the Greater Bandung, which textile is a leading industry. Hence, groundwater usage greatly accelerated conforming to the above situation.

In 1995 municipal water supply abstracted groundwater 18 Mega liter/day, together with spring water and surface water, it supplied about 43 % drinking water demand in the Greater Bandung, while most rest of it relies on groundwater resources.

In the same period, 66.9 million m³ of groundwater has been abstracted from deeper aquifer system, 80 % of which is used by the industrial sector. This figure was recorded from 2225 licenced wells, while it was believed that many illegal wells tapped the groundwater unrecorded. It is estimated 80 million m³ of groundwater has been pumped by the textile industries alone in 1995. Even there is a great efforts to control groundwater abstraction and to reduce groundwater usage, its effect is still low since groundwater is only the major resources. Groundwater usage is upclining exponentially in the basin after 1970 (Fig. 2), correspond to the increasing of population and industrial development.

Local domestic supply used groundwater from dug wells or shallow boreholes. There is no exact figure concerning the total abstraction from shallow aquifer. However, assuming that 60 % of the total population of 3.5 million used 90 litres per capita per day of groundwater, it is estimated that 69 million m³ of groundwater has been abstracted from the shallow aquifers in Greater Bandung, in 1995.

Lowering of Piezometric Heads

Due to excessive abstraction by industries, piezometric head of groundwater in the basin during the actual state lies far below the initial state. In the early 1900’s piezometric head in the areas which are now occupied by industrial area, was between 20 and 25 m above surface, while now it lies generally more than 50 m below surface.

In the area where many textile industries are concentrated, cone of depression are occured. As recorded by 48 observation wells, which are spread out in the basin, piezometric head has been declining continuosly almost in the entire of the basin, with rate of lowering is between 2 - 4 m/year (Fig. 3).

During initial state in early 1900, piezometric head in Western Bandung (Cimahi - Leuwigajah, at present is industrial area) was 20 to 25 m above surface, while in 1995 the deepest piezometric was recorded between 58 and 86 m below surface with rate of lowering of 2.5 to more than 4 m/year between 1990 - 1995. Here, wells tapped the Cibeureum aquifer.

In the Dayeuhkolot, south of Bandung, where many textile industries are located, in 1960 piezometric head was 3 m above surface. At present it is lying between 20 to 80 m below surface. Continous lowering of piezometric head is recorded between 2 to 2.4 m/year during five years of observation. Most of wells in this area tapped both Cibeureum and Kosambi aquifers.

The similar condition of groundwater has also been faced in another textile industrial center in central and east of the Greater Bandung. During the initial state in 1950, piezometric head lied 1.0 m above surface, while in 1995 it was recorded between 11.0 and 35 m below surface. Rate of lowering is observed 0.6 to 2.4 m/year during the last six year observation. Most of wells here, tapped the Kosambi and the Cikapundung aquifers.

This situation has changed the flow of groundwater system because the piezometric head is generally below the phreatic head nearly every where in the Greater Bandung (Fig. 4). Downward recharge from the upper system to the deep system, therefore, is occured and making the deep aquifer system is vulnerable to pollution. However, up to now there is no evident of pollution to deep system has been recorded.

Change of Recharge

Urbanization and industrial development has changed land-usage of the Greater Bandung. Increasing population due to its natural growth and migration needs more land for providing houses.

Land which formerly was paddy field, bare land or as open space has changed to densely populated residential compound. And it is often that new residential area occupied the hilly area surrounding the basin, where is considered as primary recharge area.

There is no industrial estate in the Greater Bandung, actually. Factories are mostly located scattered in the plain area. Since it needs many employees, the existing of the factories attracted people to live nearby and build houses. Then, area enclosed to the factories growing to be residential compound, locally knows as "kampung", high density population in generally one storey building. It used more land rather than multi storey building.

Present urban land use (settlement, housing and industrial areas) as result of those development occupies 9 % of the total area of the basin, while paddy field, both irrigated and rained fed, still occupies the largest portion of the basin about 34.3 % (Hoffmann, et al, 1990), although it has changed many to the urban areas, particularly in the low plain of the basin for nearly last three decades..

Since more land has been being occupied by housing complexes, business districs, and industrial areas, it changed the recharge potential to the aquifer system in the basin. Up to now there is no evaluation in comparison between pre and post urban recharge in the greater Bandung. However, referring to Foster, et al, 1994, and Sunjoto, 1996 (personal communication) which calculated post urban recharge in volcanic product is 1.4 greater than pre urban recharge, post urban recharge in the Bandung basin might be greater than pre urban recharge, particularly in the northern part of the basin. In the flat plain area which occupied by dense urban areas, groundwater recharge might be decreased while surface run-off increases, which is proved by extending of flood prone area every year, since 1980. Extension of flood prone area in the Bandung basin was 571 ha in 1980 and 3,358 ha in 1994, while in the same period Citarum river flow in the Nanjung gauging station, southwest of the basin, was recorded 220 and 374 m³/sec respectively (Anonymous, 1996).

Deterioration of the Groundwater Quality

In the densely populated areas, such as "kampung", are often lack or poor of drainage and sewerage system.

Industrial waste water is in most cases released, without treatment, and if any is not properly treated, into streams or channels (actually prohibited by law), in the basin are primarily from the textile industries.

Surface water pollution, therefore, is obvious in many river course within the "kampung" of downstream section of textile factories by a conspicuous colour of the stream water and by increased salinity and low oxygen saturation.

