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<Technology Needs for Lake Management in Indonesia - Investigation of Rawa Danau and Rawa Pening, Java> Q. Conclusions on Technological Needs for Rawa Pening (Section 1 to 5) 1. Conceptual problems and practical viewpoints In the course of the preceding pages the problems of Rawa Pening have been examined in some detail. It will be apparent that there is a major gap between the perceptions of some of the administrative organisations dealing with the lake and the perceptions of many of the groups of people who depend for their living on the lake itself. This is one of the major difficulties in dealing with the lake and so this is one of the major obstacles to be dealt with in this assessment. There was some difficulty in getting any of the apparently capable administrators and managers of individual organisations to consider the possibility of the creation of a body which might be responsible for the sustainable management of the lake using environmentally sound technologies. Such a body might have been seen as being charged with management of the lake to achieve optimal benefit for the present users, usually the people living near the lake. In retrospect, and now being aware of the continued existence of the Jratunseluna Project, it may be that this Project was clearly in the minds of the local administrators. If the Jratunseluna Project were to be implemented, then a regional management body would be created to control and manage the water resources of the region. Such a regional management body would automatically have authority over the water resource of Rawa Pening, since Rawa Pening is envisaged in the Jratunseluna Project as having the role of a holding reservoir, supplying water as required to some of the thirteen dams proposed for construction as part of that Project. In that Project, as it is understood, there is little attention paid to the problems of Rawa Pening or to the management of Rawa Pening. The emphasis is on the increased area of irrigated land nearer the coast which could be used for rice production, and on the increased guarantee of availability of water supplies for that irrigation, irrespective of seasonal drought. Thus a management body oriented towards the environmentally sustainable management of Rawa Pening and of its catchment, in relation to the needs of the local population round the lake, would prove to be completely incompatible with the management for that water body which might be envisaged by the Government under a resuscitated Jratunseluna project. Many of the difficulties encountered by the investigating team would be explicable in this context. Hence, taking these possibilities into account, it is appropriate to consider the technological needs for sustainable management of Rawa Pening, in terms of environmentally sound technologies, under three different scenarios. These three scenarios are not mutually exclusive in certain respects. Much of our information and most of our suggestions deal with the first scenario as no indication was given to the investigators, when they were in the area, of any other possibilities. 2. Technological needs for organisation, collection and retrieval of data Irrespective of which of the above scenarios may be implemented eventually, there will always be a need to ensure cooperation and effective integrated decision making by the managers of the system. The soft technologies for this are well known. There is a need for the definition of a group structure and for the components of the group to be defined. The position of the group in the administrative hierarchy must be established and legalised, and its responsibilities defined. Financial resources must be provided or a source of finance detailed, and the accessories of any administrative structure (buildings, staff and office equipment) must be found and financed. Vehicles will be a necessity to allow sampling and field investigation of the lake systems. The management body will require access to appropriate computer software for statistical data collection and analysis. Other computer software can provide different types of decision making programs. Eventually one might expect that much of the data collection of physical parameters in the system being managed would be collected automatically and transmitted by radio to the central processing facility, as is done by Perum Jasa Tirta for the management of the Brantas River System. This includes data from automatic weather stations including rain gauges, river flow assessment, temperature, lake levels, etc. Other data monitoring systems include assessment of the amount of water used in power production and irrigation, and the volume being supplied to towns and cities for domestic use. Some automatic monitoring equipment should be established to report on road traffic flows on major roads, and on levels of air pollutants in key intersections in cities. Both of these parameters are vital for assessment of possible lead levels in the air and in run-off from roads. The adverse impact on human populations of lead, in the air and in water supplies, is well known. Basic laboratory facilities for the chemical and physical analysis of water should be available to the management body though these need not necessarily be under the direct control of the management body. They could, for instance, be situated in a local University. In many Indonesian Universities Environmental Study Centres have been created. These are generally underfunded, but staff are usually keen to participate in any environmental problem if adequate funds for equipment and chemicals are available. Initially, it will be necessary to deal with the analyses of phosphates and nitrates, and common elements such as iron, sodium, calcium, potassium, and magnesium, along with the normal physical parameters such as conductivity, colour, transparency, suspended solids and absorption spectra. Chemical analyses should include, eventually, the possibility of assessment of concentrations of individual heavy metals by Atomic Absorption Spectrophotometry. Also it should be possible, eventually, to utilise automated systems for the analyses of many of these elements. 