Quantification of Riverbank Macroplastic Contamination in The Lower Citarum River

Plastic waste generation has been increasing over the last decades. Rivers represent complex environments where plastics may be stored and remobilized. Studies on riverine plastic, including riverbank contamination, are still lacking. Riverbank surveys were carried out in the Citarum River, Indonesia, at three river sections in Purwakarta, Karawang, and Muara Gembong in March-April 2021. The aim was to quantify the abundance of plastic waste at different points in the riverbank zone. The sample 'monolith' was taken by digging a quadrat of 30x30x10 cm³. All material was then weighed. Three replicates along the length of the bank and three replicates across the bank were taken. The non-plastic fraction was weighed and its composition was estimated. Plastic fraction was classified into categories, counted, and weighed. The result show that plastic litter was found in all monolith ranging from 0.7-301 g of plastic litter per monolith. The largest proportion of plastic contaminant was found in Karawang with 2.85% of plastic in a single monolith and the largest average plastic contaminant was about 0.78% of the total monolith weight, showing that plastic contamination is prevalent. Enhancing waste management, reducing single-use plastics, and plastic recycling are recommended to tackle plastic contamination in the study area.