Seasonal changes of pollutants along the upper Citarum River

Seasonal changes in the concentration of several pollutants along the length of the upper Citarum River in West Java are reported. The upper Citarum is the most polluted area in Citaruum Basin. Measure­ ments of the water quality parameters in the upper Citarum indicate that the majority of the pollutants were high in the dry season and de­ crease in concentration at the beginning and peak of the rainy season.The concentrations are the lowest at the peak, however some of pol­ utants are still above the standard water quality criterion. During the dr season river in an anaerobic condition, the DO concentration was found to below I mg/ l, so degradation of carbon compounds and nitrification was not occurred. Besides that the Pb and Cd were found re­ main high, at this time. Tendencies of water quality parameters con­ tribution were calculated against sampling sites bu means of principal component analysis [PCA]. Custer analysis was used in calculating sampling site similarities. The results of analysis using PCA have proved that although there is correlation between sampling sites and pollutants, however is still difficult to identify the source of the pollut­ants. In the dr season sites 4 and 6 have similarities, while in the rain season sites 8 and 9. Environmental education for inhabitant in the Citarum catchment area is important to protect water quality.