3. Use of water by local people and their expection as regards quality and supply Considering the first scenario as the basis for initial consideration of the technological opportunities offered by the lake, one has to examine the expectations of the local population at the present time. In the area of Central Java which forms the catchment of Rawa Pening, there are numerous small villages, several towns and one small city. In the city and possibly in some of the small towns, there is an expectation that good quality tap water should normally be available when one turns on a tap. It may be that in periods of drought the supply becomes less reliable and water may not be available from the tap at all times. For domestic washing and laundry work the water can be used directly from the tap, but for drinking purposes it is best to boil it first and allow it to cool down to eliminate any chance of stray bacteria having got into the supply. Bottled water (such as Aqua or Aedes) can be bought for drinking, but is relatively expensive. In small villages such as some on the shores of Rawa Pening or on the slopes of the mountains far from any road, there is no piped water. Water for domestic use is taken from wells or boreholes, and pumped into buckets. There are defined areas on rivers for personal washing and laundry is commonly washed in the rivers also. Water from wells and boreholes is carried into the houses and is boiled before being used for drinking or food preparation. Even in drought conditions some water is usually available from the boreholes and wells near the lake. Rivers do not usually dry up completely in this area. The team did not investigate the situation in the villages on hillsides in the remote parts of the catchment. The lower household incomes in rural areas make the purchase of bottled water relatively more expensive. If one objective of Scenario I is to improve the standard of living of the people in the area of the lake and its catchment, then some attention should be given to the problem of water supplies for small rural communities. The main thrusts of any improvement should be towards the development of a reliable supply of better quality water for rural communities. The costs of a reticulated water supply for a rural area of the size of this catchment with its associated topography would be beyond the foreseeable resources of the Central Java administration at this time. Similarly there is little guarantee that such a reticulated supply over a large area of volcanic hillsides would be able to survive the periodic earth tremors which occur in Central Java. This leads to the question of what exactly are the sources of pollution in the water from wells, boreholes and from rivers. It may be more feasible and realistic at this time to limit the extent of water pollution in rivers. 4. Appropriate technology for the reduction of the bacteriological content of water supplies in rural areas The main source of poor water quality in rural areas is pollution of ground water and the existence of surface flows of polluted water during wet periods. The pollution comes from ineffective septic tanks, from screened toilet areas constructed over streams, or from areas of waste ground used by villagers as communal toilets. Often the banks of rivers and streams are used as public toilets and this can be seen in any city in Java. The improvement of water quality in the rural areas in the Rawa Pening catchment depends primarily on an improvement in the social behaviour of the population. However the population of the rural areas has, for centuries, used the bushes on the banks of rivers as toilet facilities. The screened toilet over the stream is regarded as an advance. So the necessity for change is opposed by the ingrained social habits of past generations. A substantial change in social habits would call for a coordinated campaign on TV, radio, newspaper, and through the village administrative system. Such a campaign would require the backing of Government and would more appropriately be expanded to cover the whole of Java. Again this would call for a very substantial investment by the Government in the management of Javanese water resources. Despite the importance of an adjustment of social habits, it is also necessary to consider the range of technologies which might be employed in the treatment of water contaminated with sewage in this catchment. Technologies involving the initial separation of solids from sewage followed by the treatment of the effluent by ground infiltration are quite inappropriate here, as the topography is unsuitable, as is the geology, and the land is too expensive. Theoretically the introduction of dry self composting sewage systems for each house would be feasible but is quite unlikely to be considered by the authorities in Central Java as the costs would be excessive. It is more appropriate to examine the feasibility of relatively cheap community sewage treatment plants. In selection of an environmentally sound sewage treatment system for a community one might first consider the total population to be served. As a general principle, in rural areas it is more economically efficient to maximise the numbers of people who can be served by one sewage treatment plant. In the type of topography involved in this catchment, small gravity fed reticulation systems for sewage would be feasible in hilly areas, provided the velocity in the pipes is at or in excess of 1 metre per second, to minimise