Wagner et al (1991), noted that Cl and SO₄ concentrations in the shallow groundwater abstracted from dugwells nearby industrial areas are distinctly higher. Concentrations of NO₂ and NH₄ are elevated in many samples from those shallow wells.

No distinctive signs for an impact of industrial organic contaminants have been found in this industrial area.

Rosadi et al (1993) and Matahelumual et al (1995), also noted that elevated heavy metal contents were analysed from shallow wells in industrial areas. Zn (up to 170 ug/l), Cu and Pb have been found in shallow wells in the Leuwigajah industrial area. However, these values are still lower than admissible levels of drinking water standards. Finally Rosadi concluded that the result of a few random samples of shallow groundwater in the Greater Bandung area indicate serious pollution by chlorinated solvents in the industrial area, particularly in the Leuwigajah area.

In the Leuwigajah area, pollution of groundwater in many dugwells or shallow bore holes is indicated by NO₂ of NH₄ contents above 50 ug/l. Elevated contents of halogenated hydrocarbons (AOX values above 30 ug/l), which are certainly derived from industrial pollution, have been found in 10 shallow wells.

High contents of NO₂ (more than 400 ug/l) have been found in fifty percent of the samples collected from shallow wells in the Dayeuhkolot area. However, it is still doubtful whether high NO₂ contents are caused by domestic or industrial waste.

There is no significant differentiation of chemical composition and heavy metal contents in the shallow groundwater from the last analyses compared to results of analyses done in five years back.

Matahelumual also noted that most of groundwater samples from residential compound of ‘kampung’ and nearby the waste disposal site, content of collifom 2400 colonies/100 ml. This figure is much higher than permissible standard (50 colonies/100 ml) for raw drinking water in Indonesia. It is suspected originated from latrines or contaminated water courses.

Effort

To minimize the impacts due to urban and industrial development to the groundwater, efforts has been made both from legal and technical aspects.

Recommendations for primary land use from the environmental geology point of view have been submitted to local government. Those recommendations among others contain which parts of the Greater Bandung should be protected its groundwater quality, where is proper waste disposal site should be located and recommended for foresty areas. Local government put these recommendations into consideration of spatial planning of the Greater Bandung and try to applied it strictly. In order to increase recharge rate to the basin, buy law it is obliged to new building to build shallow recharge wells, which collects rain water from roof catchment.

To reduce groundwater usage by industry, some parts of the Greater Bandung area since December 1993 have been decided as restricted from new abstraction of groundwater for industrial purposes.

There is a plan to increase of surface water usage for industries by building new small dams in the Citarum river tributaries. By 2005, the usage of groundwater for industrial purposes will be reduced to 32 million m³, while the usage of surface water will be increased to 146 million m³. Other option is to relocate industries to the Cililin industrial park, which will be located nearby source water, Saguling dam, in west of the basin, which will supply about 44.3 million m³ by 2005 (Anonymous, 1996).

Closing Remarks

Groundwater resources play an important role for supplying water demand both for domestic and industrial purposes in the Greater Bandung.

Urban and industrial development has led to the deterioriation both quantity and quality of groundwater resources due to increasing of groundwater usage and its waste disposal.

Efforts have been made to restore groundwater resources in the Bandung basin, however, up to now there are no significant effects so far. Lack of resources other than groundwater, disobedience to groundwater and environment law by some groundwater users are among major constrains to implement those efforts.

The best solution to overcome the problem and to minimize its impacts is to reduce or stop the groundwater usage, whereas surface water usage has to be increased. However, to conduct such solution is not simply matters. Highly population, land-usage conflicts and socio-economic problems such as unemployment and financial will be the major obstacles.

Acknowledgement

Due to the title and topic of this paper, which are requested by the Organizing Committee, parts of this paper content using similar material of my paper which was presented at the 2^nd Asian Regional Scope Workshop on Groundwater Contamination, Adelaide, South Australia, 21 - 25 November 1994.

The author wishes to thank to the Centre for Groundwater Studies, Western Australia for the invitation and its sponsorship, to make his attendance in the conference possible.

 

References

Anonymous, 1996, The Solution of Water Shortage ini the Bandung Basin (in Bahasa Indonesia), Final Report, Provincial Government of West Java, Bandung.

Foster S.S.D., Morris B.L., and Lawrence A.R., 1994, Effects of Urbanization on Groundwater Recharge, ICE International Conference, London.

Geyh, M.A., 1990, Isotopic Hydrological Sounding in the Bandung Basin, Indonesia, GEGATI - DEG, Bandung.

Hoffmann, R, Adiwidjaja R., and Suhendar R., 1990, Assessment for Agricultural Land Use of the Bandung Basin, GEGATI - DEG, Bandung.

Matahelumual, B.C., Susana M., and Suratmi, 1995, Groundwater Quality surrounding Leuwigajah Industrial Area, GEGATI - DEG, Bandung.

Rosadi, D., Sukrisno, and Wagner, W., 1993, Groundwater Quality and Protection in Selected Parts of the Bandung Basin, Directorate of Environmental Geology, Bandung.

Sunjoto, 1996, Water Balance of the Area of Transmigration Training Centre Yogyakarta, University of Gadjah Mada, Yogyakarta (personal communication).

Wagner, W., Ruchiyat, S., and Rosadi D., 1991, Groundwater Resources and Groundwater Protection in the Bandung Basin, Directorate of Environmental Geology, Bandung.