Water Quality in The Bandung Basin: Towards a better understanding of the Water Quality in the Upper Citarum River Basin

Field: Environmental Science (Physical Sciences)

The Alliance of Water, Health and Development is developing a water quality model for the Upper Citarum River Basin, or Bandung Basin, located in West Java, Indonesia. This thesis aims to increase the understanding of the water quality problem of the Bandung Basin and the available data, in order to support the development of this model. Four succeeding steps give insight in the current condition of the basin.
1. Six drivers of the water quality problem of the basin were identified using system analysis.
1) The natural conditions of the basin, a large floodplain surrounded by eroding volcanic mountains, contribute to high concentrations of suspended solids in the river water. Dilution as a result of rainfall-runoff is an import determinant of observed concentrations.
2) Industrial effluents, mainly originating from abundant textile industry, highly contribute to the pollution as a result of inadequate wastewater treatment.
3) Large quantities of solid waste end up in the water system as a result of insufficient refuge collection.
4) On many places sewage is discharged to the river water, because there is a lack of sanitation infrastructure.
5) As a result of crop farming practices, large amounts of sediments, pesticides and fertilizers are flushing to the river water.
6) Practically all manure originating from stockbreeding activities is directly discharged to the surface water.
All these factors can be traced back to insufficient social and governmental institutions. The pollution of the basin is a threat to the environment and the health of the citizens: the reservoir downstream of the basin is heavily polluted, many citizens are directly exposed to polluted river water, wells are contaminated because water infiltrates in aquifers and heavy metals accumulate in fish consumed by the citizens.
2. The current monitoring activities and the data obtained with it were investigated. Monitoring of polluting sources is very scarce, and inadequate. Therefore, emissions for modelling purposes have to be estimated based on literature and spatial data. Rainfall data can be obtained from measuring stations or satellite images. Recent discharge data is scarce, inconsistent and often unreliable. River water quality data is obtained from five different organizations. The number of locations, sampling frequency, measured parameters and the timing is very different for every dataset. Validation of the data shows that there are inconsistencies between certain datasets, so that data should be checked before use. However, the data can certainly be used to develop and validate a baseline scenario for the current water quality of the Citarum.
3. Three Levelogger sensors were installed to collect continuous temperature, water level and conductivity data. The design of the sensor frame and the collaboration with the local community was successful. However, the large amounts of solid waste clogging to the devices reduce the reliability of the obtained data, especially the conductivity measurements. The obtained data revealed that river water originating from a catchment dominated by textile industries is characterized by high water temperatures (5 - 10 ⁰C above normal conditions) and high specific conductivity (1000 - 2000 μS/cm). In contrast, in the river water from a catchment dominated by agricultural activities and small settlements normal temperatures and very low specific conductivity (around 200 μS/cm) were found. TRMM-satellite rainfall data is clearly linked with the observed water level data, indicating that the satellite data can be used for analyzing the water quality data. In contrast to the expectations, no differences between day and night or working days and weekends were found in temperature or specific conductivity of the industry dominated river water. However, clear correlations were found between conductivity and water level in both rivers.
4. The data obtained in the second and third step was converted to a format suitable for data analysis and import in database software. The data was analyzed using qualitative and quantitative methods which revealed the following about the water quality in the Bandung Basin:
- The water quality in the basin exceeds the governmental standards for almost all parameters at most locations during the whole year.
- Stockbreeding activities in the first 28 km of the Citarum lead to high nitrate concentrations and large quantities of fecal coliform bacteria.
- The most obvious deterioration of water quality in the Citarum is due to the industry clusters in the basin. Industrial emissions account for high pH, temperature, TDS, BOD, COD and [Zn] of the water.
- Domestic areas are another important source of pollution in the basin, mainly correlating with zinc and fecal coliform, but also with BOD and COD.
- The parameters currently monitored do not give insight in emissions from crop growing.
- In general it can be said that the water quality during the dry season is worse compared with the wet season; as a rule of thumb the TDS, BOD and COD are two times higher during the dry season. However, some parameters like TSS show an opposite pattern.
The Alliance should start the modelling with the parameters BOD, COD, zinc and TDS because estimations of these concentrations can be based on the available data. The Indonesian government is recommended to start cleaning up the Bandung Basin by reducing emissions from industry clusters and by improving the sanitation infrastructure of Bandung City. Reduction of these emissions will take away the principal part of the pollution of the basin.