the chances of blockages. Access points are normally provided at junctions and at places where the gradient changes. The design and construction of sewerage reticulation systems is well known and details are available in standard reference works. The steep topography in the area would prevent any possibility of the use of artificial swamps with macrophytes as the main agents in the water treatment process. These have been demonstrated successfully in the Netherlands, where relatively flat land is available cheaply after reclamation from the sea. Since Java has one of the highest population densities in the world, the cost of land, particularly flat arable land, is high, and any sewage system has to be compact to minimise the area of land committed to sewage treatment. It is likely that the numbers of households served economically by one set of reticulated pipes would be less than 2,000, in this catchment, as the cost of reticulation of sewage increases as the diameter of the pipes increases. The cost of installation also increases. For these reasons it is unlikely that a sewage reticulation system would extend as far as the shore of the lake from the upper reaches of the catchment. Equally, it is unlikely that the numbers of households served by one plant would be so large as to justify the construction of a trickling filter system or of a large activated sludge plant. It is most likely that the optimal system for the rural areas would be small activated sludge processing units. In country areas on hillsides in the catchment, sewage effluent could be piped to a central collecting pond by gravity. The absence of toilets in some houses might pose a problem. In such cases small wooden huts could be constructed for use as communal facilities to replace the communal latrines constructed over streams and small rivers. For small villages an activated sludge processing unit such as a Pas Veer Ditch could be used to treat the raw sewage after passage through a grating to remove garbage. An average sized Pas Veer Ditch should accommodate the needs of a village of approximately 4,000 people. The land area involved in construction of the ditch is not large. The major problem might be the supply of electricity. The paddles must be kept in operation to move the slurry round the ditch continuously and to ensure the slurry is aerated. There is no point in constructing activated sludge processing plants unless they are to be used. So, in association with the construction of such a unit there has to be a campaign to ensure that people use toilets which drain to the central Pas Veer unit. Some nominal penalties must be imposed on individuals found using the banks of rivers as toilets after the sewage treatment unit has been installed. Psychological education campaigns must be conducted with maximum publicity to ensure compliance with the system as described earlier. The effluent from a Pas Veer Ditch is usually of good quality. Under environmental conditions in Central Java the water quality of the discharge cannot be predicted. It should be suitable for discharge to the lake itself, though not necessarily suitable for discharge to the nearest river. Therefore it may be desirable to plan for the construction of a network of such waste water transport systems. The end point of discharge of the effluent might be the lake or it could be that the effluent was found to be suitable for usage in irrigation agriculture in padi fields. Certainly, after processing in a Pas Veer Ditch, while the bacterial content is much lower, the content of phosphates remains high and substantial quantities of nitrogenous compounds are present. These are crucial components of fertilisers and could make a positive contribution to the growth of crops. The question of disease transmission remains for investigation. Various designs of anaerobic digesters for domestic waste and farm effluent have been produced. Some of these might be employed in isolated villages in the catchment. The most appropriate might follow the designs of those used in China and Taiwan. Biogas, largely methane, is produced after a period of digestion and the gas can be used for heating and cooking. The residual sludge is a good fertiliser. The possibility of transmission of some diseases from incompletely processed effluent has to be assessed. In the case of the small villages on the shores of the lake itself, there is no good solution under the present seasonal regime. Some of the villages are left effectively as islands during the wet season, being about half a metre above the level of the lake water, except during floods, when they are to varied extents under water. Many of the houses in such villages are raised slightly above then ground. A Pas Veer Ditch is quite unacceptable under such circumstances. For these villages, the only solution appears to be the discharge of sewage into inefficient septic tanks. Any better solution would have to wait for improved economic circumstances, when the entire village could be moved to higher ground. The discharge of sewage effluent to the lake and its escape from septic tanks during floods will affect the health of local residents. There is no effective sewage system at present even for those residents of the town of Ambarawa whose homes are below the embankment of the former railway, and whose homes are often flooded during the wet season. At such times sewage is commonly seen floating through the settlements. For villagers living in small settlements far out of the flat shore of the lake, supplies of water for domestic use must come from pipes carrying water from the incoming rivers before they reach the lake shore. Such systems would be gravity fed and would start in small dams on the incoming rivers. The water would have a substantial bacterial content, but, if the preceding program of water quality improvement had been implemented, the bacterial content would be less than at present. It is noteworthy that the solutions proposed here involve considerable capital cost as well as an investment in time and labour. The success of the proposals would depend on the degree of cooperation from local residents as well as on the extent of education programs and engineering initiatives on the part of the Department of Public Works. 5. Technological problems in dealing with solid waste in the catchment In addition to the problem of the bacterial content of the water resulting from faecal pollution, there is the problem of the bacterial output from solid waste as well as the problem of the disposal of the solid waste itself. In towns such as Salatiga and Ambarawa the system of garbage collection is organised with door to door collectors using large wheel barrows to empty garbage bins and carry the garbage to collection points. These become high (3 to 4 metres high) unsightly, smelly, fly ridden piles of rotting food scraps, discarded cans and plastic bags. Rats and stray dogs survive on the pickings from these heaps, which are supposedly contained within concrete walls and are exposed to rain and wind. Often the amount of garbage is such that the trucks which are supposed to empty them are unable to do so and the waste is left until the next collection. During rain the run-off from these piles of garbage flows into gutters and from there into streams and rivers. Traditionally, in former days solid waste in rural villages was collected and burned, the ashes being put in a pit in the garden and hopefully the minerals were recycled as fertiliser for crops. Solid waste in those days was mainly scraps of food and occasional pieces of wood, paper or cardboard, all of which would burn to some extent on a dry day. Nowadays the solid waste includes aluminium and steel cans, plastic bags and soft drink bottles, discarded pieces of cars and bicycles, broken glass, cement and pieces of brick. In many rural villages, the traditional burn and burial system is still followed, with some bafflement and laughter because the stuff will not burn. The result has been the development in all the towns and major cities in Central Java of enormous solid waste land fill sites. Unfortunately, land is a valuable commodity in Java, and garbage is not seen as valuable or important. So often the land used as solid waste disposal areas is not appropriate. In Jogjakarta, in Central Java, garbage dumps are found on the banks of rivers in the city area. During the heavy rain falls which occur regularly, water streams from the garbage into the rivers. This is presumably why the dumps are placed beside the rivers. The official attitude is that the rivers are a suitable method of getting rid of the dangerous liquid soaking out of the garbage. It is necessary to change this attitude on the part of the administrators. Solid waste is valuable since it can cause a great deal of damage to the environment if it is not treated properly. Land fill sites should be selected in such a way that the run-off, if any, does not flow directly to a river. In cities such as Jogjakarta and to a lesser extent in smaller cities such as Salatiga there is an efficient recycling system for solid waste. Individual collectors will go round garbage buckets checking the contents for particular items. One may collect only cardboard, another any metal items. Yet another will be collecting glass and bottles. At the entrance to the land fill sites, stalls are often erected by buyers of such items. The scrap metal dealer will have scales available to assess the payment for particular items, as will the cardboard buyer. Often it is only torn plastic bags, food scraps and garden refuse which end up on the land fill. In this case it would be feasible to consider the use of the land fill material for the production of gas for domestic use. Most of the residual land fill material is certain to decompose in the course of time and lose perhaps 90% of its volume. Consequently the land is unstable and even if covered with soil will sink gradually. The organic content is a source of energy which is not used. Already in Europe, countries are considering the possibility of the use of solid waste dumps as a source of methane and similar gases. If this is a viable technology in countries with a cold winter, then how much more profitable would it be in a country such as Indonesia? The major obstacle to development of such as gas production scheme is the fact that Indonesia has enormous quantities of natural gas and oil, as well as coal. The cost of petrol and gas supplies to the public are subsidised by the Government. Were this not the case, then gas production from such solid waste might be economically profitable. In parts of Java, during the dry season, the garbage dumps are set on fire to reduce the fly and rat hazards. During this process in which wet or half dry rotting food scraps are partially burned or scorched and may smoulder for days. Plastic bags, plastic bottles plastic soft drink containers are also burned, heated and scorched, presumably emitting in the process toxic gases. These too will be carried into the streams flowing into the lake. While a system for the collection, recycling and disposal of solid waste exists in the area, there is some room for improvement in that system. The International Source Book on Environmentally Sound Technologies for Municipal Solid Waste Management has been published by IETC as part of its Technical Report Series (No. 6), while it has considered the principles involved in the process in Report No. 2, Principles of Solid Waster Management. The information contained in these publications could be used as the basis for re-examination of the methods used in Central Java.
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